Severe thrombocytopenia in patients treated with suramin: evidence for an immune mechanism in one.
Although suramin has long been used to treat human trypanosomiasis, recent clinical trials have tested its efficacy against the acquired immunodeficiency syndrome (AIDS) and various malignancies. Thromobocytopenia was observed in early trials with suramin in AIDS, but has been uncommon in patients treated for solid tumors. Here we describe 5 patients out of a total of 67 (7%) who developed severe thrombocytopenia while receiving suramin as part of a phase II clinical trial for metastatic prostate carcinoma refractory to hormonal therapy. IgG purified from one patient's plasma caused suramin-dependent platelet aggregation. There was also evidence of crossreactivity between suramin and heparin in this system. An immune mechanism, however, could not be documented in the other cases, suggesting that multiple mechanisms may be responsible for severe thrombocytopenia in this patient population.
Tisdale
J F
JF
Hematology Branch, National Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Figg
W D
WD
Reed
E
E
McCall
N A
NA
Alkins
B R
BR
Horne
M K
MK
D000970:Antineoplastic Agents / Q000009:adverse effects*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D010974:Platelet Aggregation / Q000276:immunology; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D013498:Suramin / Q000009:adverse effects*; D013921:Thrombocytopenia / Q000139:chemically induced* / Q000276:immunology
D000970:Antineoplastic Agents; D007074:Immunoglobulin G; D013498:Suramin