Urogenital Tuberculosis in a Patient With AIDS: An Unusual Presentation

Summary and The Case

Summary

Background: A 38-year-old man with AIDS presented to hospital with a 3-month history of fevers, bilateral lumbar pain, dysuria and increased urinary frequency. Six years earlier he had received 6 months' treatment for pulmonary tuberculosis. At presentation, he was on antiretroviral therapy with a combination of efavirenz, stavudine and lamivudine.
Investigations: Physical examination, evaluation of HIV viral load, CD4 count, measurement of serum hemoglobin concentration, white blood cell count, urinalysis, urine culture for usual pathogens, direct smear and urine culture for Mycobacterium tuberculosis, chest radiography, abdominal CT, measurement of serum creatinine concentration and estimated creatinine clearance.
Diagnosis: Urogenital tuberculosis.
Management: The patient's symptoms and radiological abnormalities persisted despite antibiotic therapy for presumed bacterial infection. After urine culture had confirmed M. tuberculosis infection, he was administered pharmacological treatment comprising isoniazid, rifampin, pyrazinamide and ethambutol for 2 months, with isoniazid and rifampin given for a further 7 months. His symptoms improved within a few days of initiating treatment. Six months after treatment started, CT revealed a nonfunctioning right kidney and a functional left kidney with areas of scarring. The patient refused right nephrectomy, and completed his pharmacological treatment. No evidence of disease recurrence was observed during 2 years of follow-up.

The Case

A 38-year-old man presented to hospital with a 3-month history of fevers, bilateral lumbar pain, dysuria and increased urinary frequency. The patient had previously been an intravenous drug user. Six years before presentation he had been diagnosed with pulmonary tuberculosis, for which he had been successfully treated with a 6-month course of isoniazid (400 mg per day) and rifampin (600 mg per day), plus pyrazinamide (2,000 mg per day) for the first 2 months. Sputum culture for Mycobacterium tuberculosis was negative at 2 months and at the end of treatment. AIDS had also been diagnosed at this time. He was receiving antiretroviral therapy with a combination of one non-nucleoside reverse-transcriptase inhibitor (efavirenz, 600 mg per day) and two nucleoside reverse-transcriptase inhibitors (stavudine 40 mg twice-daily and lamivudine 300 mg per day). At presentation, his AIDS was clinically stable, with undetectable HIV viral load (by polymerase chain reaction evaluation of HIV RNA copies) and a stable CD4 count of 185 cells/mm³ (normal range 500–1,500 cells/mm³).

The patient was admitted to hospital for investigation. Physical examination was unremarkable and revealed no tenderness of the abdomen. His serum hemoglobin concentration was 10.2 g/l (normal range 12.0–18.0 g/l) and his white blood cell count was 3,000 cells/ml (normal range 5,000–10,000cells/ml). His serum electrolyte levels and the results of liver function and coagulation studies were normal. Urinalysis showed 35,000 leukocytes/ml (normal <10,000 leukocytes/ml) and urine culture was positive for Escherichia coli. The direct smear for M. tuberculosis was negative and urine culture for this pathogen was started. Chest radiography was normal and abdominal CT revealed enlarged retroperitoneal lymph nodes with central necrosis and multiple hypodense areas in both kidneys, consistent with renal abscesses (Figure 1A). The right kidney also exhibited dilatation of the collecting system and renal parenchymal atrophy in the upper pole (Figure 1B). The patient's serum creatinine concentration was 1.0 mg/dl (88.4 μmol/l; normal range 0.6–1.2mg/dl [53.0–106.1 μmol/l]). He was started on antibiotic therapy with ceftriaxone (1,000 mg twice-daily) and oxacillin (1,000 mg four times per day) for presumed bacterial infection.

Figure 1. (click image to zoom) Abdominal CT of the patient before treatment. (A) Imaging revealed bilateral and multiple hypodense kidney areas consistent with renal abscesses and enlarged retroperitoneal lymph nodes with central necrosis (arrow). (B) The right kidney exhibited collecting system dilatation and renal parenchymal atrophy in the upper pole. The left kidney exhibited parenchymal abscesses.

One month after the initiation of antibiotic therapy, the patient remained in hospital. His fevers and urinary symptoms had not improved, and ultrasonography showed no change in his renal abscesses. Urinalysis showed a persistent elevated leukocyte count (>30,000 leukocytes/ml) but urine culture was negative for usual pathogens. The patient's urine culture for M. tuberculosis, started at initial examination, was positive, and pharmacological treatment for tuberculosis was initiated, consisting of isoniazid 400 mg, rifampin 600 mg, pyrazinamide 2,000 mg and ethambutol 1,200 mg daily for 2 months, with isoniazid and rifampin continued for a further 7 months; the patient's antiretroviral therapy was not adjusted. His symptoms improved after a few days of treatment, with resolution of fever and gradual improvement of urinary symptoms.

After 6 months of treatment, CT revealed a nonfunctioning right kidney, with dilatation of the collecting system and diffuse renal parenchymal atrophy, and a functional left kidney with areas of scarring (Figure 2). The patient's serum creatinine concentration was elevated at 1.9 mg/dl (168.0μmol/l) and his estimated creatinine clearance was 42 ml/min/1.73m² (normal >60ml/min/1.73m²). The patient refused right nephrectomy and completed his 9-month antituberculosis treatment regimen without any toxic complications. Over a follow-up period of 2 years, he showed no disease recurrence or urinary symptoms. Annual urine culture for M. tuberculosis was negative, his renal function remained stable and annual abdominal ultrasonography showed no further renal changes. The patient had been advised of the risk of tuberculosis recurrence, but was lost to follow-up after 2 years.

Figure 2. (click image to zoom) Abdominal CT of the patient after treatment. The right kidney is nonfunctional with collecting system dilatation and diffuse renal parenchymal atrophy. The left kidney shows areas of scarring.