X-linked lymphoproliferative syndrome is an immunodeficiency disorder that results from an abnormality in T cells and natural killer cells and results in an abnormal response to Epstein-Barr virus infection.
People with X-linked lymphoproliferative syndrome develop a serious, sometimes fatal form of infectious mononucleosis after being infected with Epstein-Barr virus.
Doctors diagnose the disorder by genetic testing and sometimes other tests.
Stem cell transplantation is necessary for survival and may cure the disorder.
(See also Overview of Immunodeficiency Disorders.)
T cells are white blood cells that identify and attack foreign cells and substances. Natural killer cells are a type of T cell that recognizes and kills abnormal cells (such as certain infected cells and cancer cells). Deficiency or malfunction of T cells increases the risk of serious infection.
X-linked lymphoproliferative syndrome is a primary immunodeficiency disorder. It is inherited as an X-linked recessive disorder. X-linked means that the disorder is due to a mutation in one or more genes on the X (sex) chromosome. X-linked recessive disorders occur only in boys.
There are 2 types, which result from different gene mutations but cause similar symptoms.
In the first type, too many white blood cells (which help the body fight infection) are produced in response to Epstein-Barr virus (EBV) infection. The EBV causes several disorders, including infectious mononucleosis. Also, natural killer cells do not function.
The second type can cause a rare but serious disorder called hemophagocytic lymphohistiocytosis, which causes immunodeficiency in infants and young children. In hemophagocytic lymphohistiocytosis, too many blood cells in the immune system are activated. The result is widespread inflammation. Sometimes this overactivation is triggered by infectious organisms such as EBV.
Symptoms of X-Linked Lymphoproliferative Syndrome
Usually, people with X-linked lymphoproliferative syndrome have no symptoms until Epstein-Barr virus (EBV) infection develops. Then, a serious, sometimes fatal form of infectious mononucleosis develops. The liver malfunctions, resulting in liver failure. People who survive develop other disorders, such as lymphoma, aplastic anemia, another immunodeficiency disorder, and an enlarged spleen.
Diagnosis of X-Linked Lymphoproliferative Syndrome
Blood tests
Genetic testing
Sometimes bone marrow biopsy
Doctors suspect X-linked lymphoproliferative syndrome in young boys who have severe EBV infection, other characteristic problems, or family members with similar symptoms.
The diagnosis is confirmed by genetic testing. However, genetic testing can take weeks to complete, so doctors may do specialized blood tests, such as flow cytometry (analysis of proteins on the surface of white blood cells), to check for abnormalities in immune cells.
Laboratory and imaging tests are done yearly to check for lymphoma and anemia. Sometimes a bone marrow biopsy is also done to check for these disorders.
Genetic testing is recommended for family members.
Prenatal genetic screening is recommended for people if a mutation that causes X-linked lymphoproliferative syndrome has been identified in their family.
Treatment of X-Linked Lymphoproliferative Syndrome
Stem cell transplantation
About 80% of people who receive a stem cell transplant survive. But without transplantation, 75% of people die before age 10 years, and all die by age 40. Transplantation can cure X-linked lymphoproliferative syndrome if it is done before EBV infection or other disorders become too severe.
Gene therapy is being studied in people with X-linked lymphoproliferative syndrome.
More Information
The following English-language resource may be useful. Please note that The Manual is not responsible for the content of this resource.
Immune Deficiency Foundation: Other primary cellular immunodeficiencies: General information on primary cellular immunodeficiencies, including information on diagnosis and treatment
