Polyposis of gastrointestinal tract after COVID-19 mRNA vaccination: a report of two cases.

Cronkhite-Canada syndrome is a rare gastrointestinal polyposis syndrome with distinctive clinical features and endoscopic findings. Diagnosis can be challenging without suspicion, and the disease carries high mortality due to complications such as infection, gastrointestinal bleeding, and malignancies. This paper presents two cases of Cronkhite-Canada syndrome occurring after coronavirus disease 2019 (COVID-19) mRNA vaccination. Both cases exhibited typical clinical findings, including hypogeusia, onychodystrophy, alopecia, and weight loss. Typical polyposis in the gastrointestinal tract was confirmed through endoscopies. As symptomatic treatment did not improve the symptoms, corticosteroids were administered, and symptoms and laboratory test results improved immediately. The patients improved upon corticosteroids tapering. These cases illustrate typical presentations of Cronkhite-Canada syndrome and the course of the disease following corticosteroid treatment. Additionally, they suggest the possibility that Cronkhite-Canada syndrome may be triggered by COVID-19 mRNA vaccination.

Ocular motor and vestibular dysfunction in central nervous system lymphoma.

BACKGROUND AND PURPOSE: Diagnosis of lymphoma involving the central nervous system (CNS) is challenging. This study aimed to explore the abnormal vestibular and ocular motor findings in CNS lymphoma. METHODS: A retrospective search of the medical records identified 30 patients with CNS lymphoma presenting ocular motor and vestibular abnormalities from four neurology clinics of university hospitals in South Korea (22 men, age range 14-81 years, mean 60.6 ± 15.2). The demographic and clinical features and the results of laboratory, radiological and pathological evaluation were analyzed. RESULTS: Patients presented with diplopia (13/30, 43%), vestibular symptoms (15/30, 50%) or both (2/30, 7%). In 15 patients with diplopia, abnormal ocular motor findings included ocular motor nerve palsy (n = 10, 67%), internuclear ophthalmoplegia (n = 2, 13%), external ophthalmoplegia (n = 2, 13%) and exophoria (n = 1, 7%). The vestibular abnormalities were isolated in 14 (82%) of 17 patients with vestibular symptoms and included combined unilateral peripheral and central vestibulopathy in three from lesions involving the vestibular nuclei. CNS lymphoma involved the brainstem (53%), cerebellum (33%), leptomeninges (30%), deep gray nuclei (23%) or cranial nerves (17%). Two patients showed the "double-panda" sign by involving the midbrain. CONCLUSIONS: This study expands the clinical and radiological spectra of CNS lymphoma. Neuro-ophthalmological and neuro-otological evaluation may guide the early diagnosis of CNS lymphoma.

Risk of malignancies and chemopreventive effect of statin, metformin, and aspirin in Korean patients with ulcerative colitis: a nationwide population-based study.

Background/Aims: We investigated the incidences of overall and site-specific malignancies and chemopreventive effects of statin, metformin, and aspirin in patients with ulcerative colitis. Methods: We collected data using the Health Insurance Review and Assessment claims database from January 2007 to April 2020. Results: The overall malignancy risk among the 35,189 ulcerative colitis patients was similar to that of the general population (standardized incidence ratio, 0.94; 95% confidence interval, 0.88-1.00). In male patients, standardized incidence ratios were high for thyroid cancer and low for stomach cancer, colorectal cancer, liver cancer, and lung cancer. Concurrently, standard incidence ratios were high for liver cancer and central nervous system cancer in female patients. While 122 cases of colorectal cancer occurred in the study patients, the standardized incidence ratio was 0.83 (95% confidence interval, 0.69-0.99). Treatment for ulcerative colitis was not associated with an increased adjusted hazard ratio, while comorbidities increased it for all malignancies. Treatment for ulcerative colitis was associated with an increased adjusted hazard ratio, while comorbidities did not increase it for colorectal cancer. After adjusting for age, sex, comorbidities, and ulcerative colitis treatment, statins showed a dose-dependent chemopreventive effect for all malignancies (P=0.002), while metformin and aspirin did not show any. Conclusions: In ulcerative colitis patients, standardized incidence ratios for all malignancies and colorectal cancer did not increase. Adjusted hazard ratios for all malignancies increased with comorbidities and those for colorectal cancer with ulcerative colitis treatment. Statins have a dose-dependent chemopreventive effect for all malignancies.

