Membranous Nephropathy Associated with Tuberculosis

Correspondence To the Editor: Glomerulonephritis (GN) due to Mycobacterium tuberculosis (M. tuberculosis) is rare, [1] and membranous nephropathy (MN) associated with tuberculosis is seldom reported. Because of atypical and nonspecific manifestations, tuberculosis‑associated GN (TB‑GN) is difficult to diagnose. Patients usually present with hematuria, proteinuria, edema, and varying degrees of hypertension or renal insufficiency, which are similar to symptoms of primary GN. Thus, patients may be misdiagnosed as having primary GN rather than TB‑GN. Treatment with glucocorticoids or immunosuppressive agents may lead to the spread of TB and deterioration of renal function, a potentially life‑threatening condition. Here, we report a case of a 15‑year‑old girl with MN secondary to pulmonary tuberculosis [Figure 1a and 1b]. The girl was presented with a 2‑week history of soy urine and lower extremity edema. Before admission, she presented 3+ protein, 3+ red blood cells and 1–3 white blood cells per high‑power field by urinalysis in a local hospital. She was then diagnosed with acute GN. After treatment with an intravenous injection of penicillin for 10 days, urinalysis remained abnormal, and she was transferred to Shanghai First People's Hospital for further treatment. She had no complaints of fever, cough, expectoration, anorexia, or weight loss. She admitted to have suffered from anemia for the last 2–3 years. Her menstrual cycles were normal. Otherwise, her medical, travel, and family histories were unremarkable. The physical examination revealed a blood pressure of 104/60 mmHg, body temperature of 37.0°C and body mass index of 18.22 kg/m 2. The patient presented moderate pallor and bilateral pitting pedal edema. No palpable lymphadenopathy or skin rash was noted. factor), and serum/urine immunofixation electrophoresis were all negative. Tumor markers were negative. Urinalysis showed protein, 2+; red blood cells, 3+; white blood cells, 2+. The 24‑h urinary protein excretion was 2.38 g. The estimated glomerular filtration rate was 83 ml • min −1 • 1.73 • m −2. Kidney ultrasonography revealed the normal diameters of the kidneys without good corticomedullary differentiation. At day 2 of admission, renal biopsy was performed. By light microscopy, the kidney specimen contained 16 glomeruli with a cellular crescent in one of them [Figure 1c and 1d]. The mesangial areas were slightly enlarged by proliferated mesangial cells and increased matrix. Mild to moderate neutrophilic infiltration was noted in some glomeruli. Silver staining showed thickened glomerular basement membranes with small projections (spikes). Tubules showed patchy atrophy. There was no granuloma in the renal …