Detection of drug-dependent, platelet-reactive antibodies by solid-phase red cell adherence assays.
We developed a simple modification of the solid-phase red cell adherence (SPRCA) assay system that can be used to identify drug-dependent platelet antibodies (DDPAs) reactive by either the hapten or immune complex reaction mechanisms. Between January 1994 and August 1996 we tested sera from 173 patients [123 (71%) with unexplained thrombocytopenia and 50 (29%) because of poor responses to platelet transfusions not explicable by alloimmunization or the clinical situation] for DDPAs possibly associated with the receipt of 61 different drugs. We correlated positive results with patients' clinical courses. DDPAs were identified in samples from 138 (80%) of the patients tested. Antibodies reactive only by the hapten mechanism were identified in 51 (37%) of those sera exhibiting positive reactions. The clinical courses of 108 (78%) patients were evaluable. Discontinuation of the implicated drug(s) resulted in prompt (<5 d) resolution of the thrombocytopenia or improvement in response to transfusion in all of these patients. In four cases thrombocytopenia returned upon re-exposure to the implicated drug. This adaptation of SPRCA provides a simple means of investigating the possibility of DDPAs and documents a higher frequency of these antibodies than has previously been suspected.
Leach
M F
MF
Transfusion Services, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire 03756, U.S.A.
Cooper
L K
LK
AuBuchon
J P
JP
D000906:Antibodies / Q000032:analysis*; D000917:Antibody Formation; D001792:Blood Platelets / Q000276:immunology*; D006403:Hematologic Tests / Q000379:methods*; D006801:Humans; D013921:Thrombocytopenia / Q000139:chemically induced*
D000906:Antibodies