Molecular Epidemiological Analysis Of HBV Infection And Occult Hepatitis B Virus Infection In Leukemia Patients

Objectives To investigate the prevalence of HBV infection and occult HBV infection inleukemia patients and evaluate the correlation between gender, age, test results ofbiochemics, HBV serological markers, and the prevalence of occult HBV infection toexplain the possible molecular mechanism of OBI from S gene mutation.Methods①Collection of cases and sample: A total of257patients with leukemiaduring the period September2010to November2011at the First Affiliated Hospital ofAnhui Medical University, and377patients with bone fracture as control group.②Treatment of HBV DNA:The classic proteinase K digestion-phenol-chloroform methodwas uesed.③To check the occult HBV infection by nested PCR: according toliteratures home and abroad as well as HBV reference sequences we designed a pair ofnested primers located at S、C and X gene respectively. At least two regions werepositive, the patient can be defined as occult HBV infection.④The quantitiative ofHBV serological markers of occult HBV infections were tested with Abbott Architect I2000R electrochemiluminescence instrument. Comparing gender, age, test results ofbiochemics, HBV serological markers etc. of patients with occult HBV infection, withthat of patients without occult HBV infection.⑤According to HBV referencesequences we designed a pair of primers in the S gene of HBV for amplifying andsequencing to find the possible mutations related to occult HBV infection and analyzegenotype and mutations in “a” determinant of HBsAg. Also, the controls were aslosequenced and compared with occult HBV infections. Results①The serum hepatitis B surface antigen (HBsAg) positivity rate wassignificantly higher in leukaemia group (10.9%vs5.6%,P<0.01) than in control group;The serum HBsAg positive rates in acute myeloid leukemia and chronic lymphocyticleukemia patients were10.9%and33.3%, significantly higher than that in the controlgroup (P<0.05); The ALT abnormal rate in HBsAg positive leukemia patients werehigher than in HBsAg negative patients,with respectively35.7%and19.3%(P=0.04).②Among229HBsAg negative Leukemia,27were diagnosed with occult HBVinfection, with Prevalence of occult HBV infection in leukemia were11.8%. Inleukemia patients, the incidence of occult HBV infection in anti-HBc(44.4%，12/27)was significantly higher than other patterns of serological marker(23.8%，48/202)(P=0.022),③In leukemia patients,22of27occult HBV infection who weresuccessfully sequenced with18genotype C and the4genotype B.④Sequencing ofHBV S gene in22cases of leukemia who were successfully sequenced revealed12mutant strains in “a” determinant and4cases who from terminant codon in advancewith a storted amino acid sequence. And I126T were more common of occult HBVinfections in leukemia patients. Two patients with joint mutation were found which wasQ129R/D144E/S155Y and I126T/S143T.Conclusions①In this geographic area the incidence of HBV infection and occultHBV infection in leukemia patients is about10.9%and11.8%.②There is significantcorrelation between occult HBV infection and the presence of isolated anti-HBc inleukemia patients.③The genotype in occult HBV infection of leukemia weresignificantly different than in HBsAg positive patients of Leukemia.④The mutationin S region, especially in “a” determinant of HBsAg may be the molecular basis ofoccult HBV infection.