Determination of immune complexes in sera from dogs with various diseases by mastocytoma cell assay.

Canine immunoglobulin G complexed with particulate or soluble antigen can bind to the Fc receptors on the mastocytoma cells. Attachment of immune complexes composed of immunoglobulin G and soluble antigen (ovalbumin) to mastocytoma cells was detected by an inhibition of rosette formation with indicator cells (sensitized sheep erythrocytes). Therefore, canine circulating immune complexes may also attach to mastocytoma cells and inhibit rosette formation (mastocytoma cell assay). Sera from 326 dogs with various diseases and from 50 clinically normal dogs were assayed for immune complexes. The incidence of immune complexes in sera from normal dogs was 6% as compared with 25% in dogs with various diseases. The immune complexes were demonstrated in 37% of sera from dogs with various neoplastic diseases, 40% of sera from dogs with diabetes, 24% of sera from dogs with hypothyroidism, 50% of sera from dogs with mycotic disease, 75% of sera from dogs with arthritis, 38% of sera from dogs with kidney disorders, 40% of sera from dogs with neurological diseases, 45% of sera from dogs with various parasitic diseases, and 27% of sera from dogs with liver disorders. Only 19% of sera from dogs admitted to the hospital for various surgeries gave positive results. The incidence of the positive sera from dogs with various diseases is discussed in regard to their counterparts of human diseases.