Familial porphyria cutanea tarda

The results of erythrocyte uroporphyrinogen decarboxylase estimations of members of the family of a child with porphyria cutanea tarda are reported.     

Latent porphyria cutanea tarda

A total of 142 subjects have been examined; of these 49 healthy relatives of patients with manifest porphyria cutanea tarda (PCT) (group 1), 48 subjects with melanodermal skin changes characteristic of PCT abd with anamnesis aggravated for alcoholism (group 2), and 45 patients with chronic liver diseases (group 3). None of the examinees has developed photosensitization symptoms. The findings have been compared to the results of examinations of 24 normal subjects and of 145 patients with manifest PCT. Minimal abnormalities of porphyrin metabolism have been detected in 43 subjects (30.2%). In group 1 subjects these abnormalities presented as increased levels of uroporphyrin and fecal coproporphyrin, in Groups 2 and 3 as secondary coproporphyrinuria and a symptomatic rise of fecal protoporphyrin level. Latent PCT has been diagnosed in 18 patients (12.7%). In latent PCT the total porphyrin excretion with the urine has been 10-fold lower than in manifest PCT, not exceeding 1000 nmol/day; in has been associated with a relative elevation of uroporphyrin level (up to 42-65% of the total porphyrin content). Increased coproporphyrin concentrations have been recorded, with coproporphyrin share making up over 60% of the total amount. It is possible that the minimal shifts of porphyrin metabolism anticipate the development of the biochemical syndrome of latent PCT. The author suggests criteria for the early diagnosis of the latent forms of the disease. He considers that the examinees should be referred to a group at risk of developing manifest PCT.     

The genetic basis of porphyria cutanea tarda

In order to confirm the genetic character of porphyria cutanea tarda (PCT), the quantitative and qualitative porphyrin excretion from 56 unrelated PCT patients and 259 relatives was analyzed by a sensitive fluorimetric thin-layer chromatographic technique. Porphyrin excretion abnormalities were observed in 111 (35.24%) of the 315 subjects studied. Of the 259 relatives, 55 (21.24%) suffered from manifest (24 cases) or subclinical (31 cases) PCT. The relatives from the older generation or a generation similar to the propositi were more frequently affected than those from a younger generation. A clear family incidence was observed in 32 families, while PCT was apparently limited to the propositi in the remaining 24. It is discussed whether these latter families correspond to the so-called "sporadic" type of PCT or include porphyric gene carriers lacking biochemical expression of the disease. While the measurements of the activity of the defective enzyme (uroporphyrinogen decarboxylase) for the genetic research of PCT turned out to be impracticable in hepatic tissue and contradictory in erythrocytes, our study confirms that the familial character of this disease may be revealed by the chromatographic analysis of the porphyrin excretion pattern.     

Artefacts in porphyria cutanea tarda

A 56-year-old patient suffering from porphyria cutanea tarda (PCT) was sufficiently treated with chloroquine and occasional bleeding. After 19 months of therapy, the laboratory finding showed absolutely normal values, whereas the clinical symptoms still persisted. Intensive exploration led to the diagnosis artefacts clinically imitating florid PCT remarkably well.     

The genetic basis of porphyria cutanea tarda

Summary In order to confirm the genetic character of porphyria cutanea tarda (PCT), the quantitative and qualitative porphyrin excretion from 56 unrelated PCT patients and 259 relatives was analyzed by a sensitive fluorimetric thin-layer chromatographic technique.Porphyrin excretion abnormalities were observed in 111 (35.24%) of the 315 subjects studied. Of the 259 relatives, 55 (21.24%) suffered from manifest (24 cases) or subclinical (31 cases) PCT. The relatives from the older generation or a generation similar to the propositi were more frequently affected than those from a younger generation. A clear family incidence was observed in 32 families, while PCT was apparently limited to the propositi in the remaining 24. It is discussed whether these latter families correspond to the so-called sporadic type of PCT or include porphyric gene carriers lacking biochemical expression of the disease.While the measurements of the activity of the defective enzyme (uroporphyrinogen decarboxylase) for the genetic research of PCT turned out to be impracticable in hepatic tissue and contradictory in erythrocytes, our study confirms that the familial character of this disease may be revealed by the chromatographic analysis of the porphyrin excretion pattern.     

Pregnancy and porphyria cutanea tarda

A 31-year-old woman developed typical clinical and laboratory signs of PCT at the end of her second pregnancy coincident with the summer season. She had elevated liver function values without history of alcoholism, hepatitis or chemical liver damage. She had taken oral contraceptive only before her first pregnancy which was normal. Her hormone analytic values including estrogens corresponded to normal values in pregnancy. Venesections had a beneficial affect on her condition.     

Oestrogen-induced familial porphyria cutanea tarda

Two brothers with cutaneous hepatic porphyria are reported. One, aged 64 years, had his disease apparently precipitated by the oestrogen treatment given for carcinoma of the prostate.