NATRIUETIC PEPTIDE RELEASE PREDICTS CARDIAC TRANSPLANT REJECTION AND MAY BE MEDIATED BY CYTOKINE PRODUCTION.:

1043 Cardiac natriuretic peptides (NP) are polypeptide hormones whose release by cardiocytes increases with cardiac hypertrophy and failure, with atrial natriuretic factor (ANF) arising primarily from the atria and brain natriuretic peptide (BNP) from the ventricles. Our previous studies showed ANF remains elevated after cardiac transplant despite normalization of filling pressures. Plasma ANF and BNP were measured in 10 consecutive pts before and after transplant at 24 hrs and at serial endomyocardial biopsies. Eight treated rejection episodes occurred in 4 pts. All rejection episodes (biopsy ISHLT grade 3-4) requiring treatment were associated with an increase in BNP > 400 pg/ml. Steadily increasing BNP levels preceded rejection and BNP dropped dramatically after treatment. Since OKT3 decreased BNP, increased BNP may be mediated by cytokine production by T-cells. Increased BNP was not always associated by increased ANF suggesting upregulation of BNP during rejection. (Figure)FigurePlasma NP pre- and post transplant in patient with rejection treated with OKT3 (BNP: black bars, ANF: shaded bars, prednisone and OKT3: arrows) BNP levels could form a sensitive screening test for rejection after cardiac transplant and BNP release during rejection may be mediated via cytokines.