[Toxic hydroxychloroquine-induced cardiomyopathy complicating systemic lupus treatment]

Hydroxychloroquine (HCQ) is considered as efficient and safe to treat systemic lupus. We report a case of fatal toxic cardiomyopathy, an underrecognized adverse effect of HCQ. A 72-year-old woman with systemic lupus erythematosus treated for 24 years by HCQ received a kidney allograft. One year later she developed a cardiomyopathy with conductive disorders. An endomyocardial biopsy showed severe non-specific myocardial fibrosis and hypertrophic vacuolated myocytes. Transmission electron microscopy showed curvilinear bodies and pseudomyelin figures consistent with HCQ-induced cardiomyopathy. At immunohistochemistry LC3b, p62 and beclin-1 accumulated in vacuolated cardiac myocytes suggesting impaired cell autophagy. When unexplained cardiac disease develops in patients receiving long-term HCQ treatment, toxic cardiomyopathy should be considered leading to a diagnostic endomyocardial biopsy.