Psoriasis & Psoriatic Arthritis

Psoriasis and immune complexes—Circulating IgA immune complexes in patients with psoriasis (J Invest Dermatol 1983 Jun[1]): Using a sensitive and specific Raji cell radioimmunoassay, authors of this study analyzed the sera of 35 patients with psoriatic arthritis for IgA-containing circulating immune complexes (IgA-CIC). Additionally, measurements for circulating immune complexes (CIC) containing IgG or IgM were performed using the 125I-Clq binding assay and the Raji IgG radio-immunoassay. Results showed that, “Twenty-eight of thirty five (80%) patients with PsA were found to have IgA-containing circulating immune complexes. In contrast, only 13 of 35 (37%) had IgG-containing circulating immune complexes detected using the Raji IgG assay and 10 of 33 (33%) had IgG- or IgM-containing immune complexes detected using the 125I-Clq binding assay.”  Frequency, level, or subclass of immune complexes did not correlate with different types or severities of cutaneous psoriasis. However, the level of IgA-CIC did significantly correlate with the severity of psoriatic arthritis—higher levels of IgA-CIC corresponded with more severe psoriatic arthritis. The authors concluded, “The finding of IgA-containing circulating immune complexes in 80% of patients with psoriatic arthritis as well as the significantly higher levels of these complexes in the patients with more severe arthritis suggests that IgA-containing circulating immune complexes may play a role in the pathogenesis of psoriatic arthritis.” Generally speaking, because IgA is the subclass of antibody/immunoglobulin that is used to defend mucosal surfaces such as the mouth, throat, respoiratory tract, and the gastrointestinal and genitourinary tracts, elevations of IgA and IgA-CIC naturally incline physicians to strongly consider microbial colonization of one or more mucosal surfaces. Additionally, since IgA-CIC are cleared by the liver for excretion into the bile and therefore into the intestines, additional attention (phytotherapeutic and physiologic) to ensuring optimal hepatobiliary and intestinal functions is likely to be of clinical benefit