Development of panel reactive antibodies following continuous flow micromed-debakey VAD implantation and subsequent effects on allograft rejection

Abstract

Background: Literature proves significant sensitization of the HLAsystem in patients with pulsatile ventricular assist devices (VAD). Elevated levels of panel reactive antibodies (PRA) prior to heart transplantation (HTx) demonstrate a significantly higher incidence of allograft rejection and survival is adversely affected. Materials and Methods: We evaluated the incidence of sensitization by monthly PRA screening following implantation of the MicroMed DeBakey continuous flow axial pump in 19 patients (age: 51 9 yrs; 1/1999 to 7/2003) to investigate its possible relationship with subsequent post-HTx rejection and mortality. Endomyocardial biopsies (EMB) were routinely performed 1, 2, 3, 4, 7, 12, 26, and 52 weeks after HTx. Results: Out of 19 patients, 13 revealed no sensitization at all after VAD implant. Five individuals demonstrated temporary elevation of PRAs ( 17%) and dropped to 0% at time of HTx. Only one female VAD recipient, who initially required RVAD support for 1 week developed a peak of 37 % but subsequently dropped to 7 %. Sixteen patients underwent successful HTx 154 56 days after VAD support, one is still ongoing. In 16 patients, subsequent post-HTx EMB samples gave no evidence of allograft rejection, only one single patient revealed one episode of ISHLT grade 3B. Conclusion: The incidence of the development of PRAs in patients, who underwent implantation of the MicroMed-DeBakey-VAD remained extremely low and appears to be significantly lower than previously reported with other VADs. Additionally, no significant number of rejections was observed in patients who were subsequently successfully transplanted.