The Awareness and Experience About Endoscopic Adverse Events Among South Korean Endoscopists.

BACKGROUND/AIMS: The number of endoscopic procedures and related adverse events is increasing. We investigated South Korean endoscopists' awareness and experience of endoscopic adverse events. MATERIALS AND METHODS: We used Google Forms to conduct an online questionnaire survey among South Korean endoscopists from December 11 to 29, 2020. The survey comprised 30 questions developed by members of the Quality Management Committee of the Korean Society of Gastrointestinal Endoscopy. RESULTS: In total, 475 endoscopists participated in the survey. Of these, 454 (95.6%) were board-certified gastroenterologists and 255 (53.7%) had >10 years of endoscopy experience. Most participants had experienced serious adverse events requiring hospitalization (80.4%, 382/475); however, only 100 (21.1%) were aware of programs for the prevention and management of adverse endoscopic events in their affiliated endoscopy centers. Most participants (98.5%, 468/475) agreed with the need for education on medical accidents for healthcare workers. Responses were inconsistent regarding the definition of adverse events formulated by the 2010 American Society for Gastrointestinal Endoscopy Workshop. Most participants were not aware of the minimal standard terminology (76.6%, 364/475) and had not used it when writing endoscopy reports (88.8%, 422/475). Responses were inconsistent regarding which events to record in endoscopy records. CONCLUSION: Further discussion on the nationwide adverse-event reporting system and education program for adverse events related to endoscopy is needed to ensure the safety of patients and endoscopists.

Korean Guidelines for Postpolypectomy Colonoscopic Surveillance: 2022 revised edition.

Colonoscopic polypectomy is effective in decreasing the incidence and mortality of colorectal cancer (CRC). Premalignant polyps discovered during colonoscopy are associated with the risk of metachronous advanced neoplasia. Postpolypectomy surveillance is the most important method for managing advanced metachronous neoplasia. A more efficient and evidence-based guideline for postpolypectomy surveillance is required because of the limited medical resources and concerns regarding colonoscopy complications. In these consensus guidelines, an analytic approach was used to address all reliable evidence to interpret the predictors of CRC or advanced neoplasia during surveillance colonoscopy. The key recommendations state that the high-risk findings for metachronous CRC following polypectomy are as follows: adenoma ≥10 mm in size; 3 to 5 (or more) adenomas; tubulovillous or villous adenoma; adenoma containing high-grade dysplasia; traditional serrated adenoma; sessile serrated lesion containing any grade of dysplasia; serrated polyp of at least 10 mm in size; and 3 to 5 (or more) sessile serrated lesions. More studies are needed to fully comprehend the patients who are most likely to benefit from surveillance colonoscopy and the ideal surveillance interval to prevent metachronous CRC.

Risks of colorectal cancer and biliary cancer according to accompanied primary sclerosing cholangitis in Korean patients with ulcerative colitis: a nationwide population-based study.

