Autoimmune Lymphoproliferative Syndrome (ALPS)

by National Institute of Health

ALPS (autoimmune lymphoproliferative syndrome) is a rare disease discovered by a team of doctors and scientists at the National Institutes of Health (NIH). The National Institute of Allergy and Infectious Diseases (NIAID) and the National Human Genome Research Institute (NHGRI) are components of the NIH working on ALPS. Our team of doctors and scientists is continuing to search for better ways to diagnose and treat ALPS. This brochure is designed to answer questions that many ALPS patients and their families have asked.

You or one of your relatives has been invited to visit doctors at the National Institutes of Health (NIH) because of health problems related to the immune system. We first began to study these problems in 1990, when we saw a child who had immune system symptoms that did not fit any previously known disorders. Since then, dozens of other children and adults with similar problems have been identified and followed at the NIH.

In 1995, we gave this newly identified condition a name - ALPS. By August 1999, we diagnosed ALPS in 58 individuals from 35 families. These families come from all over the country and are of many different racial backgrounds.

We hope that this brochure will help answer some of your questions about ALPS. Share it with your family, physicians, members of your community, and your children's teachers so that they can understand ALPS better, too.

Alps-What Is It

ALPS is a rare disease that affects both children and adults. ALPS stands for Autoimmune LymphoProliferative (lim-fo-pro-lif'-er-a-tive) Syndrome. Each of these three words helps describe the main features of this condition. The word autoimmune (self-immune) identifies ALPS as a disease of the immune system. The tools used to fight germs turn against our own cells and cause problems. The word lymphoproliferative describes the unusually large numbers of white blood cells (called lymphocytes (lim'-fo-sites)) stored in the lymph nodes and spleens of people with ALPS. The word syndrome refers to the many common symptoms shared by ALPS patients.

Clinical Features of ALPS

Some signs of ALPS are ones that people can feel or see, and some of them can be detected only by laboratory tests. Not all people with ALPS will have all of its possible symptoms. Some people have only a few. Some things that are seen most often in people with ALPS include:

• an enlarged spleen
• enlarged lymph nodes, especially in the neck and underarms
• an enlarged liver
• skin rashes
• frequent nose bleeds
• anemia (low blood counts)
• an increase in certain types of white blood cells (including double-negative T cells)
• an increased life-span of some white blood cells that are no longer needed
• an alteration in a gene

What We've Found Out So Far At The NIH

At this time we are still learning about ALPS. Based on our experience, we believe the following to be true: ALPS is a disorder that develops in early childhood. ALPS is not cancer; it is not contagious; it is not AIDS. There is a wide spectrum of illness in ALPS. For some, it is very mild; for others, it is more severe. Once a person has ALPS, he or she does not become sicker and sicker over time. In fact, the problems seem to improve as children get to be teenagers and young adults. Most people with ALPS have episodes of autoimmune problems. These can happen at any age, but they appear worse in childhood.

Types of Autoimmune Problems

Common autoimmune problems in ALPS include:

Very low red blood cell counts (hemolytic anemia) that can make one weak. Very low platelet counts (immune-mediated thrombocytopenia, or ITP) that cause bruises and nose bleeds, and may pose a risk for hemorrhage (excessive bleeding). Little spots called petechiae (pet-eek'-ia) may also show up on the skin when platelets are low. Very low white blood cell counts (autoimmune neutropenia), creating a risk for bacterial infection. Less often, other autoimmune problems can occur in almost any organ - skin, liver, kidney and nerves are examples.

A Brief Introduction to Immunology

You may wonder what the connection is between the findings in ALPS and the immune system. To understand what happens in ALPS, we would like to review some basic information about the immune system. It is the immune system that defends our bodies against germs. There are many components of the immune system. Two major components are the spleen and white blood cells. The spleen is a fist-sized organ found to the left of your stomach. It has a special job of filtering the blood, by cleaning out dead blood cells that aren't needed any more. The blood contains many types of cells: red blood cells help transport oxygen to your tissues, platelets help to form blood clots, white blood cells are the soldiers in your immune system.

One major class of white blood cells is called lymphocytes. There are many kinds of lymphocytes to combat the variety of germs in the world. B cells and T cells are two major kinds of lymphocytes.

About the Author

NIH is the nation's medical research agency - making important medical discoveries that improve health and save lives. The National Institutes of Health (NIH), a part of the U.S. Department of Health and Human Services, is the primary Federal agency for conducting and supporting medical research.