THROMBOCYTOPENIA ASSOCIATED TO INFECTION BY THE HUMAN-IMMUNODEFICIENCY-VIRUS - IMMUNOLOGICAL STUDY IN 60 INTRAVENOUS DRUG-ADDICT PATIENTS

BACKGROUND: The immunologic study of 60 intravenous drug addict patien ts who were seropositive for the human immunodeficiency virus (HIV) an d who developed thrombacytopenia (TP] is reported with the aim of esta blishing the relation of possible pathogenic factors which may trigger this complication. METHODS: In all the patients the presence of antip latelet antibodies was studied by direct and indirect immunofluorescen ce together with cryptoantibodies, immune complexes, lymphocytotoxic a ntibodies, antiphospholipid antibodies, immunoglobulins, lymphocytic p opulations and subpopulations and serology against different infectiou s agents. RESULTS: Antiplatelet antibodies were detected in 71 % of th e patients of which 50 % corresponded to immunoglobulins of IgG class, 12 % to IgM, 21 % to IgG plus IgM, 7 % IgM plus IgA, 5 % to IgG plus IgA and 5 % IgG plus IgM plus IgA. In these patients a characteristic membrane fluorescence pattern was observed in which the fluorescein is distributed forming a thick, hard point. In 3 patients EDTA dependent cryptoantibodies were detected which in one case determined pseudothr ombocytopenia. The immune complexes were demonstrated in 50 % of the c ases. Other findings were: hypergammaglobulinemia (86 %), decrease in the CD4 population (47 %), CD4/CD8 ratio < 1 (71 %), lymphocytotoxic a ntibodies (70 %), antiphospholipid antibodies [60 %), and seropositivi ty for cytomegalovirus (62 %), Epstein-Barr virus (10 %) and hepatitis B virus (anti-HBc 75 %, HBsAg 33 %). CONCLUSIONS: Thrombocytopenia as sociated to infection by the human immunodeficiency virus in intraveno us drug addict patients is due to the concurrence of multiple factors. The relevance of each may vary according to the risk practice of the collective analysed and even within the same group of same individuals or others. The numerous serologic findings in these patients fundamen tally express the existence of a chronic polyclonal stimulation of B c ells which may be initiated by the action of the drug itself and which becomes aggravated during the course of the multiple acquired infecti ons among which that due to the human immunodeficiency virus is of not e.