Spotlight on factors in ulcerative colitis severity
An analysis of patients who had been hospitalized for acute severe ulcerative colitis found certain factors at admission predicted need for colectomy within a year, and a Danish genetic study identified a specific allele tied to severe ulcerative colitis.
Two recent studies looked at factors that might predict severity of disease in ulcerative colitis.
One study, published by Inflammatory Bowel Diseases on Oct. 9, included 94 patients who were hospitalized for acute severe ulcerative colitis at any of five academic hospitals in the U.S. in December 2018 to December 2021. Patients were followed for up to a year. A total of 11 (12%) patients required colectomy during the index admission; 21 (22.3%) required colectomy within the year of follow-up. Several predictors of colectomy were identified after adjustment: a body mass index (BMI) less than 21.5 kg/m2 (odds ratio [OR], 6.16; P=0.02), a simple clinical colitis activity index greater than 8 (OR, 14.44; P=0.01), and an admission albumin level less than 2.4 g/dL (OR, 10.61; P=0.04). The study authors noted that some of their findings confirmed existing evidence but that the impact of BMI at admission on the risk of colectomy was new. “There remains the need to generate new ways of phenotyping patients to predict disease outcomes. Further studies integrating molecular profiling, cytokine panels, immunohistochemical analysis, or metabolomics could be useful to identify individual patient factors associated with refractoriness to medications or the need for colectomy and inform a greater mechanistic understanding of the drivers of [acute severe ulcerative colitis],” they wrote.
The other study, published as a research letter in JAMA on Oct. 15, aimed to identify biomarkers related to severe versus less severe ulcerative colitis, using Danish genome-wide association data. The study used two cohorts of patients—4,153 diagnosed with ulcerative colitis from 1981 to 2022 and 338 diagnosed with inflammatory bowel disease from 1978 to 2020. The combined cohort of 4,491 patients had a mean age at diagnosis of 23.3 years and 53% were women; 27% had severe disease. The results showed that a chromosome 6 locus within the human leukocyte antigen (HLA) region was significantly associated with more severe ulcerative colitis (OR, 2.23; 95% CI, 1.96 to 2.50). Specifically, the HLA-DRB1*01:03 allele explained this association (OR, 3.32; 95% CI, 2.25 to 4.89). No other allele had a P value below the genome-wide significance threshold, but HLA-DRB1*01:03 was significantly associated with need for a major operation (OR, 6.38 [95% CI, 3.89 to 10.46]; P<0.001), at least two hospitalizations (OR, 5.24 [95% CI, 3.49 to 7.86]; P<0.001), and use of at least 5,000 mg of systemic corticosteroids (OR, 2.30 [95% CI, 1.42 to 3.71]; P=0.001). “This study supports earlier, targeted genetic studies comparing patients with healthy controls reporting an association with total disease and severe disease requiring colectomy,” wrote the study authors. “Given the low cost of typing a single HLA allele, HLADRB1*01:03 could be a valuable tool for risk assessment of patients with ulcerative colitis at diagnosis.”