AN EPIDEMIOLOGIC-STUDY OF APLASTIC-ANEMIA - RELATIONSHIP OF DRUG EXPOSURES TO CLINICAL-FEATURES AND OUTCOME

Two hypotheses were examined in the combined data from 3 case-control studies of aplastic anaemia, conducted in Thailand, Europe/Israel and the US: 1. Cases exposed to drugs associated with a significantly incr eased risk of aplastic anaemia are more Likely to present with thrombo cytopenia (e.g. petechiae, easy bruising); and 2. cases exposed to the se drugs are more likely to recover quickly than non-exposed cases. Af ter excluding all cases who lacked information on timing of symptoms a nd those whose symptoms began greater than or equal to 180 d before ho spital admission, 392 cases remained for analysis. A total of 51 (13%) had been exposed to one of the significantly associated drugs; the re maining 341 (87%) had not. Among the former, 31% reported thrombocytop enia either before or at the same time as non-bleeding symptoms (e.g. pallor, fatigue); the corresponding proportion among the non-exposed w as 53%. Data on time to recovery (return of the 3 blood cell lines to normal levels) were not available for the Thai cases; among the others , the median time to recovery for the non-fatal cases was 7 and 6 mont hs in the 29 exposed and the 83 non-exposed cases, respectively. The d ata do not support either hypothesis: the two groups of aplastic anaem ia cases appeared to be similar in both the presenting symptoms and th e recovery time.