Quality evaluation and clinical applicability of pyrosequencing assay kit for detecting hepatitis B virus resistance / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To evaluate the quality and clinical applicability of pyrosequencing assay kit for detecting hepatitis B virus resistance (HBV DRT).</p><p><b>METHODS</b>Serial dilutions of the International Standard for HBV DNA were used to test the detection limit of the PCR for HBV DRT. Plasmids containing the either a wild-type (WT) copy or one of 10 mutant (MT) copies of the HBV RT gene were used to prepare a series of samples with various mutation ratios. To construct the linear relationship between the true mutation rate and the detected mutation rate, each sample was repeated at least 10 times. A total of 102 clinical samples were analyzed by Sanger sequencing and retested by the PCR for HBV DRT to determine the concordance of these two methods.</p><p><b>RESULTS</b>The lower detection limit of the PCR for HBV DRT was 50 IU/ml. Except for the RT236 MT, the correlation between the true mutation rate and the detected mutation rate for the other nine resistance-related mutation sites were excellent, with R² more than 0.98 (P less than 0.001). Among the 102 clinical samples, four were not amplified successfully by PCR. The results were significantly different between the PCR for HBV DRT method and the Sanger sequencing method (x² = 71.2, P less than 0.001), and concordance was observed for 897/969 (92.6%) amino acid positions in 98 samples. Concordant results were achieved in 46/98 (46.9%) samples at all 10 mutation sites. For detection of a single mutation site, concordance rates ranged from 71.5% to 100% at the 10 mutation sites, respectively. Analysis of discordant samples showed that in 87.5% (63/72), Sanger sequencing detected WT and the PCR for HBV DRT detected WT/MT. In 5.6% (4/72) of samples, Sanger sequencing detected WT/MT and the PCR for HBV DRT detected WT. In the remaining 6.9% (5/72) of samples, Sanger sequencing detected WT but PCR for HBV DRT detected MT.</p><p><b>CONCLUSION</b>The PCR for HBV DRT showed high sensitivity and accuracy in detecting antiviral drug-resistant mutations. The method is superior to Sanger sequencing for detecting minor mutations and can be used for early detection of a resistance mutation.</p>

Assessment of renal function and risk factors for renal impairment in patients with hepatitis B virus-related liver cirrhosis / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the renal function in treatment-naive patients with hepatitis B virus (HBV) related cirrhosis and to identify the risk factors for renal impairment.</p><p><b>METHODS</b>We collected the data of 860 HBV-related cirrhosis patients hospitalized in our unit between Jan 1, 2011 and Dec 31, 2011. Liver function of the patients was assessed with Child-Pugh score system, and the renal function with estimated glomerular filtration rate (eGFR) calculated by Modification of Diet in Renal Disease (MDRD) equation recommended by Kidney Disease Outcomes Quality Initiative (K/DOQI). We investigated the prevalence of renal impairment (eGFR>60 ml/min/1.73 m(2)) among these patients and explored the risk factors for renal impairment.</p><p><b>RESULTS</b>Of the 860 patients, 296 had complete clinical data and were included in our analysis. The overall incidence of renal impairment among the enrolled patients was 8.45% (25/296). Patients with Child-Pugh stage C showed a significantly higher incidence of renal impairment than those with stages B and A (17.17% [17/99] vs 6.67%[7/105] vs 1.09% [1/92], P<0.001). Age, history of hyperuricemia, and Child-Pugh score were identified as the risk factors for renal impairment in these patients.</p><p><b>CONCLUSION</b>In patients with HBV-related liver cirrhosis, the incidence of renal impairment increases significantly with deterioration of the liver function, and renal function should be regularly monitored in these patients for appropriate antiviral treatment.</p>