Objective: To preliminarily investigate the role of toll-like receptor 3 (TLR3) in RhD alloimmunization. Methods: Between January 10, 2018 and April 1, 2019, RhD negative plasma donors were recruited for active RhD alloimmunization. A panel of four RhD 15-mer peptides was synthesized to stimulate T-cell proliferation. Peripheral blood mononuclear cells (PBMCs) were collected from successfully immunized donors (responders) and divided into an experimental group (pre-incubated with anti-TLR3 antibody before adding RhD peptides) and a control group (RhD peptides only). PBMCs proliferation was assessed using a cell proliferation enzyme-linked immunosorbent assay (BrdU), while TLR3 and IFN-α levels in cell culture supernatants and serum were detected via ELISA. Results: PBMCs proliferation was significantly lower in the experimental group compared to the control group [(31 234±15 300) vs (61 225±25 073) rlu/s, P<0.001]. TLR3 expression levels in the cell culture supernatants were also reduced in the experimental group [(3.49±0.32) vs (4.01±0.35) ng/mL, P<0.001]. TLR3 protein levels were detectable in responders but undetectable in the serum of non-responders [(1.43±1.44) vs 0 ng/mL, P<0.001]. A strong linear correlation was observed between TLR3 and IFN-α levels in serum, described by the regression model Y=2.957X+1.004 (r =0.91, P<0.001). Conclusion: TLR3 activation may promote RhD alloimmunization by inducing IFN-α secretion, indicating a critical role of the TLR3 signaling pathway in RhD immune responses.

Objective:Analysis of the characteristics of influenza epidemic in Anhui Province and quantification of the impact of different factors on influenza occurrence, providing scientific basis for better influenza prevention and control.Methods:Descriptive analysis and factor analysis were conducted on influenza-like illness (ILI) cases and RT-PCR results in Anhui Province from 2013 to 2021 using data from China's Influenza Monitoring Information System.Results:The percentage of influenza-like illness (ILI%) of sentinel hospitals in Anhui Province from April 1, 2013 to March 31, 2021 was 3.80% (1 209 142/31 779 987), showing an overall increasing trend, with a relatively high proportion in 2017-2018 at 4.30% (191 148/4 448 211). The proportion of ILI cases in infants and young children aged 0-4 years was a relatively high at 54.14% (654 676/1 209 142), and the highest ILI% was observed in Fuyang City, Anhui Province (6.25%, 236 863/3 788 863). Laboratory monitoring results showed that the positive rate of ILI cases in sentinel hospitals in 8 influenza monitoring years was 16.38% (34 868/212 912), showing an increasing trend year by year, with a relatively proportion in 2017-2018 at 26.19% (6 936/26 488). The detection rate of school-age children aged 5-14 years was a relativelyhigh at 28.81% (13 869/48 144), and the positive rate was a relatively high in Wuhu City among the 16 cities, reaching 22.01% (2 693/122 237). Influenza activity showed a single peak in winter-spring and alternating double peaks in winter-spring and summer, with different subtypes alternating, and A (H3N2) was the dominant subtype in summer. The results of a multiple logistic regression model showed that the positive rate was higher in 2017-2018, among children aged 5-14 years, in winter, and in southern Anhui.Conclusions:Influenza epidemic in Anhui Province has a clear seasonal pattern, and the ILI% and detection rate have shown an upward trend from 2013 to 2021. Therefore, it is suggested to ensure vaccine supply before the winter-spring influenza season arrives, and to strengthen vaccine uptake and health education to avoid the risk of infection during the peak period of influenza.

【Objective】 To explore the safety of RhD-positive red blood cells (RBCs) immunization schedules in RhD-negative volunteers, so as to facilitate the development of domestic anti-D immunoglobulin. 【Methods】 From January 2018 to April 2020, 23 RhD negative volunteers with informed consent were enrolled and divided into initial immunization group and booster immunization group. The initial immunization included first immunization, second immunization and third immunization. Four groups, i. e. 3 cases of 20 mL, 8 of 30 mL, 6 of 40 mL, and 6 of 50 mL, were involved in initial immunization. After the initial immunization response, booster immunizations were performed every 3 months. According to the anti-D titer before each immunization, the booster immunization doses were set to 0.5, 1 and 2 mL. Whole blood samples of 5mL/ person (time) were collected 24 h and 1 week after each infusion, and the blood routine, liver, kidney and blood coagulation function and anti-D titer were detected. The differences of detection (index) values at 24 h and 1 week after the first immunization and booster immunization in each (dose) group were compared. 【Results】 No statistically significant differences were observed in hemolysis index values (all within the range of medical reference values) 24 h or 1 week after initial immunization among RhD positive RBCs of 20, 30, 40 and 50mL(P>0.05). The differences between the hemolysis index values and the basic values before the immune response (all within the range of medical reference values) after 0.5 or 1 mL booster immunizations were also not statistically different (P>0.05). However, the differences (μmol/L)between total bilirubin levels and the basic values before the immune response (1.55±1.87, 6.29±2.66) were significantly different after 2 mL booster immunization (P<0.05). 【Conclusion】 No risks affecting the safety of RhD negative volunteers was found in the immunization schedule proposed in this study.