The relationship of HLA-G 14-bp insertion/deletion genetic polymorphism to the risk of multiple sclerosis and its clinical phenotypes

Study of HLA-G gene polymorphism and serum level of soluble HLA-G in patients infected with Mycobacterium tuberculosis

Tuberculosis affects about one-third of the world population. The incidence of the disease differs significantly among populations living under almost similar conditions, indicating the role of genetic factors. The present study aimed to appraise the impact of HLA-G gene polymorphisms and soluble HLA-G on the susceptibility to pulmonary tuberculosis. 48 patients with pulmonary tuberculosis and other 42 age- and sex-matched healthy individuals were included in the study. Both groups evaluated two gene polymorphisms in the HLA-G gene and soluble HLA-G protein. The frequency of Del/Del genotype of rs66554220 (14-bp Ins/Del) polymorphism in patients was 8.33% which was higher than that of controls (2.38%) with a significant difference (crude OR= 9.26, 95%CI=1.06-80.93, p=0.044). Such association remained significant after adjusting for confounding factors, including smoking, family history, socioeconomic status and residence (adjusted OR= 11.83, 95%CI=2.77-50.51, p= 0.01). The median serum level of soluble HLA-G in patients was 34.0 ng/ml (range 6.18-74.25 ng/ml), which was greater than that of controls (median 20 ng/ml, range 312-71.98 ng/ml) with a significant difference. We can conclude that The Del/Del genotype of rs66554220 (14-bp Ins/Del) polymorphism is an independent risk factor for pulmonary tuberculosis in the Iraqi population Keywords: Mycobacterium tuberculosis, HLA-G gene, single nucleotide polymorphism

Immunogenetic Relationship of HLA-G 14 bp Insertion/Deletion Polymorphism and Toll-Like Receptor 9 with Systemic Lupus Erythematosus in Egyptian Patients: A Case-Control Study

Introduction

The level of expression of the immunoregulatory human leukocyte antigen-G (HLA-G) has been suggested to play a role in the immunopathogenesis of systemic lupus erythematosus (SLE). A 14 bp insertion/deletion (ins/del) polymorphism in the 3ˊuntranslated region of HLA-G gene may influence the level of expression. The role of Toll-like receptor 9 (TLR9) in the pathogenesis of SLE has been highlighted. Data among Egyptian patients are quite limited.

Purpose

To detect the association of HLA-G 14 bp ins/del gene polymorphism with the susceptibility to SLE and to correlate TLR9 serum level with disease activity among Egyptian patients.

Patients and Methods

A case-control study that included 102 SLE female patients and 102 healthy matched volunteers as controls was carried out. Disease activity in patients was determined using the modified Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). HLA-G 14 bp ins/del genotype was detected by polymerase chain reaction (PCR). TLR9 serum level was estimated using enzyme-linked immunosorbent assay (ELISA) technique.

Results

The ins/ins genotype was significantly increased among SLE patients compared to healthy subjects (58.8% vs 9.8%; odds ratio [OR] = 11.79, P < 0.001). The 14 bp ins allele was significantly more frequent in SLE patients than in healthy subjects (65.7% vs 27.9%, respectively) and significantly associated with an increased risk of SLE (OR 4.94, P < 0.001). The mean TLR9 serum level showed a significant increase in SLE patients compared to healthy subjects (397.04±137.86 vs 195.22±45.14 ng/L, p < 0.001) and was significantly associated with disease activity as well as to patients’ HLA-G genotypes (p < 0.001).

Conclusion

Among Egyptian population, HLA-G 14 bp ins/ins homozygous genotype and ins allele may constitute a potential risk for SLE susceptibility, while TLR9 serum level is significantly associated with disease activity.