SCID Conference Registration now open!

Registration for ”SCID Conference 2008″ at Wintergreen Resort in Wintergreen, VA has started. Please register now by clicking the down loadable registration form at: http://www.primaryimmune.org/pubs/SCID_Conf_2008_registration.pdf

OR credit card users can go to the link at: http://www.primaryimmune.org/conferences/scid_conference_2008.htm

Remember, the registration fee is $250 per room (each room will accommodate approximately 2 adults and 2 children).

The registration deadline is June 3, 2008 so REGISTER NOW! Space is limited and will be assigned on a first-come, first-served basis.

linkback url: http://scidconference2008.wordpress.com/2008/05/06/register-now/

---

Hope keeps growing in Chelmsford

By Kevin Zimmerman/Staff Writer

Wed Mar 19, 2008, 10:52 AM EDT

Chelmsford -

• StumbleUpon
• Newsvine
• del.icio.us
• Digg

Chelmsford - Sen. John Kerry, D-Mass., dropped by the Chelmsford Senior Center Sunday morning to announce his plan to file legislation to reform how Medicare helps people with primary immunodeficiency disease cover the cost of treatments.Kerry opted to make his announcement at a blood drive in Chelmsford to honor Team Hope — a local group which advocates for patients with primary immunodeficiency — and resident Stefani Bush who has worked for several years to get the word out about her children, Will and Sasha, and their debilitating illness.“Sometimes the democratic process — little D — really works,” said Kerry. “When people make their voices heard, and they come together in a community like this and they bring an awareness to something that people didn’t normally have an awareness of.”Sunday’s blood drive, sponsored by Team Hope and administered by the American Red Cross, was an effort to collect gamma globulin, a blood plasma protein that helps fight infections.

The only treatment for primary immunodeficiency disease consists of gamma globulin replacement therapy, which involves a weekly infusion of the blood product.

Under the current Medicare system, doctors do not receive full reimbursement for this costly medicine many believe helps patients lead a more normal life.

Kerry hopes to change that.

He believes because the treatment decreases the amount of time patients spend in hospitals or away from work, it ultimately saves money.

And, because primary immunodeficiency is caused by genetics, Kerry thinks it’s unfair to force families and private insurers to make up the difference in what Medicare will reimburse.

“We’re going to try to change that. There is legislation thanks to your efforts,” said Kerry. “I want to thank Team Hope. Team Hope has given hope. And it has brought an awareness to all of us. Thanks to all of you. We’re going to try to remedy this situation.”

For Bush, Sunday’s announcement comes after two years of telling anyone who would listen about primary immunodeficiency and the need to help some families pay for treatments.

“It means so much to have someone like Senator Kerry behind us,” said Bush. “Just the fact that he made a public announcement shows his commitment. He feels it is a worthy cause.”

Bush believes her job now is to keep spreading the word about primary immunodeficiency and the need to educate parents about it.

Susan Bennett, 36, of Methuen, knows education is important. She spent her whole life fighting one infection after another but no one could tell her why.

“They said it was allergies, or it runs in the family, or there’s no real reason for it,” said Bennett.

Finally, three years ago, Bennett met a doctor who ran a blood test to check for an immune deficiency. It turns out Bennett has a disorder called common variable immune deficiency. With globulin infusions, she has seen a dramatic increase in her energy level and a decrease in infections.

“I live more of a normal life,” said Bennett. “I basically got my life back.”

Team Hope works to make a story like Bennett’s the norm.

That is one of the reasons Team Hope organizes blood drives, so more people can learn about the disease and help defeat it.

Bush likens it to a quilt hanging on the wall at the Senior Center.

Although many people may have helped sew the different squares, you don’t look at a quilt as a collection of separate pieces. You need to step back and see the quilt for what it is — one complete project.

“Everybody is important, no matter how small the contribution,” she said. “It’s amazing the cascading effect one person can have.”

For more information on Team Hope and its upcoming Promise of Hope Wine Tasting on May 3, check out its Web site at www.teamhope.info.

Kevin Zimmerman can be reached at chelmsford@cnc.com.

linkback url: http://www.wickedlocal.com/chelmsford/news/x691151782#comments

Genetic screening raises tough ethical issues

Although this story was written about CF, the controversy  could just as easily have been written about SCID

Genetic screening raises tough ethical issues

Monday, March 10, 2008

BY CAROL ANN CAMPBELL

Star-Ledger Staff

The number of babies born with cystic fibrosis declined by half in Massachusetts after genetic screening started to identify carriers of the gene, suggesting similar declines may be happening across the nation, according to a recent report in the New England Journal of Medicine.

