Abstract 10450: Interleukin-17A-Correlated Myocarditis in Patients With Psoriasis

Background. Psoriasis is a common immune-mediated disease of the skin with possible extension to joints, aorta and eye. Myocardial inflammation has been rarely suggested. However, its incidence and pathologic mechanism have not been elucidated so far. Methods. One hundred consecutive patients (62M/38F, mean age 55 ± 13.7 years) with psoriasis were screened for cardiac involvement. Among them, five male patients (mean age 56 ± 9.5 years) showed a dilated cardiomyopathy (LVEF < 40%) with normal coronary arteries and valves, and underwent a left ventricular endomyocardial biopsy for evaluation of myocardial substrate. Endomyocardial samples were processed for histology and immunohistochemistry, including myocardial expression of Toll-Like Receptor 4 (TLR4) and interleukin-17A (IL-17A), which plays a major role in psoriasis pathogenesis. Real-time PCR for cardiotropic viruses and Western blot analysis for myocardial expression of IL-17A were also performed. As controls for IL-17A expression, myocardial samples from 10 male patients with inflammatory cardiomyopathy and no psoriasis were included. Patients’ sera were tested for anti-heart autoantibodies. Results. An active lymphocytic myocarditis was revealed in all 5 patients, characterized by absence of viral genomes at PCR, positive anti-heart autoantibodies, overexpression of TLR-4 and of IL-17A at both immunohistochemistry (Figure 1A vs 1B) and Western blot analysis (mean value 44 ± 6.7 vs 12 ± 61.9 in patients with no-psoriatic myocarditis and 4± 1.5 in normal controls; Figure 1C). Conclusion. Interleukin-17A-related myocarditis can occur in up-to 5% of patients with psoriasis. It manifests as a progressive dilated cardiomyopathy that can potentially benefit from immunosuppression or monoclonal antibodies as the skin disease.