Lactate dehydrogenase and its isoenzymes in vaginal fluid in vaginitis/vaginosis cases and in healthy controls.

The objective of the study was to measure the lactate dehydrogenase (LD) activity in vaginal lavage fluid of women with vaginitis/vaginosis and in healthy pre- and post-menopausal controls. Also to analyse the LD isoenzyme patterns in such samples and compare the influence on the LD activity by different storage and sampling methods. Twenty of the women studied, who had no signs of inflammation as evidenced from vaginal wet smears, were pre-menopausal and 8 post-menopausal. Fifty-eight non-pregnant patients with vaginitis/vaginosis or non-inflammatory gynaecological conditions were analysed for LD isoenzyme patterns. The LD activity was correlated to vaginal pH. Furthermore, the LD activity was determined in another 100 women screened for Chlamydia trachomatis. Finally, the influence on the LD activity when sampling was made by a cytological brush vs vaginal lavage and analysed after different storage periods, as studied. The LD activity was elevated, i.e. >2 micro kat/L, in all but two of the women with leucorrhoea. Only women with bacterial vaginosis (BV) without leucorrhoea, had an increased LD activity. An increased vaginal pH correlated to the LD concentration. The LD activity was elevated in cases with vulvovaginal candidiasis, trichomoniasis, chlamydial cervicitis and senile colpitis. Storage of samples for up to six hours had no influence on the test outcome. Brush and lavage fluid samples did not differ with regard to the rate of positive LD tests. In healthy women, the LD activity is low and predominated by slow-migrating isoenzymes, i.e. LD 4 and 5. The LD activity is generally increased in cases of vaginitis and in women with BV and chlamydial cervicitis. In trichomoniasis, particularly high concentrations of LD 5, are found.