A Rapid Screening Test for Pyroluria; Useful in Distinguishing a Schizophrenic Subpopulation

An assay procedure is presented which has proven extremely useful in delineating a subpopulation of schizophrenic patients. The procedure is a highly sensitive rapid screening test for urinary pyrroles such as kryptopyrrole and urobilinogen. An extensive investigation of this test and the original assay procedure for kryptopyrrole described by Irvine indicates that free kryptopyrrole arises primarily as an artifact of the original procedure and that it exists ordinarily in a bound form in the urine. The patient population described as excreting kryptopyrrole probably suffers from a general pyroluria where elevated amounts of pyrrole metabolites such as kryptopyrrole, urobilinogen, and urobilinoid pigments can be detected in the urine. The presence of these compounds may lead to a zinc deficiency, and possibly also to a deficiency in vitamin B6, which results in the most severe clinical symptoms exhibited by these patients.