Comparison of two quantitative real-time PCR methods for serum HBV RNA in patients with HBeAg-positive chronic hepatitis B: A propensity score matching study / 临床肝胆病杂志

ABSTRACT

Objective To investigate the consistency between Shengxiang (S) and Xinbo (X) real-time PCR methods in the quantification of HBV RNA. Methods In the prospective follow-up cohort of 108 chronic hepatitis B (CHB) patients established from July 2007 to August 2008, 20 patients with HBeAg seroconversion were selected, and 20 patients without seroconversion were selected by propensity score matching at a ratio of 1∶ 1. The two quantification methods from S and X companies were used, and a retrospective analysis was performed for HBV RNA in serum samples at baseline and weeks 12, 24, and 48. The paired t -test was used for comparison of normally distributed continuous data between groups, and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between groups; the chi-square test was used for comparison of categorical data. The Pearson correlation coefficient, intraclass correlation coefficient (ICC), and the Bland-Altman method were used to evaluate the consistency of the two quantification methods. Results A total of 132 serum samples were tested by S reagent, and 154 were tested by X reagent; the detection rate of HBV RNA was 100% by both reagents. A total of 131 serum samples were tested by both reagents, with 34 samples at baseline and 29, 35, and 33 samples, respectively, at weeks 12, 24, and 48 of follow-up; at these four time points, the HBV RNA quantification data detected by X reagent were significantly higher than those detected by S reagent (5.75±1.64/5.43±1.73/5.13±1.54/4.76±1.55 log 10 copies/mL vs 4.80±1.48/4.52±1.53/4.10±1.50/3.92± 1.43 log 10 copies/mL, t =8.348, t =5.341, Z =-5.086, Z =-4.762, all P < 0.001). The correlation analysis of the two methods showed a Pearson correlation coefficient of 0.915 (95% confidence interval [ CI ] 0.836-0.957) and an ICC of 0.771(95% CI -0.021 to 0.931) at baseline, a Pearson correlation coefficient of 0.849(95% CI 0.701-0.927) and an ICC of 0.733(95% CI 0.138-0.902) at week 12, a Pearson correlation coefficient of 0.951(95% CI 0.905-0.975) and an ICC of 0.776(95% CI -0.058 to 0.942) at week 24, and a Pearson correlation coefficient of 0.933(95% CI 0.867-0.967) and an ICC of 0.804(95% CI -0.014 to 0.944) at week 48 (all P < 0.05). The Bland-Altman analysis showed that the difference of 96.18%(126/131) samples tested by the two methods was within the mean difference±1.96 standard deviation. Conclusion HBV RNA quantification by X reagent is higher than that by S reagent, while the two real-time PCR quantification methods show a good consistency in CHB patients with HBeAg seroconversion and those without seroconversion.