Clinical predictors of significant findings on EUS for the evaluation of incidental common bile duct dilation.

BACKGROUND AND AIMS: Although EUS is highly accurate for the evaluation of common bile duct (CBD) dilation, the yield of EUS in patients with incidental CBD dilation is unclear. METHODS: Serial patients undergoing EUS for incidental, dilated CBD (per radiologist, minimum of >6 mm objectively) from 2 academic medical centers without active pancreaticobiliary disease or significantly elevated liver function test results were evaluated. Multivariable logistic regression identified predictors of EUS with significant findings and a novel prediction model was derived from one center, internally validated with bootstrapping, and externally validated at the second center. RESULTS: Of 375 patients evaluated, 31 (8.3%) had significant findings, including 26 choledocholithiasis, 1 ampullary adenoma, and 1 pancreatic mass. Predictors of significant findings with EUS included age of ≥70 years (odds ratio [OR], 3.7; 95% confidence interval [CI], 1.5-10.0), non-biliary-type abdominal pain without chronic pain (OR, 6.1; 95% CI, 2.3-17.3), CBD diameter of ≥15 mm or ≥17 mm with cholecystectomy (OR, 6.9; 95% CI, 2.7-18.7), and prior ERCP (OR, 6.8; 95% CI, 2.1-22.5). A point-based novel clinical prediction model was created: age of ≥70 years = 1, non-biliary-type abdominal pain without chronic pain = 2, prior ERCP = 2, and CBD dilation = 2. A score of <1 had 93% (development) and 100% (validation) sensitivity and predicted a <2% chance of having a significant finding in both cohorts while excluding the need for EUS in ∼30% of both cohorts. Conversely, a score of ≥4 was >90% specific for the presence of significant pathology. CONCLUSIONS: Less than 10% of patients undergoing EUS for incidental CBD dilation had pathologic findings. This novel, externally validated, clinical prediction model may reduce low-yield, invasive evaluation in nearly one-third of patients.

Evolving data on risk and current screening recommendations for colorectal cancer in cystic fibrosis: Pre- and posttransplant.

Advances in treatment for cystic fibrosis (CF), including cystic fibrosis transmembrane conductor regulator (CFTR) modulators, have ushered in an era where patients with CF have much longer life expectancies. This shift in life expectancy demands increased attention to diseases of aging in patients with CF. A notable complication of CF is early-onset colorectal cancer (CRC), which is especially prevalent in patients with severe mutations and after transplant. CFTR acts as a tumor suppressor gene based on knockout models. Lack of CFTR expression promotes carcinogenic processes such as intestinal inflammation and deleterious gut microbiome changes. The consensus Cystic Fibrosis Foundation recommendations advocate treating this population as a high-risk group, using a colonoscopy-only screening strategy starting at age 40 in patients without transplant and at age 30 after transplant. Screening should be considered every 5 years if negative and every 3 years or sooner for patients with adenomatous polyps. Future research will determine the role of noninvasive CRC screening tools in this population, as well as the effects of CFTR modulators on the risk of developing CRC.

Identification of human short introns.

Canonical pre-mRNA splicing requires snRNPs and associated splicing factors to excise conserved intronic sequences, with a minimum intron length required for efficient splicing. Non-canonical splicing-intron excision without the spliceosome-has been documented; most notably, some tRNAs and the XBP1 mRNA contain short introns that are not removed by the spliceosome. There have been some efforts to identify additional short introns, but little is known about how many short introns are processed from mRNAs. Here, we report an approach to identify RNA short introns from RNA-Seq data, discriminating against small genomic deletions. We identify hundreds of short introns conserved among multiple human cell lines. These short introns are often alternatively spliced and are found in a variety of RNAs-both mRNAs and lncRNAs. Short intron splicing efficiency is increased by secondary structure, and we detect both canonical and non-canonical short introns. In many cases, splicing of these short introns from mRNAs is predicted to alter the reading frame and change protein output. Our findings imply that standard gene prediction models which often assume a lower limit for intron size fail to predict short introns effectively. We conclude that short introns are abundant in the human transcriptome, and short intron splicing represents an added layer to mRNA regulation.