No increase in cervicovaginal proinflammatory cytokines after carraguard use in a placebo-controlled randomized clinical trial

BACKGROUND: Assessment of cervicovaginal cytokine levels may be helpful to evaluate subclinical epithelial inflammation during safety evaluations of candidate microbicides.

METHODS: Fifty-five HIV-seronegative Thai women were enrolled in a safety trial of the candidate microbicide Carraguard and were randomized to use Carraguard or placebo gel before vaginal sex. Cervicovaginal lavages were collected at baseline and after 1 month of gel use; levels of interleukin (IL)-1beta, IL-6, IL-8, and secretory leukocyte protease inhibitor (SLPI) were measured using microwell plate-based enzyme immunoassays. Median levels were compared between the baseline and 1-month follow-up visits using paired t tests; the median change between groups was compared using Wilcoxon rank sum tests. Women were examined for the presence of genital findings; the association between genital findings and cytokine levels was studied.

RESULTS: No increase in levels of proinflammatory cytokines after use of Carraguard gel or placebo gel was observed during the study. The median change from the baseline to 1 month of follow-up was not significantly different between Carraguard and placebo groups (IL-1beta: -0.3 pg/mL vs. -3.93 pg/mL; P = 0.4, IL-6: -0.3 pg/mL vs. 0 pg/mL; P = 0.3, IL-8: -40.1 pg/mL vs. -53.2 pg/mL; P = 0.8, and SLPI: -26.5 pg/mL vs. 12.6 pg/mL; P = 0.07). Genital findings with intact epithelium were found in 16 (29%) women; these women tended to have somewhat higher IL-6 levels than those with normal epithelium (14.9 pg/mL vs. 8.8 pg/mL; P = 0.08).

CONCLUSION: We found no increase in proinflammatory cytokines after Carraguard and placebo gel use, suggesting that neither gel causes inflammation. Further studies to assess the role of cytokines in microbicide safety studies are warranted.