CD4 and HIV infectious disease: To provide a view of the CSF neopterin changes across the spectrum of HIV infection and HIV-related CNS injury within the context of other biomarkers, we examined a cross-sectional sample derived from four clinical centers that included HIV seronegative subjects, untreated neuroasymptomatic HIV-infected subjects grouped according to blood CD4+ T cell, ADC neurological diagnoses, two groups of treated HIV-patients and five groups with CNS opportunistic diseases.