Recommendations for Adult Immunization by the Korean Society of Infectious Diseases, 2023: Minor Revisions to the 3rd Edition.

The Korean Society of Infectious Diseases has been regularly developing guidelines for adult immunization since 2007. In 2023, the guidelines for the following seven vaccines were revised: influenza, herpes zoster, pneumococcal, tetanus-diphtheria-pertussis (Tdap), human papillomavirus (HPV), meningococcal, and rabies vaccines. For the influenza vaccine, a recommendation for enhanced vaccines for the elderly was added. For the herpes zoster vaccine, a recommendation for the recombinant zoster vaccine was added. For the pneumococcal vaccine, the current status of the 15-valent pneumococcal conjugate vaccine and 20-valent PCV was described. For the Tdap vaccine, the possibility of using Tdap instead of tetanus-diphtheria vaccine was described. For the HPV vaccine, the expansion of the eligible age for vaccination was described. For the meningococcal vaccine, a recommendation for the meningococcal B vaccine was added. For the rabies vaccine, the number of pre-exposure prophylaxis doses was changed. This manuscript documents the summary and rationale of the revisions for the seven vaccines. For the vaccines not mentioned in this manuscript, the recommendations in the 3rd edition of the Vaccinations for Adults textbook shall remain in effect.

Kidney, ureter, and urinary bladder segmentation based on non-contrast enhanced computed tomography images using modified U-Net.

This study was performed to segment the urinary system as the basis for diagnosing urinary system diseases on non-contrast computed tomography (CT). This study was conducted with images obtained between January 2016 and December 2020. During the study period, non-contrast abdominopelvic CT scans of patients and diagnosed and treated with urinary stones at the emergency departments of two institutions were collected. Region of interest extraction was first performed, and urinary system segmentation was performed using a modified U-Net. Thereafter, fivefold cross-validation was performed to evaluate the robustness of the model performance. In fivefold cross-validation results of the segmentation of the urinary system, the average dice coefficient was 0.8673, and the dice coefficients for each class (kidney, ureter, and urinary bladder) were 0.9651, 0.7172, and 0.9196, respectively. In the test dataset, the average dice coefficient of best performing model in fivefold cross validation for whole urinary system was 0.8623, and the dice coefficients for each class (kidney, ureter, and urinary bladder) were 0.9613, 0.7225, and 0.9032, respectively. The segmentation of the urinary system using the modified U-Net proposed in this study could be the basis for the detection of kidney, ureter, and urinary bladder lesions, such as stones and tumours, through machine learning.

Limited Generalizability of Retrospective Single-Center Cohort Study in Comparison to Multicenter Cohort Study on Prognosis of Hepatocellular Carcinoma.

Introduction: We aimed to evaluate the generalizability of retrospective single-center cohort studies on prognosis of hepatocellular carcinoma (HCC) by comparing overall survival (OS) after various treatments between a nationwide multicenter cohort and a single-center cohort of HCC patients. Methods: Patients newly diagnosed with HCC between January 2008 and December 2018 were analyzed using data from the Korean Primary Liver Cancer Registry (multicenter cohort, n=16,443), and the Asan Medical Center HCC registry (single-center cohort, n=15,655). The primary outcome, OS after initial treatment, was compared between the two cohorts for both the entire population and for subcohorts with Child-Pugh A liver function (n=2797 and n=5151, respectively) treated according to the Barcelona-Clinic-Liver-Cancer (BCLC) strategy, using Log rank test and Cox proportional hazard models. Results: Patients of BCLC stages 0 and A (59.3% vs 35.2%) and patients who received curative treatment (42.1% vs 32.1%) were more frequently observed in the single-center cohort (Ps<0.001). Multivariable analysis revealed significant differences between the two cohorts in OS according to type of treatment: the multicenter cohort was associated with higher risk of mortality among patients who received curative (adjusted hazard ratio [95% confidence interval], 1.48 [1.39-1.59]) and non-curative (1.22 [1.17-1.27]) treatments, whereas the risk was lower in patients treated with systemic therapy (0.83 [0.74-0.92]) and best supportive care (0.85 [0.79-0.91]). Subcohort analysis also demonstrated significantly different OS between the two cohorts, with a higher risk of mortality in multicenter cohort patients who received chemoembolization (1.72 [1.48-2.00]) and ablation (1.44 [1.08-1.92]). Conclusion: Comparisons of single-center and multicenter cohorts of HCC patients revealed significant differences in OS according to treatment modality after adjustment for prognostic variables. Therefore, the results of retrospective single-center cohort studies of HCC treatments may not be generalizable to real-world practice.

