Sustained Tubulointerstitial Inflammation in Kidney with Severe Leptospirosis.

Leptospirosis is frequently associated with acute kidney injury. Some survivors are known to progress to chronic kidney disease due to sustained tubulointerstitial inflammation. We present a case of severe leptospirosis with acute renal failure. Although antibiotic therapy resolved the infection, moderate renal dysfunction remained. A renal biopsy demonstrated marked inflammatory infiltration in the tubules and interstitium. Many of the inflammatory cells were CD68-positive monocytes/macrophages, predominantly M1 phenotype. An intermediate dose of oral corticosteroids normalized the patient's serum creatinine levels. We suggest that corticosteroid therapy may be a therapeutic option for some patients with sustained tubulointerstitial nephritis who survive severe leptospirosis.