Higher Ustekinumab Levels in Maintenance Therapy are Associated with Greater Mucosal Healing and Mucosal Response in Crohn's Disease: An Experience of 2 IBD Centers.

BACKGROUND: Ustekinumab (UST), a human monoclonal antibody that binds the p40 subunit of interleukin 12 (IL-12) and IL-23, is licensed for induction and maintenance therapy of moderate to severe inflammatory bowel disease (IBD). To date, there is limited data published on any potential association between ustekinumab serum trough levels and mucosal healing in order to guide treatment strategies and appropriate dosing. AIM: This study aims to identify a relationship between maintenance ustekinumab serum trough levels and mucosal healing and/or response in patients with Crohn's disease in an observational cohort study. METHODS: Ustekinumab serum trough levels and antibody titres were analyzed in patients on maintenance drug using an ELISA drug-tolerant assay. Mucosal response (MR) was defined as ≥50% reduction in fecal calprotectin level (FC) and/or ≥50% reduction in the Simple Endoscopic Score for Crohn's Disease (SES-CD score). Mucosal healing (MH) was defined as FC ≤150 µg/mL and/or global SES-CD score ≤5. Median trough levels were analyzed using the Kruskal-Wallis test, and logistic regression was used to determine sensitivity and specificity of levels predicting mucosal response. RESULTS: Forty-seven patients on maintenance ustekinumab for Crohn's disease were included in this study. The majority were female (66%), with a median age of 40 years (21-78 years). The majority of patients were biologic-experienced (89.4%, n = 42). Patients with histologically confirmed Crohn's disease represented 100% (n = 47) of the cohort. Over one-third of patients (n = 18, 38.3%) were on higher than standard dosing of 90 mg every 8 weeks. Patients with mucosal healing (n = 30) had significantly higher mean serum ustekinumab levels (5.7 µg/mL, SD 6.4) compared with those with no response (1.1 µg/mL, SD 0.52; n = 7, P < .0001). A serum ustekinumab trough level greater than 2.3 µg/mL was associated with MH, with a sensitivity of 100% and specificity of 90.6% (likelihood ratio 10.7). Similarly, for patients with MR (n = 40), we observed a higher mean serum ustekinumab trough level (5.1 µg/mL, SD 6.1) compared with those with no response (1.1 µg/mL, SD 0.52; n = 7, P < .0001). Furthermore, a serum ustekinumab trough level greater than 2.3 µg/mL was associated with a 10-fold increased likelihood of mucosal response vs mucosal nonresponse (sensitivity 100%, specificity 90.5%, likelihood ratio 10.5). CONCLUSION: This study demonstrates that higher ustekinumab serum trough levels are associated with a greater likelihood of achieving mucosal healing and mucosal response in patients with Crohn's disease regardless of prior biologic exposure. Further prospective studies are required to correlate target maintenance trough levels and the optimal time to dose-escalate in order to improve patient outcomes.

Gender equality in academic gastroenterology: a review of gastroenterology literature over four decades.

BACKGROUND: Historically males have dominated the physician ranks, although in recent years, there has been an increase in the proportion of female doctors to redress this imbalance. With such attention being paid to gender equality in society, this study aimed to characterise the changing prevalence of female authorship of peer-reviewed published research with in the field of gastroenterology. AIMS: In order to quantitatively assess the growth of female gastroenterologists, we decided to examine the changing face of gender equality within the field of academic gastroenterology from 1971 to 2010. METHODS: All research published in the January and July issues of Gastroenterology from 1971 to 2010 was reviewed. The gender of the first author and last author (considered the senior author) of each study was recorded. Research was subsequently categorised by type: basic science research, clinical trials, and epidemiologic research. Data was analysed in 5-year time periods. RESULTS: Author gender could be identified from a total of 865 abstracts from 80 journal issues. In total, there were 120 (13.8%) female first authors and 91 (10.5%) female senior authors. Female first authorship has tripled since 1995, from 11% (1991-1995) to 32% (2006-2010). Female senior authorship has also tripled since 2000, from 7% (1996-2000) to 24% (2006-2010). DISCUSSION: Results demonstrated that there has been a significant increase in the prevalence of female authorship of published research in Gastroenterology since 1995. The increasing prevalence of females within the field of academic gastroenterology can therefore be extrapolated to demonstrate the growing numbers of female gastroenterologists in the entire field including clinical and academic gastroenterology.