Lack of association between early on-treatment HBeAg seroclearance and development of hepatocellular carcinoma or decompensated cirrhosis.

Background & Aims: The association between hepatitis B envelope antigen (HBeAg) seroclearance during long-term nucleos(t)ide analogue (NA) treatment and the risk of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB) remains unclear. Here, we aimed to investigate the association of HBeAg seroclearance during potent NA treatment with the development of HCC and decompensated cirrhosis. Methods: Using a multicenter historical cohort including 2,392 non-cirrhotic adult patients with HBeAg-positive CHB who initiated NA treatment with tenofovir or entecavir, the risk of HCC and decompensated cirrhosis was compared between patients who achieved HBeAg seroclearance within 36 months of NA treatment (the HBeAg-loss group) and those who did not (the HBeAg-maintained group), using inverse probability of treatment weighting. Results: Over a median of 6.6 years of NA treatment, 1,077 patients achieved HBeAg seroclearance (HBeAg loss rate = 6.0 per 100 person-years), 64 patients developed HCC (HCC incidence rate = 0.39 per 100 person-years), and 46 patients developed decompensated cirrhosis (decompensation incidence rate = 0.28 per 100 person-years). The HBeAg-loss and HBeAg-maintained groups had a similar risk of developing HCC (hazard ratio 0.89; 95% CI 0.47-1.68; p = 0.72) and decompensated cirrhosis (hazard ratio 0.98; 95% CI 0.48-1.81; p = 0.91). Compared with delayed HBeAg seroclearance beyond 10 years of NA treatment, the risk of HCC was comparable in those who achieved earlier HBeAg seroclearance at any time point within 10 years, regardless of baseline age and fibrotic burden. Conclusions: Early HBeAg seroclearance during NA treatment was not associated with a reduced risk of development of HCC or decompensated cirrhosis in non-cirrhotic HBeAg-positive patients with CHB. Impact and implications: The association between hepatitis B envelope antigen (HBeAg) seroclearance during long-term nucleos(t)ide analogue treatment and the risk of hepatocellular carcinoma in patients with chronic hepatitis B remains unclear. Our findings indicate that early on-treatment HBeAg seroclearance within 3 years was not associated with the development of hepatocellular carcinoma or decompensated cirrhosis. Achieving HBeAg seroclearance may not be an appropriate surrogate endpoint for preventing the development of liver-related outcomes in non-cirrhotic patients with HBeAg-positive chronic hepatitis B treated with nucleos(t)ide analogues.

The impact of instrumented lumbar fusion surgery on psychiatric problems in elderly patients with degenerative spinal stenosis: The observational study.

This is a prospective cohort study to investigate the effects of instrumented lumbar fusion surgery on psychiatric problems, including anxiety, insomnia, and depression, in patients with degenerative spinal stenosis, as well as on pain and the activities of daily living. Surgery was performed in the patients with Schizas grade C or D spinal stenosis with; if a patient's quality of life was impaired for at least 3 months or if patient had neurologic deficits. Finally, 69 patients were reviewed. Beck anxiety inventory, insomnia severity index, geriatric depression scale short form-Korean, visual analog scale for back pain, visual analog scale for leg pain, and Oswestry disability index was measured on the day surgery was decided on (T1), the day before surgery (T2), the day before discharge (T3), and 6 months after surgery (T4). The patients had mild degrees of anxiety, insomnia, and depression at T1, and Beck anxiety inventory, insomnia severity index, visual analog scale for back pain, visual analog scale for leg pain, and Oswestry disability index improved significantly by T4. In elderly patients with degenerative spinal stenosis, instrumented lumbar fusion surgery improves not only pain and activities of daily living, but also anxiety and insomnia. However, there was no improvement in depression over the 6-month follow-up period.

