Blood pressure regulation by CCR genes

New genetic evidence strongly supports a role for the immune system in the pathogenesis of essential hypertension (EH) through chemokines and their receptors (CCR) involvement. The aim of the present study was to evaluate the possible relation between CCR2 and CCR5 alleles and blood pressure (BP) levels in hypertensive subjects. In all, 118 essential hypertensive outpatients (male 90, female 28; stage I and II; age 27-54 years; not previously treated with antihypertensive drugs) were selected for the study. All of the subjects underwent office BP measurement. Subsequently, 24-h ambulatory BP monitoring (ABPM) was performed with a Spacelabs 90207 monitor during a regular working day. CCR264I and CCR5Delta32 polymorphisms were determined by polymerase chain reaction (PCR), following the standard molecular biology protocols. Allelic frequencies were the following: CCR5Delta32= 0.097, CCR264I=0.101. Logistic regression analysis showed an association between the CCR5Delta32 allele and the following: 24-h systolic BP (SBP >140 mmHg; p = 0.027), values over the 50th percentile of 24-h SBP (p = 0.032), and the values over the 50th percentile of nighttime SBP (p = 0.039). Office BP showed an association with the Delta32 allele in a range over the 75th percentile of SBP (p = 0.087) and the 75th percentile of DBP (p = 0.085). No significant association was observed for CCR264I and BP levels or between physiological nocturnal BP decline and genotype. The observed results not only support the role of the immune system in the development and maintenance of hypertension, but they also indicate an influence of CCR5Delta32 polymorphism on the establishment of BP levels.