NONINVASIVE MONITORING USING SERUM AMYLOID-A AND SERUM NEOPTERIN IN CARDIAC TRANSPLANTATION

The monitoring of allograft function for cardiac transplant patients s till relies on endomyocardial routine biopsies. We investigated the di agnostic value of noninvasive monitoring using the parameters serum am yloid A protein and serum neopterin. The circulating levels of the acu te phase reactant, amyloid A protein, and the macrophage product, neop terin, were measured serially in 13 patients after cardiac transplanta tion. The mean period of observation was 240 days. Nine acute cardiac allograft rejections, five cases of viral infection and eight cases of bacterial infection occurred. The levels of serum amyloid A protein a nd serum neopterin remained low ((x) over tilde = 6.0 mg/dL and 12.6 n mol/L, respectively) during the periods of stable graft function. In c ontrast, both parameters were significantly elevated (p < 0.01) during the rejection episodes ((x) over tilde = 12.7 mg/dL and 38.0 nmol/L f or serum amyloid A protein and serum neopterin, respectively). For a r eliable differentiation between rejection and stable graft function, s erum amyloid A protein had a diagnostic accuracy of 84% (with a cut-of f level of 10 mg/dL) and serum neopterin had one of 75% (with a cut-of f level of 23 nmol/L). However, significant increases in the circulati ng levels of serum amyloid A protein and serum neopterin were also obs erved during bacterial ((x) over tilde = 14.9 and 88 nmol/L, respectiv ely) and viral ((x) over tilde = 6.2 mg/dL and 44 nmol/L, respectively ) infections. The detection of immunological complications after cardi ac transplantation using serial measurements of serum amyloid A protei n and serum neopterin is possible. These parameters can be used to hel p in judging both the need and the optimal timing for the otherwise fr equent endomyocardial biopsies. (C) 1998 Elsevier Science BN. All righ ts reserved.