IMMUNOLOGIC STUDIES IN PULMONARY EMPHYSEMA

Of several standard immunological tests employed for determining the immunological affinity of horse sera for a saline extract of horse lung, only the latex fixation test was found applicable. About 30-35 of the sera tested from normal horses and about 60 of the sera tested from emphysematous horses reacted with a horse lung preparation in the latex fixation test. Most of these positive sera did not react with normal horse serum when tested in a similar manner, but nearly all of the positive sera which were tested for their reactivity with horse kidney showed positive reactions. The affinity of the sera for the lung extract is removed by absorption with lyophilized horse lung, but not by absorption with normal horse serum nor with lyophilized horse liver or horse kidney. The reactivity of positive sera is reduced by prolonged heating at 56 deg C. There may be some individual tissue antigens which cause some horse sera to react with a lung preparation from a horse of one type but not of another.