Membranous nephropathy and granulomatous interstitial nephritis due to tuberculosis

Tuberculous involvement of the genitourinary tract is well reported in the literature. However, reports of glomerular lesions of the kidney due to tuberculosis are rare. Tuberculosis has been identified as the most common infectious cause of granulomatous interstitial nephritis (GIN). We report a 23-year-old female patient with a membranous nephropathy and GIN due to tuberculosis. She presented with renal failure and nephrotic-range proteinuria, both of which resolved with the treatment of tuberculosis. There is only one report, from Japan, of a patient with membranous nephropathy and tuberculous granulomatous nephritis. Our patient is the second with tuberculous GIN and membranous nephropathy. In our patient, the close temporal relationship between the infection and glomerulonephritis, an ulcerated tuberculin skin test, the response to the treatment and the absence of any other systemic disease that might cause the glomerulonephritis suggested an association between tuberculosis and membranous nephropathy. However, a causal association can only be speculation, because membranous nephropathy could remit spontaneously. It is also possible that it might relapse at a later date when the tuberculosis is inactive. Therefore, the association might be either coincidental or causal, and could become clearer as similar patients are reported.