Non-ischemic left ventricular dysfunction after pediatric cardiac transplantation: treatment with plasmapheresis and OKT3

ECLS for children with late (post-discharge) rejection after heart transplantation

Rejection with acute hemodynamic compromise after OHT is rare in children, and is associated with poor survival. We retrospectively reviewed the management, course and outcome of recipients with late (following initial hospital discharge) rejection with acute hemodynamic compromise who were supported on ECLS. Of 197 consecutive children undergoing OHT (84 male; mean [SD] age 8.3 [5.7] [range 0.1-18.8 yr]) between 2/2002 and 10/2012, 187 children survived and were discharged from hospital. Mean (SD) follow-up was 5.0 (3.1) (range 0.1-10.6) yr. During follow-up, seven presented with severe hemodynamic compromise after transplantation (of whom one patient had been transplanted elsewhere). All seven children, who presented in hemodynamic collapse with poor cardiac function refractory to inotropic support, were placed on ECLS-two following in-hospital cardiac arrest. The median duration of ECLS was 6 (range 5-15) days. All survived to decannulation, with one death from overwhelming sepsis 20 days after presentation. The median (range) duration (in days) of inotropic requirement post ECLS was 11 (5-27), the median ventilation time was 8 (7-30), median ICU length of stay was 14 (10-54), and median hospitalization was 24 (19-118). In all, ventricular function normalized (FS >28%) within 10 (7-22) days. There was significant short-term morbidity; however, over a median follow-up of 5.9 (range 0.7-9.2) yr, all survivors have good functional status with no significant apparent neurological sequelae. ECLS thus appears to be a good rescue therapy for children with severe acute rejection post OHT, refractory to conventional treatment, leading to good medium-term outcome.

Mortality and Morbidity in Pre-sensitized Pediatric Heart Transplant Recipients With a Positive Donor Crossmatch Utilizing Peri-operative Plasmapheresis and Cytolytic Therapy

BACKGROUND

The difficulty in obtaining a prospective negative donor/recipient crossmatch limits the ability to successfully transplant pediatric heart transplant candidates who show evidence of antibodies to multiple human leukocyte antigens (pre-sensitized patients).

METHODS

We utilized a protocol that included peri-operative plasmapheresis, thymoglobulin and cyclophosphamide in 17 pre-sensitized (panel-reactive antibodies [PRA] >10%) pediatric patients to accept donors for these patients without a prospective crossmatch between 1995 and 2005. A retrospective review of survival, rejection and infection was performed, comparing the frequency of rejection and infection in our patients who were transplanted with a complement-dependent cytotoxic (CDC)-positive donor/recipient crossmatch to those patients transplanted with a negative crossmatch.

RESULTS

Thirteen of 17 patients were found to have a CDC-positive crossmatch. Actuarial survival after transplantation was 85% at 1 year and 73% at 3 years. Twelve of 13 (92%) of these patients experienced rejection, and 5 of 13 (38%) had recurrent rejection, generally in the first 2 months after transplantation. Rejection was associated with hemodynamic compromise in 58% of first rejection episodes and 67% of episodes of recurrent rejection. The frequency of rejection in these patients was significantly greater than the frequency in patients with a negative crossmatch in the first 6 months after transplantation, but not afterward. The frequency of infection episodes was not significantly different between the groups.

CONCLUSIONS

Heart transplantation in pre-sensitized pediatric recipients with a CDC-positive donor/recipient crossmatch may result in reasonable short-term survival, but with a high frequency of early rejection, often with hemodynamic compromise.

Surveillance for transplant coronary artery disease in infant, child and adolescent heart transplant recipients: an intravascular ultrasound study

BACKGROUND

Transplant coronary arteriopathy (TCAD) limits graft survival after heart transplantation in adult and pediatric heart transplant recipients. Intravascular ultrasound (IVUS) provides a highly sensitive technique to detect TCAD. However, its use to determine factors associated with TCAD in pediatric recipients has been limited and its utility in surveillance for symptomatic TCAD in this population is uncertain.

METHODS

One hundred fifty-eight IVUS studies from 66 patients (27 <1 year and 39 >1 year at time of transplant) were performed 12 to 144 months after transplantation within the routine surveillance for TCAD. Maximal intimal thickness (MIT) and intimal index (II) were measured, and the Stanford classification was utilized to grade overall severity of disease. Mixed repeated-measures linear regression models were used to investigate the main and interaction effects of age at transplant, age at time of study, time since transplant and rejection events.

