α-Amylase in Vaginal Fluid: Association With Conditions Favorable to Dominance of Lactobacillus.

Vaginal glycogen is degraded by host α-amylase and then converted to lactic acid by Lactobacilli. This maintains the vaginal pH at ≤4.5 and prevents growth of other bacteria. Therefore, host α-amylase activity may promote dominance of Lactobacilli. We evaluated whether the α-amylase level in vaginal fluid is altered in women with bacterial vaginosis (BV) and vulvovaginal candidiasis (VVC) and whether its concentration was associated with levels of lactic acid isomers and host mediators. Vaginal fluid was obtained from 43 women with BV, 50 women with VVC, and 62 women with no vulvovaginal disorders. Vaginal fluid concentrations of α-amylase, secretory leukocyte protease inhibitor (SLPI), hyaluronan, hyaluronidase-1, ß-defensin, and elafin were measured by enzyme-linked immunosorbent assay (ELISA). Vaginal concentrations of neutrophil gelatinase-associated lipocalin (NGAL), matrix metalloproteinase (MMP) 8, and d- and l-lactic acid levels in these patients were previously reported. The median vaginal fluid α-amylase level was 1.83 mU/mL in control women, 1.45 mU/mL in women with VVC, and 1.07 mU/mL in women with BV. Vaginal levels of α-amylase were correlated with d-lactic acid (P = .003) but not with l-lactic acid (P > .05) and with SLPI (P < .001), hyaluronidase-1 (P < .001), NGAL (P = .001), and MMP-8 (P = .005). The exfoliation of glycogen-rich epithelial cells into the vaginal lumen by hyaluronidase-1 and MMP-8 may increase glycogen availability and promote α-amylase activity. The subsequent enhanced availability of glycogen breakdown products would favor proliferation of Lactobacilli, the primary producers of d-lactic acid in the vagina. Concomitant production of NGAL and SLPI would retard growth of BV-related bacteria.

Leukocyte esterase activity in vaginal fluid of pregnant and non-pregnant women with vaginitis/vaginosis and in controls.

OBJECTIVES: To determine the leukocyte esterase (LE) activity in vaginal lavage fluid of women with acute and recurrent vulvovaginal candidosis (VVC and RVVC respectively), bacterial vaginosis (BV), and in pregnant and non-pregnant women without evidence of the three conditions. Also to compare the result of LE tests in women consulting at different weeks in the cycle and trimesters of pregnancy. The LE activity was correlated to vaginal pH, number of inflammatory cells in stained vaginal smears, type of predominating vaginal bacteria and presence of yeast morphotypes. METHODS: One hundred and thirteen women with a history of RVVC, i.e. with at least four attacks of the condition during the previous year and who had consulted with an assumed new attack of the condition, were studied. Furthermore, we studied 16 women with VVC, 15 women with BV, and 27 women attending for control of cytological abnormalities, who all presented without evidence of either vaginitis or vaginosis. Finally, 73 pregnant women were investigated. The LE activity in vaginal fluid during different weeks in the cycle of 53 of the women was measured. RESULTS: In the non-pregnant women, an increased LE activity was found in 96, 88, 73 and 56% of those with RVVC, VVC and BV and in the non-VVC/BV cases, respectively. In 73% of pregnant women in the second trimester, and 76% of those in the third, the LE test was positive. In all groups of non-pregnant women tested, the LE activity correlated with the number of leukocytes in vaginal smears, but it did not in those who were pregnant. There was no correlation between LE activity and week in cycle. The vaginal pH showed no correlation to LE activity in any of the groups studied. CONCLUSIONS: The use of commercial LE dipsticks has a limited value in the differential diagnosis of RVVC, VVC and BV. There is no correlation between the LE activity in vaginal secretion on one hand and vaginal pH, week in the menstrual cycle and trimester in pregnancy on the other. Women with BV often have signs of inflammation as evidenced by a positive LE test and inflammatory cells in genital smears.