Natural killer cell function in women with vestibulitis.

OBJECTIVE To assess natural killer (NK) cell activity in patients with vestibulitis. STUDY DESIGN Twenty-two patients who met the International Society for the Study of Vulvar Disease criteria for vestibulitis and 17 age-, sex- and race-matched controls were recruited. NK cell activity was examined using a standard, four-hour 51Cr-release assay, freshly and after stimulation with interleukin 2 (IL2) or alpha interferon (IFN alpha). RESULTS The subject samples had significantly decreased fresh NK cell activity (mean lytic units [LU]/10(6) peripheral blood leukocytes [PBLs] of 0.93 vs. 4.19, P < .001). This activity was augmented in response to either IFN or IL2. However, it remained significantly lower than in the control samples (12.07 vs. 20.6 LU/10(6) PBL, P = .007 for IL2 and 5.98 vs. 15.33 LU/10(6) PBL, P < .001 for IFN). This difference was not universal since the major histocompatibility-nonrestricted T killer cell activity of the subject samples was not significantly different from that in the control samples. CONCLUSION This pilot study suggests that patients with vulvar vestibulitis have markedly decreased NK cell activity. Although this activity is increased in response to IL2 or IFN, it remains significantly impaired in comparison to the control samples.