Flow cytometric lymphocyte subset analysis (FCLSA) is essential for assessing immune status across various diseases and clinical settings. We surveyed current clinical laboratory practices related to FCLSA to establish a baseline reference for future standardization in Korea. Nine university hospitals actively performing FCLSA responded to the 22-question survey, which covered seven categories of laboratory practice. These hospitals used commercial reagent antibody kits from either Beckton Dickinson Biosciences (N = 4) or Beckman Coulter Diagnostics (N = 5). Most hospitals performed daily instrument setup and scheduled maintenance every 2–6 months. Two levels of commercial quality control materials were routinely used each day. Sample and reagent antibody volumes varied across hospitals, even when the same reagent kit was used. Acquired cell counts ranged from 5 × 10 3 to 5 × 10 4 cells, with two hospitals adjusting counts based on the cell type analyzed. Most laboratories reported percentages and general opinions; some additionally reported white blood cell and lymphocyte counts, along with lymphocyte percentages. This is the first comprehensive survey on the clinical laboratory practice of FCLSA in Korea.Standardization of FCLSA should be accelerated to ensure reliable and reproducible results.

Older adults living alone face challenges in managing diabetes, yet research on glycemic control in this group is limited. This study analyzed data from the Korean National Health and Nutrition Examination Survey (2016~2021) to identify factors associated with glycemic control in 453 older adults with diabetes living alone. Methods: Glycemic control was categorized as good (glycated hemoglobin [HbA1c]<7.0%) or poor (HbA1c≥7.0%). Complex sample logistic regression examined demographic, disease and health-related, behavioral, and psychological factors associated with glycemic control. Results: Older adults aged ≥80 years had better glycemic control than those aged 65~69 years, while a diabetes duration of ≥15 years and higher body mass index were linked to poorer control. Strength training 5~7 days per week was associated with better control, whereas non-adherence to a healthy diet was unexpectedly linked to better outcomes. Conclusion: These findings highlight the need for tailored interventions to improve diabetes self-management and support healthy aging among older adults living alone. They also offer practical insights into shaping community-based health programs and social support systems for this population.

Probiotics have gained increasing clinical attention as adjunctive treatment for lower gastrointestinal disorders. However, evidence supporting their therapeutic efficacy remains limited, particularly with regard to sex-related differences. This expert review provides evidence-based insights and practical recommendations for the use of probiotics in patients with irritable bowel syndrome (IBS), functional constipation (FC), and Clostridioides difficile infection (CDI), considering possible sex-related differences. Evidence from randomized controlled trials and meta-analyses indicates that probiotics can modestly improve global symptoms, abdominal pain, and bloating in IBS and enhance bowel movement frequency and stool consistency in FC. However, these effects are strain-specific and heterogeneous. Although clinical studies on probiotics in IBS have not confirmed significant sex-related differences, experimental animal studies using stress-induced IBS models have demonstrated sex-dependent responses to specific probiotic strains, supporting the biological plausibility of such differences. For CDI, the efficacy of probiotics in preventing primary or recurrent infections remains inconsistent across large trials, and current guidelines usually do not recommend their routine use. However, sex and age difference of immunology supports the clinical differences of CDI. Probiotics are generally considered safe for healthy individuals, although caution is advised in patients who are immunocompromised or critically ill. Clinicians should select probiotic products based on strain-specific clinical evidence, adequate viable doses, patient's characteristics, or patient’s sex. In conclusion, probiotics might play a role as adjunctive therapy for IBS and FC, with variability in responses influenced by microbial, host, and potential sex-related factors. Further research is needed to establish optimized personalized probiotic strategies.

Background: Handgrip strength (HGS) is an indicator of late-life health, associated with disability, cardiovascular and all-cause mortality. While exercise helps maintain HGS, diabetes may reduce its benefits. This study investigated the association between exercise and low HGS (LHGS) stratified by diabetes status and sex. Methods: Data from 16,443 participants in the 2017–2019 Korea National Health and Nutrition Examination Survey were analyzed. HGS was measured using a digital dynamometer. Exercise type and frequency were assessed by questionnaire. Three-way and twoway interaction terms were analyzed for exercise, sex and diabetes. Results: Aerobic exercise, resistance exercise, and diabetes were significantly associated with LHGS (P<0.05). A significant interaction between diabetes and aerobic exercise was observed in females (odds ratio [OR] of LHGS=1.704, 95% confidence interval= 1.073–2.707). Among males, both exercise types were associated with lower odds of LHGS regardless of diabetes status, except for aerobic exercise in non-diabetic males. Among males, the ORs of LHGS for aerobic and resistance exercise were 0.479 (0.278– 0.827) and 0.317 (0.165–0.611) with diabetes, 0.757 (0.554–1.035) and 0.536 (0.360–0.798) without diabetes. Among females, the ORs of LHGS for aerobic exercise and resistance exercise were 1.109 (0.716–1.719) and 0.529 (0.224–1.249) with diabetes, 0.676 (0.539–0.848) and 0.795 (0.564–1.121) without diabetes. Conclusions The modifying effect of diabetes on the relationship between exercise and grip strength was observed in females but not in males. Females with diabetes may require tailored exercise guideline to prevent LHGS.