Therapeutic effects of a novel synthetic α-secretase.

Excessive accumulation of amyloid-ß (Aß) has been associated with the pathogenesis of Alzheimer's disease (AD). Clinical studies have further proven that elimination of Aß can be a viable therapeutic option. In the current study, we conceptualized a fusion membrane protein, referred to as synthetic α-secretase (SAS), that can cleave amyloid precursor protein (APP) and Aß specifically at the α-site. In mammalian cells, SAS indeed cleaved APP and Aß at the α-site. Overexpression of SAS in the hippocampus was achieved by direct injection of recombinant adeno-associated virus serotype 9 (AAV9) that expresses SAS (AAV9-SAS) into the bilateral ventricles of mouse brains. SAS enhanced the non-amyloidogenic processing of APP, thus reducing the levels of soluble Aß and plaques in the 5xFAD mice. In addition, SAS significantly attenuated the cognitive deficits in 5xFAD mice, as demonstrated by novel object recognition and Morris water maze tests. Unlike other Aß-cleaving proteases, SAS has highly strict substrate specificity. We propose that SAS can be an efficient modality to eliminate excessive Aß from diseased brains.

Development of an anti-tauopathy mucosal vaccine specifically targeting pathologic conformers.

Alzheimer's disease (AD) and related tauopathies are associated with pathological tau protein aggregation, which plays an important role in neurofibrillary degeneration and dementia. Targeted immunotherapy to eliminate pathological tau aggregates is known to improve cognitive deficits in AD animal models. The tau repeat domain (TauRD) plays a pivotal role in tau-microtubule interactions and is critically involved in the aggregation of hyperphosphorylated tau proteins. Because TauRD forms the structural core of tau aggregates, the development of immunotherapies that selectively target TauRD-induced pathological aggregates holds great promise for the modulation of tauopathies. In this study, we generated recombinant TauRD polypeptide that form neurofibrillary tangle-like structures and evaluated TauRD-specific immune responses following intranasal immunization in combination with the mucosal adjuvant FlaB. In BALB/C mice, repeated immunizations at one-week intervals induced robust TauRD-specific antibody responses in a TLR5-dependent manner. Notably, the resulting antiserum recognized only the aggregated form of TauRD, while ignoring monomeric TauRD. The antiserum effectively inhibited TauRD filament formation and promoted the phagocytic degradation of TauRD aggregate fragments by microglia. The antiserum also specifically recognized pathological tau conformers in the human AD brain. Based on these results, we engineered a built-in flagellin-adjuvanted TauRD (FlaB-TauRD) vaccine and tested its efficacy in a P301S transgenic mouse model. Mucosal immunization with FlaB-TauRD improved quality of life, as indicated by the amelioration of memory deficits, and alleviated tauopathy progression. Notably, the survival of the vaccinated mice was dramatically extended. In conclusion, we developed a mucosal vaccine that exclusively targets pathological tau conformers and prevents disease progression.

Tacrolimus-loaded chitosan-based nanoparticles as an efficient topical therapeutic for the effective treatment of atopic dermatitis symptoms.

Atopic dermatitis (AD) is a chronic cutaneous disease with a complex underlying mechanism, and it cannot be completely cured. Thus, most treatment strategies for AD aim at relieving the symptoms. Although corticosteroids are topically applied to alleviate AD, adverse side effects frequently lead to the withdrawal of AD therapy. Tacrolimus (TAC), a calcineurin inhibitor, has been used to treat AD, but its high molecular weight and insolubility in water hinder its skin permeability. Herein, we developed and optimized TAC-loaded chitosan-based nanoparticles (TAC@CNPs) to improve the skin permeability of TAC by breaking the tight junctions in the skin. The prepared nanoparticles were highly loadable and efficient and exhibited appropriate characteristics for percutaneous drug delivery. TAC@CNP was stable for 4 weeks under physiological conditions. CNP released TAC in a controlled manner, with enhanced skin penetration observed. In vitro experiments showed that CNP was non-toxic to keratinocyte (HaCaT) cells, and TAC@CNP dispersed in an aqueous solution was as anti-proliferative as TAC solubilized in a good organic solvent. Importantly, an in vivo AD mouse model revealed that topical TAC@CNP containing ~1/10 of the dose of TAC found in commercially used Protopic® Ointment exhibited similar anti-inflammatory activity to that of the commercial product. TAC@CNP represents a potential therapeutic strategy for the management of AD.

