Mocci Francesco, Nettuno Marina
Occupational Medicine Institute, University of Sassari, Via Matteotti 58, 07100 Sassari, Italy.
J Occup Environ Med. 2006 Feb;48(2):158-64. doi: 10.1097/01.jom.0000183097.72738.a7.
The objective of this study was to examine the presence of mutant-p53 protein (p53Ag) and antibodies to p53 protein (p53Ab) in a population of workers exposed to vinyl chloride (VC).
We have investigated the presence of two cancer markers in the plasma of 151 subjects exposed to varying concentrations of VC (4-2823 ppm). The investigation took place in two sessions: in 1999, the analysis was limited to p53Ab, and in 2000, the analysis was repeated and extended to include also the mutant-p53Ag. The available information on the subjects in this study includes age, total years of employment in the VC polymerization industry, exposure concentration, results of abdominal ultrasonogram, hepatitis status, smoking and alcohol drinking status, and clinical records. Logistic regression analyses were performed to calculate the association between prevalence of positivity for p53Ab or mutant-p53Ag and cumulative VC exposure concentration after adjustment for confounding factors. t test and chi analyses were performed to test significant differences among groups.
Three (1.9%) of the 151 workers exposed to VC resulted seropositive for the mutant-p53Ag and five (3.3%) for the p53Ab. All seropositive subjects are distributed in the highest exposure classes (>1000 ppm). No seropositivity was found among controls. The stratified relationship between seropositivity and exposure appeared statistically significant (chi = 23.65 for mutant-p53Ag and 30.35 for p53Ab).
revealing its presence in subjects having a history of VC exposure greater than 1000 ppm. On the basis of this study, and the clinical experience of the authors, the presence of a minimum threshold for the carcinogenic effects of VC is hypothesized.
本研究的目的是检测氯乙烯（VC）暴露工人群体中突变型p53蛋白（p53Ag）和p53蛋白抗体（p53Ab）的存在情况。
我们调查了151名暴露于不同浓度VC（4 - 2823 ppm）的受试者血浆中两种癌症标志物的存在情况。调查分两个阶段进行：1999年，分析仅限于p53Ab；2000年，重复分析并扩展至包括突变型p53Ag。本研究中受试者的可用信息包括年龄、在VC聚合行业的总工作年限、暴露浓度、腹部超声检查结果、肝炎状况、吸烟和饮酒状况以及临床记录。进行逻辑回归分析以计算在调整混杂因素后p53Ab或突变型p53Ag阳性率与累积VC暴露浓度之间的关联。进行t检验和卡方分析以检验组间的显著差异。
151名暴露于VC的工人中有3名（1.9%）突变型p53Ag血清阳性，5名（3.3%）p53Ab血清阳性。所有血清阳性受试者均分布在最高暴露组（>1000 ppm）。对照组中未发现血清阳性。血清阳性与暴露之间的分层关系在统计学上具有显著意义（突变型p53Ag的卡方值 = 23.65，p53Ab的卡方值 = 30.35）。
揭示其在VC暴露史大于1000 ppm的受试者中的存在情况。基于本研究以及作者的临床经验，推测VC致癌作用存在最低阈值。
