Hypertrophic cardiomyopathy in a lupus patient: a case of hydroxychloroquine cardiotoxicity

Abstract

Hydroxychloroquine (HCQ) is a well-established and effective immunomodulatory therapy for systemic lupus erythematosus and other autoimmune diseases. While retinal toxicity is a well-recognized complication, cardiotoxicity is lesser known. This case consists of a 63-year-old Filipina on chronic HCQ treatment that led to severe biventricular hypertrophy, increased filling pressure, systemic and pulmonary hypertension, and elevated brain natriuretic peptide. Genetic testing ruled out lysosomal storage disorders but revealed five rare variants of uncertain significance, including one that was temporarily re-classified as likely pathogenic. Endomyocardial biopsy demonstrated myeloid bodies admixed with curvilinear bodies, most consistent with a diagnosis of HCQ toxicity. This case illustrates the importance of clinical integration of multiple causes of cardiomyopathy, recognition of HCQ cardiotoxicity, and increased uncertainty in genetic test findings among racial minorities.

Keywords: Hydroxychloroquine; Hypertrophic cardiomyopathy; Minority; Myeloid bodies; Variant of uncertain significance.

Figure 1

Electrocardiogram demonstrated findings consistent with left ventricular hypertrophy. Twelve‐lead electrocardiograms demonstrated voltage criteria for left ventricular hypertrophy and prominent anterolateral horizontal ST depression and T wave inversion (A). One year later, the patient developed atrial fibrillation (B).

Figure 2

Cardiac magnetic resonance imaging demonstrated hypertrophic cardiomyopathy phenotype. Cardiac magnetic resonance imaging demonstrated normal left ventricular size and left ventricular hypertrophy and mildly dilated right and left atria (A) and dilated pulmonary artery measuring (B).

Figure 3

Cardiac endomyocardial biopsy demonstrated histological findings consistent with hydroxychloroquine cardiotoxicity. (A) Haematoxylin and eosin stain demonstrated diffusely vacuolated myocytes, scale bar = 50 μm. Ultrastructural evaluation by electron microscopy demonstrated (B) intracellular accumulation of myeloid bodies (star) and curvilinear bodies (arrow) and vacuoles containing electron‐dense autophagolysosomes (C); evaluation, original magnification ×16 000.