Chiral Kirigami for Bend-Tolerant Reconfigurable Hologram with Continuously Variable Chirality Measures.

Despite the commonality of static holograms, the holography with multiple information layers and reconfigurable grey-scale images at communication frequencies remain a confluence of scientific challenges. One well-known difficulty is the simultaneous modulation of phase and amplitude of electromagnetic wavefronts with a high modulation depth. A less appreciated challenge is scrambling of the information and images with hologram bending. Here, this work shows that chirality-guided pixelation of plasmonic kirigami sheets enables tunable multiplexed holography at terahertz (THz) frequencies. The convex and concave structures with slanted Au strips exhibit gradual variations in geometries facilitating modulation of light ellipticity reaching 40 deg. Real-time switching of 3D images of the letter "M" and the Mona Lisa demonstrates the possibility of complex grey-scale information content and importance of continuously variable mirror asymmetry. Microscale chirality measures of each pixel experiences little change with bending while retaining controllable reconfigurability upon stretching, which translates to remarkable resilience of chiral holograms to bending. Simplicity of their design with local chirality measures opens the door to information technologies with fault-tolerant THz encryption, wearable holographic devices, and new communication technologies.

A hydrogen radical pathway for efficacious electrochemical nitrate reduction to ammonia over an Fe-polyoxometalate/Cu electrocatalyst.

Electrochemical nitrate (NO3-) reduction to ammonia (NH3), which is a high value-added chemical or high-energy density carrier in many applications, could become a key process overcoming the disadvantages of the Haber-Bosch process; however, current electrocatalysts have severe drawbacks in terms of activity, selectivity, and stability. Here, we report the hydrogen radical (H*) pathway as a solution to overcome this challenge, as demonstrated by efficacious electrochemical NO3- reduction to NH3 over the Fe-polyoxometalate (Fe-POM)/Cu hybrid electrocatalyst. Fe-POM, composed of Preyssler anions ([NaP5W30O110]14-) and Fe cations, facilitates efficient H* generation via H2O + e- → H* + OH-, and H* transfer to the Cu sites of the Fe-POM/Cu catalyst enables selective NO3- reduction to NH3. Operando spectroelectrochemical spectra substantiate the occurrence of the H* pathway through direct observation of Fe redox related to H* generation and Cu redox related to NO3- binding. With the H* pathway, the Fe-POM/Cu electrodes exhibit high activity for NO3- reduction to NH3 with 1.44 mg cm-2 h-1 in a 500 ppm NO3-/1 M KOH solution at -0.2 V vs. RHE, which is about 36-fold higher than that of the pristine Cu electrocatalyst. Additionally, it attains high selectivity with a faradaic efficiency of up to 97.09% at -0.2 V vs. RHE while exhibiting high catalytic stability over cycles.

Effect of direct-acting antivirals on disease burden of hepatitis C virus infection in South Korea in 2007-2021: a nationwide, multicentre, retrospective cohort study.

