Ehrlich porphyria

Ehrlich s aldehyde test can be used to confirm a diagnosis of acute intermittent porphyria. Equal volumes of urine and Ehrlich s reagent are mixed a pink colour indicates raised urinary concentration of either porphobilinogen or urobilinogen. In acute intermittent porphyria, raised porphobilinogen is present and the pink precipitate formed is insoluble in chloroform. 

In 1931 Sachs discovered that the urine of patients with acute porphyria reacted with the Ehrlich reagent " in acid solution to produce a pink color. The condensation product had two absorption bands, one at 515-535 m/i, and the other at 550-575 m/i, and was insoluble in CHCI3. 

An intermediate in the synthesis of porphyrins. It is formed by the condensation of glycine and succinate, a reaction catalysed by the enzyme 6-ALA synthetase. 5-ALA excretion in urine is increased in some types of porphyria and in lead poisoning. 6-ALA can be measured in urine and serum by its reaction with Ehrlich s reagent. 

An intermediate in the synthesis of haem. Increased urinary excretion of porphobilinogen occurs in many of the porphyrias. It can be estimated by its condensation with p-dimethylamino-benzaldehyde (Ehrlich s reagent) to give a red colour. 

The isolation of PBG by Westall (7) and the determination of its structure by Cookson and Rimington (77, 78) were crucial steps in the detailed description of the biosynthesis of porph3rrin. PBG (Fig. 11) was first detected by Sachs 88) in the urine of patients with acute porphyria, since the urine turned red with Ehrlich s reagent (p-dimethylaminobenzaldehyde in acid solution). This red compound was insoluble in CHClj thus differentiating it from urobilinogen. Waldenstrom (83) recognized PBG as a distinct entity. It has been also found in the liver and feces 84,85) of these patients. 

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