Impact of frequency and duration of freeze-dried inactivated tissue culture hepatitis A vaccine (Aimmugen®) vaccination on antibody titers; a japanese cross-sectional study.

BACKGROUND: The effect of the timing of additional doses and the long-term persistence of lyophilized inactivated tissue culture hepatitis A (HA) vaccine (Aimmugen®) on antibodies is unknown. METHODS: A single-center, cross-sectional, observational study was conducted in collaboration with the Japan Air Self-Defense Force, whose personnel were immunized with Aimmugen® when deployed to endemic areas. Patients who consented to this study after a medical examination with blood sampling between June 2022 and February 2023 were included; HA-IgG level in the residual serum was measured using the chemiluminescent immunoassay method. The exact vaccination history was investigated based on immunization records maintained by the Ministry of Defense, and a questionnaire was used to collect confounding factors. RESULTS: Of the 181 participants observed, 49 were in the unvaccinated group, and 132 were in the vaccinated group. Out of the vaccinated group, 6.8 % received either one or two doses, 40.9 % received three doses, and 52.3 % received more than four doses. IgG antibody titers (S/CO value) in each group (0, 1 or 2, 3, and over 4) increased in a frequency-dependent manner, with those vaccinated over four times showing significantly higher IgG antibody titers than all other groups (0.19 ± 0.10 vs 3.66 ± 3.00 vs 7.63 ± 3.57 vs 10.57 ± 1.86, respectively). When the number of months elapsed from the last vaccination to the date of blood collection in each group was plotted against IgG antibody titer, the slope of the regression line flattened out from a decreasing trend in the order 1 or 2, 3, over 4. CONCLUSIONS: Three doses of Aimmugen® are efficacious, but four or more doses induce more robust and sustained antibody production. Additionally, four or more doses may be effective when there is a need to ensure long-term immunity or risk of prolonged exposure.

Atypical immunohistochemical patterns can complement the histopathological diagnosis of oral premalignant lesions.

BACKGROUND: The histopathological diagnosis of oral premalignant lesions (OPLs) such as oral epithelial dysplasia (ED) and carcinoma in situ (CIS), as well as epithelial hyperplasia (EHP), is important for the early detection and precise treatment of oral squamous cell carcinoma. However, the standardization of detection and treatment by histological criteria alone remains challenging owing to the complicated and varied histology. We evaluated practically useful immunohistochemical (IHC) markers that might complement the histopathological diagnosis of OPLs. METHODS: We re-evaluated the histopathological diagnoses and IHC patterns of Ki-67, TP53, CK13, and CK17 in 200 cases of OPLs and performed multiple logistic regression analyses for their predictive accuracy. RESULTS: We identified and compared atypical IHC patterns in OPLs and in the normal epithelium. Ki-67 expression showed specific patterns in categorized OPLs as EHP, low-grade dysplasia (LED), high-grade dysplasia (HED), and CIS. Multiple logistic regression analyses in the quadrant categories revealed that EHP and CIS had high predictive accuracies of 90.1% and 96.2%, respectively, and in binary categories, combined EHP and LED versus combined HED and CIS showed predictive accuracies of 92.1% and 89.9%, respectively. Binominal logistic regression analysis between each quadrant category revealed satisfactory predictive accuracy of EHP vs. LED, LED vs. HED, and HED vs. CIS (75.2%, 78.9%, and 87.9%, respectively), and Ki-67 showed the highest adjusted odds ratio, followed by TP53. CONCLUSION: The proposed atypical IHC patterns might serve as useful markers to supplement the morphological diagnosis of OPLs, and established IHC methods for Ki-67 and TP53 might provide stable results.