immunology allergic disorders
X linked Lymphoproliferative Syndrome
Diagnosis of X linked Lymphoproliferative Syndrome
Genetic testing The diagnosis of X-linked lymphoproliferative syndrome should be considered in young males who have severe Epstein-Barr virus infection, hemophagocytic lymphohistiocytosis, a suggestive family history, or other common manifestations. Genetic testing is the standard test for confirming the diagnosis (before and after EBV infection and symptoms develop) as well as the carrier state. However, genetic testing can take weeks to complete, so other testing is done if the diagnosis must be made earlier (eg, flow cytometry to assess SH2D1A protein expression). Suggestive findings include Decreased antibody responses to antigens (particularly to EBV nuclear antigen) Impaired T-cell proliferative responses to mitogens Decreased NK-cell function An inverted CD4:CD8 ratio These findings are typical before and after Epstein-Barr virus infection. A bone marrow biopsy can help confirm hemophagocytic lymphohistiocytosis. In survivors, laboratory and imaging tests are done yearly to check for lymphoma and anemia. Genetic testing is done in relatives when a case or carrier is identified in a family. Prenatal screening is recommended for people if a mutation that causes XLP has been identified in their family. 