بررسي ميزان بيان گيرنده كموكيني CCR5 بر سطح لنفوسيت هاي T CD8+ خون محيطي بيماران مبتلا به عفونت نهفته هپاتيت B

Evaluation ofexpression rate ofchemokines receptor CCR5 on peripheral blood CDS+ T cells ofoccult hepatitis B infected patients

Background and purpose: Occult hepatiti s B infection (OBI) is defined as a form of hepatitis B that despite absence of detectable HBsAg, HBV-DNA is present in pat ient ʹs peripheral blood. Genetic and immunological differences appear to play important roles in producing OBI. Therefore, this project was aimed to examine the expression of a chemokine receptor (CCR5) on CDS+T cells of OBI patients. Materials and methods: In this experimental study, 3,700 HBsAg- plasma samples were collected. Samples were tested for anti-HBc antibody and all of HBsAg)anti-HBc+ samples were screened for HBV-DNA by PCR. HBV-DNA positive samples were assigned as OBI cases. Also, flow cytometry analysi s was performed to examine the expre ssion ofCCR5 on CDS+T cell s of OBI patients. Results: Results of current study showed that 352 (9.5%) cases of samples were positive for antiHBc. Examination ofHBsAg"/anti-HBc+ samples for HBV-DNA by PCR showed that 57 (16.1%) cases had HBV-DNA. flow cytometrie studies indicated lymphoeytosis in these patients; however, the number of cells which expressed CDS+ and CCR5 is decreased significantly in patients, compared to healthy control. In addition to CDS+T cells, the expression ofCCR5 is also decreased on all immune cells . Conclusion: One of the chemokine receptors which are expr essed by CDS" T cells is CCR5 and these cells are recruited to infected tissues, including liver by CCR5 . Therefore, based on results of this investigation, one may conclude that due to the decreased expression of CCR5, the CDS+ T cells are unable to respond to the chemokines (CCRS ligands) and, hence, can not immigrate to the infected liver and incorporate in clearance of hepatitis B virus