[Immunoenzyme determination of ABO and secretor status in paraffin-embedded autopsy material]

Using the indirect immunoperoxidase technique (PAP method), A, B, and H antigens were identified on formaldehyde-fixed, paraffin-embedded kidney tissue from 100 autopsies. Comparison with the serologic findings showed all our blood group determinations to be correct. The labeling of the collecting tubules was evaluated as characteristic of the secretor. The secretor status determined according to this parameter was unequivocally confirmed by the Lewis constellation in 78 of 82 cases; group Le(a-b-) could be differentiated with immunohistochemical methods in secretors and nonsecretors. Determination of ABO blood groups and secretion behavior with immunohistochemical methods was correct even in those cases where classic serology failed due to hemolysis and decomposition. Immunohistologic results obtained with monoclonal antibodies were better than those obtained with human sera.