Probiotics have gained increasing clinical attention as adjunctive treatment for lower gastrointestinal disorders. However, evidence supporting their therapeutic efficacy remains limited, particularly with regard to sex-related differences. This expert review provides evidence-based insights and practical recommendations for the use of probiotics in patients with irritable bowel syndrome (IBS), functional constipation (FC), and Clostridioides difficile infection (CDI), considering possible sex-related differences. Evidence from randomized controlled trials and meta-analyses indicates that probiotics can modestly improve global symptoms, abdominal pain, and bloating in IBS and enhance bowel movement frequency and stool consistency in FC. However, these effects are strain-specific and heterogeneous. Although clinical studies on probiotics in IBS have not confirmed significant sex-related differences, experimental animal studies using stress-induced IBS models have demonstrated sex-dependent responses to specific probiotic strains, supporting the biological plausibility of such differences. For CDI, the efficacy of probiotics in preventing primary or recurrent infections remains inconsistent across large trials, and current guidelines usually do not recommend their routine use. However, sex- and age-related immunologic differences support the clinical differences of CDI. Probiotics are generally considered safe for healthy individuals, although caution is advised in patients who are immunocompromised or critically ill. Clinicians should select probiotic products based on strain-specific clinical evidence, adequate viable doses, patient characteristics and sex. In conclusion, probiotics might play a role as adjunctive therapy for IBS and FC, with variability in responses influenced by microbial, host, and potential sex-related factors. Further research is needed to establish optimized personalized probiotic strategies.

Purpose: Neoadjuvant chemotherapy (NAC) significantly revolutionized the management of locally advanced breast cancer, especially in human epidermal growth factor receptor 2 (HER2)-positive and triple-negative subtypes. However, its effectiveness is limited in estrogen receptor (ER)-positive, HER2-negative breast cancer. This study investigates the clinical response and prognosis of ER-positive, HER2-negative breast cancer after NAC. Methods: The clinicopathological characteristics and treatment responses of 149 patients with ER-positive, HER2-negative breast cancer treated with NAC and surgery at The Catholic University of Korea, Seoul St. Mary’s Hospital between 2018 and 2023 were retrospectively analyzed. Pathologic complete response (pCR) was defined as the absence of invasive tumors (ypT0/is, ypN0). Disease-free survival (DFS) and overall survival (OS) were analyzed using Kaplan-Meier methods, stratified by age (≤50 years vs. >50 years). Results: Among 149 patients, 13 (8.7%) achieved pCR, 87 (58.4%) attained partial responses, 40 (26.8%) had stable disease, and 9 (6.0%) experienced progressive disease. RECIST responses differed significantly by age (P = 0.003). DFS (P = 0.011) and OS (P = 0.005) were significantly associated with clinical response in patients aged ≤50 years. Post-NAC Ki-67 was associated with DFS (P = 0.013) but not OS (P = 0.083) in patients aged ≤50 years. Clinical responses and post-NAC Ki-67 were not associated with DFS (P = 0.544) or OS (P = 0.569) in patients aged >50 years. Conclusion In ER-positive, HER2-negative breast cancer, clinical responses and post-NAC Ki-67 were significant prognostic factors in patients aged ≤50 years but not in older patients. These findings highlight the need for tailored therapeutic approaches that consider age-specific prognostic differences.

Objectives: Allergic rhinitis (AR) is a chronic inflammation of the nasal mucosa triggered by environmental allergens. Although its pathophysiology has been extensively investigated, the influence of environmental aggravating factors—particularly combined pollutant exposure—remains insufficiently characterized. This study aimed to assess the impact of coexposure to PM2.5, formaldehyde, and Zn on allergic inflammation in a murine AR model and to delineate the associated immunological and histopathological responses. Methods: Female BALB/c mice were sensitized with ovalbumin (OVA) and challenged intranasally to induce AR. On days 21–24, the mice were exposed to PM2.5, formaldehyde, and Zn, either individually or in combination with OVA. Allergic symptoms were evaluated through behavioral observation, while immune responses were assessed by analyzing nasal and bronchoalveolar lavage fluids (NALF and BALF), serum immunoglobulin levels, nasal histopathology, and cytokine profiles. Results: Combined exposure to PM2.5, formaldehyde, and Zn significantly intensified allergic inflammation compared with single exposures. Coexposure to PM2.5 and Zn led to synergistic increases in total and OVA-specific immunoglobulin E levels, eosinophilic infiltration, nasal rubbing, sneezing, and Th2/Th17 cytokine levels in NALF and BALF. Histological analysis demonstrated epithelial thickening and goblet cell hyperplasia after combined exposure. Other combinations, including PM2.5 with formaldehyde, also produced additive or modestly amplified inflammatory responses. Conclusions Coexposure to PM2.5, formaldehyde, and Zn aggravated allergic inflammation in an OVA-induced murine model, with PM2.5+Zn yielding the strongest synergistic effects. These findings emphasize the role of pollutant–pollutant interactions in allergic airway diseases and highlight the need for further research to clarify long-term health effects and relevance to human disease.

