Case Presentation: A 32-year-old male patient, Jehovah’s Witness, of no known medical history presented with a 3-month duration of intermittent bloody diarrhea, fatigue and progressive 14 kg weight loss. He denied any fever, chills, night sweats, abdominal pain, rash, or travel outside the state. Symptoms were heralded by a routine lab workup where he was found to have hemoglobin of 6.8 g/dL and creatinine of 7.3 mg/dL. He was admitted with a preliminary diagnosis of chronic diarrhea and acute kidney injury secondary to pre-renal azotemia. An extensive lab workup including urine and stool studies, renal ultrasound and serologic markers were done to evaluate his diarrhea and renal failure. Renal ultrasound revealed normal size kidneys and no hydronephrosis. His renal and gastroenterology exams, including ANCA antibodies, anti-GBM, HIV, serum complement levels, hepatitis panel, C. diff toxins, H. pylori serology and celiac panel were all negative. He also underwent esophagogastroduodenoscopy and colonoscopy. Pathology from the small and large bowel biopsy were notable for mild acute ileitis with non-necrotizing granulomata and active moderate chronic colitis suggestive of inflammatory bowel disease (IBD), Crohn’s. By the fifth hospital day, his kidney function continued to deteriorate despite aggressive fluid hydration and a bloodless approach to correct his anemia. His creatinine continued to rise from 7.3 to 8.2 mg/dL. At that point, he underwent a renal core biopsy revealing chronic moderate to severe active interstitial nephritis, moderate to severe tubular atrophy and interstitial fibrosis. The patient was started on mesalamine and prednisone for treatment of Crohn’s disease and concomitant tubulointerstitial nephritis. Three months after treatment initiation he had significant improvement of his kidney function and no flare-ups.
Discussion: A variety of conditions are associated with IBD, also known as extra-intestinal manifestations. Common findings include uveitis, hepatobiliary, pulmonary and skin manifestations. Renal disease is not a well reported extra-intestinal finding. Some case reports have highlighted this connection; however it remains unclear if the renal manifestation developed as an adverse effect to 5-ASA compound or from IBD. It is important to differentiate whether interstitial nephritis is subtending from the disease or its therapy, as interstitial nephritis etiologies include multiple drugs such as NAIDS and numerous systemic diseases. We present a case of tubulointerstitial nephritis in a patient diagnosed with IBD on no previous medications.
Conclusions: This case illustrates tubulointerstitial nephritis as an extra-intestinal manifestation of IBD. Since the progressive decline of the patient’s renal function occurred prior to the start of 5-ASA therapy, it is reasonable to conclude that the main precipitating factor of his severe interstitial nephritis was IBD; connecting two channels in a single inflammatory disease.
To cite this abstract:Bazi L, Shah A. Where Two Channels Meet. Abstract published at Hospital Medicine 2015, March 29-April 1, National Harbor, Md. Abstract 452. Journal of Hospital Medicine. 2015; 10 (suppl 2). https://www.shmabstracts.com/abstract/where-two-channels-meet/. Accessed January 24, 2020.