Rituximab in combination with mycophenolate mofetil in a patient with rapidly progressive systemic sclerosis and cyclophosphamide cardiotoxicity

Introduction: Male gender and rapidly progressive involvement of the skin and organs, including the heart, are associated with an unfavorable prognosis in the course of systemic sclerosis (SSc).Case description: A 37-year-old man was diagnosed with SSc in October 2023 with the presence of Raynaud's syndrome, ulcers on the fingertips, mRSS 45 points.Cyclophosphamide 1 g/month was introduced.In 01/2024 he developed myocarditis and pericarditis.Pulses of methylprednisolone were added to the treatment and cyclophosphamide was continued, after which atrial fibrillation with ventricular bigeminy occurred.Cyclophosphamide was discontinued; a follow-up magnetic resonance imaging examination showed non-ischemic fibrous changes in the myocardium.The patient was further treated with mycophenolate mofetil (MMF) and prednisolone 5 mg/d, with no improvement in cardiac function, progression of fibrotic changes and involvement of the gastrointestinal tract.On March 2024, the patient received pulses of rituximab 1.0 g in combination with MMF.Assessment after 3 months: NT-proBNP decreased from 61,172 pg/ml to 3,562 pg/ml, and CRP concentration from 47 mg/l to 25 mg/l.In the patient's subjective assessment, there was a decrease in skin hardness (mRSS from 43 to 41 points).In the follow-up ultrasound examination: an enlarged heart, left ventricular ejection fraction of 50%, traces of fluid in the pericardium.Conclusions: Treatment with rituximab in combination with MMF may be effective in patients with an unfavorable prognostic profile, who are not eligible for immunoablation supported by autologous hematopoietic cell transplantation due to cardiac involvement, and in whom treatment with cyclophosphamide pulses is impossible due to cardiotoxicity.