A 21-year-old Vietnamese man presented to Asahikawa Medical University Hospital with hemorrhagic stool. He did not have any personal or family history of IBD or TB. A physical examination revealed the following: body height, 171.0 cm; body weight, 63.8 kg; body mass index, 21.8; body temperature, 36.7 ℃; blood pressure, 115/58 mmHg; heart rate, 71 beats/min; and SpO2, 99% on room air. A laboratory examination revealed high levels of inflammation markers, mild anemia and hypoalbuminemia: white blood cell (WBC) count, 11060/µl; hemoglobin, 12.9 g/dL; platelet count, 33.3×104/µl; C-reactive protein (CRP), 4.43 mg/dL; and albumin, 3.7 g/dL. Serological tests for infection markers, including the interferon gamma release assay (IGRA), were all negative.
Upper gastrointestinal endoscopy showed multiple vertical small erosions in the duodenum. Small bowel capsule endoscopy (SBCE) showed multiple small ulcers in the jejunum and multiple longitudinal ulcers in the ileum. Colonoscopy showed multiple longitudinal ulcers and a cobblestone appearance in the terminal ileum and multiple small erosions and aphtha throughout the colon (Fig. 1A). An intestinal juice culture examination and polymerase chain reaction (PCR) for any bacteria, including acid-fast bacilli, showed negative findings. Contrast-enhanced computed tomography (CT) revealed a nodular lesion at the apex of the right lung and thickening of the wall with a contrast effect at the terminal ileum (Fig. 2A). A pathological examination did not demonstrate granuloma at the longitudinal ulcer in the terminal ileum.
He was diagnosed with ileo-colonic CD based on the endoscopic findings. The nodular lesion at the apex of the right lung was suspected of being latent TB. However, his serological IGRA and several culture tests (including sputum, urine and intestinal juice) were all negative. Thus, he did not receive a diagnosis of latent TB. His disease activity was a Crohn’s disease activity index (CDAI) of 167, Lewis score of 1368 and simple endoscopic score for Crohnʼs disease (SES-CD) of 13. Because of his young age and the presence of high-activity inflammatory lesion throughout the small intestine and colon, the intravenous administration of IFX-BS with an immunomodulator was initiated as induction therapy. His CDAI and CRP levels immediately decreased after the induction of IFX-BS.
However, at 17 weeks after the initiation of IFX-BS, he visited our hospital with a high fever. A laboratory examination revealed high levels of inflammation markers: WBC count, 6560/µl; and CRP, 10.33 mg/dL. CT revealed the expansion of the nodular lesion at the apex of the right lung (Fig. 2B). Furthermore, his serological IGRA and acid-fast bacillus culture tests of gastric juice had all turned positive. He was diagnosed with reactivation of latent TB. IFX-BS with an immunomodulator was immediately discontinued, and anti-TB therapy with polypharmacy of rifampicin, isoniazid, ethambutol and pyrazinamide was initiated. At 10 weeks after the initiation of anti-TB therapy, his general condition and inflammation markers had recovered: WBC count, 4850/µl; CRP, < 0.10 mg/dL.
In July 2019, he had maintained clinical remission of CD without medication. However, colonoscopy still showed an active ulcer in the terminal ileum (Fig. 1B). Regarding his disease activity, he had a CDAI of 85 and SES-CD of 4. His endoscopic findings were improved compared with before induction therapy of IFX-BS, but he had not achieved mucosal healing. Thus, another intervention therapy for CD that would not induce a relapse of active TB was considered. VDZ has a favorable safety profile with low incidence rates of serious infections, so VDZ was selected for maintenance therapy.
In June 2020, all of his ulcerative lesions in the small intestine and colon had improved and changed to ulcer scars on SBCE and colonoscopy (Fig. 1C). Regarding his disease activity, he had a CDAI of 80, Lewis score of 0 and SES-CD of 0. CT revealed shrinkage of the nodular lesion at the apex of the right lung (Fig. 2C). Thus, he achieved both clinical remission and mucosal healing by maintenance therapy with VDZ without relapse of active TB.