BACKGROUND/AIMS: We conducted a nationwide population-based study to investigate incidence rates of colorectal and biliary cancers according to accompanying primary sclerosing cholangitis in Korean ulcerative colitis patients. METHODS: We used the Health Insurance Review and Assessment claim database from January 2007 to April 2020. Standardized incidence ratios of colorectal and biliary cancers in ulcerative colitis patients were calculated. RESULTS: Among 35,189 newly diagnosed ulcerative colitis patients, 1,224 patients were diagnosed with primary sclerosing cholangitis. During the study period, 122 and 52 patients were diagnosed with colorectal and biliary cancers, respectively. Incidences of colorectal cancer were not higher in ulcerative colitis patients than those in the general population (standardized incidence ratios, 0.83; 95% confidence interval, 0.69-0.99), regardless of accompanied primary sclerosing cholangitis (standardized incidence ratio, 0.73; 95% confidence interval, 0.24-1.71). While incidences of biliary cancer were not higher in ulcerative colitis patients than those in the general population (standardized incidence ratio, 1.14; 95% confidence interval, 0.80-1.58), these were much higher with accompanied primary sclerosing cholangitis (standardized incidence ratio, 10.07; 95% confidence interval, 5.75-16.36). Cumulative incidences of colorectal and biliary cancers increased in patients who were diagnosed with ulcerative colitis at an older age. CONCLUSIONS: In Korean ulcerative colitis patients, colorectal cancer incidences were not higher than those in the general population regardless of accompanied primary sclerosing cholangitis. However, biliary cancer incidences were much higher in ulcerative colitis patients with primary sclerosing cholangitis than in those without, or in the general population.

Korean guidelines for postpolypectomy colonoscopic surveillance: 2022 revised edition.

Colonoscopic polypectomy is effective in decreasing the incidence and mortality of colorectal cancer (CRC). Premalignant polyps discovered during colonoscopy are associated with the risk of metachronous advanced neoplasia. Postpolypectomy surveillance is the most important method for the management of advanced metachronous neoplasia. A more efficient and evidence-based guideline for postpolypectomy surveillance is required because of limited medical resources and concerns regarding colonoscopy complications. In these consensus guidelines, an analytic approach was used to address all reliable evidence to interpret the predictors of CRC or advanced neoplasia during surveillance colonoscopy. The key recommendations state that the high-risk findings for metachronous CRC following polypectomy are as follows: (1) adenoma ≥10 mm in size; (2) 3 to 5 (or more) adenomas; (3) tubulovillous or villous adenoma; (4) adenoma containing high-grade dysplasia; (5) traditional serrated adenoma; (6) sessile serrated lesion (SSL) containing any grade of dysplasia; (7) serrated polyp of at least 10 mm in size; and (8) 3 to 5 (or more) SSLs. More studies are needed to fully comprehend the patients most likely to benefit from surveillance colonoscopy and the ideal surveillance interval to prevent metachronous CRC.

[Korean Guidelines for Postpolypectomy Colonoscopic Surveillance: 2022 Revised Edition].

Colonoscopic polypectomy is effective in decreasing the incidence and mortality of colorectal cancer (CRC). Premalignant polyps discovered during colonoscopy are associated with the risk of metachronous advanced neoplasia. Postpolypectomy surveillance is the most important method for managing advanced metachronous neoplasia. A more efficient and evidence-based guideline for postpolypectomy surveillance is required because of the limited medical resources and concerns regarding colonoscopy complications. In these consensus guidelines, an analytic approach was used to address all reliable evidence to interpret the predictors of CRC or advanced neoplasia during surveillance colonoscopy. The key recommendations state that the high-risk findings for metachronous CRC following polypectomy are as follows: 1) adenoma ≥10 mm in size; 2) 3-5 (or more) adenomas; 3) tubulovillous or villous adenoma; 4) adenoma containing high-grade dysplasia; 5) traditional serrated adenoma; 6) sessile serrated lesion (SSL) containing any grade of dysplasia; 7) serrated polyp of at least 10 mm in size; and 8) 3-5 (or more) SSLs. More studies are needed to fully comprehend the patients who are most likely to benefit from surveillance colonoscopy and the ideal surveillance interval to prevent metachronous CRC.

Erratum: Isolated Vestibular Syndrome With "Double-Panda" Sign in CNS Lymphoma.

This corrects the article on p. 111 in vol. 18, PMID: 35021288.

