Allergen immunotherapy (AIT) has been used for over a century and has been demonstrated to be effective in treating patients with various allergic diseases. AIT allergens can be administered through various routes, including subcutaneous, sublingual, intralymphatic, oral, or epicutaneous routes. Sublingual immunotherapy (SLIT) has recently gained clinical interest, and it is considered an alternative treatment for allergic rhinitis (AR) and asthma. This review provides an overview of the current evidence-based studies that address the use of SLIT for treating AR, including (1) mechanisms of action, (2) appropriate patient selection for SLIT, (3) the current available SLIT products in Korea, and (4) updated information on its efficacy and safety. Finally, this guideline aims to provide the clinician with practical considerations for SLIT.

Allergen immunotherapy (AIT) is a causative treatment of allergic diseases in which allergen extracts are regularly administered in a gradually escalated doses, leading to immune tolerance and consequent alleviation of allergic diseases. The need for uniform practice guidelines in AIT is continuously growing as the number of potential candidates for AIT increases and new therapeutic approaches are tried. This updated version of the Korean Academy of Asthma Allergy and Clinical Immunology recommendations for AIT, published in 2010, proposes an expert opinion by specialists in allergy, pediatrics, and otorhinolaryngology. This guideline deals with the basic knowledge of AIT, including mechanisms, clinical efficacy, allergen standardization, important allergens in Korea, and special consideration in pediatrics. The article also covers the methodological aspects of AIT, including patient selection, allergen selection, schedule and doses, follow-up care, efficacy measurements, and management of adverse reactions. Although this guideline suggests the optimal dosing schedule, an individualized approach and modifications are recommended considering the situation for each patient and clinic.

Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019.In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virusinfected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105PFU; however, 1×102 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.

Background/Aims: The etiology of irritable bowel syndrome (IBS) is associated with intestinal mucosal barrier damage. However, changes in the tight junction (TJ) proteins in IBS have not been fully elucidated. This study aimed to evaluate TJ protein changes in IBS patients and the relationship between aging and disease severity. Methods: Thirty-six patients with IBS fulfilling the Rome IV criteria and twenty-four controls were included. To evaluate the change of TJ in the colonic mucosa, quantitative reverse transcription polymerase chain reaction, western blot, and immunohistochemistry (IHC) were performed, respectively. Results: The entire IBS group (n = 36) exhibited decreased levels of claudin-1 and -2 mRNA compared to the control group (n = 24), with statistical significance (p < 0.05). Additionally, in western blot analyses, both claudin-1 and ZO-1 levels were significantly reduced in the IBS group compared to the control group (n = 24) (p < 0.05). IHC analysis further revealed that ZO-1 expression was significantly lower in the IBS group than in the control group (p < 0.001). This trend of reduced ZO-1 expression was also observed in the moderate-to-severe IBS subgroup (p < 0.001). Significantly, ZO-1 expression was notably lower in both the young- (p = 0.036) and old-aged (p = 0.039) IBS groups compared to their respective age-matched control groups. Subtype analysis indicated a more pronounced decrease in ZO-1 expression with advancing age. Conclusions ZO-1 expression was especially decreased in the aged IBS group. These results suggest that ZO-1 might be the prominent TJ protein causing IBS in the aging population.

Purpose: This study aimed to investigate the oncologic outcomes and prognostic factors of salvage treatments in patients with recurrent oropharyngeal squamous cell carcinoma (OPSCC) after radiotherapy (RT)-based treatment. Materials and Methods: A cancer registry was used to retrieve the records of 337 patients treated with definitive RT or concurrent chemoradiotherapy (CRT) from 2008 to 2018 at a single institution. The poor-responder group (PRG) was defined as patients with residual or recurrent disease after primary treatment, and the oncologic outcomes for each salvage treatment method were analyzed. In addition, prognostic indicators of recurrence-free survival (RFS) and overall survival (OS) were identified in patients who underwent salvage treatment. Results: After initial (C)RT, the PRG comprised 71 of the 337 patients (21.1%): 18 patients had residual disease, and 53 had recurrence after primary treatment (mean time to recurrence 19.5 months). Of these, 63 patients received salvage treatment (surgery 57.2%, re-(C)RT 23.8%, and chemotherapy 19.0%), and the salvage success rate was 47.6% at the last follow-up. The overall 2-year OS for salvage treatments was 56.4% (60.8% for the salvage surgery group and 46.2% for the salvage re-(C)RT). Salvage surgery patients with negative resection margins had better oncologic outcomes than those with close/positive resection margins. Using multivariate analyses, locoregional recurrence and residual disease after primary surgery were associated with poor outcome after salvage treatment. In Kaplan-Meier analyses, p16 status was significantly associated with OS in the initial treatment setting but not in the salvage setting. Conclusion In recurrent OPSCC after RT-based treatment, successful salvage was achieved in 56.4% patients who had undergone salvage surgery and radiation treatment. Salvage treatment methods should be selected carefully, given recurrence site as a prognostic factor for RFS.

