Comparison of human immunodeficiency virus biological phenotypes isolated from cerebrospinal fluid and peripheral blood

Quantitative human immunodeficiency virus (HIV) cultures were carried out on cerebrospinal fluid (CSF), peripheral blood mononuclear cells (PBMCs), and plasma from patients with HIV in order to compare the infectious HIV load. The HIV strains isolated were studied for syncytiuminducing (SI) capacity, using the MT‐2 cell line, in order to compare the HIV strain phenotype of blood and CSF isolates. Forty‐two patients with HIV‐1 infection were enrolled in the study, 33 of whom had neurological symptoms and 9 of whom were without neurological symptoms. HIV was isolated from 16 (38%) of the 42 CSF cultures, with a low mean titer of 6.3 ± 3.4 tissue‐culture‐infective doses (TCID) per milliliter. Patients with HIV‐positive CSF culture had a viral load in PBMCs of 40.5 ± 15.5 TCID per 106 PBMC and in plasma of 104.7± 9.3 per milliliter. Two (15%) of the 13 CSF isolates were Sl strains, compared to 17 (56.6%) of the 30 PBMC isolates and 13 (54%) of the 24 plasma isolates (P