Cross-reactivity of anti-human antibodies in canine tissues using immunohistochemistry

Dogs represent the most common domesticated animal outside of the research arena for whom tissue for pathological diagnosis is requested. Currently, there is a paucity of literature describing the cross-reactivity of anti-human antibodies on canine tissue for oncological diagnosis. This study aimed to evaluate the cross-reactivity of commonly used anti-human diagnostic antibodies in veterinary histopathology. One hundred seventy-one various samples from 153 canine tissues were processed to paraffin and tested with 76 fully validated anti-human antibody clones frequently employed in hospital pathology laboratories using immunohistochemistry methods to determine which ones exhibited comparable cross-reactivity and therefore potential use in veterinary pathology laboratories. Some of the anti-human antibodies were excluded from the study due to a lack of comparable canine tissues on which to test. However, almost half of the antibodies demonstrated results similar to those in human tissues and about one quarter showed weaker or less consistent labeling. The antibodies that demonstrated weaker or inconsistent labeling suggest areas where further development and modification could improve their employment on canine specimens. Fully one-third of antibodies tested failed to show labeling congruent with human tissues. The outcomes from this study could facilitate the adoption of established anti-human antibody markers in veterinary histopathology practices.