Correlation of sulfur mustard exposure and tobacco use with expression (immunoreactivity) of p53 protein in bronchial epithelium of Iranian "mustard lung" patients.

A unique chronic obstructive pulmonary disease (COPD), provisionally called "mustard lung", which occurs as a late complication of sulfur mustard (SM) exposure among SM-exposed Iranians, is presently poorly characterized. This investigation evaluates p53 immunoreactivity in bronchial epithelium of individuals with histories of tobacco use and/or SM exposure, as a tool to help define mustard lung. In this study, 68 COPD patients were segregated into two groups, 35 mustard-exposed patients (including 8 smokers) and 33 unexposed patients (including 16 smokers). Disease severity was assessed with pulmonary function tests. p53 protein in bronchial tissue obtained as biopsies was quantitated by immunostaining. Among nonsmokers, 41.2% of unexposed subjects and 14.8% of exposed subjects expressed p53. Among smokers, 25% of the unexposed group and 50% of the exposed group expressed the protein. Initial data trends suggest an additive contribution of SM exposure and smoking to p53 immunoreactivity. These results illustrate the use of p53 immunoreactivity in the characterization of COPD, including mustard lung.