Serum lysozyme activity in ceramic pneumoconiosis workers

Lysozyme (LZM) activities in sera of 236 persons including 159 persons with pneumoconiosis in a group of ceramic workers and 77 healthy persons were measured by tubidity method. The results were summarized as follows; LZM value in sera of controls was 5.6±1.2 μg/ml (M±S.D.) and those of subjects with each form of pneumoconiosis roentgenogram was 6.4±1.3 in PR1 (n=40), 7.1±1.8 in PR2 (n=33), 7.0±1.6 in PR3 (n=52) and 7.0±2.1 in PR4 (n=34). There were significant differences (p<0.01, respectively) between that of controls and of subjects with each form of pneumoconiosis, but no significant difference among those of subjects in PR2, PR3 and PR4. Increased values of LZM above 8.1 μg/ml (M+2S.D. of controls) appeared 2.6% in controls, 15.0% in PR1, 27.3% in PR2, 15.3% in PR3 and 17.6% in PR4. Those rates in subjects with each form of pneumoconiosis were significantly higher (p<0.01, respectively) in comparison with that of controls, but no significant difference among 4 forms was recognized. In the relationship between LZM values in sera and the results of the score evaluation of radiographic severity in pneumoconiosis, there was significant correlation with the scores of rounded opacities (r=0.39, p<0.01) and were no correlations with the score of other radiographic findings. In the relationship between LZM values in sera and the data of various pulmonary function tests in the group of pneumoconiosis, there was significant negative correlation with only the values of V₂₅/H/pre (r=-0.21, p<0.01). There were no significant differences in LZM values between subjects with and without subjective symptoms (e.g. dyspnea, cough, sputum) in PR3 or PR4. The correlation between LZM and ACE (Angiotensin Converting Enzyme) values in sera of subjects with pneumoconiosis was significantly recognized (r=0.43, p<0.01). LZM values in sera were not related with the years of occupational exposure in the group of pneumoconiosis.