Use of a solid-phase radioimmunoassay and formalin-fixed whole bacterial antigen in the detection of antigen-specific immunoglobulin in prostatic fluid.

The prostatic fluid of two patients with Escherichia coli bacterial prostatitis was analyzed for evidence of a local immune response to bacterial infection. A solid-phase radioimmunoassay was modified to measure the immunoglobulin (Ig)A and IgG antigen-specific antibody responses to infecting bacteria in serum and prostatic fluid from patient. Formalin-fixed whole E. coli were used as antigen. In one patient with acute E. coli prostatic infection, measurements of antigen-specific antibody confirm the presence of a systemic and local immune response. However, in another patient with a chronic E. coli prostatitis, a primarily local immune response was demonstrated. The response measured in the prostatic fluid appears to be locally stimulated and specific for the infecting bacteria. Furthermore, IgA was the predominant immunoglobulin involved in the local prostatic immune response to infection. Although elevations of serum IgA antigen-specific antibody levels were short-liver after treatment of prostatic infection, local IgA antigen-specific antibodies were detected for as long as 1 yr after the initial infection in both patients studied.