Streptococcus pyogenes tonsillar infection in early onset
psoriasis patients can be associated with severe course and biological
therapy. Chronic plaque psoriasis patients (CPPP) have higher incidence of
sore throat compared to controls. Plasma from untreated CPPP (n=27) and
healthy controls (HC, n=21) were analyzed for the presence of IgA and IgG
against S. pyogenes extract (SE). Also, circulating CLA+/- T cells from the
same patients were cultured with autologous epidermal cells with or without
SE stimulation. All CPPP had Anti-Streptolysin O titer <200IU. Increased
levels of anti-SE IgA were detected in CPPP compared to HC (p<0,001). Of
note, CPPP with higher anti-SE IgA levels showed stronger CLA+ T cellassociated
IL17F (2433,92pg/ml) and IL17A (298,50pg/ml) response in SE
stimulated cultures, when compared to low anti-SE IgA patients and
controls. Increased IFNγ levels were also observed but it was not restricted
to CLA+ T cells. Noteworthy, IgA was IgA alpha 1 and not alpha 2,
suggesting upper orogastric and respiratory tracts production after chronic
infection. Not such distinction between patients is observed for anti-SE IgG
levels, which are more related to an accute tonsillar infection. Patients
heterogeneity may shape clinical course and response to treatments. We
propose S. pyogenes specific IgA as a potential biomarker to stratify CPPP,
and a feasible tool to understand CPPP heterogeneity.

IgA plasma levels, but not IgG, against Streptococcus pyogenes identifies Anti-Streptolysin O negative chronic plaque psoriasis patients with increased specific CLA+ T cells IL17A and IL17F producers