RESUMEN
BACKGROUND: Inflammatory cytokines including the IL-1 family, TNF-alpha and IL-6 mediate the formation of thrombosis on the luminal surface of atherosclerotic plaques. Gene polymorphisms that regulate these cytokines' expression may explain part of the variation in susceptibility to stroke in patients with carotid atherosclerosis. The aim of this study was to evaluate the role of single-nucleotide polymorphisms (SNPs) and haplotypes in inflammatory genes as they relate to symptomatic carotid atherosclerosis. METHODS: The study included 95 subjects with symptomatic (transient ischaemic attacks or stroke) and 113 subjects with asymptomatic carotid atherosclerotic disease. A panel of evenly spaced SNPs including previously reported functionally significant polymorphisms were genotyped for IL-1beta (10 SNPs), IL-1alpha (nine SNPs), IL-1RN (11 SNPs), IL-6 (seven SNPs) and TNF-alpha and TNF-beta (seven SNPs). RESULTS: Using single SNP analysis, IL-1RN rs315934 (P=0.025), IL-1RN rs315946 (P=0.042), IL-1RN rs315921 (P=0.035), IL-6 rs1180243 (P=0.018) and IL-1alpha rs2071373 (P=0.025) were associated with decreased odds of symptomatic carotid disease. Additionally, two diplotypes of the IL-1RN gene (P=0.023 and 0.0064) and one diplotype in the IL-1alpha gene (P=0.02) were associated with a protective affect from cerebral ischaemic events. Logistic analysis for interaction of the protective SNPs reveals an additive effect of all SNP pair combinations. CONCLUSION: These results suggest that genetic polymorphisms in proinflammatory genes may contribute to interindividual differences in the development of symptomatic carotid atherosclerotic disease.
Asunto(s)
Aterosclerosis/genética , Aterosclerosis/patología , Arterias Carótidas/patología , Inflamación/genética , Accidente Cerebrovascular/genética , Accidente Cerebrovascular/patología , Anciano , Estudios de Cohortes , ADN/genética , Femenino , Marcadores Genéticos , Pruebas Genéticas , Haplotipos , Humanos , Interleucina-1/genética , Interleucina-6/genética , Recuento de Leucocitos , Desequilibrio de Ligamiento , Masculino , Polimorfismo de Nucleótido Simple , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Riesgo , Factor de Necrosis Tumoral alfa/genéticaRESUMEN
BACKGROUND: Pain patients are often depressed and anxious, and benefit less from psychotropic drugs than pain-free patients. We hypothesize that this partial resistance is due to the unique neurochemical contribution to mood by afferent pain projections through the spino-parabrachial-hypothalamic-amygdalar systems and their projections to other mood-mediating systems. New psychotropic drugs for pain patients might target molecules in such brain systems. We propose a method to prioritize molecular targets by studying polymorphic genes in cohorts of patients undergoing surgical procedures associated with a variable pain relief response. We seek molecules that show a significant statistical interaction between (1) the amount of surgical pain relief, and (2) the alleles of the gene, on depression and anxiety during the first postoperative year. RESULTS: We collected DNA from 280 patients with sciatica due to a lumbar disc herniation, 162 treated surgically and 118 non-surgically, who had been followed for 10 years in the Maine Lumbar Spine Study, a large, prospective, observational study. In patients whose pain was reduced >25% by surgery, symptoms of depression and anxiety, assessed with the SF-36 Mental Health Scale, improved briskly at the first postoperative measurement. In patients with little or no surgical pain reduction, mood scores stayed about the same on average. There was large inter-individual variability at each level of residual pain. Polymorphisms in three pre-specified pain-mood candidate genes, catechol-O-methyl transferase (COMT), serotonin transporter, and brain-derived neurotrophic factor (BDNF) were not associated with late postoperative mood or with a pain-gene interaction on mood. Although the sample size did not provide enough power to persuasively search through a larger number of genes, an exploratory survey of 25 other genes provides illustrations of pain-gene interactions on postoperative mood--the mu opioid receptor for short-term effects of acute sciatica on mood, and the galanin-2 receptor for effects of unrelieved post-discectomy pain on mood one year after surgery. CONCLUSION: Genomic analysis of longitudinal studies of pain, depression, and anxiety in patients undergoing pain-relieving surgery may help to identify molecules through which pain alters mood. Detection of alleles with modest-sized effects will require larger cohorts.