Erythropoietic protoporphyria (EPP) is complicated by severe liver disease in 1–5% of patients. There is no means of identifying patients at risk of severe liver complications.

Histological analysis of the removed liver in EPP patients requiring liver transplantation, shows severe fibrosis and cirrhosis. The cirrhosis probably develops slowly and silently, terminating in the final illness.

Blood liver function tests are poor at identifying gradually progressive fibrosis, and are more useful for acute hepatic inflammation and obstruction. Liver biopsies are too invasive and hazardous for monitoring for developing fibrosis in EPP. In recent years liver fibroscanning (‘transient elastography’) has become widely used by Hepatologists for the detection and staging of liver fibrosis. It is non-invasive, and the machines can be used in an outpatient clinic by operators after minimal training.

We have carried out liver fibroscanning to assess its potential to identify early hepatic fibrosis in this exploratory pilot study.

We included all EPP patients over 18 years attending our Clinic in a 23 month period. No patient had XLDPP, 1 had previously had autoimmune hepatitis which was in biochemical remission. No patients developed severe liver disease or died during the study.

The fibroscan measure of fibrosis is the ‘liver stiffness measure’ (LSM). We used the normal and fibrotic ranges of LSM values established in Hepatitis C studies (normal <7.1 kPa; early fibrosis 7.1–12.5 kPa; advanced fibrosis > 12.5 kPa).

64 patients (83.1%) of patients had LSM values in the normal range. 13 (16.9%) had abnormal values indicating fibrosis, 8 (10.4%) in the mild fibrosis range, and 5 (6.5%) in the advanced fibrosis range.

This study did not include further fibrosis investigations, including liver biopsy histology.

We also examined other patient variables for correlations with fibroscan results indicating advanced fibrosis: age, alcohol intake, body mass index (BMI), liver function test results, and red cell protoporphyrin concentration. The only variable which correlated at the 5% significance with advanced fibrosis on fibroscanning, was BMI. BMI was significantly higher in patients with advanced fibrosis than the rest. Obesity has not previously been suggested as a risk factor for severe hepatic disease in EPP. However, it is a major risk factor for cirrhosis in the general population.

Our results suggest that liver fibroscanning may be of value to identify EPP patients developing liver fibrosis, of applications in routine clinical care and in drug trials. Our data also suggest that managing obesity may be important in EPP. Future studies are needed to confirm these findings with liver histology.