Background: It is unclear whether direct-acting antivirals (DAAs) treatment improves the disease burden in hepatitis C virus (HCV) infection. This study aimed to investigate the effect of DAA treatment on the reduction of disease burden in patients with HCV infection using individual participant data. Methods: This nationwide multicentre retrospective cohort study recruited patients with HCV infection from 29 tertiary institutions in South Korea. The data collection was done from medical records in each institution. The study included the untreated patients and the DAAs-treated patients and excluded those with a history of interferon-based treatments. Disease burden was the primary outcome, as represented by disability-adjusted life years (DALYs). Improvement in fibrosis after DAA treatment was assessed using APRI, FIB-4 index, and liver stiffness (LS) as assessed by transient elastography. Clinical outcomes were hepatocellular carcinoma (HCC), decompensation, and mortality. Findings: Between January 1, 2007, and February 17, 2022, data from 11,725 patients with HCV infection, 8464 (72%) of whom were treated with DAAs, were analysed. DAA treatment significantly improved APRI- (median 0.64 [interquartile range (IQR), 0.35-1.31]-0.33 [0.23-0.52], p < 0.0001), FIB-4- (median 2.42 [IQR, 1.48-4.40]-1.93 [1.31-2.97], p < 0.0001), and liver LS-based fibrosis (median 7.4 [IQR, 5.3-12.3]-6.2 [4.6-10.2] kPa, p < 0.0001). During the median follow-up period of 27.5 months (IQR, 10.6-52.4), 469 patients died (4.0%), 586 (5.0%) developed HCC, and 580 (4.9%) developed decompensation. The APRI-based DALY estimate was significantly lower in the DAA group than in the untreated group (median 4.55 vs. 5.14 years, p < 0.0001), as was the FIB-4-based DALY estimate (median 5.43 [IQR, 3.00-6.44] vs. 5.79 [3.85-8.07] years, p < 0.0001). The differences between the untreated and DAA groups were greatest in patients aged 40-60 years. In multivariable analyses, the DAA group had a significantly reduced risk of HCC, decompensation, and mortality compared with the untreated group (hazard ratios: 0.41 [95% confidence interval (CI), 0.34-0.48], 0.31 [95% CI, 0.30-0.38], and 0.22 [95% CI, 0.17-0.27], respectively; p < 0.0001). Interpretation: Our findings suggest that DAA treatment is associated with the improvement of liver-related outcomes and a reduction of liver fibrosis-based disease burden in patients with HCV infection. However, further studies using liver biopsy are needed to clarify the effect of DAA treatment on the reduction in the exact fibrosis-based disease burden beyond noninvasive tests. Funding: The Korea Disease Control and Prevention Agency.

Reduction of GaAs Buffer Thickness and Its Impact on Epitaxially Integrated III-V Quantum Dot Lasers on a Si Substrate.

Monolithic integration of III-V quantum dot (QD) lasers onto a Si substrate is a scalable and reliable approach for obtaining highly efficient light sources for Si photonics. Recently, a combination of optimized GaAs buffers and QD gain materials resulted in monolithically integrated butt-coupled lasers on Si. However, the use of thick GaAs buffers up to 3 µm not only hinders accurate vertical alignment to the Si optical waveguide but also imposes considerable growth costs and time constraints. Here, for the first time, we demonstrate InAs QD lasers epitaxially grown on a 700 nm thick GaAs/Si template, which is approximately four times thinner than the conventional III-V buffers on Si. The optimized 700 nm GaAs buffer yields a remarkably smooth surface and low threading dislocation density of 4 × 108 cm-2, which is sufficient for QD laser growth. The InAs QD lasers fabricated on these ultrathin templates still lase at room temperature with a threshold current density of 661 A/cm2 and a characteristic temperature of 50 K. We believe that these results are important for the monolithically integrated III-V QD lasers for Si photonics applications.

Dysplasia Detected in Patients With Serrated Epithelial Change Is Frequently Associated With an Invisible or Flat Endoscopic Appearance, Nonconventional Dysplastic Features, and Advanced Neoplasia.