The Massachusetts study is among the first to examine the implications of widespread genetic screening, which is expected to increase as scientists discover genes for other genetic disorders.

Researchers say they cannot definitively explain the decline, but they surmise that couples who learn both carry the CF gene may decide not to have children, may turn to donor sperm or eggs or may test embryos before they are implanted in the womb. Also, pregnant women who learn they are CF carriers may test the fetus and have abortions if the test is positive.

“We think genetic screening has impacted the number of babies born with this disease,” said Richard Parad, an author of the brief journal report and a physician at Children’s Hospital Boston.

The study by the New England Newborn Screening Program, at the University of Massachusetts Medical School, looked at the number of babies born with CF — a serious genetic disorder that affects the lungs and digestive system — before and after 2002. That’s when the National Institutes of Health and the American College of Obstetrics and Gynecology recommended nationwide prenatal screening to identify carriers of CF.

The simple blood test, which costs around $100 to $200, determines if a person is a carrier of the CF gene. One out of every 29 Caucasians and one out of every 65 African Americans are carriers. If both parents are carriers, each child has a one in four chance of having CF. About 1 in 3,000 babies are born each year with the disease.

The Massachusetts researchers compared the four-year periods before and after 2002 and found the number of infants with CF dropped by 50 percent after the new screening recommendation. For each year after genetic screening became more widespread, the number of CF babies dropped from about 25-30 to 15 annually. In addition, among babies born with CF, far fewer than expected had the gene mutation associated with the most severe form of the disease.

Parad said scientists should examine the repercussions of recommending that four million women each year be tested for the CF gene.

“I think you might want to see what happens when you do that kind of widespread testing,” he said. “What do people do with this information?”

TROUBLING QUESTIONS

Genetic screening for CF presents unique ethical questions, particularly since many people with the disease live into adulthood. “There is a tendency to act as if genetic testing is about choice and information, and not really make the connection to the consequences,” said Arthur Kaplan, director of the Center for Bioethics at the University of Pennsylvania. “I believe the reason we pay for genetic testing is partly we know people will make reproductive decisions that will lead to less prevalence of the disease.”

Kaplan said the ethical questions will become more complex as genetic screening expands.

“What if there was a test for homosexuality? Or short stature?” he asked.

In cystic fibrosis, pancreatic, intestinal and lung secretions tend to be thick, clogging organs, especially the lungs. Complications can include lung collapse, heart failure and liver damage. In the past 25 years, medical advances have doubled the average life expectancy for people with CF, according to the Cystic Fibrosis Foundation, a national organization. Life expectancy is now 37.

The organization, in a statement, called genetic testing a personal matter and said it is too early to know if the Massachusetts decline is being duplicated in other parts of the country.

Preston W. Campbell III, the foundation’s executive vice president for medical affairs, said prospective parents should know that promising drugs are in the pipeline.

“Most babies born today with cystic fibrosis will live long and full lives,” he said.

Parents involved with the New Jersey State Organization of Cystic Fibrosis said they understand the joys and frustration of raising CF children.

Bob Frees of Linden has five children, two with CF, including a 26-year-old daughter who recently underwent a double lung transplant. Frees said he and his wife are happy genetic testing was not available when his children were born.

“We would not want to have to go through those difficult decisions,” he said.

In contrast, Frees said his married son with CF fears passing the disease on to his children and wants testing.

“He doesn’t want to see a child suffer they way he has suffered,” Frees said.

Another parent, Beth Maisto of Little Egg Harbor, has three children — two with CF. She did not learn she and her husband were carriers of the gene until she was tested during her third pregnancy. The knowledge led doctors to test her older son, who had frequent respiratory problems; they found he had CF. “They sent us to counseling and asked if I wanted to terminate the pregnancy,” she said. “But I couldn’t do it.”

Life with Michael, 7, and Julie, 4, can be difficult. Each is on multiple medications. She and her husband work opposite shifts to care for their children.

“The unknown is scary,” Maisto said. “But when you have an actual child in your arms, you see it’s not that bad. My kids are the best thing in my life.”

