ABSTRACT
Objective To study the uncertainty and traceability of HBV DNA assays and discuss the comparability of results among different detection systems. Methods Different detecting systems were used to detect HBV DNA using the national standard substance as "quality control substance". The uncertainty of the results was evaluated referring "Guidelines for estimating and reporting measurement uncerTAinty of chemical test results" of NATA The results were traced back to the national standard substance. According to the CLSI document EP9-A2, the results were analyzed and subjected to bias estimation with the t(0.05sv) √u2b1+ u2b2 as the criterion clinically accepted to investigate the comparability of different detecting systems. Results The means (-y) measured by 3 HBV DNA assay systems were 6.15,5.88,and 6.31 lg(kIU/L) respectively. Except system A,both the biases of system B and C had statistical significance (all P ＜ 0. 05) and expanded uncertainty of three detection systems was varied, but the difference was within the maximum acceptable range (± 0. 5) of the external quality assessment by National Center for Clinical Laboratory. Being traceable to national standard substance, the results of HBV DNA of the three detecting systems were (5.45 ± 1.23), (5.55 ± 1.32) and (5.42 ± 1.25) lg(kIU/L), respectively.There was significant difference among three systems (F = 5.63, P ＜ 0. 05). Comparing system A and B,there was significant difference in statistic (q = 5. 12, P ＜ 0. 05) and the difference between system B and C also had statistically significant (q = 6. 85, P ＜ 0. 05), but the results between system A and C had no statistical difference (q = 1.85,P ＞ 0. 05). Among these three systems, the difference of any two detection systems had no statistical significance (all P ＞ 0. 05). It showed that system bias was acceptable in clinical application and the results between different systems were comparable. Conclusions It is necessary to estimate the uncertainty and traceability when comparing the HBV DNA assay among the different labs. It also needs to estimate the bias of different systems and evaluate the clinical acceptability to ensure the accuracy and comparability of the results.
ABSTRACT
Objective To study Kaposi's sarcoma-associated herpesvirus(KSHV)infection in chronic hepatitis B(CHB)patients and its correlation with hepatitis B virus(HBV)replication and treatment-related factors.MethodsEnzyme-linked immunosorbent assay(ELISA)with recombination protein KSHV ORF65 was employed to detect the KSHV antibody and real-time polymerase chain reaction(PCR)was performed to detect KSHV DNA and HBV DNA in CHB patients.Age,HBV replication and licorice preparation treatment of patients were further analyzed.Comparison of rates was done using X~2 test.Results KSHV ORF65 antibody positive rates were 27.3% in 161 male CHB patients and 30.0% in 50 female patients(X~2=0.135,P＞0.05).The KSHV infection rates were increased with age,but this tendency was not obvious in patients older than 40 years old.The highest infection rate was in age group of 31-40 years old which was 37.1%.The positive rate of HBV DNA in CHB patients with KSHV infection was 73.5%,which was 56.3% in uninfected patients(X~2=3.969,P＜0.05).The average plasma level of KSHV DNA in patients treated with licorice preparations was 204.7 copy/mL and that in patients without licorice preparation treatment was 533.9 copy/mL.Eight patients were KSHV DNA positive(KSHV DNA＞ 100 copy/mL)in 16 patients treated with licorice preparations and 23 were positive in 33 patients without licorice preparation treatment.Conclusions The KSHV infection rates are increased with age of CHB patients.KSHV infection may interfere with HBV replication and licorice preparations may suppresss KSHV replication in vivo.
