Rheumatoid Arthritis Associated With Anti-Signal Recognition Particle Immune-Mediated Necrotizing Myopathy: A Case Report.

Immune-mediated necrotizing myopathy (IMNM) is a rare subtype of idiopathic inflammatory myopathy that is characterized by severe subacute proximal weakness, myofiber necrosis, and significantly elevated serum creatine kinase. Anti-signal recognition particle (SRP) and anti-3-hydroxy-3-methylglutaryl-coenzyme-A reductase autoantibodies have been found in about two-thirds of patients with IMNM. This myopathy is usually idiopathic and there is a scarce literature concerning its association with connective tissue diseases. Herein, we report an unusual case of a young woman who presented with both rheumatoid arthritis and severe anti-SRP IMNM. Thankfully to a therapeutic protocol combining rituximab and cyclophosphamide, an important improvement was achieved, and notably no serious side effect was observed.

Pericardiectomy and Mechanical Mitro-Aortic Valve Replacement in a Young Patient With Erdheim-Chester Disease.

Erdheim-Chester disease is a rare histiocytosis that primarily affects the skeletal system, but cardiovascular manifestations occur in 75% of cases and are associated with a poor prognosis. Given the small number of cases, the evolution and management of the disease are uncertain. Therefore, it is important to report and share Erdheim-Chester cases. This report presents the case of a young patient with constrictive pericarditis and mitral valve regurgitation resulting from Erdheim-Chester disease.