Immunologic studies of heart tissue. III. Occurrence of bound gamma globulin in auricular appendages from rheumatic hearts. Relationship to certain histopathologic features of rheumatic heart disease.

Using fluorescent antibody methods, deposits of bound gamma globulin, as determined in unfixed washed sections of auricular appendages from rheumatic hearts, were noted in a significant number (18 per cent) of 100 specimens studied. Such deposits were observed in myofibers, sarcolemma, interstitial connective tissue, and vessel walls. Albumin and fibrin were generally found absent from these sites. Control hearts from normal and pathologic material, including postmortem and biopsied specimens, in general, did not reveal such deposits. These various tissue sites which contained bound gamma globulin frequently exhibited evidence of alteration as indicated both by enhanced affinity for eosin and by strongly positive reaction with the periodic acid-Schiff reagent, and appeared comparable in some cases to "fibrinoid." Bound gamma globulin was not observed in cellular or stromal components of Aschoff lesions, nor was the occurrence of Aschoff lesions correlated with presence of bound gamma globulin. It is suggested that deposition of gamma globulin and the eosinophilic alteration associated with such deposition are related to certain of the pathologic changes of rheumatic heart disease. The nature of such deposits of gamma globulin was considered from immune and non-immune points of view.