Molecular studies of cerebrospinal fluid in human immunodeficiency virus type 1-associated opportunistic central nervous system diseases--an update.

Although the incidence of opportunistic central nervous system (CNS) diseases has markedly declined in developed countries following the advent of highly active antiretroviral therapies (HAARTs), they still represent a major diagnostic and therapeutic challenge over the world. The application of nucleic acid amplification techniques to the study of cerebrospinal fluid (CSF) has contributed substantially to their diagnosis. The detection of specific microbial genomes in the CSF is now the preferred test for some CNS opportunistic diseases, such as progressive multifocal leukoencephalopathy or cytomegalovirus encephalitis. More recent developments of these techniques are the quantitative amplification techniques and postamplification studies. Quantification of nucleic acids in CSF is an important aid both at the time of diagnosis, for the interpretation of positive findings, and during patient follow-up. Postamplification analyses can provide important information with regard to clinical patient management, e.g., detection of genotypic resistance to antimicrobial drugs, and in the attempt to elucidate disease epidemiology and pathogenesis.