Risk of Metachronous Colorectal Advanced Neoplasia and Cancer in Patients With 3-4 Nonadvanced Adenomas at Index Colonoscopy: A Systematic Review and Meta-Analysis.

INTRODUCTION: This systematic review and meta-analysis evaluated the available evidence on the risk of metachronous advanced neoplasia (AN) and colorectal cancer (CRC) in patients with 3-4 nonadvanced adenomas (NAAs). METHODS: We searched MEDLINE, EMBASE, and Cochrane Library databases up to January 2021 for studies evaluating metachronous AN and CRC risk by comparing 3 groups (1-2 vs 3-4 vs ≥5 NAAs) at index colonoscopy. The estimates for risk of metachronous AN and CRC were evaluated using random-effects models. RESULTS: Fifteen studies (n = 36,375) were included. The risk of metachronous AN was significantly higher in the 3-4 NAAs group than in the 1-2 NAAs group (relative risk [RR] 1.264, 95% confidence interval [CI] 1.053-1.518, P = 0.012; I2 = 0%); there was no difference between the ≥ 5 NAAs and 3-4 NAAs groups (RR 1.962, 95% CI 0.972-3.958, P = 0.060; I2 = 68%). The risks of metachronous CRC between the 1-2 NAAs and 3-4 NAAs groups (RR 2.663, 95% CI 0.391-18.128, P = 0.317; I2 = 0%) or the 3-4 NAAs and ≥ 5 NAAs groups (RR 1.148, 95% CI 0.142-9.290, P = 0.897; I2 = 0%) were not significantly different. DISCUSSION: Although the risk of metachronous AN was greater in the 3-4 NAAs group than in the 1-2 NAAs group, the risk of metachronous AN and CRC between the 3-4 NAAs and ≥ 5 NAAs groups was not different. This suggests that further studies on metachronous AN and CRC risk in the 3-4 NAAs group are warranted to confirm a firm ≥5-year interval surveillance colonoscopy.

Combined Endoscopic and Radiologic Healing Is Associated With a Better Prognosis Than Endoscopic Healing Only in Patients With Crohn's Disease Receiving Anti-TNF Therapy.

INTRODUCTION: Although endoscopic healing (EH) is recommended as the therapeutic goal in patients with Crohn's disease (CD), combined EH and radiologic healing (RH) could be a more ideal therapeutic goal considering the transmural nature of CD. We compared the prognosis of patients with CD who achieved EH, RH, both EH and RH (deep healing; DH), or no healing under treatment with anti-tumor necrosis factor (TNF) agents. METHODS: We analyzed 392 patients with CD who received anti-TNF treatment for more than 1 year and evaluated with CT enterography or magnetic resonance enterography together with colonoscopy within 3 months between July 2017 and December 2018. Major outcomes (anti-TNF dose intensification, switch to other biologics, CD-related bowel resection, and hospitalization) were compared according to the EH and RH status. RESULTS: During the follow-up (median 18 months; interquartile range, 15-21), the DH group showed a better rate of major outcome-free survival compared with other groups (P < 0.001). In multivariable analysis, elevated C-reactive protein (adjusted hazard ratio [aHR], 2.166; 95% confidence interval [CI], 1.508-3.110; P < 0.001), EH-only (aHR, 3.903; 95% CI, 1.635-9.315; P = 0.002), RH-only (aHR, 3.843; 95% CI, 1.545-9.558; P = 0.004), and no healing (aHR, 8.844; 95% CI, 4.268-18.323; P < 0.001) were associated with increased risks of major outcomes. DISCUSSION: Patients with CD who achieved DH under anti-TNF therapy showed a better prognosis compared with those who only achieved EH. The possibility of DH being used as a new therapeutic target for patients with CD should be investigated in further studies.

Clinical Course of Hepatitis B Viral Infection in Patients Undergoing Anti-Tumor Necrosis Factor α Therapy for Inflammatory Bowel Disease.

