CD8alpha+ dendritic cells enhance the antigen-specific CD4+ T-cell response and accelerate development of collagen-induced arthritis

To investigate the role of CD8alpha(+) DCs in the development of collagen-induced arthritis (CIA). The immunogenic properties of CD8alpha(+) and CD8alpha(-) DC subsets were investigated by mixed-lymphocyte reaction and cytokine enzyme-linked immunoassay. CII-pulsed CD8alpha(+) DCs or CD8alpha(-) DCs with CD4(+) T cells from CIA mice were adoptively transferred onto the hind footpad of DBA mice. The onset of arthritis and the arthritis index were examined for 14 weeks after adoptive transfer. Expression of MHC-II and CD80 but not CD86 and CD40 was higher in CD8alpha(+) DCs than in CD8alpha(-) DCs from the spleens of CIA mice. Culturing CD8alpha(+) DCs with CD4(+) T cells significantly increased the proliferative response of CD4(+) T cells in the presence of CII. The production of interleukin (IL)-12p70, IL-17, interferon (IFN)-gamma, and tumor necrosis factor (TNF)-alpha was slightly increased in CD8alpha(+) DCs than in CD8alpha(-) DCs. DBA/1 mice that were adoptively transferred with CII-pulsed CD8alpha(+) DCs and CD4(+) T cells into the footpads showed accelerated onset of CIA compared to control group. By contrast, CD8alpha(-) DCs showed a partial inhibitory effect on CIA. These findings show that CD8alpha(+) DCs accelerated the onset of CIA when aoptively transferred with CD4(+) T cells and that CD8alpha(+) DCs provoke the development of CIA probably by stimulating the immune responses of CII-reactive CD4(+) T cells and by increasing the production of inflammatory cytokines.     

Effectiveness and safety of single transseptal ablation for atrial fibrillation in real‐word practice

BackgroundWe have previously reported that unilateral groin‐single transseptal (ST) ablation in patients with paroxysmal atrial fibrillation (AF) was safe and significantly reduced patient discomfort compared with bilateral groin‐double transseptal (DT) ablation.HypothesisIn the present study, we hypothesized that ST ablation would be as effective and safe as DT ablation in real‐world practice like previous study. Among the 1765 consecutive patients in the Yonsei AF ablation cohort from October 2015 to January 2020, 1144 patients who underwent radiofrequency ablation were included for the analysis. Among them, 450 underwent ST ablation and 694 underwent DT ablation.ResultsThe total procedure time, ablation time, and fluoroscopy time were longer in the ST group than in the DT group (p < .05 for all). The hospital stay after catheter ablation was 1.3 ± 1.1 days which was longer in DT group than ST group (p = .001). No significant difference was observed in the complication rate (p = .263) and AF‐free survival rate (log‐rank p = .19) between the groups. However, after excluding patients who used antiarrhythmic drugs when AF recurred, the AF‐free survival rates were lower in the DT group than in the ST group before and after propensity score matching (log‐rank p = .026 and .047, respectively).ConclusionAlthough the ST approach increases the procedure time compared with the DT approach owing to the need for more frequent catheter exchanges, the ST approach is a feasible and safe strategy for AF ablation in terms of rhythm outcomes and risk of complications.     

Incidence of tuberculosis in Korean patients with rheumatoid arthritis (RA): effects of RA itself and of tumor necrosis factor blockers

OBJECTIVE: To elucidate the incidence rate and relative risk of tuberculosis (TB) in patients with rheumatoid arthritis (RA) and in patients with RA treated with tumor-necrosis-factor (TNF) blockers in Korea. METHODS: Using data from the Korean National Tuberculosis Association (KNTA) as a control and data from a single-center cohort of patients with RA, we conducted an evaluation of 1285 patients with RA not exposed to TNF blockers and reviewed medical records of 90 and 103 patients with RA treated with infliximab and etanercept, respectively, between 2001 and 2005. RESULTS: The mean incidence rate of TB, reported by the KNTA, was 67.2 per 100,000 person years (PY) from 2001 to 2004. In the TNF-blocker-na?ve RA cohort, 9 cases of TB developed during 3497 PY of followup (257 per 100,000). In the infliximab-treated RA group, 2 cases of TB developed during 78.17 PY of followup (2558 per 100,000 PY), and there was no case of TB during 73.67 PY of followup in the etanercept-treated RA group. The risk of TB was higher in RA patients not treated with TNF blockers (sex- and age-adjusted risk ratio 8.9; 95% confidence interval 4.6-17.2), and in those treated with infliximab (sex- and age-adjusted risk ratio, 30.1; 95% confidence interval, 7.4-122.3) compared with the general Korean population. CONCLUSION: The risk of TB infection is 8.9-fold higher in Korean patients with RA and 30.1-fold higher in RA patients treated with infliximab, compared with the general Korean population.     

Characteristics of Pulmonary Vein Enlargement in Non-Valvular Atrial Fibrillation Patients with Stroke

Purpose

The association between pulmonary vein (PV) dilatation and stroke in non-valvular atrial fibrillation (AF) patients remains unknown.

Materials and Methods

We examined the left atrium (LA) and PV in control (n=138) and non-valvular AF patients without (AF group, n=138) and with non-hemorrhagic stroke (AF with stroke group, n=138) using computed tomography.

Results

The LA, LA appendage (LAA), and all PVs were larger in the AF than control patients. The orifice areas of the LAA (5.6±2.2 cm² vs. 4.7±1.7 cm², p<0.001), left superior PV (3.8±1.5 cm² vs. 3.4±1.2 cm², p=0.019), and inferior PV (2.3±1.0 cm² vs. 1.8±0.7 cm², p<0.001) were larger in the AF with stroke than in the AF only group. However, right PVs were not different between the two groups. In a multivariate analysis, the orifice areas of the left superior PV [odds ratio (OR) 1.25, 95% confidence interval (CI) 1.03-1.51, p=0.02], left inferior PV (OR 1.97, 95% CI 1.41-2.75, p<0.001), and LAA (OR 1.30, 95% CI 1.13-1.50, p<0.001) were independent predictors of stroke.

Conclusion

Compared to the right PVs, the left PVs and LAA exhibited more significant enlargement in patients with AF and stroke than in patients with AF only. This finding suggests that the remodeling of left-sided LA structures might be related to stroke.