HIV-1 P24 BUT NOT PROVIRAL LOAD IS INCREASED IN THE INTESTINAL-MUCOSACOMPARED WITH THE PERIPHERAL-BLOOD IN HIV-INFECTED PATIENTS

Objective: To investigate differences in viral and proviral load betwe en the peripheral blood and the intestinal mucosal immune system in HI V-infected patients. Design: HIV-1 p24 and HIV DNA content were compar ed in blood samples and intestinal biopsies from HIV-infected patients . Methods: Intestinal biopsies and peripheral blood were simultanously obtained from 27 HIV-infected patients undergoing diagnostic endoscop y. The p24 concentrations were measured in serum and homogenized intes tinal biopsies by enzyme-linked immunosorbent assay after acid-dissoci ation of immune complexes. Proviral load was determined in blood and i ntestinal biopsies by a quantitative competitive polymerase chain reac tion amplifying the HIV-1 nef gene from genomic DNA. Results: No signi ficant differences were found in proviral load comparing HIV copies pe r 1.5 x 10(5) cell equivalents in blood [2650 (600-44 000)] and intest inal biopsies [4200 (1325-19 625)]. Paired analysis revealed a strong positive correlation between serum and mucosal proviral load. In contr ast, HIV core protein p24 was detected in intestinal biopsies from 18 patients in much higher concentrations than in serum [858 (262-4111) p g/g versus 34 (9-242) pg/g; P < 0.005]. The p24 concentrations in seru m and intestinal biopsies did not correlate and no significant correla tion was observed in serum or intestinal biopsies between proviral loa d and p24 concentrations. No clear correlations were observed between clinical parameters and HIV DNA or HIV p24 levels in blood or biopsies . Conclusions: Our findings demonstrate a homogenous distribution of H IV proviral load in the peripheral blood and the intestinal mucosal im mune system. The high viral antigen load in the intestine therefore in dicates that mucosal HIV production is upregulated at the transcriptio nal and/or translational level. The intestinal mucosa is a major reser voir for HIV in HIV-infected patients.