FK506 vs. cyclosporin. Pathologic findings in 1067 endomyocardial biopsies

Case report of a Quilty lesion within a coronary artery

The Quilty lesion is the moniker of a lymphoid proliferation that resides predominantly in the endocardium and underlying myocardium within transplanted hearts. It has been described in the endocardium, myocardium, and epicardium. Although its pathogenesis is not understood, it is generally considered that the Quilty lesion is not a manifestation of acute rejection. However, its clinical significance and relation to acute rejection, such as its pathogenesis, are still not completely understood. Immunohistochemical studies distinguish between the cellular infiltrates of Quilty lesions and those associated with acute rejection. We describe, what we believe to be, the first case of a Quilty lesion in an epicardial coronary artery from an 8-year-old girl with congenital heart disease who required retransplantation 25 months after her cardiac transplantation for severe graft coronary artery disease. The lesion consisted of an intramural nodular aggregate of numerous T and B lymphocytes, with fewer macrophages, characteristic of a Quilty lesion.

Freedom From Graft Vessel Disease in Heart and Combined Heart- and Kidney-transplanted Patients Treated With Tacrolimus-based Immunosuppression

BACKGROUND

In end-stage cardiomyopathy where concomitant chronic renal failure is a contraindication for cardiac transplantation (HTx), simultaneous heart and kidney transplantation (HKTx) may be the only feasible therapeutic option. Due to the increased donor shortage, the clinical outcome of combined HKTx patients on tacrolimus-based immunosuppression was assessed and compared with a group of HTx patients.

METHODS

Three hundred forty-nine HTxs, including 13 (4%) combined HKTxs, were performed since 1995. Two hundred twenty-one HTx and all HKTx recipients received tacrolimus-based immunosuppression. Acute rejection episodes (AREs), infections, renal function and clinical outcome were evaluated. Pre-operative renal diagnoses for HKTx patients included cystic nephropathy (n = 4), glomerulonephritis (n = 4), cytostatica-induced nephropathy (n = 1), chronic rejection after renal transplant (n = 1), reflux nephropathy (n = 2) and chronic calcineurin-inhibitor -induced nephropathy after HTx (n = 1). Twelve patients (92%) were on hemodialysis pre-operatively, 1 underwent implantation of a left ventricular assist device (LVAD) before HKTx.

RESULTS

After 4.7 +/- 2 years, 92% of HKTx compared with 85% of HTx patients had survived (p = 0.42). Acute cardiac rejection episodes were more frequent in HTx than in HKTx patients (0.04 +/- 0.09 vs 0.02 +/- 0.04 ARE/100 patient-days; p = 0.07). Incidence of infection was comparable (0.3 +/- 0.2 vs 0.5 +/- 0.4 infection/100 patient-days). Freedom from transplant vasculopathy was 100% in the HKTx group compared with 71% in the HTx group after 4 years (p = 0.04).

CONCLUSIONS

Tacrolimus-based immunosuppression yields promising long-term results in HKTx and HTx. The incidence of transplant vasculopathy seems to be lower after HKTx than after HTx. If these results are secondary to a protective effect of tacrolimus-induced tolerance or of tolerance-associated co-transplantation they will need to be investigated in prospective multicenter trials.

The yield of surveillance endomyocardial biopsies as a screen for cellular rejection in pediatric heart transplant patients

Endomyocardial biopsy is commonly used to screen for cellular rejection in pediatric heart transplant patients. The yield of EMBs when combined with newly developed immunohistochemical techniques and modern immunosuppression in pediatric heart transplant patients is unknown. After OHT, surveillance biopsies were performed on a routine basis on all pediatric patients. EMBs were also performed on symptomatic OHT patients suspected to have rejection. All positive results (greater than ISHLT grade 1B) were confirmed with immunohistochemical staining. A retrospective review of consecutive EMBs performed in this institution from January 1995 to January 2003 was performed. The echocardiographic results, clinical history and treatment changes at the time of every biopsy were also catalogued. Of the 1093 EMB results from 136 pediatric heart transplant grafts (127 patients, 64 male) reviewed, 825 biopsies were performed on patients managed with tacrolimus and 268 were performed on patients managed with cyclosporine. The patients managed with tacrolimus had an incidence of 0.85% (7/825) for significant rejection (greater than ISHLT grade 1B rejection) vs. an incidence of 4.1% (11/268) for the patients on cyclosporine (p < 0.0005). In the asymptomatic tacrolimus patients, only two screening biopsies (0.26%) manifest significant rejection, and both of these were performed within the first month after transplantation. Of the symptomatic tacrolimus patients, 9.1% (n = 5) had findings on biopsy consistent with significant cellular rejection. There were 25 patients with grade 1B rejection. Twenty-two of these patients were not treated, and all cases of grade 1B rejection resolved without clinical sequelae. For pediatric patients more than 30 days after OHT, EMB has failed to reveal significant episodes of cellular rejection in asymptomatic patients managed with tacrolimus.