Epidemiological risk factors for hypersensitivity reactions to abacavir*

Abstract
We investigated risk factors for hypersensitivity reactions (HSR) to abacavir in a case–control study. In a multivariate analysis, white race [odds ratio (OR), 5.16; 95% confidence interval (CI), 1.16–22.97] and a higher CD8 cell count at initiation of abacavir (>850 vs. ≤850 cells: OR, 3.74; 95% CI, 1.19–11.77) were found to be significantly associated with the development of HSR. Age, gender, stage of disease, prior antiretroviral exposure and type of concurrent antiretroviral therapy were not associated with HSR. Differences in predisposition to HSR according to ethnicity and baseline CD8 cell count may be explained by the reported MHC genetic associations with HSR.