Myelin basic protein in the cerebrospinal fluid of patients infected with HIV.

The major pathological abnormalities of HIV encephalopathy are infiltrates of macrophages, multinucleated giant cells, microglial nodules and demyelination. Elevated myelin basic protein (MBP) levels in the cerebrospinal fluid (CSF) provide a marker for central nervous system demyelination. The purpose of this study was to investigate the possible role of CSF MBP as a useful and early marker for HIV encephalopathy. The CSF of 40 consecutive patients with HIV infection of various clinical stages was investigated, including 13 patients with clinical signs of HIV encephalopathy. CSF MBP was elevated in 2 patients (5.0 and 5.3 ng/ml), both of whom had moderate to severe HIV encephalopathy. The course of the disease was rapid in both patients. In the remaining 38 patients, CSF MBP levels were marginally elevated (n = 12) or normal (n = 26). Our results suggest that CSF MBP is not a sensitive marker for the diagnosis and evaluation of HIV encephalopathy, but may be an indicator of prognosis for the course of the disease. There were only few findings of elevated CSF MBP levels in patients with HIV encephalopathy in the current study, and this may be because the disorder progressed slowly in most patients. It is possible that CSF MBP levels in HIV encephalopathy may only be elevated with acute clinical deterioration but are normal in slowly progressive forms of demyelination, as seen in multiple sclerosis.