title: Genotyping of occult hepatitis B virus infection in Egyptian hemodialysis patients without hepatitis C virus infection.
abstract: BACKGROUND
  Occult hepatitis B viral infection is the presence of hepatitis B viral nucleic acids in the serum and/or liver in the absence of hepatitis B surface antigen.
  
  
  OBJECTIVE
  The study aimed to determine the prevalence of occult hepatitis B virus infection among hepatitis C virus-negative hemodialysis patients and to identify their genotypes.
  
  
  METHODS
  of 144 patients on maintenance hemodialysis, 50 hepatitis B surface antigen and hepatitis C virus nucleic acid-negative patients were selected according to strict inclusion criteria to avoid the effect of confounding variables. The following investigations were done: serum AST and ALT; HBsAg; HBcAb; HCV-Ab; HCV-RNA; and HBV-DNA.
  
  
  RESULTS
  Positive hepatitis B viral nucleic acid was confirmed in 12/144 (8.3%) hemodialysis patients and 12/50 (24%) in our study group (occult infection). Mean hemodialysis periods for negative patients and occult hepatitis B virus patients were 27.3±18.8 and 38.4±8.14 months, respectively, and this difference was significant (p-value=0.02). Mean alanine transaminase levels were 20.27±5.5IU/L and 25.3±9.6 in negative patients and occult infection patients, respectively. This difference was non-significant. Aspartate transaminase levels were 21.4±10.2IU/L and 27.3±4.6IU/L, respectively, in negative patients and infected patients; this difference was significant (p-value=0.03). Half (6/12) of the positive samples belonged to genotype 'B', 33.3% (4/12) to 'C', and 16.6% (2/12) to genotype 'D'.
  
  
  CONCLUSIONS
  OBI is likely among hemodialysis patients even without HCV coinfection (24%). Genotype D cannot be the only genotype distributed in Upper Egypt, as the current study reported relatively new results that 50% of the patients with occult B carry genotype B, 33.3% carry genotype C and only 16.6% carry genotype D.
authors.affiliation: Microbiology and Immunology Department, Faculty of Medicine, Minia University, El Minia 61519, Egypt. Electronic address: monaabdelmonem22@yahoo.com.
authors.forename: Mona A
authors.initials: MA
authors.lastname: Esmail
authors.affiliation: Microbiology and Immunology Department, Faculty of Medicine, Minia University, El Minia 61519, Egypt.
authors.forename: Wafaa K M
authors.initials: WK
authors.lastname: Mahdi
authors.affiliation: Microbiology and Immunology Department, Faculty of Medicine, Minia University, El Minia 61519, Egypt. Electronic address: rashakhiry1@gmail.com.
authors.forename: Rasha M
authors.initials: RM
authors.lastname: Khairy
authors.affiliation: Internal Medicine Department, Faculty of Medicine, Beni Suif University, Egypt. Electronic address: Mostafa.Gedan@gmail.com.
authors.forename: Nilly H
authors.initials: NH
authors.lastname: Abdalla
mesh_terms: D000328:Adult; D004279:DNA, Viral / Q000097:blood / Q000235:genetics*; D004534:Egypt / Q000453:epidemiology; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D060005:Genotyping Techniques; D006509:Hepatitis B / Q000453:epidemiology* / Q000821:virology*; D006515:Hepatitis B virus / Q000145:classification* / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis
chemical_list: D004279:DNA, Viral
keywords: Genotyping study; Hemodialysis; Occult HBV infection (OBI); Real time-PCR