Investigating the link between Helicobacter pylori infection and psoriatic disease: an immunological study

Helicobacter pylori (Hp) has been postulated as an infectious trigger of psoriatic disease, namely psoriasis (Ps) and psoriatic arthritis (PsA), but meticulous antibody (ab) reactivity against all dominant and subdominant Hp antigens in demographically matched PsA and Ps patients and healthy controls has not been performed so far. IgG anti-Hp ab testing was performed by combining immunoblotting and line assays in 263 serum samples from 89 patients with PsA, 114 patients with Ps, and 60 demographically matched healthy controls (HCs). Anti-Hp positivity did not differ between PsA, Ps, and HCs (P > 0.05 for all comparisons). In PsA, anti-p75, anti-p67-FSH, anti-p66-UreB, anti-p54-flagellin, anti-p41, and anti-p30-OMP abs were more frequent in patients compared to HCs (P < 0.001, P = 0.028, P = 0.010, P = 0.003, P = 0.012, P = 0.020 respectively). In Ps, anti-p66-UreB and anti-p54-flagellin abs were more frequent than HC (P = 0.015 and P = 0.011, respectively), while anti-p50 abs were less frequent than HCs (P = 0.008). Anti-p75, anti-p67-FSH, anti-p50, anti-p41, anti-p30-OMP, anti-p29 = UreA and anti-p26 ab levels were higher in PsA compared to Ps (P = 0.012, P = 0.036, P < 0.001, P = 0.021, P = 0.002, P = 0.006 and P = 0.021 respectively). DAS28 scores were positively correlated with anti-p19 ab levels (r = 0.349, P = 0.050) in PsA patients by linear regression analysis. No other significant clinical association with anti-Hp responses was noted in patients with PsA and Ps. Our results demonstrate that several antigen-specific anti-Hp abs are more frequent in patients with psoriatic disease; however, negative correlations also exist, raising doubts about whether Hp is immunologically linked to psoriatic disease.