Objectives: This study aimed to investigate differences in the anti-hepatitis A (HAV) antibody seropositivity rate by age and gender. Methods: We collected information on anti-HAV immunoglobulin G and immunoglobulin M status from samples submitted for HAV antibody testing in 2012–2022. A total of 1,333,615 cases were included in the analysis. Results: By age, the seropositivity rate was represented by a U-shaped curve, such that the rate was low for the group aged 20 to 39 years and higher in those who were younger or older. Over time, the curve shifted rightward, and the seropositivity rate declined gradually in the group aged 35 to 39 years and older. A gender-based difference in antibody seropositivity rate was especially noticeable in the group aged 20 to 29 years. This difference between genders widened in the participants’ early 20s—when men in the Republic of Korea enlist in the military—and the divergence continued subsequently for older individuals. Conclusion These results indicate a higher risk of severe infection among older individuals and a gender-based difference in seroprevalence. Therefore, it is necessary to implement policies to promote vaccination in adults.

BACKGROUND: The association between baseline renal impairment (RI) and the prognosis of diffuse large B-cell lymphoma (DLBCL) was previously not defined. The aim of this study was to evaluate the prognostic value of RI in patients with DLBCL treated with three-weekly rituximab plus cyclophosphamide, Adriamycin, vincristine, and prednisolone immunochemotherapy (R-CHOP21). METHODS: Patients with newly diagnosed de novo DLBCLs treated with ≥1 cycle of R-CHOP21 were analyzed retrospectively. Pretreatment blood samples were collected and the glomerular filtration rate (GFR) was calculated. RI was defined by a GFR of <60 mL/min/1.73 m2 according to the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula. RESULTS: Of the 185 patients enrolled in the present study, 19 patients (10.3%) had RI. The reasons for baseline RI were pre-existing CKD (N=5), acute kidney injury due to either obstruction (N=2) or electrolyte imbalance (N=2) related to DLBCL, and undefined causes (N=10). Patients with baseline RI showed inferior overall survival (OS) compared to those without RI (P<0.001). In multivariate analysis, RI was identified as an International Prognostic Index (IPI)-independent prognostic indicator. A baseline hemoglobin level of <10 g/dL and the presence of RI effectively discriminated a portion of the patients with far inferior event-free survival and OS among the patients having high or high-intermediate risk cancers according to either the standard- or the National Comprehensive Cancer Network-IPI. CONCLUSION: Pretreatment RI was an independent prognostic marker for inferior OS in patients with DLBCL treated with R-CHOP21 immunochemotherapy.
Acute Kidney Injury ; B-Lymphocytes* ; Cooperative Behavior ; Cyclophosphamide ; Disease-Free Survival ; Doxorubicin ; Epidemiology ; Glomerular Filtration Rate ; Humans ; Lymphoma, B-Cell* ; Multivariate Analysis ; Prednisolone ; Prognosis ; Renal Insufficiency ; Renal Insufficiency, Chronic ; Retrospective Studies ; Rituximab ; Vincristine