Pharmacogenomic variations may significantly influence responses to commonly prescribed stroke medications. Despite accumulating evidence, genetic testing has not yet been widely integrated into stroke care. This review summarizes current evidence and provides practical guidance for clinical implementation. Pharmacogenomic studies and clinical guidelines related to antiplatelet agents, anticoagulants, and statins were reviewed, with particular emphasis on East Asian populations. Substantial evidence supports genotype-guided use of clopidogrel (CYP2C19), warfarin (CYP2C9, VKORC1, CYP4F2), and statins (SLCO1B1, ABCG2). For aspirin, PTGS1/2 and PEAR1 variants have been investigated; however, current data remain insufficient for clinical application. Regarding direct oral anticoagulants (DOACs), candidate genes such as ABCB1 and CES1 demonstrate pharmacokinetic associations, though robust clinical outcome data are lacking. Distinct allele frequencies in East Asians—such as higher prevalence of CYP2C19 and ABCG2 variants—underscore the need for population-specific strategies. Beyond single-gene approaches, polygenic risk scores, pharmacogenomic panels, and integration with multi-omics data and artificial intelligence represent promising directions for personalized therapy. Pharmacogenomic testing can enhance stroke pharmacotherapy, particularly in populations with high frequencies of actionable variants. Broader implementation requires rapid testing platforms, clinician education, tailored clinical guidelines, and real-world validation of aspirin, DOACs, and multi-gene approaches. Future research should expand population-specific studies and integrate pharmacogenomics within the broader framework of precision medicine to ensure equitable clinical benefit.

Purpose: Radiotherapy (RT) remains a cornerstone of curative treatment for localized and locally advanced prostate cancer. However, dose escalation to improve tumor control is often constrained by the proximity of the rectum, which increases the risk of gastrointestinal (GI) and genitourinary toxicities. Biodegradable rectal spacers inserted between the prostate and rectum have emerged as an effective approach to reduce rectal radiation exposure. This guideline provides evidence-based recommendations on indications, contraindications, procedural standards, and clinical management for biodegradable rectal spacer insertion during prostate cancer RT. Materials and Methods: This guideline was developed by a multidisciplinary expert panel through a systematic review of the literature, analysis of international guidelines (National Comprehensive Cancer Network, European Association of Urology, American Society for Radiation Oncology), and expert consensus among radiation oncologists, radiologists, and urologists with clinical experience in spacer insertion. The strength of each recommendation and the level of evidence were classified according to the modified GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system. Results: Spacer insertion is conditionally recommended (Grade C, Level I) for patients receiving definitive external-beam RT without rectal invasion. It reduces the high-dose rectal irradiation volume (V70–75) by >50%, decreases acute GI toxicity, and helps maintain bowel-related quality of life. However, the benefit for late severe toxicity (grade 2 or higher) remains debated in recent meta-analyses. Contraindications include rectal invasion, anatomical inaccessibility, infection, and material hypersensitivity. Procedures should be performed under local anesthesia in a sterile environment by trained physicians. Short-course antibiotics and simulator-based training, including completion of multiple supervised cases, are advised. Conclusion Biodegradable rectal spacer insertion is clinically validated and effective in reducing acute rectal toxicity. Although pivotal trials demonstrated a favorable procedural safety profile, real-world postmarket data include reports of rare but severe procedural complications. This guideline provides standardized recommendations tailored to Korean clinical practice while remaining consistent with international standards, emphasizing the importance of operator training and careful patient selection.

Background: The heterogeneity of chronic kidney disease (CKD) and fragmented analysis methods hinder the precise identification of novel biomarkers. We addressed this challenge using two independent cohorts to integrate genomics and metabolomics, aiming to identify cause-specific biomarkers for CKD in the Korean population. Methods: A longitudinal genome-wide association study using the Cox proportional hazards model was conducted using the Ansan and Ansung cohort. To validate these genomic biomarkers and integrate them with plasma metabolomics biomarkers, we utilized a hospital-based biopsy cohort to identify cause-specific CKD biomarkers. Within the biopsy cohort, we analyzed four disease subsets, including type 2 diabetic kidney disease (DKD), hypertensive nephropathy (HN), immunoglobulin A nephropathy (IgAN), and membranous nephropathy (MN), and compared them with healthy individuals. Significant single nucleotide polymorphisms(SNPs) and metabolites for each CKD subset were identified through logistic regression and correlation-based network analyses. Subsequently, we analyzed the risk of disease progression associated with the identified pairs. Results: A total of 448 variants associated with CKD occurrence were identified, with significant differences in several genetic variants and metabolites observed among patients with DKD, HN, IgAN, and MN compared to healthy individuals. Among 36 SNP-metabolite pairs, those involing FOXB1 and ZFP42 were associated with DKD, whereas pairs involving MMRN1 and SYNJ2 were linked to MN. Notably, the rs1025170 variant in FOXB1 and tyrosine pair was correlated with DKD progression. Conclusion Integrating genomics and metabolomics across independent cohorts enables the discovery of cause-specific biomarkers for the occurrence and progression of CKD in the Korean population.