Abstract
BACKGROUND: The objectives of this study were to determine (i) the expression of oral secretory leukocyte protease inhibitor (SLPI) in HIV-infected subjects compared with non-HIV controls, (ii) the oral SLPI expression in HIV-infected subjects with antiretroviral therapy (ART) compared with those without ART, and (iii) factors associated with the expression of oral SLPI. METHODS: Oral tissues and samples of both un-stimulated and stimulated saliva were collected from HIV-infected subjects with and without ART, and non-HIV individuals. The expression of SLPI mRNA in the tissue was determined by quantitative real-time PCR. Salivary SLPI protein was detected using ELISA. Chi-square test and logistic regression analysis were performed to determine the association between HIV/ART status and the expression of oral SLPI. RESULTS: One hundred and fifty-seven HIV-infected subjects were enrolled: 99 on ART (age range, 23-57 years; mean, 39 years), 58 not on ART (age range, 20-59 years; mean, 34 years), and 50 non-HIV controls (age range, 19-59 years; mean, 36 years). The most common ART regimen was 2NRTIs + 1NNRTI. The expression of oral SLPI in stimulated saliva was significantly decreased with HIV infection (P < 0.001). The expression was also significantly different with respect to ART use (P = 0.007). Smoking, CD4(+) cell count, and HIV viral load were the factors associated with the oral SLPI expression. CONCLUSION: The expression of oral SLPI is altered by HIV infection and use of ART. Thus, oral SLPI may be the useful biomarker to identify subjects at risk of infections and malignant transformation due to HIV infection and long-term ART.