Circulating prostatic acid phosphatase-immunoglobulin complexes in Sjogren's syndrome

Elevated level of serum prostatic acid phosphatase (PAP) activity in a patient with Sjogren's syndrome was found to be due to the presence of PAP-immunoglobulin complexes in circulation. The patient did not have a prostatic malignancy. The complexes were demonstrated by counter-immunoelectrophoresis, protein A-Sepharose immunoprecipitation and agarose-gel electrophoresis. Free enzyme was not detected in serum, and the activity of the complexed enzyme was probably unaltered on binding with the immunoglobulins.