RM Najarian et al. JPGN 2019; 68: 835-40. This retrospective study found microscopic/’backwash’ ileitis in 16% (17/105) of patients with new-onset ulcerative colitis. This occurred predominantly in patients with pancolitis (82%). The authors note that the term “backwash ileitis” was derived from an unproven hypothesis that the inflammation was related to retrograde contact with inflammatory substances, though some now consider ileal involvement as a secondary involvement “akin to the upper tract inflammation that can be seen in a subset of patients with UC.” The authors recommend that isolated histologic inflammation of the ileum should “not be construed as being diagnostic of either ‘indeterminant colitis’ or CD [Crohn’s disease].”
K van Hoeve et al. JPGN 2019; 68: 847-53. This retrospective study of 35 children found that higher infliximab levels during induction was associated with higher rates of clinical and biologic remission at 52 weeks. Groups at risk for lower troughs included patients with a lower weight and/or lower hemoglobin level.