Immunohistochemical Investigation of the Heart Allograft Myocardium (1991-1998).

What is a contribution of the humoral (vascular) and mixed type of the rejection episodes to all the episodes of heart allograft rejection is not quite clear, though this factor is of considerable importance for the choice of the treatment methods. The hearts from recipients, as well as endomyocardial biopsies of the heart allografts and postmortem material were investigated with the aim to determine the immunopathological process. Overall, 420 samples from 80 patients were analyzed. Immunofluorescence examination of endomyocardial biopsy showed that in 8 from 44 patients with heart allograft in postoperative period for the first six weeks there were revealed the immunomorphological signs of the acute humoral rejection, manifested as fixation of immunoglobulins and complement in capillaries. Six of them exhibited rejection of mixed type. Most patients in the later postoperative period exhibited a discrete local fixation of immunoglobulins and complement in myocardium, that can be assessed as one of the compartments of the chronic rejection process. In cases of the secondary administration of serum preparations, the fixation of immune complexes was shown in sarcolemma and capillaries, and can be proposed as a sign of serum disease. Repeated acute rejection episodes of humoral or mixed types raised at the first six weeks after transplantation. In the period from 1-5 years after operation, patients displayed discrete deposits of the immunoglobulins and complement as part of the chronic rejection process.