Kidney damage in acute intermittent porphyria.

Acute intermittent and variegate porphyria are an autosomal dominant hereditary diseases caused by the deficient activity of porphobilinogen deaminase in the haem biosynthesis. Acute intermittent porphyria (AIP) in 11 patients (8 women and 3 men) and variegate porphyria (VP) in one patient were diagnosed and long-term treated during 15-22 years. Eleven patients had in acute attack abdominal pain, they were agitated and restless and suffered from insomnia. Besides they had various neurological signs. Examination of kidney function during remission showed hypertension and tubulointerstitial impairment of the kidneys in 10 patients (hyposthenuria and impairment of tubular excretory phase in isotopic renography). Deficiency of serum erythropoietin in 4 patients, significant deficiency of plasma and erythrocyte vitamin B6, significant hyperoxalaemia and hyperoxaluria in all patients were found. Direct relationship between plasma oxalic acid and effect of pyridoxal-5-phosphate (PLP), (effect of PLP was in indirect relationship with the concentration of erythrocyte vitamin B6), in AIP patients was found. Deficiency of vitamin B6 was probably a cause of hyperoxalaemia and hyperoxaluria in those patients. The effective therapy was repeated i.v. administration of haem-arginate during acute attacks (4-5 days). Besides during remission the patients were treated by pyridoxine (40-60 mg/day), by glucose, sodium chloride and phenothiazines. All patients showed significant improvement and had regular ambulatory check-up every three months. Currently, they are in clinical and laboratory remission.