Use of immunohistochemistry techniques in patients exposed to sulphur mustard gas.

We performed a pathologic study with further using an immunohistochemical technique (using anti-p63 and anti-CK5) on tissues obtained by open lung biopsy from 18 patients with previous exposure to sulphur mustard (SM) as case group and 8 unexposed patients (control group). The most frequent pathologic diagnosis was constrictive bronchiolitis (44.4%), followed by respiratory (22.2%) and chronic cellular bronchiolitis (16.7%) in the case group, and hypersensitivity bronchiolitis (50%) in the control group. The pathologic diagnoses were significantly different in the case and control groups (P = 0.042). In slides stained by anti-p63 and anti-CK5, the percent of stained cells and the mean number of epithelial cells were lower in the case group in comparison to the control group. This difference was significant for the mean number of cells stained by anti-CK5 (P = 0.042). Furthermore, there was a significant correlation between pathologic diagnosis and total number of cells and mean number of cells stained with anti-p63 and anti-CK5 (P  value = 0.002, <0.001, 0.044). These results suggest that constrictive bronchiolitis may be the major pathologic consequence of exposure to SM. Moreover, decrease of p63 in respiratory tissues affected by SM may suggest the lack of regenerative capacity in these patients.