Cellular immune responses in aspergillosis

Diminished platelet aggregation responses to one or more aggregating agents were found in 25 of 32 patients with nasal allergy studied at the peak of the allergy season. Abnormal in-season platelet aggregation induced by epinephrine and collagen was significantly improved when repeated out-of-season, while incomplete platelet aggregation induced by adenosine diphosphate (ADP) and thrombin was unchanged. Recombination of an in-season serum factor with autologous, out-of-season normally aggregating platelets caused marked inhibition of platelet aggregation. Mean bleeding times of 20 symptomatic patients were also prolonged during the height of the pollination season. These data suggest that the allergic diathesis is a model for the study of cyclic, nondrug induction of platelet dysfunction.