Carol Ann Campbell may be reached at ccampbell@starledger.com.

linkback url: http://www.nj.com/news/ledger/index.ssf?/base/news-13/
1205127414154160.xml&coll=1&thispage=1

Cord Blood Stem Cells Give Life- A medical option that’s now available

Cord Blood Stem Cells Give Life

A medical option that’s now available

Rumbo, News Feature, Liliana Cadavid, Posted: Feb 24, 2008

Editor’s Note: Umbilical cord blood is gaining acceptance as a source for transplant stem cells to save babies with Leukemia and adults who cannot find matching bone marrow traits. Although this practice is considered controversial in certain medical and parenting circles, its successes have proliferated a number of cord blood banks nationwide. Liliana Cadavid, a Fellow of the DNA Ethnic Media Fellowship sponsored New America Media and SoundVision Productions, is a health reporter. She wrote this story for Rumbo, a Spanish-language publication based in San Antonio, Texas.

Cord Blood Stem Cells treatments are a feasible, accessible and increasingly available option in modern medicine that helps to save hundreds of lives. Camilla Alecia Diaz-Weber, 2 years old, had a big smile when she came in to the transplant clinic at the Methodist Hospital in San Antonio for her monthly check up.

She moved her little arms hurriedly, excited to see the clinic staff. Everybody was very familiar for her. She has been there many times after the cord blood stem cells (CBSC) transplant that she received four months ago.

When Camilla, from Eagle Pass, Texas, was 19 months old, she was diagnosed with severe combined immunodeficiency (SCID), a rare genetic disease that according to the National Human Genome Research Institute (NHGRI) affects 40 to 100 children in the United States each year.

Children with SCID are very susceptible to any type of infection because they lack an immune system, according to hematologist Jaime Estrada, member of the Transplant Program at the Texas Transplant Institute in San Antonio (TTI). “The only treatment that can cure these children is the bone marrow or cord blood stem cells transplant. If they are not treated the prognosis is fatal,” he said.

Stem Cells have the ability to develop into other types of cells with specific functions, explained hematologist Anthony Infante, professor of Immunology at the University of Texas Health Science Center in San Antonio. The blood from the umbilical cord, he added, is particularly rich in cells that have the ability to mature into others cells that form blood.

“Currently, CBSC are widely used to treat leukemia, diseases of the immune system and other inborn related disorders in children,” he said.

Camilla was fortunate. On July 14 2007, she received a transplant at the TTI, covered by her family’s private health insurer. The transplant saved her life.

“Her doctor told us that in about a year she should be totally cured,” said Lori Diaz Weber, Camilla’s mother.

Similarly to Camilla, Ithzbel Aurora Huerta, 3 years old, from Laredo, Texas, was treated with CBSC, was covered by Medicaid, but suffered from a different disease. When she was two months old, she was diagnosed with an inborn bone marrow failure known as Severe Aplastic Anemia and received the transplant. “If it had not been for the CBSC transplant, I would not have her with me today,” said Arizbel Perez, Ithzbel’s mother.

Arizbel said she never heard of treatment with CBSC, but now that she has learned about it, she tells all her girl friends if they decide to become mothers, they need to plan on donating their babies’ cord blood to a public bank. “Someone who did this at a certain moment, saved my daughter life,” she said.

The CBSC transplant has many advantages, according to Donna Wall, Director of the Bone Marrow and Cord Blood Stem Cells Children’s Transplant at TTI. The most important thing in a transplant, she explained, is to find a donor who is compatible and certainly one of the things that we like the most about CBSC is that we don’t have to find a donor that has exactly the same type of immune system.

Also, she added, it is easier to find a cord blood unit in a public bank than it is to find a live bone marrow donor. “When we perform transplants in children, the CBSC is our preferred source from an individual outside the family.”
But when it comes to treating adults, the CBSC might not always be so helpful.
The problem of CBSC transplants is that the cells that are available are the ones that were obtained at the baby’s delivery; there are no more, said Dr. Yago Nieto, professor of the Department of Stem Cells Transplant at MD Anderson in Houston.

“Sometimes, a unit of cord blood can be very small to treat an adult patient”, Yago said. “It can work well but we have to make sure that the number of cells will be enough according to the patient’s weight.”

Right now, scientists are studying an option to work in laboratories to expand the number of stem cells in a cord blood unit, said Infante, but “the idea is being able to do so without altering the stem cells’ ability to function properly.”

