S. Cauci et al., IMMUNOGLOBULIN-A RESPONSE AGAINST GARDNERELLA-VAGINALIS HEMOLYSIN ANDSIALIDASE ACTIVITY IN BACTERIAL VAGINOSIS, American journal of obstetrics and gynecology, 178(3), 1998, pp. 511-515
OBJECTIVE: The aim of this study was to investigate the correlation be
tween the immunoglobulin A immune response to Gardnerella vaginalis he
molysin and sialidase activity in vaginal fluids from patients with ba
cterial vaginosis. STUDY DESIGN: Nonpregnant women who were examined a
t a gynecologic clinic, in an age range of 18 to 62 years, were enroll
ed. The study population comprised 131 healthy volunteers, 32 women wi
th bacterial vaginosis that was positive for immunoglobulin A to Gardn
erella vaginalis hemolysin, 40 women with bacterial vaginosis that was
negative for immunoglobulin A to Gardnerella vaginalis hemolysin, and
19 women with Candida vaginitis. Bacterial vaginosis was diagnosed by
clinical criteria and Gram stain. RESULTS: Sialidase activity was pre
sent in 75% (54/72) of patients with bacterial vaginosis. Women having
bacterial vaginosis and lacking a specific immunoglobulin A response
had a significantly higher level of sialidase activity than patients w
ho had an immune response against Gardnerella vaginalis hemolysin. Sia
lidase activity was detected in 87% (35/40) of the former subgroup of
patients with bacterial vaginosis and in 59% (19/32) of women of the l
atter subgroup. No sialidase activity was measured in patients with ca
ndidiasis. Specificity of the assay for healthy controls was 95% (124/
131 women without sialidase activity). CONCLUSIONS: Sialidases produce
d by Prevotella bivia and other microorganisms present in the microflo
ra of patients with bacterial vaginosis are very likely a virulence fa
ctor not only by destroying the mucins and enhancing adherence of bact
eria but also by impairing a specific immunoglobulin A immune response
against other virulence factors such as cytotoxin from Gardnerella va
ginalis.