Pulmonary co-infection with nocardia species and nontuberculous mycobacteria mimicking miliary tuberculosis in a patient with Crohn’s disease under combined immunosuppressive therapy

Abstract

Nocardiosis is a rare infection caused by ubiquitous soil-born, acid-resistant, Gram-positive bacteria that can be life-threatening in immunocompromised patients. Originally usually diagnosed in HIV-positive patients, only few cases have been reported in patients on immunosuppressive therapy for inflammatory bowel disease or rheumatologic disorders. We present a case of a 32-year-old man who was treated with infliximab, prednisolone, and azathioprine for severe terminal ileitis. Although the clinical status improved under triple immunosuppressive therapy, weight loss, weakness, and fatigue persisted. Laboratory studies revealed iron deficiency anemia, hypalbuminemia and raised inflammatory markers. Chest computed tomography scan showed multiple pulmonary nodules and a large cavity in the left upper lobe (segment 3a). Empiric tuberculostatic therapy was introduced for suspected miliary tuberculosis but stopped for lack of clinical improvement and negative tuberculosis tests (interferon-gamma release assay, microscopy, polymerase chain reaction). Finally, the diagnosis of pulmonary nocardiosis with concomitant pulmonary infection was confirmed microbiologically, and the patient was treated with high-dose co-trimoxazole, clarithromycin, ethambutol, and rifampicin for 12 months.This case report underlines the increased risk of severe and rare infections like nocardiosis with combination immunosuppressive therapy and the necessity for thorough diagnostic screening for opportunistic infection. Although long-term antibiotic treatment for nocardiosis is mandatory, the optimal timing to restart immunosuppressive therapy remains ambiguous.

Nocardiosis in glomerular disease patients with immunosuppressive therapy

“…Compound sulfamethoxazole was effective for nocardiosis in glomerular disease patients and even for disseminated nocardiosis, which was characterized by diminished subcutaneous and pulmonary abscesses as a therapeutic response. It has been suggested that nocardiosis mainly occurs in patients suffering from autoimmune diseases, chronic Abbreviation: WBC White blood cell, N% Percentage of neutrophils, CRP C reactive protein, PCT Procalcitonin, ALB Serum albumin, Sr Serum creatinine, 24 h UP 24-h urinary protein *: P < 0.05, compared to data before treatment; a : All the data in "after treatment" were obtained when antibiotic treatment stopped renal disease, hematological diseases and HIV infection, especially in those who receive glucocorticoids or other immunosuppressive treatments [29,[35][36][37][38]. Here, we observed that all 7 patients with nocardiosis had been receiving glucocorticoids alone or combined with immunosuppressive agents, which is consistent with the previous literature.…”