Background/Aims: Little is known about the clinical course of hepatitis B virus (HBV)-infected patients undergoing anti-tumor necrosis factor α (TNF-α) therapy for inflammatory bowel disease (IBD). We aimed to investigate the clinical course of HBV infection and IBD and to analyze liver dysfunction risks in patients undergoing anti-TNF-α therapy. Methods: This retrospective multinational study involved multiple centers in Korea, China, Taiwan, and Japan. We enrolled IBD patients with chronic or resolved HBV infection, who received anti-TNF-α therapy. The patients' medical records were reviewed, and data were collected using a web-based case report form. Results: Overall, 191 patients (77 ulcerative colitis and 114 Crohn's disease) were included, 28.3% of whom received prophylactic antivirals. During a median follow-up duration of 32.4 months, 7.3% of patients experienced liver dysfunction due to HBV reactivation. Among patients with chronic HBV infection, the proportion experiencing liver dysfunction was significantly higher in the non-prophylaxis group (26% vs 8%, p=0.02). Liver dysfunction occurred in one patient with resolved HBV infection. Antiviral prophylaxis was independently associated with an 84% reduction in liver dysfunction risk in patients with chronic HBV infection (odds ratio, 0.16; 95% confidence interval, 0.04 to 0.66; p=0.01). The clinical course of IBD was not associated with liver dysfunction or the administration of antiviral prophylaxis. Conclusions: Liver dysfunction due to HBV reactivation can occur in HBV-infected IBD patients treated with anti-TNF-α agents. Careful monitoring is needed in these patients, and antivirals should be administered, especially to those with chronic HBV infection.

Natural Killer-cell Enteropathy of the Stomach in an Elderly Woman: A Case Report.

Natural killer (NK) cell enteropathy is not well understood. Although NK-cell enteropathy is typically benign, aggressive NK-cell lymphoma is an important differential diagnosis. This paper reports a rare case of NK-cell enteropathy of the stomach presenting with dyspepsia and weight loss. In this case, upper endoscopy revealed an ulcer-like lesion (approximately 7 mm) surrounded by erythema, edema, and mucosal hemorrhage. The biopsy revealed atypical lymphocyte cells expressing CD56 without an Epstein-Barr virus infection, which is consistent with NK-cell enteropathy. Follow-up endoscopy 2 months later revealed lesion regression with mild erythema. The patient was observed closely for 6 months, with no evidence of lymphoma.

Anchoring the snare tip is a feasible endoscopic mucosal resection method for small rectal neuroendocrine tumors.

Small rectal neuroendocrine tumors (NETs) can be treated using cap-assisted endoscopic mucosal resection (EMR-C), which requires additional effort to apply a dedicated cap and snare. We aimed to evaluate the feasibility of a simpler modified endoscopic mucosal resection (EMR) technique, so-called anchored snare-tip EMR (ASEMR), for the treatment of small rectal NETs, comparing it with EMR-C. We retrospectively evaluated 45 ASEMR and 41 EMR-C procedures attempted on small suspected or established rectal NETs between July 2015 and May 2020. The mean (SD) lesion size was 5.4 (2.2) mm and 5.2 (1.7) mm in the ASEMR and EMR-C groups, respectively (p = 0.558). The en bloc resection rates of suspected or established rectal NETs were 95.6% (43/45) and 100%, respectively (p = 0.271). The rates of histologic complete resection of rectal NETs were 94.1% (32/34) and 88.2% (30/34), respectively (p = 0.673). The mean procedure time was significantly shorter in the ASEMR group than in the EMR-C group (3.12 [1.97] vs. 4.13 [1.59] min, p = 0.024). Delayed bleeding occurred in 6.7% (3/45) and 2.4% (1/41) of patients, respectively (p = 0.618). In conclusion, ASEMR was less time-consuming than EMR-C, and showed similar efficacy and safety profiles. ASEMR is a feasible treatment option for small rectal NETs.

