[Evaluation of the usefulness of the antimyosin monoclonal antibody (AMA) uptake in the diagnosis of heart transplant (HT) rejection].

OBJECTIVE

To ascertain whether a given level of antimyosin monoclonal antibody (AMA) uptake in the endomyocardial biopsy (EMB) can identify patients with rejection.

MATERIAL AND METHOD

186 examinations were performed on 65 patients (8 women and 57 men) with orthotopic heat transplant (HT): Mean age 51 +/- 13 years. There were 3 examinations per patient (range 1-6). The studies were conducted 13 to 880 days after the HT. The C/p uptake indexes were obtained according to the Carrió y cols. method and the results were compared with the biopsy findings. Rejection was considered to be when the biopsy showed at least one site of necrosis.

RESULTS

1. We analyzed the C/P index in accordance with the post-HT interval and with the degree of rejection obtained by EMB. No group showed any significant differences between the patients with an without rejection (p > 0,05). 2) We applied a variable threshold based on post-HT interval, using an exponential curve defined on the basis of the interval of the values corresponding to patients without rejection and good progress compared with that of the rejection patients. This approach also did not contribute any improvement compared to the use of a fixed threshold due to the significant overlay of the values for patients with and without rejection. 3) Finally, we analyzed the individual evolution of the C/P indexes for each patient in terms of time. In patients whose clinical progress was good, the C/P indexes were observed to drop progressively over time. In those whose clinical progress was poor, abrupt increases in the index values were observed.

CONCLUSION

We were unable to differentiate significantly between patients with and without rejection in EMB using fixed and variable thresholds of the C/P index. However, the different patterns of evolution for each patient provide information on the lack of complications and could be used as a follow-up technique.