Nefritis tubulointersticial probada por biopsia: Revisión clínico-patológica

Introduction: Tubulointerstitial nephritis is one of the most frequent causes of acute kidney injury that may progress to chronic kidney disease. The use and abuse of nephrotoxic drugs are the main cause. Renal biopsy contributes to diagnosis in most cases. Objective: To perform a clinical and pathologic description of patients diagnosed with tubulointerstitial nephritis and their outcome. Materials and methods: A descriptive, retrospective study for cases of tubulointerstitial nephritis proven by renal biopsy between 2000 and 2013 was performed. To determine histological features, clinical presentation and outcome, renal biopsies and clinical records were reviewed. Results: A total of 55 cases were included, six child and 49 adults, on age range of five to 81 years, 61,8% of them were men. Of cases, 40 had acute kidney injury, 10 chronic renal disease, three rapidly progressive glomerulonephritis, one nephritic syndrome, and one sub-nephrotic proteinuria. All biopsies showed interstitial inflammation. The median of initial serum creatinine was 4,6 mg/dL (0,7 – 23,0). Tubulointerstitial nephritis was associated to: antibiotics (27,3%), nonsteroidal anti-inflammatory drugs (21,8%), toxins (7,3%), herbal medicines (5,5%), others causes (12,7%) and unknown cause (25,5%). From 50 follow-up patients, 72% presented complete remission and 28% chronic kidney disease. Conclusions: Tubulointerstitial nephritis is a renal disease with good prognosis. It is not possible to determine the causative factor in a significant percentage of cases, so it is recommended to implement mechanisms of information to determine the incidence, prevalence and etiologic factors in our population.