Problem: To evaluate vaginal nitric oxide (NO) production in response to alterations in the vaginal microbial flora.
Method of study: Cervicovaginal lavage samples from 206 women at 18-22 weeks of gestation were tested for NO, interleukin-1beta (IL-1beta), IL-1 receptor antagonist (IL-1ra), tumor necrosis factor-alpha and the inducible 70 kDa heat shock protein (hsp70). Bacterial vaginosis (BV) was diagnosed based on gram staining of vaginal smears.
Results and conclusions: Elevated NO (>2.14 mmol/L) was associated with a diagnosis of BV (38% versus 11%, P < 0.008) as well as an increased median vaginal IL-1ra concentration (72.5 ng/ml versus 36.6 ng/ml, P = 0.041). Elevated vaginal NO was also associated with vaginal hsp70 and this relationship was independent of BV status or IL-1ra concentrations (P < 0.026). We conclude that vaginal hsp70 release in response to abnormal vaginal microflora may trigger NO production in an attempt to minimize the pathological consequences of this altered milieu.