【Objective】 To investigate the distribution of ABO and RhD blood groups among voluntary blood donors in Guangzhou, in order to ensure clinical blood safety and better serve blood donors. 【Methods】 Routine ABO and RhD blood group screening tests were carried out among voluntary blood donors from January 2021 to December 2022. The composition ratio of ABO blood group was statistically analyzed. The samples with discrepancy between forward and reverse blood grouping and negative RhD blood group samples were further verified by serological test to analyze the ABO subtypes and the reasons for missed detection. 【Results】 A total of 749 123 blood samples were screened from January 2021 to December 2022, and 513 291 samples were collected after excluding repeat blood donors, with the ABO blood groups as 208 126(40.55%) of O type, 138 859(27.05%) of A type, 130 987(25.52%) of B type and 35 319(6.88%) of AB type. The screening results showed discrepancy between forward and reverse blood grouping in 506 samples, of which 58 were with weak/non-erythrocyte reaction, 16 with erythrocyte reaction, 215 with weak/non-serum reaction, and 217 with serum reaction. Further serological test indicated that 44 samples were ABO subtypes, among which 13 were subtype A, 26 subtype B, 5 subtype AB and 3 B (A) and 14 Bombay-like blood group. The blood group with the highest missed detection rate in repeat blood donors were A3/B3 subtype (68.42%). A total of 128 unexpected antibody positive samples were detected among 513 291 samples A total of 2 277 samples were screened negative for RhD blood type, of which 2 188 were confirmed to be Rh negative (2 188/513 291, 0.43%), 89 were D variants (89/513 291, 0.02%, ) and 30 were detected with unexpected antibodies (30/2 188, 1.37%). 【Conclusion】 The ABO blood group distribution of blood donors in Guangzhou is O>A>B>AB, and the proportion of RhD negative population is 0.43%, slightly highter than 0.3%-0.4% of Han population nationwide. The ABO blood group subtype is dominated by B subtype. The detection rate and missed detection rate of A3/B3 subtypes in routine blood group tests are the highest.

【Objective】 To investigate the population data of human immunodeficiency virus (HIV) infections among voluntary blood donors in Guangzhou between 2012 and 2022, and analyze its characteristics and trends, so as to provide valuable data for formulating targeted prevention and ensuring blood safety. 【Methods】 Voluntary blood donors samples from 2012 to 2022 were screened for p24 antigen and anti-HIV by two ELISA diagnostic kits and HIV RNA by nucleic acid test(NAT). The reactive blood samples were sent to the Disease Control and Prevention Center of Guangzhou for anti-HIV confirmatory test by Western blot. The population characteristics of blood donors with confirmed-positive HIV were subsequently analyzed. 【Results】 There were a total of 3 351 596 blood samples from voluntary blood donors in Guangzhou from 2012 to 2022, of which 708 samples were confirmed-positive of anti-HIV, with a total positive rate of 21.12/100 000, showing a decreasing trend (P<0.05). 1) The positive rates of age groups from high to low were 25-34 year old group, 35-44 year old group, 18-24 year old group, and≥45 year old group. The differences among various groups are statistically significant; 2) The anti-HIV positive rate of first-time blood donors (39.23/100 000) was significantly higher than that of repeat blood donors (10.78/100 000) (P<0.05); 3) The anti-HIV positive rate of male blood donors was 30.45/100 000, which was significantly higher than that of female blood donors (3.46/100 000); 4) The anti-HIV positive rate of individual blood donors (32.18/100 000) was higher than that of group blood donors (9.10/100 000) (P<0.05). 【Conclusion】 From 2012 to 2022, the confirmed-positive rate of anti-HIV among voluntary blood donors in Guangzhou showed a downward trend, which was significantly correlated with the implementation of voluntary blood donation and AIDS prevention policies. Young blood donors are of high risk of HIV, and it is necessary to enhance publicity and education on AIDS prevention through multiple channels among young population. Given that the anti-HIV positive rate of first-time blood donors is much higher than that of repeat blood donors, it is recommended to further optimize the health consultation and physical examination process before blood donation, and take multiple measures to screen high-risk behavior groups. Besides, more efforts should be made to promote publicity and education on AIDS prevention among regular blood donors. It is also important to recruit blood donors from low-risk groups and inform the donors about confidential unit exclusion.

【Objective】 To establish and verify a new nucleic acid extraction method for OBI detection with large volume and high sensitivity, and apply it in the quantitative determination of OBI samples with low viral load. 【Methods】 The method for nucleic acid extraction with large volume was established based on the method of Roche nucleic acid detection kit. HBV standards were configured into 10 000 IU/mL, 1 000 IU/mL, 100 IU/mL, 10 IU/mL and 1 IU/mL respectively, and nucleic acid was extracted from the 10 mL standards by magnetic beads. CT values of each concentration were detected by fluorescence quantitative PCR and each concentration gradient was detected in parallel duplicates. The logarithm of virus concentration was taken as the X-axis and the average CT values of two tests were taken as the Y-axis to construct the fluorescence quantitative standard curve and regression equation. Three repeated experiments were conducted to verify the stability of the method. This method was used to extract nucleic acid from OBI samples with low viral load, and fluorescence quantification was performed. 【Results】 The amplification efficiency of fluorescence quantitative standard curves ranged from 90% to 105%, and the regression equation was greater than 0.99. The variation coefficients of variation of CT values were 0.63%, 0.78%, 1.52%, 1.36% and 0.78%, respectively. This method can extract nucleic acid from OBI samples with viral load of 1 IU/mL for quantification. 【Conclusion】 The detection limit of HBV nucleic acid quantitative detection system can reach 1 IU/mL, and it has strong stability and high sensitivity, which can be used for the quantitative detection of OBI with low viral load.

【Objective】 To establish a quality control mechanism based on the Poisson distribution for monitoring contamination in nucleic acid testing (NAT) laboratories. 【Methods】 The study collected NAT single-reactivity rates and discriminatory test reactivity rates from the Grifols Panther NAT system from 2022 to 2023. The Poisson distribution probability method was used to calculate the daily probability of nucleic acid single reactivity. Sensitivity and specificity of the quality control model were further validated using single-reactivity rates, discriminatory reactivity rates and ROC curve analysis, followed by proposing corresponding multi-rule quality control strategies. 【Results】 Using P=0.05 as the threshold for out-of-control, the Poisson distribution probability quality control model identified 40 out-of-control points with P<0.05. After manual verification using discriminatory reactivity rates, 20 out-of-control points were confirmed. The sensitivity of determining out-of-control was 60.0%, and the specificity was 95.6%. Due to the high number of out-of-control points, it is recommended to combine discriminatory reactivity rates and employ multi-rule quality control methods for quality monitoring. Under the multi-rule quality control, there were 18 warning points and 2 out-of-control points for NAT single reactivity from 2022 to 2023. 【Conclusion】 The multi-rule NAT single-reactivity monitoring mechanism based on the Poisson distribution probability is more suitable for nucleic acid laboratories to monitor and warn of laboratory contamination, thereby enhancing the management capabilities and detection quality of nucleic acid laboratories.