HLA Allele E*01:01 Is Associated with a Reduced Risk of EBV-Related Classical Hodgkin Lymphoma Independently of HLA-A*01/*02.
BACKGROUND
An inefficient immune response against Epstein-Barr virus (EBV) infection is related to the pathogenesis of a subgroup of classical Hodgkin lymphomas (cHL). Some EBV immune-evasion mechanisms target HLA presentation, including the non-classical HLA-E molecule. HLA-E can be recognized by T cells via the TCR, and it also regulates natural killer (NK) cell signaling through the inhibitory CD94/NKG2A receptor. Some evidences indicate that EBV-infected B-cells promote the proliferation of NK subsets bearing CD94/NKG2A, suggesting a relevant function of these cells in EBV control. Variations in CD94/NKG2A-HLA-E interactions could affect NK cell-mediated immunity and, consequently, play a role in EBV-driven transformation and lymphomagenesis. The two most common HLA-E alleles, E*01:01 and E*01:03, differ by a single amino acid change that modifies the molecule function. We hypothesized that the functional differences in these variants might participate in the pathogenicity of EBV.


OBJECTIVE
We studied two series of cHL patients, both with EBV-positive and-negative cases, and a cohort of unrelated controls, to assess the impact of HLA-E variants on EBV-related cHL susceptibility.


RESULTS
We found that the genotypes with at least one copy of E*01:01 (i.e., E*01:01 homozygous and heterozygous) were underrepresented among cHL patients from both series compared to controls (72.6% and 71.6% vs 83%, p = 0.001). After stratification by EBV status, we found low rates of E*01:01-carriers mainly among EBV-positive cases (67.6%). These reduced frequencies are seen independently of other factors such as age, gender, HLA-A*01 and HLA-A*02, HLA alleles positively and negatively associated with the disease (adjusted OR = 0.4, p = 0.001). Furthermore, alleles from both HLA loci exert a cumulative effect on EBV-associated cHL susceptibility.


CONCLUSIONS
These results indicate that E*01:01 is a novel protective genetic factor in EBV-associated cHL and support a role for HLA-E recognition on the control of EBV infection and lymphomagenesis.
Group of Molecular Pathology, Instituto de Investigación Sanitaria Puerta de Hierro (IDIPHIM), Majadahonda, Spain.
Paloma
P
Martín
Department of Hematology, Instituto de Investigación Sanitaria Puerta de Hierro (IDIPHIM), Majadahonda, Spain.
Isabel
I
Krsnik
Department of Hematology, Instituto de Investigación Sanitaria Puerta de Hierro (IDIPHIM), Majadahonda, Spain.
Belen
B
Navarro
Department of Oncology, Instituto de Investigación Sanitaria Puerta de Hierro (IDIPHIM), Majadahonda, Spain.
Mariano
M
Provencio
Department of Pathology, MD Anderson Cancer Center, Madrid, Spain.
Juan F
JF
García
Group of Molecular Pathology, Instituto de Investigación Sanitaria Puerta de Hierro (IDIPHIM), Majadahonda, Spain.
Carmen
C
Bellas
Group of Immunogenetics and Histocompatibility, Instituto de Investigación Sanitaria Puerta de Hierro (IDIPHIM), Majadahonda, Spain.
Carlos
C
Vilches
Group of Immunity and lymphoproliferative diseases, Instituto de Investigación Sanitaria Puerta de Hierro (IDIPHIM), Majadahonda, Spain.
Natalia
N
Gomez-Lozano
D000328:Adult; D000368:Aged; D000483:Alleles; D016022:Case-Control Studies; D004198:Disease Susceptibility; D004843:Epistasis, Genetic; D020031:Epstein-Barr Virus Infections / Q000150:complications*; D005260:Female; D005838:Genotype; D015234:HLA-A Antigens / Q000235:genetics*; D004854:Herpesvirus 4, Human; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006689:Hodgkin Disease / Q000209:etiology* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010641:Phenotype; D012306:Risk; D000097625:HLA-E Antigens
D015234:HLA-A Antigens; D015395:Histocompatibility Antigens Class I; D000097625:HLA-E Antigens