THE DIAGNOSTIC CAPACITY OF SERUM AMYLOID-A PROTEIN FOR EARLY RECOGNITION OF KIDNEY ALLOGRAFT-REJECTION

We used new micro-ELISA test with sequence-specific antibody for every day monitoring of serum amyloid A protein (SAA) in 20 patients with k idney allografts in order to facilitate an early diagnosis of rejectio n. Altogether 44 SAA peaks were observed (beside those caused by surge ry) and 22 of them were caused by allograft rejections. When allograft rejection occurred in postsurgical period (first 4 days), SAA levels rose to mean 706 +/- 161 mg/l while initial SAA peaks (caused by surgi cal trauma) reached the mean value 306 +/- 55 mg/l. The statistical si gnificance was very high, P < 0.0001. In all nine rejection episodes i n this period SAA peaks were higher than 400 mg/l, so we chose this le vel as a reference limit for this period. SAA peaks caused by allograf t rejection in later period were also markedly higher (mean 461 +/- 17 6 mg/l) than those caused by infections or other complications (mean 1 33 +/- 82 mg/l, P < 0.0001) Baseline mean level was 9 +/- 5 mg/l. In a ll 13 rejection episodes in this period SAA peaks were higher than 200 mg/l, so we chose this level as a reference limit for this period. In 20 of 22 rejection episodes (91%) SAA elevation predicted rejection a nd usually started to rise sharply 2 days before it. An excellent corr elation between kidney allograft rejection and SAA reaction was found in this study (better than with CRP reaction) so we recommend everyday monitoring of SAA concentrations in patients with kidney allograft as a valuable aid in the early diagnosis and prediction of acute allogra ft rejection.