Association of pretransplantation antiheart antibodies with clinical course after heart transplantation.

METHODS

Sera from 129 patients awaiting heart transplantation were assayed for the presence of IgM and IgG antiheart antibodies by means of sodium dodecyl sulphate-polyacrylamide gel electrophoresis and Western blotting. The patients' posttransplantation clinical course was assessed with regard to the amount of methylprednisolone, rabbit antithymocyte globulin, and OKT3 anti-T cell antibody, and the number of biopsy-confirmed rejection episodes. Before undergoing heart transplantation, approximately half the patients had weak IgM (45%) and weak IgG (48%) antiheart antibodies. However, 22.5% of the patients had strong IgM antiheart antibodies before transplantation, and they required more methylprednisolone than those who were negative and weak and approximately twice as much rabbit antithymocyte globulin as those who were negative, weak, or moderate. Six of the patients in this group required OKT3 therapy, and additionally they had a significantly greater number of rejection episodes than those patients who were negative (p = 0.006), or who had weak antiheart antibodies before transplantation (p = 0.001).

RESULTS AND CONCLUSIONS

Analysis of the pattern of banding of strong IgM antiheart antibody sera showed antiheart antibodies most frequently against myocardial proteins of 35, 42, 50, 60, 70, 110, 120, 150, 180, and 200 kDa. Several of these proteins were characterized by two-dimensional polyacrylamide gel electrophoresis and Western blotting as tropomyosin (35 kDa), actin (42 kDa), heat shock protein 60 (60 kDa), and heat shock protein 70 (70 kDa). All strong antiheart antibody sera showed reactivity against a 200 kDa protein corresponding to myosin heavy chain.