HIV-associated brain pathology: a comparative international study.

Little is known about the frequency and variation of HIV-associated brain pathology in different geographical centres. To assess whether there is an association between the frequency of disease and demographic factors we examined the neuropathological findings in four European and two American cities. The cities included London, Edinburgh, Paris, Budapest, Baltimore and Newark. Information was collected on a total of 1144 cases. HIV encephalitis was the most common observation in all the centres. although its frequency varied between them (P < 0.01). Furthermore, there were significant differences (P < 0.001) between the various categories of exposure and the frequency of HIV encephalitis in Edinburgh and other centres. The occurrence of toxoplasmosis, progressive multifocal leukoencephalolpathy (PML) and cryptococcal infection also differed between the various centres (P < 0.01). None of the findings was attributable to age, sex, or ethnic origin, but the introduction of anti-retroviral treatment, such as Zidovudine, may have been important. Overall, this study highlights geographical variability and the potential importance for group of exposure and anti-retroviral medication as factors affecting the development of various HIV-associated brain lesions.