To Store or to donate- a dilemma
Is it better to pay for storing a cord blood unit of a newborn baby or to donate it to a public bank?

That’s a common question among mothers- to- be. It is also a frequent question that Dr. Donna Wall of the Texas Transplant Institute in San Antonio is asked by doctors, lawyers and moms. “Public Banks have an important purpose: provide units of CBSC to those that need them”.

The majority of people, she continued, are not going to ever need a transplant. “So, why pay to store a baby’s cord blood in order to use it for that same baby in the future, if that is not likely to happen”, she said. “On the other hand, many of the disorders we treat are inherited, so the blood is going to have the same problem.”

Doctor Yago Nieto, from MD Anderson in Houston, suggested that people should donate cord blood to a public bank. “Doing this causes no harm to health, it can help save lives and it does not cost anything. To store cord blood in a private bank will cost a lot”.

linkback url: http://news.ncmonline.com/news/
view_article.html?article_id=8c94c16ef6e3c58bc3047676db7766e8

Risk Factors For Severe RSV Infection In Immunocompromised Children Identified

ScienceDaily (Feb. 4, 200 — St. Jude Children’s Research Hospital investigators and collaborators have shown how to predict if a child who is infected with respiratory syncytial virus (RSV) while being treated for cancer or another catastrophic disease is at high risk for developing severe infection. The finding will help clinicians improve guidelines for managing these infected children.

RSV is a common cause of pneumonia among infants, children and adults during winter, frequently causing fever, runny nose and coughs. It can be much more severe in patients who are undergoing cancer treatments and whose immune systems are suppressed. In these patients, the virus can move into the deep lung, causing pneumonia and other respiratory problems that can be fatal. However, it is difficult to predict which infected patient is likely to develop a serious lower respiratory tract illness and which one will continue to simply have a mild runny nose and cough.

The St. Jude team and collaborators found that if these children are under 2 years old and have very low levels of immune system cells in their blood called lymphocytes, they are at high risk for the RSV infection to become serious by moving into the lung. Such infections are especially dangerous because they can be fatal in some immunocompromised children, and there is no standard effective treatment for these infections, the researchers said. A report on the retrospective findings appears in the February issue of the journal “Pediatrics.”

“The new information is important because it helps identify children who are most at risk for severe disease using easily available clinical information,” said Aditya Gaur, M.D., assistant member of the St. Jude Department of Infectious Diseases and the paper’s senior author. “This narrows down the patient population who needs to be considered for antiviral therapy, which is costly and often inconvenient to receive from a child’s perspective. For example, one treatment for RSV infection is to have the child breathe an aerosolized form of the antiviral drug ribavirin for 12 to 18 hours, which is tough for the child and the parent.”

The findings of this study require confirmation in prospective studies, Gaur said. Results of the study also help define which children should receive medications that can help prevent RSV infection.

Another significant finding was that–unlike some previous reports in immunocompromised adults with RSV–neutropenia is not a risk factor for lower respiratory track infection, Gaur said. Neutropenia is an abnormally low level of neutrophils, immune system cells that engulf and digest germs.

“This finding is important because with cancer patients, clinicians are used to identifying those at risk for bacterial and fungal infections based on a patient having neutropenia,” Gaur said. This study shows that for RSV, which is a viral infection, lymphopenia and not neutropenia is what identifies children at risk.

Previous studies have shown that lower respiratory track infection, is more common in children whose immune system is suppressed, who are receiving chemotherapy or who have received a hematopoietic stem cell transplant (HSCT). However, while some studies report that lower respiratory track infection, due to RSV is fatal in 50 to 100 percent of infected adults, there is little information about this type of infection in immunocompromised children.

“We decided to analyze the course of RSV infection in children being treated for cancer to identify factors that could help us predict which ones were at highest risk for severe disease or death due to a lower respiratory tract infection with this virus,” Gaur said. HSCT is the transplantation of special cells from the blood or bone marrow that can give rise to all the blood cells of the body (red and white cells and platelets).

The St. Jude team studied clinical and laboratory information from the records of 58 patients who had tested positive for RSV infection. Among these children, 23 (40 percent) had acute lymphoblastic leukemia, 11 (19 percent) had solid tumors and 24 patients (41 percent) had acute myeloid leukemia (AML), severe combined immunodeficiency syndrome (SCIDS), or had undergone bone marrow transplantation. RSV disease in these infected children was classified as upper respiratory track infection only or lower respiratory tract infection; and children with both upper and lower respiratory track infections, were defined as having lower respiratory track infection.