RESULTS

Age at catheterization (p = 0.0002), transplantation at age >12 months (p = 0.014), increasing time after transplantation (p = 0.021) and the combination of late rejection and hemodynamic compromising rejection (p = 0.05) were significantly associated with increasing MIT. Age at catheterization (p = 0.0149), transplantation at age >12 months (p = 0.016), time from transplantation (p = 0.0076) and rejection with hemodynamic compromise (p = 0.01) were significantly associated with increased II. Nine patients developed evidence of severe (Stanford Class 4) TCAD by IVUS, but only 2 (22%) developed symptomatic TCAD, with a median follow-up of 44 months. Four of the 7 patients who developed symptomatic TCAD had no or minimal TCAD (Stanford Class 0 or 1) on a surveillance examination within 18 months of the onset of symptoms.

CONCLUSIONS

Increasing time after transplantation, recipient age and age at transplantation as well as rejection history, especially rejection with hemodynamic compromise, are associated with the development of TCAD as detected by IVUS in pediatric heart transplant recipients. Severe TCAD detected by IVUS does not often rapidly progress to symptomatic TCAD. Symptomatic TCAD may develop rapidly even in patients with little or no TCAD detected by IVUS.

Heart and lung transplantation in children

During the past two decades, several advances have resulted in marked improvement in medium-term survival for infants and children undergoing heart transplantation. Unfortunately, progress has been less dramatic in the field of lung and heart-lung transplantation, where there is little evidence of improved outcomes. The procedures remain palliative and all transplant recipients are at risk for the adverse effects of non-specific immunosuppression, including infections, lymphoproliferative disorders, and non-lymphoid malignancies. In addition, current immunosuppressive agents have narrow therapeutic windows and exhibit a wide array of organ toxicities, posing special challenges for the young patient who must endure life-long immunosuppression. New immunosuppressive regimens have lowered the rates of acute rejection but appear to have had relatively little impact on the incidence of chronic rejection, the principal cause of late graft loss. The ultimate goal is to induce a state of donor-specific tolerance, wherein the recipient will accept the allograft indefinitely without the need for long-term immunosuppression. This quest is currently being realised in animal models of solid organ transplantation, and offers great hope for children undergoing heart and lung transplantation in the future.

OKT3 Treatment in Refractory Pediatric Heart Transplant Rejection

BACKGROUND

The anti-lymphocyte monoclonal antibody OKT3 has been shown to be effective in the management of steroid-resistant and/or fulminant heart transplant rejection in adults. In addition, some studies suggest that OKT3 may have a role in the management of transplant coronary artery disease (TxCAD). To date, there are limited data regarding the use of OKT3 treatment of refractory rejection or graft failure in children. Our study examines OKT3 treatment in steroid-resistant rejection, rejection with hemodynamic compromise, and TxCAD in children.

METHODS

Thirty-eight patients received 53 courses of OKT3 for treatment of rejection and/or graft dysfunction. Primary indications for OKT3 were steroid-resistant rejection (n = 27), rejection with hemodynamic compromise (n = 22), and TxCAD (n = 4). Resolution of rejection was considered absence of biopsy-proven rejection (< grade 2) or resolved TxCAD.

RESULTS

OKT3 use in steroid-resistant rejection was associated with a lower incidence of rejection in the 3 months after OKT3 than 3 months before OKT3, median rejection episodes of 2.5 vs 0, p < 0.0001. In rejection with hemodynamic compromise, 20 subjects (91%) demonstrated improved hemodynamics after OKT3 and survived to hospital discharge. The use of OKT3 treatment for TxCAD failed to demonstrate resolution or improvement in angiographic TxCAD in any subject. Only 5 OKT3 treatment courses were stopped secondary to severe adverse side effects.

CONCLUSIONS

OKT3 treatment in refractory pediatric heart transplant rejection is efficacious in acute rejection. OKT3 management in pediatric TxCAD is less clear, with no proven benefit identified in this study. OKT3 use in pediatric refractory heart rejection has significant side effects, but is tolerable and safe with close monitoring.