The diffuse infiltrative lymphocytosis syndrome

OBJECTIVE: To study the epidemiological, clinical, serological and immunogenetic features of the diffuse infiltrative lymphocytosis syndrome (DILS). DESIGN: Consecutive series of 35 patients with DILS diagnosed from 1992 to 1995 in a cohort of 4100 outpatients infected with HIV-1. METHODS: Thirty-five individuals with DILS were ascertained from this cohort and followed for 720 patient-months. Clinical, serological and immunogenetic features of these patients were studied and their demographics were compared with the rest of the outpatient population. RESULTS: DILS was found to be more prevalent in African Americans (60%) than in Caucasians (26%) or Mexican Americans (14%) [odds ratio (OR), 2.32; 95% confidence interval (CI), 1-12-4.81; P = 0.02] and in persons with male-to-male transmission of HIV-1 (71%) (OR, 2.82; 95% CI, 1.29-6.29; P = 0.007). All patients had bilateral parotid gland enlargement. The majority had sicca symptoms. The most common extraglandular sites of disease were lung (31%), muscle (26%), and liver (23%). Four patients had biopsy-proven polymyositis. Thirteen patients met the 1993 Centers for Disease Control and Prevention case definition of AIDS. Sixteen (52%) patients expressed human leukocyte antigen (HLA)-DRS (DRB1*1102), DR6 (DRB1*1301, *1302), or DR7, and 11 (36%) expressed HLA-DR2. CONCLUSIONS: DILS is more common in African Americans and in persons with male-to-male transmission of HIV-1. HIV-associated polymyositis appears to occur in the setting of DILS.