During the last two years of the study period HIV status was ascertained for all but 2 of the CM patients (n = 339), of whom 99% (337) were HIV positive, median CD4 cell count of 39 cells/μL; 134 of 158 TBM patients, 94% (126) of whom were HIV positive, median CD4 cell count 126 cells/μL; and 30 of the 46 bacterial meningitis cases, of whom 97% (29) were HIV positive, median CD4 cell count 287 cells/μL. The gene discussed is CD4; the disease is cutaneous mastocytosis.