| Objective: Use direct sequencing method to detect reverse transcriptase(RT)gene area point mutations in patients with chronic hepatitis B treated with nucleosi(t)de analogue(NUCs).In addition,the relation between these results and HBV infected different periods were also discussed.At the mean time,the resistance mutation patterns related to ETV and theirclinical characteristics were investigated.Methods: first part :Serum samples of 414 CHB patients with NUCs treatment from Ningbo NO.2 hospital were obtained from January 1,2014 to December 31,2016.Full-length HBV RT sequences were amplified,sequenced and fourteen mutations were analyzed: rtV173,rtL180,rtA181,rtT184,rtS202,rtM204,rtV207,rtS213,rtV214,rtQ215,rtN236,rtP237,rtN/H238 and rtM250.Epidemiological characteristics and the relations between these mutations and hepatitis B virus(HBV)infected different periods were further analyzed.Second part:samples which the resistance mutations related to ETV(T184,S202 and/or M250)were detected were screened from the samples collected in the first part.Then,the resistance mutation patterns related to ETV and their clinical characteristics were investigated.Results: In the total 414 samples,we detected resistance mutations related to ETV in 143 samples,while 35 samples(35/143,24.5%)were genotype B and 107 samples(107/143,74.8%)were genotype B,only 1 samples(1/143,0.7%)were genotype D.11 resistance mutations were detected(rtV173,rtL180,rtA181,rtT184,rtS202,rtM204,rtV207,rtS213,rtV214,rtN236 and rtM250).RtA181 incidence of genotype C was higher than that of genotype B(p=0.011),While rtS213 incidence of genotype B was higher than that of genotype C(p=0.017,0.013).RtV214 incidence in patients with liver cirrhosis was higher than that in patients with chronic hepatitis B(p=0.004).Among the 143 samples,17 samples which the resistance mutations related to ETV(T184、S202 and/or M250)were detected.Eight mutation patterns were founded,in which the rtL180+rtM204V+rtS202G/I(7/17,41.18%)and rtL180+rtM204V+rtT184A/G/I/S(3/17,11.77%)were the most frequent ones.The differences in T184A/G/I/S,S202G/I and M250V/I gene mutations between genotype B and C have no statistical significance(p=0.128,1.000,0.074).In the team of genotype C,T184A/G/I/S and S202G/I incidence was higher than that of M250V/I(p=0.005).Patients carrying rtTl84A/G/I/S mutations were associated with worse liver function(χ2=7.333,p=0.011)and higher ALT level(χ2=26.757,p=0.000).Conclusions: 1.There is genotype B,genotype C and genotype D HBV among the patients with chronic HBV infection,while genotype C is predominant.2.The most common mutation related to NUCs is rtM204,followed by rtL180.More rtA181 happened in genotype C,while more rtS213 in genotype B.The mutation rtV214 may be associated with disease progression.3.The most common mutation patterns related to ETV is rtS202G/I,followed by rtT184A/G/I/S.Most mutations happened on the basis ofrtL180+rtM204V.The mutation rtT184A/G/I/S related to ETV may be associated with the degree of hepatic inflammation and severity of liver disease. |
