Antirheumatics/prednisolone/rituximab

Abstract

Mycobacterial endocarditis: case report A 61-year-old man developed mycobacterial endocarditis following administration of chloroquine, methotrexate, prednisolone and rituximab for rheumatoid arthritis [dosages and routes not stated]. The man, who had a history of dermatomyositis, left hepatic lobectomy due to haemangioma and rheumatoid arthritis, had been receiving treatment with methotrexate, chloroquine and prednisolone. Seven years prior to the presentation, he had undergone replacement of mitral valve with biological prosthesis due to stenosis secondary to rheumatic valve disease. He presented to emergency department due to sporadic fever episodes (up to 39°C), chills and generalised myalgia. He was admitted. Upon admission, physical examination was normal. Due to the history of fever, valvular prosthesis and immunosuppression, a transesophageal echocardiography was performed, which showed bioprosthesis in mitral position with thickening of its veils and slight alteration in mobility, and multiple highly mobile echo dense images adhered to the atrial aspect, suggestive of vegetations. Blood cultures showed no growth. Based on the modified Duke criteria, possible endocarditis was considered. Due to the initial negative cultures and a history of immunosuppression, infection with atypical pathogen was suspected. Consequently, immunodiffusion test was performed. A positron emission tomography (PET)-CT scan was negative for presence of hypermetabolic foci suggestive of neoplastic and/or another infectious process, without hypermetabolism in mitral valve. During the hospitalisation, he had febrile peaks. Blood cultures were persistently negative. He had no other symptoms associated with endocarditis. Hence, non-bacterial thrombotic endocarditis due to autoimmune pathology was suspected. A repeat echocardiography showed findings identical to the prior echocardiography. He started receiving immunosuppressant drug therapy with rituximab. A significant clinical improvement without febrile peaks was noted. Hence, he was discharged. Four days following the discharge, the blood cultures for mycobacteria resulted as positive for resistant acid-alcohol bacilli. Consequently, he was contacted and re-admitted to hospital. At the time, he was asymptomatic. Mycobacterial endocarditis was diagnosed [times to reaction onsets not stated]. The man started receiving treatment with clarithromycin, moxifloxacin, rifampicin and amikacin. The biological valve was considered as a risk factor for myocardial endocarditis. Hence, the cardiovascular surgery department advised valve replacement, which was carried out without complications with implantation of a new biological valve. Pathology tests of the removed mitral biological valve showed presence of acid-alcohol-resistant bacilli. Subsequently, culture was positive for Mycobacterium malmoense. Hence, the antibiotics continued. After two weeks, he was discharged due to the good clinical evolution. The antimicrobial treatment was continued for six months. Eventually, he attained criteria for the cured disease.