The significance of serrated epithelial change (SEC), defined as endoscopically invisible hyperplastic polyp (HP)-like mucosal change identified in patients with inflammatory bowel disease (IBD), remains unclear. Although some studies reported an increased risk of synchronous and/or metachronous colorectal neoplasia in patients with SEC, including advanced neoplasia (high-grade dysplasia or colorectal cancer), the development of SEC is not significantly associated with increased colonic inflammation. This contrasts with the reported positive correlation between increased colonic inflammation and the risk of colorectal neoplasia in ulcerative colitis, arguing against the notion that SEC may represent a form of dysplasia. As such, this study aimed to characterize the features of synchronous and metachronous dysplasia detected in patients with SEC to identify factors contributing to the increased risk of colorectal neoplasia, including advanced neoplasia, observed in a subset of these patients. Clinicopathologic features of 46 IBD patients with SEC (n=109) and synchronous and/or metachronous dysplasia (n=153) were analyzed. All dysplastic lesions were subtyped as either conventional or nonconventional dysplasia. As controls, 45 IBD patients with endoscopically visible or polypoid HP (n=75) and synchronous and/or metachronous dysplasia (n=87) were analyzed. The SEC group included 28 (61%) men and 18 (39%) women with a mean age of 58 years and a long history of IBD (mean duration: 23 years). The majority of patients (n=34; 74%) had ulcerative colitis, and 12 (26%) had Crohn's disease. Thirty-nine (85%) patients had a history of pancolitis, and 2 (4%) had concomitant primary sclerosing cholangitis. Twenty-seven (59%) patients had multifocal SEC. SEC was predominantly found in the left colon (n=52; 48%) and rectum (n=34; 31%). Dysplasia in the SEC group was often endoscopically invisible or flat (n=42; 27%) and demonstrated nonconventional dysplastic features (n=49; 32%). Six nonconventional subtypes were identified in the SEC group, including 17 (11%) dysplasia with increased Paneth cell differentiation, 12 (8%) hypermucinous dysplasia, 8 (5%) crypt cell dysplasia, 7 (5%) goblet cell deficient dysplasia, 3 (2%) sessile serrated lesion-like dysplasia, and 2 (1%) traditional serrated adenoma-like dysplasia. Advanced neoplasia was detected in 11 (24%) patients. The SEC group was more likely to have nonconventional dysplasia (32%, P<0.001), invisible/flat dysplasia (27%, P<0.001), and advanced neoplasia (24%, P<0.001) than the control group (7%, 2%, and 0%, respectively). High-risk nonconventional subtypes (ie, hypermucinous, crypt cell, and goblet cell deficient dysplasias) accounted for 18% of all dysplastic lesions in the SEC group, which were not seen in the control group (P<0.001). The SEC group (n=35; 76%) also had a higher rate of concordance between the location of SEC and the area of synchronous/metachronous dysplasia than the control group (n=22; 49%) (P=0.007). In conclusion, dysplasia detected in patients with SEC is often endoscopically invisible/flat (27%), nonconventional (32%, including the high-risk subtypes), and found in the same colonic segment as SEC (76%), which may in part explain why some patients with SEC are associated with an increased risk of colorectal neoplasia, including advanced neoplasia. The finding of SEC may warrant a careful follow-up colonoscopy with increased random biopsy sampling, especially in the segment of colon with SEC.

Revisiting the steatosis-associated fibrosis estimator score in young Asian subjects with steatotic liver disease and consideration for population variability.

BACKGROUND AND AIM: The steatosis-associated fibrosis estimator (SAFE) score has been developed to distinguish clinically significant fibrosis in patients with steatotic liver disease (SLD). However, validation of its performance in Asian subjects is limited. This study aimed to evaluate the performance of the SAFE score in Asian subjects with biopsy-proven SLD and in different subgroups according to age, sex, and body mass index. METHODS: We retrospectively analyzed 6383 living liver donors who underwent a liver biopsy between 2005 and 2023. Of these, 1551 subjects with biopsy-proven SLD were included. The performance of the SAFE score was evaluated using areas under the curve and compared with those of the nonalcoholic fatty liver disease fibrosis score (NFS) and fibrosis-4 index (FIB-4). RESULTS: The prevalence of clinically significant fibrosis in the cohort was 2.2%. The proportion of subjects with a "low-risk" SAFE score was the highest (91.0%), followed by those with "intermediate-risk" (7.8%) and "high-risk" (1.2%) scores. The prevalence of fibrosis in subjects with low-risk, intermediate-risk, and high-risk scores was 1.6%, 6.6%, and 21.1%, respectively. The SAFE outperformed FIB-4 and NFS (area under the curve: 0.70 vs 0.64 for both NFS and FIB-4). However, it showed low diagnostic accuracy and sensitivity (27%) at the low cutoff (SAFE < 0) in subjects aged 30-39 years (fibrosis: 1.2%), despite having a high negative predictive value (0.99). CONCLUSION: While the SAFE score demonstrates superior performance compared with other noninvasive tests in Asian subjects with SLD, its performance varies across age groups. In younger subjects, particularly, its performance may be more limited.

