Abo-incompatible living-donor kidney transplantation in children

Background. Due to a severe shortage of suitable cadaveric allografts for c hildren awaiting kidney transplants, we have performed a series of ABO-inco mpatible living kidney transplantations (LKT) at our institution. Methods. Between July 1989 and March 2000, 16 pediatric patients (3 female, 13 male) underwent ABO-incompatible LKT. The mean age at transplantation w as 10.9 +/-4.3 years (range 5.1-15.0 years). The donor to recipient ABO blo od antigen incompatibility was as follows: A1 -->O, 5 patients; B -->O, 6 p atients; A1B --> B, 2 patients; and A1B -->B A1 -->B, or B --> A1, 1 patien t each. The median pretransplantation anti-Al titers of eight A-incompatibl e recipients were 1:128 (IgM, range 1:16 to 1:512) and 1:32 (IgG, range 1:2 to 1:128). Median anti-B titers of seven B-incompatible recipients were 1: 32 (IgM, range 1:4 to 1:128) and 1:8 (IgG, range 1:2 to 1:64). All patients received three or four sessions of plasmapheresis (PP) and/or immunoadsorp tion (IA) to remove the anti-A and/or anti-B antibodies before transplantat ion. Immunosuppression initially consisted of cyclosporine, methylprednisol one, cyclophosphamide, and antilymphocyte globulin. Splenectomy was perform ed on all recipients at the time of transplantation. Results. The patients were followed for 6 to 122 months with a mean follow- up of 63 months. All 16 recipients who underwent ABO-incompatible LKT achie ved a pretransplant isoagglutinin titer less than 1:8 with 3-4 sessions of PP/IA treatment. Of 16 patients, 10 patients had rebound increase in their IgM and/or IgG anti-A/B titers to greater than 1:64 or predepletion levels within 10 days posttransplantation. In addition, nine patients developed re nal dysfunction in association with the rebound increase in their anti-A/B. One patient lost his graft because of uncontrolled delayed hyperacute reje ction, whereas eight other recipients recovered completely with pulse stero ids and PP/IA therapy. After the third week posttransplant, there-was no co rrelation between the occurrence of AR and their isoagglutinin titers. More over, no antibody-mediated rejection was observed, even in recipients with continued high titer anti-A and/or anti-B antibodies. Patient survival is 1 00% to date. The actuarial 1-year and 5-year graft survival rates are 87% a nd 85%, respectively. No fatal infectious complications occurred despite th e combination of splenectomy and immunosuppressive drugs. Conclusions. We have demonstrated that with adequate pre- and posttransplan t management, successful kidney transplantation across the ABO barrier is p ossible in the pediatric population. "Accommodation" of the allografts occu rred within 2 weeks of transplantation. Subsequently, the long-term graft o utcome of ABO-incompatible LKT was comparable to that of ABO-compatible LKT .