The Nancy Histopathological Index has limited value in predicting clinical outcomes in newly diagnosed pediatric patients with ulcerative colitis

The Nancy Histological Index (NHI) is used to score histologic disease activity in patients with ulcerative colitis (UC). Our goal was to assess the utility of NHI at diagnosis in predicting clinical outcomes in pediatric patients with UC, in comparison to clinical and endoscopic scores. We retrospectively reviewed data at diagnosis of 106 children with UC (59 [55.7%] females; median age 14.4 [11.2–15.9] years, median Pediatric Ulcerative Colitis Activity Index [PUCAI] 35 [25–55]). During a follow-up of 116 (55–171) weeks, 33 patients (31.1%) required azathioprine therapy, and 32 (30.2%) were escalated to anti-tumor necrosis factor alpha (anti-TNFa). The PUCAI and Mayo endoscopic scores at diagnosis were significantly associated with escalation to anti-TNFa (p = 0.036 and p = 0.02, respectively), but not with initiation of azathioprine or subsequent acute severe colitis (ASC) events. However, the NHI was not associated with subsequent immunomodulators or anti-TNFa therapy (p = 0.42 and p = 0.78, respectively), nor with future ASC events (p = 0.70). In conclusion, the NHI failed to predict clinical outcomes in newly diagnosed pediatric patients with UC.