Measurement of cerebrospinal fluid retinol in subjects with HIV-1 infection

In this study, retinol was measured in cerebrospinal fluid (CSF) and blood samples from 32 HIV-1-seropositive subjects and from 27 seronegative individuals with neurologic disease. In CSF, retinol was detected in 17 out of 32 (53.1%) HIV-1-seropositive and 20 out of 27 (74.1%) seronegative individuals (p = 0.16) and did not correlate with blood retinol levels. Serum vitamin A levels consistent with deficiency (<1.05 μmol/l) were detected in three out of 27 (11.1%) HIV-1-seropositive and three out of 21 (14.3%) seronegative subjects. There was no relationship noted between CSF retinol levels and a measurement of blood-brain barrier integrity. CSF retinol was detected more frequently among individuals with (100 CD4+ lymphocytes/mm³ (11 out of 24) than among those with <100 CD4+ lymphocytes/mm³ (one out of eight; p = 0.02), and CSF retinol concentration was greater for the group with (100 CD4⁺ lymphocytes/mm³ than those with <100 CD4⁺ lymphocytes/mm3 (0.07 ± 0.018 μmol/l versus 0.007 ± 0.007 μmol/l; p = 0.01). This study suggests that CSF retinol levels are independent of measurements obtained in blood and, among HIV-1-seropositive subjects, may be lower for individuals with evidence of severe immunosuppression.