Clinicopathologic Features of Gastrointestinal Tract Langerhans Cell Histiocytosis.

Gastrointestinal (GI) tract involvement by Langerhans cell histiocytosis (LCH) is rare and its clinicopathologic characteristics have only been described in case reports and small series. We reviewed hematoxylin and eosin- and CD1a, S100, and Langerin immunohistochemical-stained slides from 47 patients with well-documented demographic and clinical findings. Our cases included 8 children and 39 adults, with a mean follow-up of 63 months. All pediatric patients had concurrent multisystem LCH, presented with GI symptoms, and showed non-polypoid lesions. Seven (88%) showed multifocal GI disease, including five with multiple GI organ involvement. All sampled lesions from children exhibited infiltrative growth. More than half had died of the disease or manifested persistent LCH at last follow-up. Twenty-five of 39 (64%) adults had LCH involving only the GI tract (single-system), with the remaining 14 (36%) exhibiting multi-system disease. Adult single-system GI LCH was typically encountered incidentally on screening/surveillance endoscopy (72%). Most exhibited isolated colorectal involvement (88%) as a solitary polyp (92%), with a well-demarcated/noninfiltrative growth pattern (70%), and excellent prognosis (100%). In comparison, adult patients with multi-system LCH more frequently presented with GI symptoms (92%, P<0.001), non-colorectal GI site involvement (50%, P=0.02), multifocal GI lesions (43%, P=0.005), non-polypoid lesions (71%, P<0.001), infiltrative histologic growth pattern (78%, P=0.04), and persistent disease (57%, P<0.001). Adult multi-system LCH patients appear to exhibit similar clinicopathologic features to those of pediatric patients. These results demonstrate that adults with single-system LCH involving the GI tract have an excellent prognosis, while multi-system LCH occurring at any age carries an unfavorable prognosis. High-risk features of GI LCH include pediatric age, GI symptomatology, non-colorectal GI involvement, multifocal GI disease, non-polypoid lesions, and infiltrative growth pattern.

High risk features in colorectal adenomatous polyps: A multi-institutional study.

High risk features in colorectal adenomatous polyps include size >1 cm and advanced histology: high-grade dysplasia and villous architecture. We investigated whether the diagnostic rates of advanced histology in colorectal adenomatous polyps were similar among institutions across the United States, and if not, could differences be explained by patient age, polyp size, and/or CRC rate. Nine academic institutions contributed data from three pathologists who had signed out at least 100 colorectal adenomatous polyps each from 2018 to 2019 taken from patients undergoing screening colonoscopy. For each case, we recorded patient age and sex, polyp size and location, concurrent CRC, and presence or absence of HGD and villous features. A total of 2700 polyps from 1886 patients (mean age: 61 years) were collected. One hundred twenty-four (5 %) of the 2700 polyps had advanced histology, including 35 (1 %) with HGD and 101 (4 %) with villous features. The diagnostic rate of advanced histology varied by institution from 1.7 % to 9.3 % (median: 4.3 %, standard deviation [SD]: 2.5 %). The rate of HGD ranged from 0 % to 3.3 % (median: 1 %, SD: 1.2 %), while the rate of villous architecture varied from 1 % to 8 % (median: 3.7 %, SD: 2.5 %). In a multivariate analysis, the factor most strongly associated with advanced histology was polyp size >1 cm with an odds ratio (OR) of 31.82 (95 % confidence interval [CI]: 20.52-50.25, p < 0.05). Inter-institutional differences in the rate of polyps >1 cm likely explain some of the diagnostic variance, but pathologic subjectivity may be another contributing factor.

Effectiveness of COVID-19 XBB.1.5 monovalent mRNA vaccine in Korea: interim analysis.

