The level of blood lead, zinc and relationship with the metallothionein gene polymorphism in chronic kidney failure

Abstract

Background. Chronic kidney disease is defined by renal damage or an estimated glomerular filtration rate less than 60 ml/min/1.73 m2. Lead is a ubiquitous environmental factor that can contribute to lengthy clinical complications in individuals with chronic kidney disease. They can be exposed to changes in zinc homeostasis. The MT2A gene also expresses a wide range of physiological and pathological effects. Materials and methods. This study involved 60 blood samples from individuals with kidney disease on hemodialysis, and 60 samples from apparently healthy individuals as a control. The purpose was to identify the molecular character of the genotype of the MT2A gene SNP (A>G) (rs28366003) in a cohort of chronic kidney disease subjects and apparently healthy controls. Results. Blood lead and zinc serum levels were compared between patients and healthy controls by flame atomic absorption spectrophotometry. Lead contents were significantly and considerably higher, with significant differences (p > 0.01) between the patient cohort and the healthy controls, while serum zinc was significantly decreased. Males are more affected than females with chronic kidney disease, and individuals older than 40 years had a greater risk of complications. Hypertension has a meaningful positive relation to chronic kidney disease, and it is therefore considered a possible risk factor. The rs28366003 A>G genotype associated with increased risk of kidney disease in Iraqi patients demonstrated considerable variation. The median age of kidney disease patients was 20 to 69 years. Genotypes and allele frequencies of rs28366003, A>G in the kidney disease population: 51.7 % (n = 31) were wild-type (AA), 33.3 % (n = 20) were heterozygous (AG) and 15 % (n = 9) were homozygous (GG). The allele frequencies of A and G were 68.3 and 31.7 %. Conclusions. Thus, the drop in zinc levels and the harmful increase in blood lead in chronic kidney failure patients who possess SNP variants of the MT2A gene, specifically rs28366003, may be involved in kidney disease susceptibility.