Diagnostic validity of multivariate combinations of biochemical analytes as markers for rejection and infection in the follow-up of patients with heart transplants.

The diagnostic validity of multivariate combinations of alpha 1-antitrypsin, alpha 2-macroglobulin, C-reactive protein, complement C3, complement C4, neopterin in serum, and neopterin in urine as markers for acute cardiac allograft rejection and for differential diagnosis of rejection and infections was investigated in the follow-up of 37 patients with heart transplants. Rejection was diagnosed by endomyocardial biopsy. Infections were classified as 'no infection', 'viral infection', and 'bacterial, fungal or mixed infections'. Although there are significant differences between the mean levels of analytes, multivariate discriminant analysis does not provide an adequate discrimination of rejection and infection states. In separate rejection diagnosis, multivariate combinations of analytes cannot replace endomyocardial biopsy. However, a multivariate combination of alpha 1-antitrypsin, alpha 2-macroglobulin, C-reactive protein, C3, C4 in serum, and neopterin in urine can be used as a screening procedure to reduce the number of endomyocardial biopsies.