Serum and secretory antibody responses to Neisseria gonorrhoeae in patients with gonococcal infections.

The present study was conducted to characterize the nature and pattern of serum and secretory antibody responses to N. gonorrhoeae by haemagglutination inhibition, opsonization, and immunofluorescence techniques in male and female patients with different clinical manifestations of gonorrhoea. Most male patients with acute gonococcal infection developed serum IgG and, less frequently, IgM antibodies against pilated gonococci within 2 weeks of infection and these antibodies declined to normal levels 1 to 2 months after treatment. This response was not noticeably different from the responses developed in male patients with subacute infection and female patients with chronic infection. Immunological analyses of the seminal plasmas and cervical fluids from these patients showed that antibodies reactive with both pilated and non-pilated N. gonorrhoeae are present in some of the cases. A small percentage of male patients who recovered from subacute gonococcal infection but not from acute infection possessed low levels of IgG and, less frequently, IgA antibodies to gonococcal antigens in their seminal plasmas. In contrast, more than half of the females with gonorrhoea had IgG antigonococcal antibodies in the cervical fluid. However, a small number of samples also showed the presence of IgA and IgM antibodies. IgA antibody in most of these IgA-positive samples was of the secretory type. The presence of secretory IgA (SIgA) in secretions and the lack of correlation between the antibody titres in serum and in secretions of these patients suggest that infection with N. gonorrhoeae may independently stimulate both a systemic and a local humoral immune response.