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Introduction Anti-fibrillarin (AFA) antibodies are a very uncommon serological subset in systemic sclerosis (SSc). They are thought to be more prevalent among Black ethnicity patients but uncertainty remains about their clinical associations. The herein objective was to characterize the phenotype of AFA+ SSc patients and determine influence of ethnicity and geographical origin on clinical presentation and patient outcomes.Material and Methods We retrospectively analysed the phenotype of AFA+ SSc patients from 18 centers across Europe and the United-States, evaluating both baseline and last available follow-up visits.Results A total of 378 patients AFA+ patients, fulfilling 2013 ACR–EULAR classification criteria for SSc were included: 133 (37%) were of Black ethnicity and 226 (63%) were of White ethnicity. Ethnicity was unknown for 19 subjects (5%). General features at baseline are reported in table 1.Black patients more frequently presented with diffuse cutaneous (dc)SSc (62% vs. 38%, p < 0.001), had higher Rodnan skin score, experienced more frequent renal crisis (10% vs. 4%, p = 0.047) and digital ulcerations (47% vs 34%, p = 0.014) than white patients. Interstitial lung disease (ILD) prevalence was similar across groups, although Black patients had significantly lower FVC and DLCO values (table 1).Multivariate analysis confirmed that ethnicity was independently associated with dcSSC with White patients showing lower risk (OR 0.21, 95% CI 0.11–0.40, p < 0.0001). White origin was significantly associated with higher DLCO compared to Black ( β = 14.01, 95% CI 7.68–20.34, p < 0.0001). At follow-up (median follow-up of 72.8 (32-143) months), overall mortality reached 26%, with no ethnic differences on univariate analysis.Regional analyses (EU versus USA) revealed that USA patients mostly exhibited lower FVC (80% vs 91 %; p=0.001), greater gastrointestinal manifestations (80% vs 57% p<0.001) and higher mortality (36% vs 13%; p<0.001). Overall, these was observed in both Black and White ethnic groups. Multivariate analysis confirmed that American origin, regardless of ethnicity, was associated with nearly a fivefold increased mortality risk (OR 4.90, CI 2,151 – 12,52 p<0.001).Conclusions This large international series provides the most comprehensive description of AFA+ SSc patients to date. Black ethnicity represents a higher risk for this immunological subset but also for global prognosis suggesting that genetic determinants including HLA have a role. In addition, we observed that geographical origin has also a key role for prognostication of AFA+ patients. Therefore, interactions between genetic susceptibility and geographical exposures may contribute to the observed heterogeneity, emphasizing on the importance of personalized management strategies.Abstract P.405 Table 1Disease features at baseline visit for whole population and ethnical subsets