THU0392 Systemic sclerosis and primary biliary cholangitis: an overlap syndrome? preliminary data from a multicentre eustar study
Authors: G. Lepri, P. Airò, O. Distler, K. Andréasson, Y. Braun-Moscovici, E. De-Langhe, C. Bruni, M. Matucci-Cerinic, Y. Allanore
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> The association between systemic sclerosis (SSc) and primary biliary cholangitis (PBC) is well known. However, classifications criteria of the 2 diseases have been recently revised and may change the relationships. Furthermore, the specific outcomes with regards to organ involvement and also of liver aspects have been only scarcely investigated. <h3>Objectives</h3> To describe clinical characteristics of SSc-PBC patients compared to SSc using a large series <h3>Methods</h3> A multicentre EUSTAR study collection data of SSc patients with known PBC or with PBC-specific antibodies (abs) and of SSc controls matched for disease duration and cutaneous subset. Data were recorded at baseline and at the last available visit. <h3>Results</h3> 229 patients were enrolled (85 SSc-PBC and 144 SSc). The mean age of the population at the SSc diagnosis was of 53±12.8. <i>Baseline characteristics.</i> The limited cutaneous subset was the most common. Anticentromere abs (ACA) were present in 82.9% of SSc-PBC patients (<i>vs</i> 68.5% in SSc, <i>p-value=0.01</i>) while anti-topoisomerase I abs were less frequently (1.2% <i>vs</i> 9.7%), <i>p-value=0.02</i>. Out of 85 SSc-PBC patients, antimitochondrial abs (AMA) were present in 80%, only 9.4% presented anti-gp210 abs and 7.1% anti-sp100 abs. The two populations did not differ for fibrosis at HRCT, lung function tests, the value of creatinine and for pulmonary arterial hypertension. A trend towards statistical significance was found in the prevalence of digital ulcers (DUs) as patients that have never suffered from past or current DUs were greater in the SSc-PBC group (78.6% <i>vs</i> 66%, <i>p-value=0.051</i>). Regarding other autoimmune associated diseases, a greater prevalence of Hashimoto thyroiditis was found in SSc-PBC (<i>p-value=0.03</i>). At baseline, transaminase, alkaline phosphatase and γGT levels were all higher in PBC-SSc (<i>p-value&lt;0.001</i>) (see Fig 1). <i>Outcomes of organ involvements.</i> The mean follow-up was of 10.5±6.8 years. During the follow-up the percentage of patients presenting ILD (defined as new appearance of fibrosis at control HRCT scan) was greater in SSc vs SSc-PBC (12.9% <i>vs</i> 2.8%, <i>p-value=0.02</i>) and PAH percentage of new cases was of 9.9% in SSc while it was not present in SSc-PBC (<i>p-value=0.003</i>). <h3>Conclusions</h3> PBC is more present in ACA positive lcSSc; SSc-PBC patients have a higher risk of polyautoimmunity. Of the most interest, SSc-PBC patients seem to have a milder SSc phenotype with less severe organ involvement and progression. Regarding PBC phenotype, only 4 patients presented portal hypertension and nobody was subjected to liver transplantation. At baseline, the SSc-PBC group had higher cholestatic liver enzymes and more than 60% were treated with deoxycholic acid. In the future, it will be useful to evaluate the PBC phenotype during the follow-up enrolling a greater number of patients. <h3>Disclosure of Interest</h3> None declared