Clinical predictors of immunotolerance in heart transplantation.
OBJECTIVE
The drugs routinely administered to prevent rejection often cause lethal side effects. Tolerant patients, therefore, should be identified to minimize these problems. The aim of this analysis was to identify clinical variables that may be associated with tolerance.


METHODS
We recruited 522 heart transplants (HT), excluding combined procedures, retransplantations, pediatric recipients, and subjects who died in the first year to obtain a cohort of 375 patients. Two groups were distinguished by the presence of echocardiographic, clinical, or pathological evidence of rejection in the first year (15 echocardiograms and 10 protocol biopsies per patient); 99 tolerant patients were compared with 276 nontolerant patients. We analyzed clinical variables related to morbidity and mortality.


RESULTS
The univariate analysis showed few differences between the groups. The multivariate analysis showed that only major histocompatibility complex (MHC)-A and MHC-DR matched recipients were significantly associated with tolerance. Thus, the likelihood of tolerance was increased by 1.7- and 2.8-fold if 1 or 2 MHC-I matches were present and by 3.4- and 3.7-fold if 1 or 2 MHC-DR matches were present, respectively survival curves showed significant differences (P=.034). Most deaths in both groups were related to immunosuppressive drugs; among tolerant subjects, deaths were due to infection and neoplasms and among nontolerant patients, deaths were due to chronic rejection, neoplasms, and infection.


CONCLUSIONS
The only clinical parameter that can determined whether a HT recipient was tolerant was MHC-A and MHC-DR matching. If there is matching, a reduced immunosuppressive load should be prescribed to prevent drug toxicity.
Heart Failure and Transplant Unit, Department of Cardiology, La Fe University Hospital, and Mixed Research Unit, Principe Felipe Research Center-University of Valencia, Valencia, Spain. jaimeaguero30@hotmail.com
L
L
Almenar
J
J
Agüero
L
L
Martínez-Dolz
J E
JE
O'Connor
I
I
Sánchez-Lázaro
J
J
Navarro
R
R
Raso
F
F
Buendía
D004562:Electrocardiography; D006084:Graft Rejection; D016027:Heart Transplantation / Q000276:immunology*; D006801:Humans; D007108:Immune Tolerance; D008285:Major Histocompatibility Complex / Q000276:immunology