Analysis of Ct value of HBV nucleic acid detection in different blood donors / 中国输血杂志

ABSTRACT

【Objective】 To analyze the difference of Ct value of HBsAg-/HBV DNA + in blood samples from different types of voluntary blood donors by double ELISA and HBV DNA (MP6) detection, and to investigate the correlation between Ct value and the frequency of repeated blood donation, the first nucleic acid reactivity and the interval time of previous blood donation, so as to provide reference for laboratory evaluation of the effectiveness of nucleic acid testing(NAT) strategy for repeated blood donors occult hepatitis B virus infection(OBI). 【Methods】 The Ct value and information of blood donors from February 2019 to January 2022 in our laboratory were collected. According to the cumulative number of blood donations, they were divided into two groupsfirst-time blood donor group (Group A) and repeated blood donor group (Group B). Group B was subdivided into Group C 1( twice of blood donation) and group C 2(three or more times of blood donation) according to the cumulative times of blood donation, and Group D 1(< 1 year), Group D 2(1-3 years), Group D 3(3 years or more) according to the first NAT reactivity and the time of previous blood donation, the difference of Ct value and resolution yeild of HBV DNA in each group was compared. The yeild of HBV DNA in two groups was compared by chi-square test, and the difference of Ct values were compared by Nonparametric test. 【Results】 From February 2019 to January 2022, a total of 270 283 blood donors were tested, including 135 695 in Group A and 134 588 in Group B. The yeild of HBV DNA in Group A was 0.150% (203/135 695), which was higher than that in Group B [0.083% (111/134 588)] (P <0.05).All Ct values were non-normal distribution by normal distribution test, and were expressed as median (quartile), the median values of MP6 and resolution Ct were 37.0(35.9,38.2) and 35.5(33.7,36.9) in Group A, 37.2(36.4,38.1) and 36.5(35.5,37.6) in Group B, respectively. Ct values of MP detection and resolution in Group A, of MP detection and resolution in group B, and of resolution in group A and B were all significant (P<0.05) From the cumulative number of blood donations to compare, the median values of MP detection and resolution Ct were 37.5(36.6,38.3) and 36.5(35.4,37.6) in Group C1,37.1(36.4, 37.9) and 36.6(35.6,37.8) in Group C2, respectively. Significant difference in resolution Ct value between Group A and Group C1, Group A and C2 was noticed(P<0.05), the median values of MP detection Ct in D1, D2 and D3 groups were 37.2(36.3,38), 37.1(36.5,37.9), 37.8(36.6.38.9),respectively, with median resolution CT values at 37.0(35.7,37.8), 35.9(34.8,36.9), 36.9(36.1,37.7), respectively. There was a significant difference in the resolution Ct values between between Group A and D1 and D3 groups (P<0.05), and there was a significant difference between the MP detection and resolution Ct values in D2 Group (P<0.05). The resolution Ct values in D2 and D3 Group were lower than those in D1 Group (P<0.05).The interquartile distribution of Ct values in Group A was wider than that in other groups, and the interquartile distribution of Ct values in Group B was more concentrated. Conclusion The Ct value of HBV DNA detected by nucleic acid in blood donors was correlated with different times of blood donation and different intervals of blood donation. The laboratories of blood station should pay attention to the nucleic acid test results of different types of blood donors to ensure blood safety.