Nocardiosis in Patients with Nephrotic Syndrome: a Retrospective Analysis of 11 Cases and a Literature Review

Objectives: We evaluated the clinical manifestations and outcomes of nocardiosis, a rare opportunistic infection that occurs in patients with nephrotic syndrome.

Methods: The records of NS patients with nocardiosis in a single hospital during 2000-2019 were retrieved and studied in detail.

Results: Eleven patients were included. The mean time to develop nocardiosis after glucocorticoid therapy was 11.5 ± 14.8 months. Most patients had fever, elevated white blood cell counts and C-reactive protein, whereas procalcitonin levels were normal or slightly elevated in 91% (10/11) patients, except one patient suffered from septic shock. Nine patients were tested for CD4 T-cell counts; of these, four patients had counts < 200 cells/μL. The most common site of nocardiosis involvement was lung (100%), followed by subcutaneous tissue (72.7%). Radiological findings for lungs in seven cases were characterized by isolated or scattered nodules and masses, usually located subpleural or close to the hilum. Positive smears of Nocardia were detected in 100% of samples of subcutaneous abscess and pleural fluid. Nine patients received oral trimethoprim-sulfamethoxazole, four of which received combined carbapenem, and the remaining two patients received carbapenem monotherapy. The long-term prognosis was excellent, with a treatment success rate of 100% in all patients.

Conclusions: NS patients can develop immunodeficiency after treatment with glucocorticoid and immunosuppressants. In cases where patients develop systemic multiple abscesses, or lung images reveal isolated or scattered nodules and masses that are subpleural or close to the hilum, nocardial infection should be considered. Early diagnosis and specific treatment may improve patient outcomes.