Tuberculosis-Associated Renal Amyloidosis Presenting as Nephrotic Syndrome: A Case Report From Ethiopia

Tuberculosis (TB) is highly prevalent in Ethiopia, and extrapulmonary manifestations pose significant diagnostic challenges. Among its rare complications, renal amyloidosis (AA type) can present with nephrotic syndrome and progressive renal dysfunction. In resource-limited settings, the absence of routine TB screening and restricted timely access to renal biopsy often lead to empirical immunosuppression, which may worsen outcomes by reactivating latent infections.

We report a case of a 43-year-old Ethiopian male with a 5-month history of generalized edema, fatigue, flank pain, and nephrotic-range proteinuria (19.7 g/24 h). Initial evaluation suggested high-risk membranous nephropathy, and empirical immunosuppression with prednisone and cyclophosphamide was initiated before biopsy confirmation due to a delay in the renal biopsy results. The patient subsequently developed axillary lymphadenopathy and "B" symptoms. Renal biopsy results obtained after initiation of chemotherapy revealed Congo red-positive deposits with green birefringence under polarized light, consistent with AA amyloidosis. At the same time, lymph node histology demonstrated necrotizing granulomatous inflammation, confirming extrapulmonary TB. Anti-TB therapy (RHZE regimen) led to initial clinical improvement and stabilization of the renal function. However, 3 weeks later, the patient developed severe pulmonary sepsis and died of septic shock despite intensive care.

This case underscores the importance of excluding infectious etiologies, particularly TB, before initiating immunosuppressive therapy in patients with nephrotic syndrome in endemic regions. Empirical immunosuppression without histopathological confirmation risks reactivating latent TB and delaying appropriate treatment. Routine TB screening with IGRA or TST, combined with timely renal biopsy, should be prioritized in resource-limited settings to prevent misdiagnosis and improve patient outcomes.