Rituximab in Patients With Acute Rheumatic Fever

Inclusion Criteria: * Children aged between \>= 5 and \< 17 years old; * Diagnosed acute rheumatic fever with at least one progressive rheumatic valvular lesion confirmed through a cardiac echography. * Informed consent, signed and dated by both parents or legal guardians of the patient Exclusion Criteria: * Simultaneous active infection, such as HIV, hepatitis B, C, tuberculosis, Epstein-Barr virus (EBV), or history of frequent, unusual or serious infections ; * Pathologies likely to affect immunity (cancer, multiple sclerosis, diabetes, other auto-immune diseases) * Recent history of drug administration that may affect the immune system, for the past 4 weeks (immunosuppressive drugs, corticosteroids, anticancer drugs); * Hypersensitivity reaction to rituximab or one of its components. Hypersensitivity to penicillin * History of monoclonal antibodies administration * Recent vaccination (less than a month) or planned within the 12 months after randomization; * History of heart failure * Renal failure with a creatinine clearance \<45 ml/min/1,73m² * Pregnancy (a negative urinary test is necessary for women who had their first menstruations or aged 14 years old and more) * Patients diagnosed with Guillain-Barré syndrome * Patient with at least one of the following biological features : Hemoglobin \< 8,5 g/dL, Platelets \< 100 G/L, Neutrophils \< 1,5 G/L, Leucocytes \< 3 G/L, AST or ALT increased \> 2,5 the normal superior limit) * Any acute or chronic infection clinically si…