Comparison of long-term recurrence-free survival between primary surgery and endoscopic resection followed by secondary surgery in T1 colorectal cancer.

BACKGROUND AND AIMS: We aimed to investigate whether endoscopic resection of T1 colorectal cancer (CRC) before surgery (secondary surgery) unfavorably affects long-term recurrence-free survival (RFS) compared with surgery without prior endoscopic resection (primary surgery). METHODS: We reviewed the medical records of patients who underwent radical surgery for T1 CRC with high-risk histologic features at a tertiary referral hospital in Korea between 2011 and 2016. The primary outcome was RFS. We performed 2 types of propensity score (PS) analyses to control for confounders. RESULTS: Of 852 patients, 388 underwent primary surgery and 464 secondary surgery. During the median follow-up period of 57.0 months (range, 41.0-63.0), cancer recurred in 18 patients (2.1%). The 5-year RFS rates did not differ between the primary and secondary surgery groups (97.0 vs 98.5%, P = .194). Further analyses of RFS rates according to nodal stages and number of high-risk histologic features showed no difference between groups. Moreover, RFS rates were not different between the groups after PS matching. In multivariable Cox proportional regression analysis, baseline serum carcinoembryonic antigen level was an independent risk factor for cancer recurrence (hazard ratio, 1.464; 95% confidence interval, 1.242-1.725; P < .001) but prior endoscopic resection of T1 CRC was not (P = .201). Both PS analyses consistently showed no increase in cancer recurrence risk in the secondary surgery group. CONCLUSIONS: Our data showed no additional cancer recurrence risk by endoscopic resection before surgery of T1 CRC with high-risk histologic features.

Cap-assisted Endoscopic Mucosal Resection of Rectal Perineurioma Mimicking a Neuroendocrine Tumor.

Colorectal perineuriomas are benign mucosal-based mesenchymal tumors composed of perineurial cells and show serrated or hyperplastic crypts in epithelium on histopathological evaluation. Most perineuriomas are usually presented as sessile polyps and often as subepithelial tumors. In this case, colonoscopy revealed a rectal subepithelial tumor (measuring approximately 7 mm) with yellowish- colored normal mucosa. A rectal neuroendocrine tumor was suspected, and cap-assisted endoscopic mucosal resection was performed. Histopathological examination of the resected specimen revealed bland spindle cells showing immunopositivity for CD34. The patient was finally diagnosed with rectal perineurioma.

Clinical outcomes and long-term prognosis of perianal Crohn's disease in an Asian population.

BACKGROUND AND AIM: The clinical impact of perianal Crohn's disease (CD) (pCD), a well-known poor prognostic factor of CD, has not been fully evaluated in Asian patients. We investigated the outcomes of CD in Korean patients according to the presence of pCD at CD diagnosis. METHODS: Using 2010-2014 data from the national health insurance claims database, we evaluated the disease course of CD according to the presence of pCD at CD diagnosis. The results were verified in a hospital-based cohort of 2923 patients. RESULTS: The cumulative risk of intestinal resection was lower in patients with pCD at diagnosis than in those without, in the population-based cohort (9.1% vs 14.7% at 5 years after diagnosis, P < 0.001), but it was similar between the two groups in the hospital-based cohort (36.8% vs 36.8% at 10 years after diagnosis, P = 0.950). Moreover, the cumulative risk of behavioral progression was not significantly different between the two groups in the hospital-based cohort (43.4% vs 41.6% at 10 years after diagnosis, P = 0.366). On multivariable analysis, pCD at CD diagnosis was not a predictor of intestinal resection, behavioral progression, CD-related hospital admission, or diverting surgery; however, it was an independent predictor of proctectomy (hazard ratio [HR] 3.210, P < 0.001) and anorectal cancer (HR 3.104, P = 0.047). CONCLUSIONS: Although the presence of pCD increased the risk of proctectomy and anorectal cancer in Asian patients, the clinical impact of pCD on the overall outcomes of patients with CD may be less significant in Asian patients compared with Western patients.

