[Diagnostic porphyrinopathies in hereditary hyperbilirubinemia].

Secondary porphyrinopathias were investigated in hereditary hyperbilirubinemias of the types Dubin-Johnson syndrome (DJS), Rotor's syndrome (RS), Gilbert's syndrome (GS) and compared with the findings in alcohol-induced cholestasis. The determination of urinary coproporphyrin excretion including its isomer I and III relation allows to diagnose and differentiate DJS from the other two forms of hereditary hyperbilirubinemias. An isomer I proportion of > 80% (normal < 32%) in association with a normal coproporphyrin excretion is pathognomonic for DJS. An increased coproporphyrinuria with about 70% isomer I is found in RS; a normal urinary coproporphyrin excretion combined with an isomer I increase of about 50-70% indicates the frequent GS. Alcohol-related cholestasis reveals a distinct pathologic coproporphyrinuria and elevated isomer I proportions between 37-67%. Due to the overlapping of isomer alterations in DJS-gene carriers, patients with GS and patients with exogenous toxically-induced cholestasis, additional diagnostic criteria are required to clarify the porphyrinopathia in its clinical context.