title: A genetic variant in the interleukin 28B gene as a major predictor for sustained virologic response in chronic hepatitis C virus infection.
abstract: OBJECTIVE
  The IL28B single nucleotide polymorphism (SNP) rs12979860 is a major predictor of treatment outcomes in hepatitis C virus (HCV) infection, but its distribution widely varies among populations and ethnicities. We undertook this study to investigate the distribution of IL28B SNP rs12979860 in Mexican patients with HCV infection and to assess its usefulness in predicting response to pegylated interferon-alpha and ribavirin (PegIFN-α/RVB) therapy.
  
  
  METHODS
  Three hundred and fifty patients with chronic HCV infection were studied. The frequency of sustained virologic response (SVR), non-responders and relapses following a course of standard therapy was longitudinally assessed in 295 of these patients. IL28B SNP rs12979860 was genotyped from genomic DNA using real-time RT-PCR. The number needed to treat (NNT) to achieve a SVR was calculated.
  
  
  RESULTS
  Seventy six (22%) patients were CC homozygous, 210 (60%) were heterozygous and 64 (18%) showed TT homozygosity for the IL28B SNP rs12979860. After a standard course of PegIFN-α/RVB, 69% of patients with the CC genotype, 46% of the heterozygous group and 38% of those with the TT genotype (p = 0.001) achieved a SVR. Conversely, the percentage of non-responders was 15, 43, and 48% (p <0.0001), respectively. The NNT to achieve a SVR was strongly influenced by the IL28B rs12979860 genotype and ranged from 2-10.
  
  
  CONCLUSIONS
  The IL-28B rs12979860 CC genotype was found in 22% of Mexican patients chronically infected by HCV. Genotyping IL28B SNP rs12979860 is useful to predict the response to a standard regimen with PegIFN-α/RVB, especially in those infected with HCV genotype 1.
authors.affiliation: Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Gastroenterologia, México, D.F., Mexico. Electronic address: ssiamx@yahoo.com.mx.
authors.forename: Ma Sara
authors.initials: MS
authors.lastname: Sixtos-Alonso
authors.affiliation: Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Gastroenterologia, México, D.F., Mexico.
authors.forename: Rosalba
authors.initials: R
authors.lastname: Avalos-Martinez
authors.affiliation: Servicio de Gastroenterología, Endoscopia y Hepatología de la UMAE, Hospital de Especialidades, Centro Medico Nacional Siglo XXI, México, D.F., Mexico.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Sandoval-Salas
authors.affiliation: Servicio de Gastroenterología, Endoscopia y Hepatología de la UMAE, Hospital de Especialidades, Centro Medico Nacional Siglo XXI, México, D.F., Mexico.
authors.forename: Margarita
authors.initials: M
authors.lastname: Dehesa-Violante
authors.affiliation: Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Gastroenterologia, México, D.F., Mexico.
authors.forename: Ignacio
authors.initials: I
authors.lastname: García-Juarez
authors.affiliation: Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Gastroenterologia, México, D.F., Mexico.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Chávez-Ayala
authors.affiliation: Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Gastroenterologia, México, D.F., Mexico.
authors.forename: Aarón
authors.initials: A
authors.lastname: Domínguez-López
authors.affiliation: Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Gastroenterologia, México, D.F., Mexico.
authors.forename: Florencia
authors.initials: F
authors.lastname: Vargas-Vorácková
authors.affiliation: Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Gastroenterologia, México, D.F., Mexico.
authors.forename: Liz
authors.initials: L
authors.lastname: Toapanta-Yanchapaxi
authors.affiliation: Departamento de Inmunología, Instituto Nacional de Cardiología Ignacio Chávez, México, D.F., Mexico.
authors.forename: Luis Manuel
authors.initials: LM
authors.lastname: Amezcua-Guerra
authors.affiliation: Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Gastroenterologia, México, D.F., Mexico.
authors.forename: Misael
authors.initials: M
authors.lastname: Uribe
authors.affiliation: Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Gastroenterologia, México, D.F., Mexico.
authors.forename: Juan Francisco
authors.initials: JF
authors.lastname: Sánchez-Ávila
mesh_terms: D000368:Aged; D000998:Antiviral Agents / Q000627:therapeutic use; D015331:Cohort Studies; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D019698:Hepatitis C, Chronic / Q000821:virology*; D006801:Humans; D007372:Interferons; D007378:Interleukins / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D000095022:Interferon Lambda
chemical_list: D000998:Antiviral Agents; D007372:Interferons; D007378:Interleukins; C000624353:interferon-lambda, human; D000095022:Interferon Lambda
keywords: Hepatitis C virus; Interferons; Interleukin 28; SNP rs12979860