Influence of Severe Vitamin D Deficiency on the Clinical Course of Inflammatory Bowel Disease.

BACKGROUND: Previous studies have shown vitamin D status to be associated with disease activity in patients with inflammatory bowel disease (IBD), but its influence on the clinical course of IBD has not been established. AIMS: We aimed to analyze whether the serum 25-hydroxyvitamin D3 [25(OH)D] status is associated with clinical characteristics and affects the risk of surgery in patients with IBD. METHODS: From the IBD registry of the Asan Medical Center, we identified all patients who had at least one 25(OH)D measurement; we then analyzed the association between clinical factors and 25(OH)D status. 25(OH)D was considered borderline deficient, deficient, and severely deficient at levels of < 30, < 20, and < 10 ng/mL, respectively. RESULTS: We included 711 Crohn's disease (CD) and 764 ulcerative colitis (UC) patients who had not undergone surgery before 25(OH)D was measured. Both in CD and in UC patients, reduced 25(OH)D was associated with higher disease activity scores and CRP levels (p < 0.001). Severe 25(OH)D deficiency was associated with ileocolonic disease and complicated behavior in CD (p < 0.05) and was relevant to the disease extent in UC (p < 0.001). Additionally, severe 25(OH)D deficiency was associated with CMV colitis in patients with UC (p < 0.001). In multivariable analysis, severe deficiency of 25(OH)D was an independent risk factor for surgery in both CD (HR 1.93, 95% confidence interval [CI] 1.38-2.70) and UC (HR 2.77, 95% CI 1.14-6.74). CONCLUSION: Severe 25(OH)D deficiency may be a marker of a more aggressive clinical course of IBD.

Early Changes in Serum Albumin Predict Clinical and Endoscopic Outcomes in Patients With Ulcerative Colitis Starting Anti-TNF Treatment.

BACKGROUND: Up to 60% of patients with ulcerative colitis (UC) ultimately fail anti-tumor necrosis factor (TNF) treatment. We aimed to investigate early predictive markers of clinical and endoscopic outcomes in patients with UC who were anti-TNF-naïve commencing anti-TNF treatment, with particular focus on changes in albumin and C-reactive protein levels in the first 2 weeks of treatment. METHODS: We retrospectively investigated 210 patients with UC who started infliximab or adalimumab between 2009 and 2016 (male, 62.4%; median age at diagnosis, 37.9 years [interquartile range, 25.5-48.9 years]; median follow-up duration, 3.3 years [1.9-5.0 years]). Logistic and Cox proportional-hazards regressions were performed to identify variables associated with primary nonresponse (PNR), endoscopic outcomes, time-to-colectomy, and anti-TNF failure. RESULTS: Forty-one patients (19.5%) experienced PNR; week 0/week 2 ratio serum albumin was associated with PNR (adjusted odds ratio [aOR], 1.8; 95% confidence interval [CI], 1.1-2.9, per interquartile range increase). Week 0/week 2 ratio albumin was also associated with endoscopic response (aOR, 0.28; 95% CI, 0.31-0.82) and endoscopic remission (aOR, 0.61; 95% CI, 0.39-0.96) at weeks 8 to 14, time-to-colectomy (adjusted hazard ratio, 2.12; 95% CI, 1.29-3.49) and time-to-anti-TNF failure (adjusted hazard ratio, 1.54; 95% CI, 1.22-1.96), regardless of age, disease severity, or in-patient status. Association with time-to-colectomy and anti-TNF failure was externally validated in an independent cohort of inpatients with UC starting infliximab. CONCLUSIONS: Change in serum albumin within the first 2 weeks of anti-TNF treatment is predictive of PNR, endoscopic outcomes, time-to-colectomy, and anti-TNF failure in patients with UC. Timely access to this biomarker enables early identification of patients with UC at risk of anti-TNF failure and may guide early optimization of anti-TNF treatment to improve disease outcomes.