Overall, 16 (28 percent) of these children developed lower respiratory track infection, due to RSV. The frequency of this type of infection was highest (42 percent) in patients who had undergone HSCT or who had AML or SCIDS. Five patients (31 percent) with LRTI died, an overall mortality rate of 8.6 percent. All deaths occurred in lower respiratory track infection patients who were severely immunocompromised from their cancer, from chemotherapy or from the HSCT.

Other researchers include C. M. El Saleeby (formerly of St. Jude and now at MassGeneral Hospital for Children, Boston), G. W. Somes (Department of Preventive Medicine, University of Tennessee, Memphis) and J.P. DeVincenzo (Le Bonheur Children’s Medical Center and University of Tennessee, Memphis).

This study was supported by the National Institutes of Health and ALSAC.

Adapted from materials provided by St. Jude Children’s Research Hospital, via EurekAlert!, a service of AAAS.

linkback url: http://www.sciencedaily.com/releases/2008/02/080204132525.htm

SCID Conference 2008

It’s been 10 years since the X-SCID Conference held in Bethesda, Maryland. Now plans are underway for another conference. Preparations are still in the early stages, but to find out what’s planned visit the SCID Conference 2008 website. The SCID Conferences are for SCID patients and their families. New information will be posted on the conference site as soon as it’s known. Check the site often for the latest information. Dates and location have already been announced: July 25th to 27th, 2008 at Wintergreen Resort and Spa in Wintergreen, Virginia. Registration will be open soon!

Shot in the arm

The Star Online > Health

Wednesday January 16, 2008

Shot in the arm

By Dr MILTON LUM

Vaccinations help prevent disease and their benefits far outweigh the risks.
Widespread vaccination has virtually eradicated many infectious diseases in the world.

ALL of us get infected by organisms like bacteria, viruses and parasites. Infants and children are particularly vulnerable. It is relevant to know how the body responds to infections and how medicine has developed ways of dealing with some infectious diseases.

Active immunity

The body responds to infections by producing antibodies, which are proteins that attach themselves to the organisms, marking them for the white blood cells to identify and destroy. As long as there are circulating antibodies, the body is protected from the infective agent. The antibody levels decrease over time and the protection may, in certain diseases, eventually disappear.

Passive immunity

In an acute infection, injecting antibodies made from the blood of humans or animals with immunity to a specific infection can provide immediate protection. Since the body is not making its own antibodies, the protection provided is temporary, as the injected antibodies do not survive for more than a few weeks, such as in the case of hepatitis A.

Another method of achieving passive immunity is to inject human immunoglobulin which is obtained from pooled donated blood containing a collection of antibodies to diseases common in the general population such as measles, mumps, rubella, hepatitis A and chicken pox. The immunoglobulins do not have antigens, which are substances that stimulate the production of an antibody in a carrier of the disease. There are also immunoglobulins made from donors who have had specific diseases, such as hepatitis B and tetanus.

As there are two types of immunity, so there are two types of immunisation, active and passive, with the former always preferable to the latter, since prevention is better than cure. However, passive immunisation may be needed to treat an acute infection. It is often not uncommon that passive and active immunisation are combined, the former providing immediate treatment while the active production of antibodies provides longer term protection. Why immunise

Widespread vaccination has virtually eradicated many infectious diseases in the world. The classical example is small pox, which now only exists in certain laboratories. The incidences of some infectious diseases have decreased considerably with vaccination. Since the World Health Organisation (WHO) launched its Global Polio Eradication Initiative in 1998, infections have decreased by about 99%, saving about five million people from paralysis.

Newer vaccines have been and are being developed and this has contributed to protection against more serious infectious diseases. The hepatitis B vaccine which was introduced about two decades ago helps in the prevention of liver cancer, while the recently introduced human papilloma virus (HPV) vaccine helps in the prevention of HPV infection, a leading causative factor of cervical cancer.

Vaccination provides protection against specific diseases. There may be side effects and risks, which are very much less than that of the disease itself. The benefits of immunisation far outweigh the risks.

