Secretory IgA against herpes simplex virus in cervical secretions

A recently developed method to recover proteins from cervical secretions was combined with methods to detect minute concentrations of herpes simplex virus (HSV) type specific antibodies to measure the concentrations of locally produced antibodies in women with genital infections. Forty nine women attending a sexually transmitted disease (STD) clinic were included. Cervical secretions were obtained by suction into a plastic catheter. Soluble proteins were recovered from the secretions by elution with hyperosmolar sodium chloride. A rabbit antibody to human secretory component, which was conjugated to horseradish peroxidase, was used to measure secretory IgA (S-IgA) that was HSV type specific. For comparison, HSV type specific IgG was measured in serum samples from the patients. Of the 49 women, 16 yielded detectable HSV type 2 (HSV 2) S-IgA in secretions. Twelve of them also reacted to the HSV type common antigen, but only five had HSV 2 IgG detectable in their serum. S-IgA against HSV was found in significantly more women with a clinical diagnosis of acute cervicitis than in others. This could be explained by a general increase in local antibody production and immunity triggered by previous contacts with HSV. It is concluded that local mucosal immunity to HSV 2 can be detected in women who do not have a specific humoral antibody response to the virus. For seroepidemiological studies of infection with HSV 2 this local immunity may be considered to be a factor that gives an underestimation of the true incidence of HSV 2 infection.