ANALYSIS OF POLYMORPHISMS IN THE INTERLEUKIN 18 GENE PROMOTOR (-137 G/C AND -607 C/A) IN PATIENTS INFECTED WITH HEPATITIS C VIRUS FROM THE BRAZILIAN AMAZON.
BACKGROUND
The hepatitis C virus has been recognized as the leading cause of chronic liver disease in the world. Host genetic factors have been implicated in the persistence of hepatitis C virus infection. Single nucleotide polymorphisms at positions -607 C/A (rs1946518) and -137 G/C (rs187238) in the IL-18 gene promoter have been suggested to be associated with delayed hepatitis C virus clearance and persistence of the disease.


OBJECTIVE
Identify these polymorphisms in a population infected with hepatitis C virus from the Brazilian Amazon region.


METHODS
In a cross-sectional analytical study conducted in Belém, Pará, Brazil, 304 patients infected with hepatitis C virus were divided into two groups: group A, patients with persistent infection; group B, patients with spontaneous clearance. The control group consisted of 376 volunteers not infected with hepatitis C virus. Samples were analyzed by RT-PCR for the detection of viral RNA and by RFLP-PCR to evaluate the presence of the -137 G/C and -607 C/A IL-18 gene promoter polymorphisms.


RESULTS
Comparison of polymorphism allele frequencies between the patient and control groups showed a higher frequency of allele C at position -607 among patients (P=0.02). When the association between the polymorphisms and viral infection was analyzed, patients carrying genotype C/A at position -607 were found to be at higher risk of persistent hepatitis C virus infection (P=0.03).


CONCLUSIONS
The present results suggest a possible role of the -607 IL-18 gene promoter polymorphism in the pathogenesis of hepatitis C virus infection.
Laboratório de Patologia Clínica das Doenças Tropicais, Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, PA, BR.
Kemper Nunes dos
KN
Santos
Laboratório de Patologia Clínica das Doenças Tropicais, Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, PA, BR.
Marcella Kelly Costa de
MK
Almeida
Laboratório de Patologia Clínica das Doenças Tropicais, Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, PA, BR.
Amanda Alves
AA
Fecury
Laboratório de Patologia Clínica das Doenças Tropicais, Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, PA, BR.
Carlos Araújo da
CA
Costa
Laboratório de Patologia Clínica das Doenças Tropicais, Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, PA, BR.
Luísa Caricio
LC
Martins
D001938:Brazil; D003430:Cross-Sectional Studies; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006526:Hepatitis C / Q000235:genetics*; D006801:Humans; D020382:Interleukin-18 / Q000235:genetics*; D008297:Male; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic / Q000235:genetics; D012367:RNA, Viral
D004279:DNA, Viral; D020382:Interleukin-18; D012367:RNA, Viral