genitourinary tuberculosis ( tb ) is the second most common extrapulmonary form of tb after lymphadenopathy . genitourinary tb accounts for 27% ( range 1441% ) of nonpulmonary cases and is usually a late complication of pulmonary tb . renal damage due to caseous destruction of renal parenchyma or obstructive uropathy is well known . made the first clinical description of granulomatous interstitial nephritis ( gin ) as the only manifestation of renal tb . overall , data on gin as the only manifestation of renal tb is limited to case reports and the most common clinical presentation is chronic renal insufficiency . interestingly , most patients of gin express active extrarenal foci , often pulmonary or peritoneal . we report a case of tuberculous gin associated with active cervical lymphadenitis and review the pertinent literature on gin due to tb in immunocompetent individuals . a 24-year - old previously healthy man developed fever and left cervical lymphadenopathy for which he was prescribed antibiotics ( erythromycin ) and antipyretics ( paracetamol ) for 2 weeks . he was also prescribed two antihypertensive drugs and advised further evaluation for proteinuria , which he deferred . two weeks later , he was referred to our center for fever , lymphadenopathy and recently detected renal failure . there was no history of treatment or contact with tb , loss of weight , red urine , skin rash , joint pains or use of native medicines . physical examination revealed pallor , bilateral pedal edema , pulse rate 92/min , blood pressure of 160/100 mmhg , temperature 38c and respiratory rate 15/min . g / l ) was decreased and erythrocyte sedimentation rate was elevated to 94 mm / h . white blood cell count of 10.9  10/l ( 410  10/l ) with neutrophils 72% , lymphocytes 23% , eosinophils 3% and monocytes 2% , platelet count 205  10/l ( 150400  10/l ) and reticulocyte count 1.2% were normal . serum creatinine was increased to 660 mol / l ( 44140 mol / l ) and the estimated four - variable modification of diet in renal disease- glomerular filtration rate was 9.59 ml / min/1.73 m . serum uric acid , calcium , inorganic phosphorus , liver function tests and lipid profile were within normal limits . there were 01 white blood cells per high power field , 810 red blood cells per high power field and no evidence of casts on microscopic examination of the urine sediment . antinuclear antibody ( negative ) , anti - dsdna ( 12.25 , 030 iu / ml ) and anti - gbm titers ( <3 cervical lymph node aspiration cytology showed granulomatous necrotizing inflammation with acid - fast bacilli ( afb ) suggestive of tb . he was initiated on antitubercular treatment ( att ) , maintenance hemodialysis and ultrasound - guided percutaneous renal biopsy were done to identify the cause of rapidly progressive renal failure ( rprf ) . on light microscopy , 19 of the 22 glomeruli were normal and 3 showed global sclerosis . interstitium showed lymphoid aggregates with well - formed epitheloid granulomas along with intense mononuclear infiltrate comprising of lymphocytes , histiocytes and plasma cells ( figures 1 and 2 ) . immunofluorescent micrography revealed absence of specific immunoglobulin or complement ( c3 , c1q ) deposits . afb were not seen on ziehl  nielsen staining and cultures for tubercle bacilli in renal biopsy were negative . on further evaluation , three samples of urine microscopy and culture for mycobacterium were negative and bone marrow examination was unremarkable . mantoux test was negative . however , urine dna - polymerase chain reaction ( pcr ) for mycobacterium tuberculosis was positive . he was started on steroid ( oral prednisolone 1 mg / kg / day ) together with att . six months since the onset of illness , his lymphadenopathy resolved but renal failure did not recover . steroids were tapered and withdrawn after 3 months and the patient is now on att and maintenance hemodialysis through radial arteriovenous fistula . renal biopsy showing epithelioid cell granuloma ( a ) , sclerosed glomerulus ( b ) , atrophic tubules ( c ) and interstitial inflammation ( d ) ; ( hematoxylin and eosin stain ; 20 magnification ) . ( a , b ) epithelioid cell granuloma surrounded by mantle of lymphocytes ( hematoxylin and eosin stain ; 40 magnification ) ( epithelioid cell marked with arrow in figure 2b ) . the interesting features in our patient were ( i ) coexistence of active renal and cervical lymph node tb in a 24-year - old male , ( ii ) gin presenting as rprf and nephrotic range proteinuria and ( iii ) diagnosis was made by positive urine pcr for m. tuberculosis , when afb could not be demonstrated in urine or renal biopsy . renal tb is rarely present in patients < 25 years of age and can occur during primary infection or pulmonary reactivation . if there is a history of pulmonary infection , the latency period from the time of the initial infection to diagnosis with renal disease ranges from 5 to 40 years . coexistence of active renal and cervical lymph node tb is a deviation from the normal time frame for development of renal tb . similar case reports of gin with pulmonary and peritoneal foci are described , but to the best of our knowledge , this is the first report of cervical adenitis in a patient with gin due to tb . it is possible that our patient had a primary infection involving the lymph node and the kidneys . another remarkable feature is the clinical presentation of hypertension , rprf and nephrotic range proteinuria , mimicking a glomerular disease . similar presentation of gin has so far been reported in only one other patient   and there is no possible explanation for the nephrotic proteinuria seen in these patients . such presentations may be seen with non - steroidal anti - inflammatory drug - induced acute interstitial nephritis but in our case , detailed evaluation for other causes of gin like drugs , infections and systemic conditions like sarcoidosis , wegener s granulomatosis revealed negative results . urine cultures ( three to five samples ) of the first urine of the day are considered gold standard in diagnosis of genitourinary tb but are often negative . in comparison to urine cultures , pcr primers and probe derived from m. tuberculosis species - specific dna insertion sequence , is6110 has an overall sensitivity of 95.59% and specificity of 98.12% in the diagnosis of genitourinary tb . summary of case reports with gin due to renal tba 
  esrd  end - stage renal disease ; na  not available ; neg  negative ; cr  complete recovery ; pr  partial recovery . other diagnostic techniques . gin is seen in only in 0.50.9% of renal biopsy and of this 5% is caused by infections [ 1113 ] . often , features on biopsy do not help to determine the cause of gin . afb may be demonstrated in the renal biopsy tissue with ziehl  nielsen or auromine - o stain but is positive only in 3243% of specimens . we suspected tb as the cause of gin due to the presence of afb in the cervical lymph node and subsequently , a positive urine dna pcr for m. 
  tuberculosis helped to confirm the diagnosis . att ( two , three or four drugs of isoniazid , rifampicin , pyrazinamide and ethambutol ) has been used to treat all these patients . it has been observed that concomitant use of steroids bring about favorable recovery in these patients . since granulomatous inflammation heals by fibrosis ; steroids may decrease the inflammation and thereby reduce the amount of interstitial fibrosis . reported a similar case presenting as rprf with nephrotic proteinuria and obtained complete renal recovery with a combination of att and steroids . remarkably , the majority of these ( rare ) cases were observed in patients from india or black africans or african - americans . this could be due to a genetic predisposition causing varied host immune response or due to variations in phage type of m. tuberculosis , tb must be considered as a cause of gin particularly in patients with asian or african origin . urine pcr can have a significant role in the diagnosis of culture negative renal tb . steroids in combination with att should be considered as the first - line treatment for gin due to tb .