PD01 Liver fibroscanning identifies hepatic fibrosis at an early stage in erythropoietic protoporphyria: a new analysis in 132 patients

Abstract Around 1–5% of patients with erythropoietic protoporphyria (EPP) develop liver cirrhosis leading to liver failure. It is not possible to predict who these patients will be, and liver disease is often not identified until late. Liver function tests are the standard screen for liver disease in EPP. However, they do not detect fibrosis. Liver ultrasound visualizes fibrosis but is complex, and its subjectivity causes interoperator variability. Liver biopsy has significant morbidity. Transient elastography (‘liver fibroscanning’) is a noninvasive investigation to detect hepatic fibrosis. It is quick and can be done in clinic with minimal training. Fibroscan liver stiffness measure (LSM) is a validated, sensitive, specific measure of liver fibrosis, and fibroscanning is widely used in hepatology. We previously reported findings from 95 scans in 77 patients with EPP over 23 months (Tavabie OD, Fassihi H, Fityan A et al. Fibrosis assessment using transient elastography identifies obesity as a risk factor for hepatic fibrosis in erythropoietic protoporphyria. Photodermatol Photoimmunol Photomed 2023; 39: 400–2). That study was too small and short to assess whether fibroscanning enables earlier identification of hepatic fibrosis in EPP. We now present data from 297 scans in 132 patients with EPP over 51 months, to assess whether fibroscanning enables early identification of fibrosis. Of the 132 patients 52% were male and 48% female, the mean age was 35 years (range 5–76) and the mean red cell protoporphyrin concentration was 24 900 nmol L−1 (range 4500–100 000). The mean number of fibroscans per patient was 2.4. The mean LSM was 5.4 kPa (normal range ≤ 7.0). Overall, 35 patients (26.5%) had at least one raised LSM. Hepatic fibrosis causes a persistently increased LSM. Only seven patients (5.3%) had a persistently raised LSM (at least two occasions). Their mean LSM was 9.0 kPa. Of these seven patients, one was lost to follow-up. One had a normal ultrasound, with a consultant hepatologist assessment of ‘low risk of developing significant fibrosis’. Two of the seven patients had normal ultrasound findings; LSM normalized with reduced alcohol consumption. One patient had nodular changes on ultrasound. Liver biopsy showed severe nodular cirrhosis with portal hypertension. In one patient, the consultant hepatologist’s assessment was ‘probably has significant fibrosis’. Liver biopsy is planned. One of the seven patients was considered to ‘have significant fibrosis’ after magnetic resonance cholangiopancreatography investigation. Liver biopsy is planned. Liver function tests were significantly abnormal in only one of these last three patients, in whom liver fibrosis is proven or strongly suspected. In summary, fibroscanning identified three patients with EPP out of 132 (2.3%) who have significant fibrosis (biopsy or opinion of the consultant hepatologist). Liver function tests were only significantly abnormal in one of the three. It is easy to miss the development of hepatic fibrosis in EPP, with potentially disastrous consequences. Fibroscanning is a cheap, effective screening tool, and should become a routine clinic investigation in patients with EPP.