A 24-year-old woman with UC diagnosed 2 years previously was transferred to our hospital due to a 1-week history of a high-grade fever, bloody diarrhea, frequent bowel movements, and severe pain on the left side of the abdomen. Her UC was not well controlled with an oral 5-ASA therapy, so she was started on IFX in July 2014. She had already received the induction doses as well as 8 maintenance doses at 5 mg/kg, and she had maintained clinical remission for about 1.5 years. The final administration was 8 weeks prior to the start of the above-mentioned symptoms. She had neither history of travel nor any recent exposure with sick individuals, and her medical history was unremarkable except for UC. On a physical examination, the patient was febrile (39.5 C) with mild tachycardia, and an abdominal examination revealed moderate tenderness with hyperactive bowel sounds and mild rebound tenderness in the left side of the abdomen.
Her laboratory examination revealed a decreased albumin of 3.4 (g/dL), elevated C-reactive protein of 8.53 (mg/dL), elevated erythrocyte sedimentation rate of 47.1 (mm), elevated white blood cell count of 124 (102/muL), with 81.0% neutrophils (normal range: 42-77%), hemoglobin within normal limits at 13.0 (g/dL), blood platelet count within normal limits at 29.9 (104/muL), negativity for hepatitis B virus antigen and antibody, negativity for hepatitis C virus antibody, negativity for chlamydia trachomatis antibody, negativity for syphilis, beta-D-glucan within normal limits at <6.0 (pg/mL), negativity for tuberculosis bacterium specific interferon gamma, and negativity for cytomegalovirus antigen. Polymerase chain reaction analyses were negative for both cytomegalovirus and tuberculosis bacterium genes in the colon lesions. No significant pathogens, including bacteria, fungi, viruses, and parasites, were isolated from her blood or were found in the contents of her colon. She tested negative for HIV and human T-lymphotropic virus type (HTLV)-I viruses.
Colonoscopy on admission revealed widespread shallow ulcers in the rectum and coarse mucosa with mucous, pus, and blood in the sigmoid colon (Fig. 1A and B). The mucosal vascular pattern disappeared, and the erythematous mucosa was friable and bled easily. Although there were no active UC findings from the cecum (terminal ileum) to the splenic flexure (Fig. 1C), we found long luminal edematous swelling and multifocal discharge of pus throughout the descending colon (Fig. 1D and E). The mucosa of the descending colon appeared to be nearly intact. Computed tomography immediately after colonoscopy showed a diffusely thickened wall with a narrowed lumen and intramural air-filled abscess cavities and multifocal low-density areas of abscesses (Fig. 2), particularly within the wall of the descending colon. There were no diverticula of the colon, which was confirmed by the prior findings of colonoscopy and computed tomography. Antimicrobial therapy with doripenem hydrate 0.5 g intravenously every 8 h was started, as well as intravenous hyperalimentation. 2 weeks after starting treatment, she became afebrile and pain-free, and her C-reactive protein level was normalized. Oral intake was restarted with an elemental diet, and she was later discharged home after confirmation of the improvement of her condition via colonoscopy (Fig. 3A and B) and computed tomography (Fig. 3C). She is still being followed up at our out-patient department, and both oral and anal administration of 5-ASA have maintained clinical remission of her UC. IFX has not been reintroduced.