Tuberculosis and tubulointerstitial nephritis: an intriguing puzzle.

Classical renal tuberculosis is a well-known cause of urinary tract scarring and calcification, and sometimes renal dysfunction. In the past two decades there have been reports, particularly from the United Kingdom among immigrants from the Indian subcontinent, of a more insidiously progressive form of renal disease. Ultrasound shows small smooth kidneys, and histology reveals tubulointerstitial nephritis including granulomas but not acid-fast bacilli. Evidence is mounting that the underlying cause may be tuberculosis, but the mechanism remains obscure.

Presentation, diagnosis, and treatment outcome of tuberculous-mediated tubulointerstitial nephritis.

Insidious Mycobacterium tuberculosis infection causing tubulointerstitial nephritis is a rare disorder. Here we report on a single-center case series of patients with tubulointerstitial nephritis due to tuberculosis, addressing clinicopathologic features and treatment outcome. Twenty-five adult patients with clinical evidence of tuberculosis and significant renal disease were assessed, 17 of whom had a kidney biopsy and were subsequently diagnosed with chronic granulomatous tubulointerstitial nephritis as the primary lesion. All patients were given standard antitubercular treatment, with some receiving corticosteroids, and showed a good response in clinical symptoms and inflammatory markers. Nine of the 25 patients, however, started renal replacement therapy within 6 months of presentation. Of the remaining 16, renal function improved for up to a year after presentation but subsequently declined through a median follow-up of 36 months. This case series supports that chronic tubulointerstitial nephritis is the most frequent kidney biopsy finding in patients with renal involvement from tuberculosis. Thus, a kidney biopsy should be considered in the clinical evaluation of kidney dysfunction with tuberculosis since tubulointerstitial nephritis presents late with advanced disease. A low threshold of suspicion in high-risk populations might lead to earlier diagnosis and treatment, preserving renal function and delaying initiation of renal replacement therapy.

Imaging of renal tuberculosis in eastern Taiwan: correlation with clinical course and different communities.

Hualien, located in eastern Taiwan, is a relatively isolated district. The population is composed of different ethnic communities. Our hospital is the only medical center in eastern Taiwan, so is the most important referral hospital for epidemic diseases. After reviewing our collected cases of renal tuberculosis (TB), we observed a great diversity in staging and outcomes. The aim of this study was to classify different imaging presentations and clinical outcomes in the ethnic communities represented by these cases (non-aboriginal and aboriginal). We retrospectively reviewed 22 cases from 1991 to 2001. We reviewed laboratory data, radiologic reports, and clinical outcomes. Before TB was proved by biopsy or culture, patients were not treated with an anti-TB regimen. Roentgenography showed that 68% of patients had renal calcification, 59% had dilated calyces, 55% had lung involvement, and 41% had auto-nephrectomy. The proportion of mild and severe forms was significantly different between aboriginal and non-aboriginal groups (0.05 > p > or = 0.00409). From this series, we recommend routine plain film roentgenography, including chest roentgenography and kidney, ureter, and bladder or abdominal roentgenography, followed by intravenous urography or computerized tomography as investigative tools for renal TB. Based on the significantly different outcomes of the disease between aboriginal and non-aboriginal groups, a stronger health education program for the isolated district in eastern Taiwan is necessary.