Some factors of local immunity in respiratory diseases

The authors examined immunoglobulins, the total LDH activity and its isoenzymes in nasopharyngeal secretion in 6-36 month old patients suffering from acute or recurrent respiratory diseases. They investigated 232 children. The mean values of IgA were 83.7 +/- 57.2 mg/100 ml and they were found in 49.7% of the examined patients. The mean IgA values were statistically significantly higher in 13-24 month than in 6-12 month old patients. The mean values of IgG were 51.3 +/- 43,8 mg/100 ml and no statistical significancies were found among the individual age groups. The mean values of total LDH activity were 7,640.8 +/- 5,681.7 U/1 and isoenzyme pattern was characterized especially by high percentages of LDH4 and LDH5 fractions. The highest values were found in purulent secretions. These results support the opinion that LDH and its isoenzymes are products of the mucous membranes.