Be alert to tuberculosis-mediated glomerulonephritis: a retrospective study

Mycobacterium tuberculosis infection causing glomerulonephritis is a rare disorder. This retrospective study analyzed the clinical characteristics of patients diagnosed with tuberculosis-mediated glomerulonephritis (TB-GN) between 2002 and 2009, as well as the diagnostic tools used. These findings were then compared with those of patients with primary glomerulonephritis (P-GN). The records of all patients were reviewed. The diagnosis of TB-GN was based on renal hematuria and/or proteinuria and cure after antituberculosis therapy alone plus urine culture positive for M. tuberculosis, demonstration of typical tubercle granulomas on renal biopsy specimens, or the detection of M. tuberculosis DNA by polymerase chain reaction (PCR) on renal specimens. Forty-six patients with TB-GN and 49 patients with P-GN were included. Compared with patients in the P-GN group, most (76%) patients with TB-GN had a history of TB. Systemic symptoms were much more frequent in patients with TB-GN than local genitourinary symptoms. Serological testing showed a statistical difference between the two groups. Immunoglobulin A nephropathy was found in the majority (72%) of patients with TB-GN. M. tuberculosis DNA detection was positive in 39 (84.8%) patients, a much higher positive rate of diagnosis than that with urine culture for M. tuberculosis. The manifestation of TB-GN is atypical and nonspecific. It warrants a high index of suspicion when patients with renal hematuria and proteinuria fail to respond to standard treatments for P-GN. Clinicians should pay close attention to the medical history and results of special laboratory tests. M. tuberculosis DNA detection on renal biopsy specimens should be considered in order to confirm the diagnosis of TB-GN.