As coronavirus disease-2019 (COVID-19) becomes an endemic disease, the virus continues to evolve and become immunologically distinct from previous strains. Immune imprinting has raised concerns about bivalent mRNA vaccines containing both ancestral virus and Omicron variant. To increase efficacy against the predominant strains as of the second half of 2023, the updated vaccine formulation contained only the mRNA of XBB.1.5 sublineage. We conducted a multicenter, test-negative, case-control study to estimate XBB.1.5 monovalent vaccine effectiveness (VE) and present the results of an interim analysis with data collected in November 2023. Patients who underwent COVID-19 testing at eight university hospitals were included and matched based on age (19-49, 50-64, and ≥65 years) and sex in a 1:1 ratio. VE was calculated using the adjusted odds ratio derived from multivariable logistic regression. Of the 992 patients included, 49 (5.3%) received the XBB.1.5 monovalent vaccine at least 7 days before COVID-19 testing. Patients with COVID-19 (cases) were less likely to have received the XBB.1.5 monovalent vaccine (case 3.5% vs. control 7.2%, p=0.019) and to have a history of COVID-19 within 6 months (2.2% vs. 4.6%, p=0.068). In contrast, patients with COVID-19 were more likely to be healthcare workers (8.2% vs. 3.0%, p=0.001) and to have chronic neurological diseases (16.7% vs. 11.9%, p=0.048). The adjusted VE of the XBB.1.5 monovalent mRNA vaccine was 56.8% (95% confidence interval: 18.7-77.9%). XBB.1.5 monovalent mRNA vaccine provided significant protection against COVID-19 in the first one to two months after vaccination.

Updated Reference Intervals for Alanine Aminotransferase in a Metabolically and Histologically Normal Population.

BACKGROUND & AIMS: This study aims to reevaluate upper reference limit (URL) for alanine aminotransferase (ALT) by considering the changing epidemiology of major liver diseases. We employed histological and metabolic parameters in Asian living liver donors. METHODS: We performed a retrospective analysis of 5455 potential living liver donors from 2005 to 2019. Participants were screened for hepatitis B, C, HIV, and alcohol use. Histologically and metabolically healthy participants were assessed using the Prati criteria (body mass index <23 kg/m2, triglyceride ≤200 mg/dL, fasting glucose ≤105 mg/dL, total cholesterol ≤220 mg/dL). The updated ALT-URL was determined as the 95th percentile among participants without hepatic steatosis and who met the Prati criteria. RESULTS: The median age was 30 years, with a male predominance (66.2%). Among 5455 participants, 3162 (58.0%) showed no hepatic steatosis, with 1553 (49.1%) meeting both the criteria for no steatosis and the Prati criteria for metabolic health. The updated URL for ALT in these participants was 34 U/L for males and 22 U/L for females, which was significantly lower than conventionally accepted values. Using this revised ALT-URL, 72.8% of males with ALT levels ≥34 U/L and 55.0% of females with ALT levels ≥22 U/L showed signs of steatosis, whereas 32.7% of males and 22.2% of females met the criteria for metabolic syndrome. CONCLUSIONS: Our study provided the newly established reference intervals for ALT levels in a metabolically and histologically verified Asian population. The proposed URL for ALT are 34 U/L and 22 U/L for males and females, respectively.

Follow-up biopsies in gastrointestinal immune checkpoint inhibitor toxicity may show markedly different inflammatory patterns than initial injury.

Colitis is a common manifestation of immune checkpoint inhibitor (ICI) toxicity and can present with varied histologic patterns of inflammation, some of which have been shown to be associated with specific ICI drug types. Although the histologic features of ICI colitis seen at the time of diagnosis have been described, there have been few reports following these patients over time. We evaluated initial and follow-up biopsies in 30 patients with ICI colitis and found that 37% of patients developed a different pattern of injury on follow-up biopsy compared to the initial biopsy. Patients with a different inflammatory pattern were more likely to have restarted ICI therapy before their follow-up biopsy (64%) compared to those without a change in inflammatory pattern (11%; P < 0.01). The majority of these patients had changed ICI drug types (86%). Additionally, many cases changed to an inflammatory bowel disease (IBD)-like pattern (36%), raising a question of de novo IBD. However, all of our patients with an IBD-like pattern experienced sustained resolution of symptoms without steroids or other immunosuppressive medications following discontinuation of ICI therapy, consistent with a diagnosis of ICI toxicity. Our findings suggest that follow-up biopsies in patients with ICI colitis may show a different histology and that this does not necessarily warrant a change in the histologic diagnosis to another disease.