Types of vaccines

Vaccines stimulate the production of antibodies without the person having the illness. There are three main types of vaccines:

# Live attenuated vaccine is an extremely weak preparation of a live infectious organism (measles, mumps, rubella)

# Inactivated vaccine is a preparation of a killed infectious organism (typhoid)

# Detoxified exotoxins and extracts of exotoxins are preparations of poisonous substances made by some bacteria that have been made safe for human use by chemical processes (diphtheria, tetanus).

Some vaccines are given as combinations, such as diphtheria-pertussis-tetanus (DPT) and measles-mumps-rubella (MMR).

Immunisation schedule

Immunisation is provided to all babies born in both the public and private sectors. Various countries have slightly different immunisation schedules, depending on the prevalence of the serious infectious diseases and affordability. It is advisable to adhere to the schedule to obtain maximum benefit.

Efforts should be made to ensure the immunisation of children who are at greater risk of infectious diseases, such as children with congenital heart disease and/or mongolism (Down’s syndrome) and those who are born premature, remain small for their age, are HIV positive or have asthma.

When not to immunise

Active immunisation with live vaccines can pose danger to certain individuals, such as those with severe immunodeficiency disorders, those who have had severe reactions to vaccines previously, anyone suffering from any acute illness and anyone on high doses of steroids or immunosuppressive medicines.

An infant who is HIV positive should receive live vaccines for measles, mumps, rubella, and polio and inactivated vaccines for hepatitis B, diphtheria, tetanus, pertussis, polio, cholera and typhoid.

Vaccination can result in severe allergic reaction in those who are very sensitive to one or more of its components. Those with egg allergy should not be given MMR vaccine as it is made in chicken eggs. Some vaccines contain very small amounts of antibiotics, for instance neomycin and polymxin, which can stimulate an allergic reaction in some individuals.

It is advisable for parents of children with food allergies to consult their doctor prior to vaccination. Vaccination should be postponed until an infant has recovered from an acute illness. Vaccination may be given to an infant who has a minor illness, without fever, or with minimal symptoms.

Most vaccines are given by injections into the skin. Some vaccines like polio are given as mouth drops.

Effectiveness and safety

Although there is no vaccine that is 100% safe or effective, all vaccines used in routine immunisation are very effective in preventing disease. It is usual to give more than one dose of a vaccine to increase the likelihood of developing antibodies.

Although vaccination is generally safe, some babies may develop side effects or adverse reactions, which are minor . Some vaccines, such as polio, have very few side effects while others, such as rubella, may produce a very mild form of the disease.

Swelling at the injection site, a low grade fever and rashes are not uncommon. This usually goes away in about 36 hours and is a sign that the baby’s immune system has been stimulated.

Serious complications are very rare. Severe allergic reaction (anaphylaxis) is extremely rare. Its incidence is one in 100,000 with measles vaccine. It is dangerous and may result in damage. It is impossible to predict who may get this unless an allergic reaction had occurred previously.

Media reports have tended to sensationalise the extremely rare, adverse reactions to vaccination. If you have any concerns about any aspect of vaccination, a discussion with your doctor instead of withholding vaccination from your child, is a wiser approach.

When children are not vaccinated, they are very vulnerable to preventable diseases. The children are much more likely to be harmed by the disease than by the vaccine itself.

# Dr Milton Lum is chairperson of the Commonwealth Medical Trust. This article is not intended to replace, dictate or define evaluation by a qualified doctor. The views expressed do not represent that of any organisation he is associated with.

linkback url: http://thestar.com.my/health/story.asp?file=/2008/1/16/health/19964204&sec=health

Immune System

The following was taken from another blog post. It was quite good, so I thought I’d reprint it here.

Thursday, December 27, 2007

IMMUNE SYSTEM

The Immune System — An Overview

The immune system is composed of many interdependent cell types that collectively protect the body from bacterial, parasitic, fungal, viral infections and from the growth of tumor cells. Many of these cell types have specialized functions. The cells of the immune system can engulf bacteria, kill parasites or tumor cells, or kill viral-infected cells. Often, these cells depend on the T helper subset for activation signals in the form of secretions formally known as cytokines, lymphokines, or more specifically interleukins. Such an understanding may help comprehend the root of immune deficiencies, and perceive potential avenues that the immune system can be modulated in the case of specific diseases.

The Organs of the Immune System

Bone Marrow — All the cells of the immune system are initially derived from the bone marrow. They form through a process called hematopoiesis. During hematopoiesis, bone marrow-derived stem cells differentiate into either mature cells of the immune system or into precursors of cells that migrate out of the bone marrow to continue their maturation elsewhere. The bone marrow produces B cells, natural killer cells, granulocytes and immature thymocytes, in addition to red blood cells and platelets.

