Renal tuberculosis diagnosis based on lipoarabinomanan assay in an immunocompetent patient: case presentation

Abstract

Background: Tuberculosis is caused by Mycobacterium tuberculosis. It is transmitted through air droplets expelled by people with active pulmonary tuberculosis. It is one of the most common causes of death by an infectious agent. Extra pulmonary TB occurs in approximately 5-45% of infected individuals. Clinical Case Description: A 52-year-old female patient with polycystic kidney disease, with 10 days of weakness, hiporexia, involuntary weight loss, vomit and occasional diarrhea. Subsequently followed by oligoanuria and dysuria. Additional studies where performed, and a urinalysis suggestive of urinary tract infection and elevated renal function levels, with criteria for acute dialysis. The kidney ultrasound confirmed bilateral polycystic kidney disease. She was initiated on empirical antibiotics with no adequate response and the urine culture did not report growth of bacteria. More tests where ordered, including lipoarabinomanano (LAM) detection, Ziehl-Nielsen test, and the nucleic acid amplification test Xpert MTB in urine samples; all of them were positive, thereby diagnosing the patient with renal tuberculosis. Conclusions: Renal tuberculosis usually goes unnoticed because of its nonspecific symptoms and signs, and difficult diagnostic approach. The LAM and Xpert MTB/Rif tests have been recommended in the guidelines for the diagnosis of pulmonary or disseminated tuberculosis in HIV patients. However, in this case they were useful for timely noninvasive diagnosis in an immunocompetent patient. Further studies should be performed in this population to assess the usefulness of these tests in resourcelimited health care settings.