Hepatocellular carcinoma (HCC) is a major cause of death in many countries, including South Korea. To provide useful and sensible advice for clinical management of patients with HCC, the Korean Liver Cancer Association and National Cancer Center Korea Practice Guideline Revision Committee have recently revised the practice guidelines for HCC management. However, there are some differences between practice guidelines and real-life clinical practice. In this review, we describe some key recommendations of the 2022 version of practice guidelines and the real-life clinical situation in South Korea, together with discussion about efforts needed to reduce the difference between guidelines and real-life clinical practice.

Background/Aims: This study aimed to investigate whether pretransplant frailty can predict postoperative morbidity and mortality after liver transplantation (LT) in patients with cirrhosis. Methods: We retrospectively reviewed 242 patients who underwent LT between 2018 and 2020 at a tertiary hospital in Korea. Results: Among them, 189 patients (78.1%) received LT from a living donor. Physical frailty at baseline was assessed by the Short Physical Performance Battery (SPPB), by which patientswere categorized into two groups: frail (SPPB <10) and non-frail (SPPB ≥10). Among the whole cohort (age, 55.0±9.2 years; male, 165 [68.2%]), 182 patients were classified as non-frail and 60 patients were classified as frail. Posttransplant survival was shorter in the frail group than the non-frail group (9.3 months vs 11.6 months). Postoperative intensive care unit stay was longer in the frail group than in the non-frail group (median, 6 days vs 4 days), and the 30-day complication rate was higher in the frail group than in the non-frail group (78.3% vs 59.3%). Frailty was an independent risk factor for posttransplant mortality (adjusted hazard ratio, 2.38; 95% confidence interval, 1.02 to 5.57). In subgroup analysis, frail patients showed lower posttransplant survival regardless of history of hepatocellular carcinoma and donor type. Conclusions Assessment of pretransplant frailty, as measured by SPPB, provides important prognostic information for clinical outcomes in cirrhotic patients undergoing LT.

Background: and Purpose The congestive heart failure, hypertension, age, diabetes, previous stroke/transient ischemic attack (CHA2DS2-VASc) and hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly, drugs/alcohol (HAS-BLED) scores have been validated in estimating the risks of ischemic stroke and major bleeding, respectively, in patients with atrial fibrillation (AF). This study investigated stroke-specific predictors of major bleeding in patients with stroke and AF who were taking oral anticoagulants (OACs). Methods: Subjects were selected from patients enrolled in the Korean ATrial fibrillaTion EvaluatioN regisTry in Ischemic strOke patieNts (K-ATTENTION) nationwide multicenter registry between 2013 and 2015. Patients were excluded if they were not taking OACs, had no brain imaging data, or had intracranial bleeding directly related to the index stroke. Major bleeding was defined according to International Society of Thrombosis and Haemostasis criteria. Cox regression analyses were performed to assess the associations between clinical variables and major bleeding and Kaplan-Meier estimates were performed to analyze event-free survival. Results: Of a total of 3,213 patients, 1,414 subjects (mean age of 72.6 years, 52.5% males) were enrolled in this study. Major bleeding was reported in 34 patients during the median follow-up period of 1.73 years. Multivariable analysis demonstrated that initial National Institutes of Health Stroke Scale scores (hazard ratio [HR] 1.07, p=0.006), hypertension (HR 3.18, p=0.030), persistent AF type (HR 2.51, p=0.016), and initial hemoglobin level (HR 0.74, p=0.001) were independently associated with major bleeding risk. Except for hypertension, these associations remained significant after adjusting for the HAS-BLED score. Intracranial atherosclerosis presented a trend of association without statistical significance (HR 2.21, p=0.050). Conclusions This study found that major bleeding risk was independently associated with stroke-specific factors in anticoagulated patients with stroke and AF. This has the clinical implication that baseline characteristics of patients with stroke and AF should be considered in secondary prevention, which would bring the net clinical benefit of balancing recurrent stroke prevention with minimal bleeding complications.

Background: Phthalates and bisphenol A (BPA) are endocrine-disrupting chemicals and may cause immunological disorders in children. Therefore, according to the region, we investigated urinary phthalates and BPA levels and the relationship between urinary phthalate, aeroallergen sensitization, and eosinophil count during the coronavirus disease 2019 pandemic. Methods: In total, 203 schoolchildren (134 residential and 69 industrial) aged 7–10 years were enrolled between July 2021 and July 2022. The BPA, metabolites of four high-molecularweight phthalates (Σ4HMWP) and three low-molecular-weight phthalates (Σ3LMWP), were measured in the urine samples. Total eosinophil count and transepidermal water loss (TEWL) were also measured along with the skin prick test. Results: The two groups had no differences in terms of BPA. The industrial group had significantly more plastic container usage, and there was a difference in the Σ3LMWP (P < 0.001) between the two groups but no difference in the Σ4HMWP (P = 0.234). The quartiles of urinary Σ4HMWP and Σ3LMWP (P < were not associated with the total eosinophil count, vitamin D level, or TEWL. After adjusting for cofactors, the quartiles of urinary Σ4HMWP and Σ3LMWP were significantly associated with total eosinophil count (P < 0.001) but not with aeroallergen sensitization or vitamin D. Conclusion Exposure to phthalates was significantly associated with eosinophil count but not with aeroallergen sensitization or vitamin D. Therefore, reducing the use of plastic containers may effectively prevent exposure to phthalates and reduce Th2 cell-mediated inflammation in children.