LAUSR

Background Psoriatic arthritis (PsA) has a genetic background, approximately 40% of patients having a family history of psoriasis or PsA in first-degree relatives, which may impact the disease features. Objectives The aim of this study was to evaluate the effects of family history of psoriasis or PsA on the disease phenotypes. Methods The demographic and clinical data were retrieved from the longitudinal, multicenter PsArt-ID (Psoriatic Arthritis-International Database). Family history of psoriasis and PsA were investigated for 1st and 2nd degree relatives separately. The effect of the family history of psoriasis and/or PsA on disease phenotypes and severity were analysed, calculating the relative risks (RR). Results 1393 patients had the data for family history, 444 (31.9%) of whom was positive for psoriasis and/or PsA. The majority of the family history was only psoriasis (333/444; 75%) and 58.5% (260/444) of the patients had first-degree relatives affected. There was no differences in maternal or parental transmission rates however women had more psoriasis and/or PsA in their family (67.3% vs 32.7% p: 0.028). Patients with a family history had an earlier onset of age for psoriasis (29±14.8 vs 31±14.9 p: 0.007), more frequent nail involvement (50.7% vs 29.6% p: 0.032), more frequent enthesitis (28.2% vs 17.7% p<0.001) and deformities (25.2% vs 19.9% p: 0.05) and were able to achieve minimal disease activity (MDA) less often. (38.6% vs 49.5% p: 0.045). Plaque psoriasis was more common if the family history was positive for psoriasis whereas pustular psoriasis was more frequent when the family history was positive for PsA (figure 1). Family history of psoriasis were found as a risk factor for a younger onset (RR: 1.138), for nail disease (RR: 1.179), for enthesitis (RR: 1.504) and for not achieving MDA (RR: 1.246) whereas family history of PsA was a risk factor for having deformities (RR: 1.215) (table 1).Abstract THU0285 – Table 1 Relative Risks in patients with or without family history of psoriasis or PsA Family history p RR 95% CI Onset of psoriasis before 40 years age Psoriasis <0.05 1.138 1.063–1.219 PsA >0.05 1.023 0.879–1.191 Nail involvement (ever) Psoriasis <0.05 1.179 1.04–1.335 PsA >0.05 1.157 0.917–1.461 Enhesitis (ever) Psoriasis <0.05 1.504 1.192–1.898 PsA >0.05 1.350 0.871–2.092 Not achieving MDA Psoriasis <0.05 1.246 1.003–1.547 PsA >0.05 1.044 0.655–1.666 Presence of deformities Psoriasis >0.05 1.215 0.928–1.592 PsA <0.05 1.786 1.170–2.727 PsA: Psoriatic Arthritis; MDA: Minimal Disease Activity Figure: Distribution of skin lesions according to the family history in patients with PsA. Numbers are given as percentages. PsO: Psoriasis; PsA: Psoriatic Arthritis Conclusions The family history of psoriasis and PsA has impacts on skin phenotypes, musculoskeletal features and the disease severity. The differences between family history of psoriasis and PsA and pustular vs plaque phenotypes may point out to a different genetic background and pathogenic mechanisms in these subsets. Disclosure of Interest None declared