ORIGINAL ARTICLE Differential distribution of IL28B.rs12979860 single-nucleotide polymorphism among Egyptian healthcare workers with and without a hepatitis C virus-specific cellular immune response Sayed F. Abdelwahab 1,2,3 • Zainab Zakaria 2 • Maha Sobhy 2 • Shaimaa Hamdy 2 • Mohamed A. Mahmoud 4 • Nabiel Mikhail 5 • Walaa R. Allam 2 • Eman Rewisha 4 • Imam Waked 4 Received: 3 January 2015 / Accepted: 30 April 2015 Ó Springer-Verlag Wien 2015 Abstract The CC genotype of the interleukin (IL)- 28B.rs12979860 gene has been associated with spontaneous hepatitis C virus (HCV) clearance and treatment response. The distribution and correlation of an IL28B.rs12979860 single-nucleotide polymorphism (SNP) with HCV-specific cell-mediated immune (CMI) responses among Egyptian healthcare workers (HCWs) is not known. We determined this relationship in 402 HCWs who serve a patient cohort with *85 % HCV prevalence. We enrolled 402 HCWs in four groups: group 1 (n = 258), seronegative aviremic subjects; group 2 (n = 25), seronegative viremic subjects; group 3 (n = 41), subjects with spontaneously resolved HCV infection; and group 4 (n = 78), chronic HCV pa- tients. All subjects were tested for an HCV-specific CMI response using an ex-vivo interferon-gamma (IFNc) ELISpot assay with nine HCV genotype-4a overlapping 15-mer peptide pools corresponding to all of the HCV proteins. All subjects were tested for IL28B.rs12979860 SNP by real- time PCR. An HCV-specific CMI was demonstrated in *27 % of the seronegative aviremic HCWs (group 1), suggesting clearance of infection after low-level exposure to HCV. The frequency of IL28B.rs12979860 C allele ho- mozygosity in the four groups was 49 %, 48 %, 49 %, and 23 %, while that of the T allele was 14 %, 16 %, 12 and 19 %, respectively, suggesting differential distributions among subjects with different HCV status. As reported, IL28B.rs12979860 predicted the outcome of HCV infection (p \ 0.05), but we did not find any relationship between the IL28B genotypes and the outcome of HCV-specific CMI responses in the four groups (p [ 0.05). The data show differential IL28B.rs12979860 genotype distribution among Egyptian HCWs with different HCV status and could not predict the outcome of HCV-specific CMI responses. Abbreviations PBMC Peripheral blood mononuclear cells CMI Cell-mediated immunity/immune response DMSO Dimethyl sulfoxide HCV Hepatitis C virus IFN Interferon IL Interleukin PBMC Peripheral blood mononuclear cells RT-PCR Reverse transcription polymerase chain reaction SEB Staphylococcal enterotoxin B SFC Spot-forming cells SNP Single-nucleotide polymorphism Electronic supplementary material The online version of this article (doi:10.1007/s00705-015-2446-7) contains supplementary material, which is available to authorized users. & Sayed F. Abdelwahab icpminia@yahoo.com; sayed.awahab@mu.edu.eg 1 Department of Microbiology and Immunology, Faculty of Medicine, Minia University, Minia 61511, Egypt 2 The Holding Company for Biological Products and Vaccines (VACSERA), 51 Wizaret El-Zeraa St., Agouza, Giza 22311, Egypt 3 Department of Microbiology, Taif Faculty of Pharmacy, Al-Haweiah, PO Box 888, Taif 21974, Kingdom of Saudi Arabia 4 Department of Hepatology, National Liver Institute, Menoufiya University, Menoufiya 32511, Egypt 5 South Egypt Cancer Institute, Asyut 71526, Egypt 123 Arch Virol DOI 10.1007/s00705-015-2446-7