Human Leukocyte Antigen (HLA) of DR type and its association with Children acute lymphoblastic Leukemia (ALL) in Basrah

Abstract

Background: Similar to other diseases, there are obvious correlation between human leukocyte antigen (HLA) and resistance to cancer.
Aim: To clarify the association between the alleles of HLA of DRB1 type with childhood acute lymphoblastic leukemia (ALL).
Patients and methods: This study was performed Basrah Specialized Hospital for children and Al-Sadder Teaching Hospital in Basrah Governorate during the period from October 2017 to march 2018. A total of 98 cases of newly diagnoses cases of acute leukemia were registered. Of them, 72 cases were diagnosed as ALL and 25 of them were enrolled in this study. Of the 25 cases, 15 were male and 10 were female and their age ranged between 1 to 12 years. Ten samples from apparently healthy individuals were considered as control group. This study included DNA extraction from 200μl whole blood. Molecular HLA-DRB1 typing for Basrah patients with acute lymphoblastic leukemia and controls using PCR-SSP (sequence- specific primers).
Results: The most common allele in DRB1 locus in Basrah patients and controls was HLA-DRB1* 07, which forms 18% (9/50) in patients and 50% (5/10) in controls, with a significant difference (P=0.015). Whereas HLA-DRB1*03 and *04 were more predominant alleles in patients (22% and 14% respectively) as compared to controls (15% and 0%, respectively), the difference not statistically significant (P>0.05). OR indicated an association between HLA-DRB1*03, *04, *11,*14 and *15 (OR= 1.598, 8.2, 3.02, 4.95 and 2.11 respectively) and susceptibility to ALL development in children. However, this finding need to be confirmed in a large scale study. HLA-DRB1*04 was more frequent in male patients with ALL compared with male controls, but the difference was not significant (10%, P=0. 3).
OR confirm an association between HLA-DRB1*03 and ALL in both gender (OR= 1.46 for male and 1.65 for female). HLA-DRB1*03 and *04 were more frequent in patients (22% for each) with age of >10 years than that in controls, but the difference was not significant. While HLA-DRB1*07 was with higher frequency in controls (55%) with age of > 10 years as compared to patients (27%), but not reach significant level. OR indicated as association between ALL and HLA-DRB1*03 (OR=2.28) and *04 (OR=5.8), but not significant.
Conclusion: This study indicated an inverse significant association between HLA-DRB1*07 and childhood Acute lymphoblastic leukemia (ALL) in all strata of analysis and may play be a protective loci against ALL in childhood. In contrast, HLA-DRB1 *03 and *04 were more common in patients than in control and OR (> 1) indicated a positive association which may reflect child susceptibility for the development of ALL. However, these findings need confirmation in a large scale study.