The 5A Allele of the MMP3-Gene Promoter Polymorphism Is a Risk Factor for Poor Outcome of Hemodialysis Patients.

Cardiovascular morbidity is the leading cause of death in dialysis patients and many risk factors have been involved in its pathogenesis. Genetic susceptibility may be of importance including polymorphism for matrix metalloproteinase 3 (MMP3), which is an enzyme that catalyzes the degradation of collagen, proteoglycans, fibronectin, laminine and elastin. The MMP3 gene promoter contains an insertion/deletion polymorphism characterised by an array of 5 or 6 adenosine residues (5A/6A) at -1612 position. Literature data show that the 5A or 6A allele of the MMP3 gene shows different risk for cardiovascular and overall outcome in general population. The aim was to analyze the -1612 5A/6A promoter polymorphism in a group of hemodialysis patients and to correlate the findings with cardiovascular morbidity and 7-year all-cause and cardiovascular mortality. This study included 196 patients on hemodialysis for longer than six months at University Medical Center Zvezdara. The leading causes of end stage renal disease were hypertension and diabetes mellitus. Venous blood was collected on midweek dialysis session and genotype analysis was performed by using polymerase chain reaction-restriction fragment length polymorphism method. Among the 198 hemodialysis patients, there were 142 (72%) 5A/6A heterozygotes, 12 (6%) 5A/5A homozygotes, and 44 (22%) 6A/6A homozygotes. These data are consistent with Hardy-Weinberg equilibrium. After 7-year follow-up, the 5A homozygotes showed the lowest all-cause and cardiovascular survival, while the 6A homozygotes showed the highest cardiovascular survival. The 5A allele of the MMP3-gene promoter polymorphism is a potential risk factor in the poor outcome of hemodialysis patients.

Calcification in arteriovenous fistula blood vessels may predict arteriovenous fistula failure: a 5-year follow-up study.

PURPOSE: Arteriovenous fistula (AVF) is the preferred vascular access for hemodialysis. The impact of vascular calcification process on AVF survival remains unclear and results of several studies about this issue are controversial. In the light of the new knowledge about the different susceptibility for calcification process in different blood vessels, the aim of our study was to analyze whether the calcification of AVF-blood vessels may have an impact on AVF longevity. METHODS: The study included 90 patients, 49 males and 41 females, all of them Caucasians, with a mean age 62 ± 11 years, on regular hemodialysis for more than 1 year with patent primary AVFs. Vascular calcification in AVF-blood vessels or in the anastomotic region was detected using X-ray examination. RESULTS: Calcification in AVF-blood vessels was found in 62% of patients. Binary logistic regression analysis demonstrated that male gender, presence of diabetes mellitus and longer duration of AVF before calcification determination were associated with calcification of AVF-blood vessels. Using a Cox proportional hazard model adjusted for these standardized predicted values revealed that patients with present AVF-blood vessels calcification had increased risk to develop AVF failure with a hazard rate of 3.42 (95% confidence interval 1.00-11.67; P = 0.049). CONCLUSIONS: Calcifications of AVF-blood vessels are found frequently among dialysis patients and may jeopardize the survival of native AVF. We suggested the local X-ray as simple and valid method for detection of patients that are at risk for AVFs failure which should be monitored more closely.