Impaired humoral immunity following COVID-19 vaccination in HTLV-1 carriers.

BACKGROUND: Whether human T-lymphotropic virus type 1 (HTLV-1) carriers can develop sufficient humoral immunity after coronavirus disease 2019 (COVID-19) vaccination is unknown. METHODS: To investigate humoral immunity after COVID-19 vaccination in HTLV-1 carriers, a multicenter, prospective observational cohort study was conducted at five institutions in southwestern Japan, an endemic area for HTLV-1. HTLV-1 carriers and HTLV-1-negative controls were enrolled for this study from January to December 2022. During this period, the third dose of the COVID-19 vaccine was actively administered. HTLV-1 carriers were enrolled during outpatient visits, while HTLV-1-negative controls included health care workers and patients treated by participating institutions for diabetes, hypertension, or dyslipidemia. The main outcome was the effect of HTLV-1 infection on the plasma anti-COVID-19 spike IgG (IgG-S) titers after the third dose, assessed by multivariate linear regression with other clinical factors. RESULTS: We analyzed 181 cases (90 HTLV-1 carriers, 91 HTLV-1-negative controls) after receiving the third dose. HTLV-1 carriers were older (median age 67.0 vs. 45.0 years, p < 0.001) and more frequently had diabetes, hypertension, or dyslipidemia than did HTLV-1-negative controls (60.0% vs. 27.5%, p < 0.001). After the third dose, the IgG-S titers decreased over time in both carriers and controls. Multivariate linear regression in the entire cohort showed that time since the third dose, age, and HTLV-1 infection negatively influenced IgG-S titers. After adjusting for confounders such as age, or presence of diabetes, hypertension, or dyslipidemia between carriers and controls using the overlap weighting propensity score method, and performing weighted regression analysis in the entire cohort, both time since the third dose and HTLV-1 infection negatively influenced IgG-S titers. CONCLUSIONS: The humoral immunity after the third vaccination dose is impaired in HTLV-1 carriers; thus, customized vaccination schedules may be necessary for them.

Improving the Effects of Imeglimin on Endothelial Function: A Prospective, Single-Center, Observational Study.

INTRODUCTION: Endothelial dysfunction is a risk factor for cardiovascular disease in patients with diabetes. We hypothesized that imeglimin, a novel oral hypoglycemic agent, would improve endothelial function. METHODS: In this study, imeglimin was administered to patients with type 2 diabetes and HbA1c ≥ 6.5% who were not receiving insulin therapy. A meal tolerance test (592 kcal, glucose 75.0 g, fat 28.5 g) was performed before and 3 months after administration, and endothelial function, blood glucose, insulin, glucagon, and triglycerides were evaluated. Endothelial function was assessed by flow-mediated dilation (FMD). RESULTS: Twelve patients (50% male) with a median age of 55.5 years old (interquartile range [IQR] 51.3-66.0) were enrolled. Fasting FMD did not differ before or 3 months after imeglimin administration (from 6.1 [3.9-8.5] to 6.6 [3.9-9.0], p = 0.092), but 2 h postprandial FMD was significantly improved 3 months after imeglimin administration (from 2.3 [1.9-3.4] to 2.9 [2.4-4.7], p = 0.013). In terms of the glucose profile, imeglimin administration significantly improved HbA1c (from 7.2 ± 0.6% to 6.9 ± 0.6%, p = 0.007), fasting glucose (from 138 ± 19 mg/dL to 128 ± 20 mg/dL, p = 0.020), and 2 h postprandial glucose (from 251 ± 47 mg/dL to 215 ± 68 mg/dL, p = 0.035). The change in 2 h postprandial FMD between before and 3 months after imeglimin administration (Δ2 h postprandial FMD) was negatively correlated with Δ2 h postprandial glucose (r = - 0.653, p = 0.021) in a univariate correlation coefficient analysis. Both patients with and without decreased postprandial glucose 3 months after imeglimin administration had improved postprandial FMD. CONCLUSION: In this small study, imeglimin administration improved 2 h postprandial FMD. Both glycemic control-dependent and -independent mechanisms might contribute to improved endothelial function. TRIAL REGISTRATION: This research was registered in the University Hospital Medical Information Network (UMIN, UMIN000046311).

Association between personality traits and glycemic control after inpatient diabetes education.

Aims: The longitudinal effect of personality traits on glycemic control is unclear. This prospective observational study explored the relationship between personality traits and glycemic control in patients with uncontrolled diabetes after inpatient diabetes education. Methods: Patients with diabetes mellitus (HbA1c ≥ 7.5%, measured by high-performance liquid chromatography) who received inpatient diabetes education were scored on the Big Five personality traits: neuroticism, extraversion, openness, agreeableness, and conscientiousness. Multiple linear analysis was used to determine whether any personality traits were independently associated with HbA1c on admission and HbA1c change from admission to 1, 3, and 6 months after discharge. Results: One hundred seventeen participants (mean age 60.4 ± 14.5 years; 59.0% male) were enrolled. HbA1c values on admission and 1, 3, and 6 months after discharge were 10.2 ± 2.1%, 8.3 ± 1.4%, 7.6 ± 1.4%, and 7.7 ± 1.5%, respectively. Multiple linear analysis showed that no personality traits were associated with HbA1c on admission. Neuroticism was negatively associated with the HbA1c change from admission to 3 months (ß = -0.192, P = 0.025) and 6 months after discharge (ß = -0.164, P = 0.043). Conclusions: Neuroticism was associated with good long-term glycemic control after inpatient diabetes education.