Nuclear Factor κB Activation in a Type V Pityriasis Rubra Pilaris Patient Harboring Multiple CARD14 Variants.

Pityriasis rubra pilaris (PRP) is a rare papulosquamous skin disorder, which is phenotypically related to psoriasis. Some familial PRP cases show autosomal dominant inheritance due to CARD14 mutations leading to increased nuclear factor κB (NFκB) activation. Moreover, CARD14 polymorphisms have also been implicated in sporadic PRP. A Hungarian PRP patient with childhood onset disease showing worsening of the symptoms in adulthood with poor therapeutic response underwent genetic screening for the CARD14 gene, revealing four genetic variants (rs117918077, rs2066964, rs28674001, and rs11652075). To confirm that the identified genetic variants would result in altered NFκB activity in the patient, functional studies were carried out. Immunofluorescent staining of the NFκB p65 subunit and NFκB-luciferase reporter assay demonstrated significantly increased NFκB activity in skin samples and keratinocytes from the PRP patient compared to healthy samples. Characterization of the cytokine profile of the keratinocytes and peripheral blood mononuclear cells demonstrated that the higher NFκB activation in PRP cells induces enhanced responses to inflammatory stimuli. These higher inflammatory reactions could not be explained solely by the observed CARD14 or other inflammation-related gene variants (determined by whole exome sequencing). Thus our study indicates the importance of investigations on other genetic factors related to PRP and their further functional characterization to bring us closer to the understanding of cellular and molecular background of disease pathogenesis.

Increased circulating anti-α6-integrin autoantibodies in psoriasis and psoriatic arthritis but not in rheumatoid arthritis.

In psoriatic skin, laminin integrity is altered, which could lead to insufficient laminin integrin interactions, leaving the α6-integrin exposed and possibly accessible for autoantibody production. Therefore we investigated the presence of anti-α6-integrin autoantibodies in the serum of patients with psoriasis vulgaris (Ps), psoriatic arthritis (PsA) and rheumatoid arthritis (RA) in comparison with healthy donors. The level of circulating anti-α6-integrin antibodies was determined by enzyme-linked immunoassay using α6-integrin fragments. Antibodies against at least one recombinant fragment were found in approximately 30% of Ps and PsA patients. In contrast, in RA patients, the frequency of antibodies was similar to healthy controls. Our study shows the presence of anti-α6-integrin antibodies in Ps and PsA but not in RA, which could indicate ongoing abnormal processes in the skin. Anti-α6-integrin autoantibodies may contribute to the formation of micro-wounds in the skin and to the characteristic wound-healing phenotype in psoriasis.

Presence of antidrug antibodies correlates inversely with the plasma tumor necrosis factor (TNF)-α level and the efficacy of TNF-inhibitor therapy in psoriasis.

Antidrug antibodies have been shown to be associated with a loss of response during biologic therapy. Despite the potential association, there has been no report on the simultaneous monitoring of the following parameters in psoriasis: presence of neutralizing antibodies, plasma tumor necrosis factor (TNF)-α concentration, TNFi concentration and disease activity. Plasma concentrations of adalimumab, infliximab, etanercept and their respective antidrug antibodies, as well as plasma concentrations of TNF-α were measured in 77 psoriasis patients receiving biologic therapy, and the values were correlated with the clinical activity of the skin disease. Antidrug antibodies were identified in the plasma of 25% of infliximab-treated patients and 29.6% of adalimumab-treated patients, but not in the etanercept group. Clinical severity scores were significantly higher in the antibody-positive patients. In patients receiving infliximab or adalimumab therapy, the presence of antidrug antibodies was directly associated with reduced plasma TNF-inhibitor concentration and elevated plasma TNF-α level.