Thymus – The function of the thymus is to produce mature T cells. Immature thymocytes, also known as prothymocytes, leave the bone marrow and migrate into the thymus. Through a remarkable maturation process sometimes referred to as thymic education, T cells that are beneficial to the immune system are spared, while those T cells that might evoke a detrimental autoimmune response are eliminated. The mature T cells are then released into the bloodstream.

Spleen – The spleen is an immunologic filter of the blood. It is made up of B cells, T cells, macrophages, dendritic cells, natural killer cells and red blood cells. In addition to capturing foreign materials (antigens) from the blood that passes through the spleen, migratory macrophages and dendritic cells bring antigens to the spleen via the bloodstream. An immune response is initiated when the macrophage or dendritic cells present the antigen to the appropriate B or T cells. This organ can be thought of as an immunological conference center. In the spleen, B cells become activated and produce large amounts of antibody. Also, old red blood cells are destroyed in the spleen.

Lymph Nodes — The lymph nodes function as an immunologic filter for the bodily fluid known as lymph. Lymph nodes are found throughout the body. Composed mostly of T cells, B cells, dendritic cells and macrophages, the nodes drain fluid from most of our tissues. Antigens are filtered out of the lymph in the lymph node before returning the lymph to the circulation. In a similar fashion as the spleen, the macrophages and dendritic cells that capture antigens present these foreign materials to T and B cells, consequently initiating an immune response.

Humans have three types of immunity — innate, adaptive, and passive:

Innate Immunity Everyone is born with innate (or natural) immunity, a type of general protection that humans have. Many of the germs that affect other species don’t harm us. For example, the viruses that cause leukemia in cats or distemper in dogs don’t affect humans.

Innate immunity works both ways because some viruses that make humans ill — such as the virus that causes HIV/AIDS — don’t make cats or dogs sick either.Innate immunity also includes the external barriers of the body, like the skin and mucous membranes (like those that line the nose, throat, and gastrointestinal tract), which are our first line of defense in preventing diseases from entering the body. If this outer defensive wall is broken (like if you get a cut), the skin attempts to heal the break quickly and special immune cells on the skin attack invading germs.

Adaptive Immunity We also have a second kind of protection called adaptive (or active) immunity. This type of immunity develops throughout our lives. Adaptive immunity involves the lymphocytes (as in the process described above) and develops as children and adults are exposed to diseases or immunized against diseases through vaccination.

Passive Immunity Passive immunity is “borrowed” from another source and it lasts for a short time. For example, antibodies in a mother’s breast milk provide an infant with temporary immunity to diseases that the mother has been exposed to. This can help protect the infant against infection during the early years of childhood.Everyone’s immune system is different. Some people never seem to get infections, whereas others seem to be sick all the time. As people get older, they usually become immune to more germs as the immune system comes into contact with more and more of them. That’s why adults and teens tend to get fewer colds than kids — their bodies have learned to recognize and immediately attack many of the viruses that cause colds.

