The serum porphobilinogen and hepatic porphobilinogen deaminase in normal and porphyric individuals.

Abstract

Abstract Methods are described for quantitative determination of serum PBG and ALA, and for hepatic PBG-D activity. The former method has been applied in cases of porphyria of various types, lead poisoning, and normal or nonporphyric individuals. PBG-D activity was assayed in liver from 2 cases of AIP and 2 of PCT, and from appropriate control samples, also in liver from normal and (griseofulvin) porphyric mice. In a fatal case of AIP with very high urinary PBG, no hepatic deaminase activity was demonstrable. In a case in remission but with markedly increased urine and serum PBG the hepatic PBG-D was about one-fourth of the nonporphyric control values. The renal clearance of PBG in these contrasting cases was essentially the same, indicating that the much greater increase of serum PBG in the fatal case was related to greater production or failure of conversion to Uro or both, in the liver. In general, the serum and urinary PBG values were quite closely correlated, but only partial correlation with neurologic symptoms was noted. Some cases in remission had outspoken increases, others normal values, while in 1 case in doubtful relapse the serum PBG was much lower than in other cases in definite remission. The serum PBG was uniformly normal in the cases of PCT and in 3 of 4 cases of VP studied, markedly increased in the fourth case in which there were acute neurologic manifestations.