Background: Tuberculosis (TB) is a common disease worldwide, but kidney affection, i.e. tubulointerstitial nephritis (TIN) caused by Mycobacterium tuberculosis is rare. More frequent in patients with TB is drug induced TIN, i.e. the result of intensive antitubercular treatment.
Patients and methods: In the time between April 2005 until August 2011 data from all patients (4 male, 1 female) with clinical evidence of active TB and significant renal disease were collected. All patients were treated with antitubercular treatment according to standard protocols. All patients underwent kidney biopsy due to progressive renal failure and all of the renal biopsies revealed an interstitial inflammation with eosinophilia. Epitheloid granulomata were found in 3 of 5 patients, whereas caseating granulomata were found in only one patient. No patient had sterile leucozyturia and all patients were negative for Mycobacterium tuberculosis on PCR; of note, none of the renal biopsies examined were positive for acid and alcohol fast bacilli by Ziehl-Neelsen staining.
Conclusions: TB associated TIN is rare, but needs a rapid recognition and an early treatment. Kidney biopsy should be performed in patients with TB and renal disease to ensure the diagnosis of renal involvement of active TB and established correct treatment (intensifying TB treatment or changing TB therapy in drug induced TIN). Additionally, negative PCR of the histopathological samples should not exclude TB associated TIN and sterile leukocyturia is less common than expected.