Things That Can Go Wrong With the Immune System

Disorders of the immune system can be broken down into four main categories:
1.immunodeficiency disorders (primary or acquired) autoimmune disorders (in which the body’s own immune system attacks its own tissue as foreign matter) allergic disorders (in which the immune system overreacts in response to an antigen) cancers of the immune system Immunodeficiency DisordersImmunodeficiencies occur when a part of the immune system is not present or is not working properly. Sometimes a person is born with an immunodeficiency — these are called primary immunodeficiencies. (Although primary immunodeficiencies are conditions that a person is born with, symptoms of the disorder sometimes may not show up until later in life.) Immunodeficiencies can also be acquired through infection or produced by drugs. These are sometimes called secondary immunodeficiencies.Immunodeficiencies can affect B lymphocytes, T lymphocytes, or phagocytes. Some examples of primary immunodeficiencies that can affect kids and teens are:IgA deficiency is the most common immunodeficiency disorder. IgA is an immunoglobulin that is found primarily in the saliva and other body fluids that help guard the entrances to the body. IgA deficiency is a disorder in which the body doesn’t produce enough of the antibody IgA. People with IgA deficiency tend to have allergies or get more colds and other respiratory infections, but the condition is usually not severe. Severe combined immunodeficiency (SCID) is also known as the “bubble boy disease” after a Texas boy with SCID who lived in a germ-free plastic bubble. SCID is a serious immune system disorder that occurs because of a lack of both B and T lymphocytes, which makes it almost impossible to fight infections. DiGeorge syndrome (thymic dysplasia), a birth defect in which children are born without a thymus gland, is an example of a primary T-lymphocyte disease. The thymus gland is where T lymphocytes normally mature. Chediak-Higashi syndrome and chronic granulomatous disease both involve the inability of the neutrophils to function normally as phagocytes. Acquired immunodeficiencies usually develop after a person has a disease, although they can also be the result of malnutrition, burns, or other medical problems. Certain medicines also can cause problems with the functioning of the immune system. Secondary immunodeficiencies include:HIV (human immunodeficiency virus) infection/AIDS (acquired immunodeficiency syndrome) is a disease that slowly and steadily destroys the immune system. It is caused by HIV, a virus which wipes out certain types of lymphocytes called T-helper cells. Without T-helper cells, the immune system is unable to defend the body against normally harmless organisms, which can cause life-threatening infections in people who have AIDS. Newborns can get HIV infection from their mothers while in the uterus, during the birth process, or during breastfeeding. People can get HIV infection by having unprotected sexual intercourse with an infected person or from sharing contaminated needles for drugs, steroids, or tattoos. Immunodeficiencies caused by medications. Some medicines suppress the immune system. One of the drawbacks of chemotherapy treatment for cancer, for example, is that it not only attacks cancer cells, but other fast-growing, healthy cells, including those found in the bone marrow and other parts of the immune system. In addition, people with autoimmune disorders or who have had organ transplants may need to take immunosuppressant medications. These medicines can also reduce the immune system’s ability to fight infections and can cause secondary immunodeficiency. Autoimmune DisordersIn autoimmune disorders, the immune system mistakenly attacks the body’s healthy organs and tissues as though they were foreign invaders. Autoimmune diseases include:Lupus is a chronic disease marked by muscle and joint pain and inflammation. The abnormal immune response may also involve attacks on the kidneys and other organs. Juvenile rheumatoid arthritis is a disease in which the body’s immune system acts as though certain body parts such as the joints of the knee, hand, and foot are foreign tissue and attacks them. Scleroderma is a chronic autoimmune disease that can lead to inflammation and damage of the skin, joints, and internal organs. Ankylosing spondylitis is a disease that involves inflammation of the spine and joints, causing stiffness and pain. Juvenile dermatomyositis is a disorder marked by inflammation and damage of the skin and muscles. Allergic DisordersAllergic disorders occur when the immune system overreacts to exposure to antigens in the environment. The substances that provoke such attacks are called allergens. The immune response can cause symptoms such as swelling, watery eyes, and sneezing, and even a life-threatening reaction called anaphylaxis. Taking medications called antihistamines can relieve most symptoms. Allergic disorders include:Asthma, a respiratory disorder that can cause breathing problems, frequently involves an allergic response by the lungs. If the lungs are oversensitive to certain allergens (like pollen, molds, animal dander, or dust mites), it can trigger breathing tubes in the lungs to become narrowed, leading to reduced airflow and making it hard for a person to breathe. Eczema is an itchy rash also known as atopic dermatitis. Although atopic dermatitis is not necessarily caused by an allergic reaction, it more often occurs in kids and teens who have allergies, hay fever, or asthma or who have a family history of these conditions. Allergies of several types can occur in kids and teens. Environmental allergies (to dust mites, for example), seasonal allergies (such as hay fever), drug allergies (reactions to specific medications or drugs), food allergies (such as to nuts), and allergies to toxins (bee stings, for example) are the common conditions people usually refer to as allergies. Cancers of the Immune SystemCancer occurs when cells grow out of control. This can also happen with the cells of the immune system. Lymphoma involves the lymphoid tissues and is one of the more common childhood cancers. Leukemia, which involves abnormal overgrowth of leukocytes, is the most common childhood cancer. With current medications most cases of both types of cancer in kids and teens are curable.Although immune system disorders usually can’t be prevented, you can help your child’s immune system stay stronger and fight illnesses by staying informed about your child’s condition and working closely with your doctor.

linkback url:http://timesharing4you.blogspot.com/2007/12/immune-system.html