Presence of "prostatic" acid phosphatase in human neutrophils.

The occurrence of natural substances with antigenic properties similar to those of the prostatic acid phosphatase was examined in one patient with neutrophilic leukemia and increased activity of serum acid phosphatase. The fraction responsible for the increased serum enzyme activity was tartrate sensitive and was identified as isoenzyme 2 by polyacrylamide gel electrophoresis. This isoenzyme originated from the leukocytes but had similar electromobility to that of the prostatic acid phosphatase isoenzyme 2. Immunohistochemical and counterimmunoelectrophoretic studies indicated that this leukocytic isoenzyme was present in the neutrophils and shared antigenic properties with the prostatic isoenzyme 2. Leukocytes from one patient with acute granulocytic leukemia, two patients with polycythemia vera with neutrophilia, and five normal subjects also contained this prostatic acid phosphatase like isoenzyme. Elevated serum "prostatic" acid phosphatase activity, therefore, may be found not only in prostatic cancer but also in granulocytic leukemia and perhaps other diseases.