2018, Number 1
Martínez EMT, Rangel VS, García MG, Martínez PA, Velbes MPE, Ferreira CRP
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ABSTRACTObjective: evaluate the clinical performance of a modified polymerase chain reaction method to detect replication of the hepatitis B virus in infected patients.
Methods: a study was conducted of 266 serum samples from patients cared for at gastroenterology, transplantation, hemodialysis and hematology services of Hermanos Ameijeiras Clinical Surgical Hospital with positive surface antigen HBsAg and high liver enzyme values (aspartate aminotransferase, aspartate aminotransglutaminase and gamma-glutamyltransferase), and 5 samples from clinically healthy individuals. The DNA was extracted by the phenol-chloroform method. Amplification was performed of a fragment of the Pre S region of the hepatitis B virus and a fragment of the β-globin gene as internal control of the reaction.
Results: the β-globin gene fragment was found in the 266 samples studied. The Pre S region of the hepatitis B virus, however, was detected in 103 of them. These were reported as positive for viral replication. The sample exhibited a prevalence of 98.15 % for replication of the hepatitis B virus. Clinical specificity of the assay was 100 %, clinical sensitivity was 38 %, positive predictive value was 100 % and negative predictive value was 64 %. Concordance analysis did not reveal any agreement (κ= 0.022 for p= 0.07) between the liver enzymes and the polymerase chain reaction. Repeatability and reproducibility assays showed that the results are reproducible. The highest positivity percentage was found in patients referred from the Hematology Service (66.7 %).
Conclusions: the polymerase chain reaction method evaluated is an accurate tool to monitor replication of the hepatitis B virus. The possibility of its implementation and application at the institution where the study was conducted is very important for the Cuban health system.