Human leukocyte antigen-DRB1 polymorphism in childhood acute lymphoblastic leukemia

Similar to autoimmune diseases, there are clear associations between resistance or susceptibility to cancer and the classic human leukocyte antigen (HLA) profile of an individual. HLA-associated susceptibility to childhood acute lymphoblastic leukemia (ALL) may provide clues to leukemo-genesis in general and to the role of other risk factors. The present study aimed to determine the association between the HLA-DRB1 genotype and susceptibility to ALL in children and to assess the prognostic value of HLA-DRB1 alleles in these patients. This study included 50 ALL patients who were consecutively admitted to the Pediatric Oncology Unit of Zagazig University Hospital and 50 gender-matched healthy volunteers as a control group. The patients were subjected to full clinical history, thorough clinical examination and routine laboratory investigations. Molecular HLA-DRB1 typing for patients and controls using the reverse sequence-specific oligonucleotide probe technique was performed. HLA-DRB1*04 allele frequency was significantly higher in female patients compared to that in female controls (P=0.03) and in patients aged <10 years compared to those aged >= 10 years at the time of diagnosis (P=0.01). HLA-DRB1*11 allele frequency was significantly higher in high-risk compared to standard-risk patients (P=0.01) and in refractory patients compared to those who achieved remission (P=0.02). In conclusion, the HLA-DRB1*04 allele appears to be a female-specific susceptibility factor for the acquisition of childhood ALL and it may affect the age of onset of ALL. In addition, the HLA-DRB1*11 allele may be of prognostic significance in childhood ALL. However, further larger studies are required to support the conclusions drawn from this study.