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L K Cooper

Publications and source records attributed to L K Cooper.

5 recordsLinked to original sources

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.

Antibodies↗

Detection of drug-dependent platelet antibodies by use of solid-phase red cell adherence techniques.

Many drugs have been reported to cause drug-dependent thrombocytopenia, either by the immune complex or by hapten mechanisms. Testing for the presence of these platelet antibodies has not been considered feasible for transfusion services because their presence was thought to be rare, and their detection involved complex and costly methods. We have developed a new technique for detection of these antibodies that can be performed without the need for specialized and expensive instrumentation. A solid-phase red cell adherence assay was used to detect drug-dependent platelet antibodies active by either the immune complex or the hapten mechanism. Three cases were evaluated for the presence of drug-dependent platelet antibodies. Two patients presented with thrombocytopenia that could not be attributed to other causes. The third case was evaluated for the presence of drug-dependent antibodies after poor responses to platelet transfusions. In these three cases, discontinuation of the implicated drugs, i.e., porcine heparin, quinine sulfate, amoxicillin, Bactrim, and albuterol, was followed by a correction of thrombocytopenia or improved platelet transfusion response within 72 hours. This test methodology and protocol has proven very useful in avoiding transfusions with little likelihood of benefit, and in identifying drugs interfering with platelet recovery or survival. Further investigations with this technique may expand our knowledge of the capability of this technique and of the observed frequency of drug-related immunologic platelet destruction.

Journal Article↗