X-linked Lymphoproliferative Syndrome Workup

Updated: Jan 24, 2022
  • Author: Karen Seiter, MD; Chief Editor: Emmanuel C Besa, MD  more...
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Laboratory Studies

Laboratory findings in X-linked lymphoproliferative (XLP) syndrome include the following:

  • Peripheral blood smears will show atypical lymphocytosis.
  • Serum chemistry profiles will show transaminitis and other findings of acute hepatitis.
  • Coagulation studies will be abnormal in patients with liver failure.

Patients with acute Epstein-Barr virus (EBV) infection will demonstrate positive serologic tests for EBV IgM antibodies and quantitative EBV-specific polymerase chain reaction (EBV-PCR). However, as many as one third of patients in the acute infection phase do not produce antibodies, probably due to impaired lymphocyte function and response to EBV antigens.

A definitive diagnosis of XLP is with mutation analysis for the SH2D1A or XIAP gene mutation. Flow cytometry can be used to measure lymphocyte SAP or XIAP protein expression and can be used to detect lymphocyte phenotypes and functional defects related to XLP. [15, 16]


Histologic Findings

Liver biopsy results typically show an intense periportal B-cell lymphoid infiltrate containing EBV-nuclear antigen (EBNA-1) often surrounded by numerous CD8-positive T lymphocytes and natural killer cells. In later stages, periportal necrosis is observed in most patients. Other organs that can be involved include the liver, heart, brain, and thymus. Findings in the bone marrow are generally reactive.