T(H)1 to T(H)2 shift of cytokines in peripheral blood of HIV-infected patients is detectable by reverse transcriptase polymerase chain reaction but not by enzyme-linked immunosorbent assay under nonstimulated conditions

Background: Dysregulation of cytokines has been implicated in the pathogene sis of HIV infection. Therefore, we determined tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), IL-4, IL-10, and interferon-ga mma (IFN-gamma) mRNA and serum levels in HIV-infected patients under nonsti mulated conditions. Material and Methods: Blood samples of 32 HIV-infected patients and 10 heal thy HIV-negative controls were analyzed. Cytokine serum levels were quantif ied by enzyme-linked immunosorbent assay (ELISA). Cytokine mRNA levels were determined semiquantitatively by competitive reverse transcriptase polymer ase chain reaction (RT-PCR) and expressed as ratios relative to those of be ta-actin. Results: Competitive RT-PCR was shown to be more sensitive than protein ELI SA in analyzing cytokine production. We found a significant correlation bet ween steady-state mRNA ratios and serum protein levels for TNF-alpha. Signi ficantly higher cytokine mRNA ratios were found in those patients with IL-1 0 and IFN-gamma levels detectable by ELISA. Steady-state mRNA ratios of TNF -alpha, IL-4, and IL-10 were significantly increased in patients with highl y replicative HIV-infection. Furthermore, elevated IL-4:IFN-gamma ratios we re related to both high viral load and loss of CD4 cells. Discussion: Determination of steady-state mRNA ratios by semiquantitative R T-PCR represents a sensitive method to analyze cytokines in peripheral bloo d of HIV-infected patients under nonstimulated conditions. The data obtaine d with this technique provide further evidence for a T(H)1 to T(H)2 cytokin e shift with progressive HIV disease.