Angioimmunoblastic T-cell lymphoma associated with an antibody to human immunodeficiency virus protein

A 58-year-old man was admitted with generalized lymphadenopathy. On admission, the patient showed polyclonal hyper-gammopathy in a blood examination, positive results in the direct/indirect Coombs test, and an elevated cold agglutinin titer. Autoimmune thrombocytopenia with a high level of platelet-associated immunoglobulin G complicated the patient's condition. An enzyme immunoassay kit for human immunodeficiency virus (HIV) recombinant proteins p24, gp41, and gp36 showed positive results. Western blot analysis showed the presence of antibodies cross-reacting with HIV p24 gag protein. HIV RNA was not detected by means of a reverse transcriptase-polymerase chain reaction assay, so the patient was not an HIV carrier. Angioimmunoblastic T-cell lymphoma (AILT) was diagnosed on the basis of lymph node biopsy specimens. We speculated that in this case some of the numerous subtypes of polyclonal gamma globulin had coincidentally cross-reacted with HIV p24. Cross-reactive phenomena with HIV in patients with systemic lupus erythematosus have been well investigated, but to our knowledge our patient is the first case of such cross-reactivity involving AILT. Physicians should pay close attention to serologic tests to determine whether the patient truly is a viral carrier.