Chimerism, graft survival, and withdrawal of immunosuppressive drugs in HLA matched and mismatched patients after living donor kidney and hematopoietic cell transplantation

Thirty-eight HLA matched and mismatched patients given combined living donor kidney and enriched CD34(+) hematopoietic cell transplants were enrolled in tolerance protocols using posttransplant conditioning with total lymphoid irradiation and anti-thymocyte globulin. Persistent chimerism for at least 6 months was associated with successful complete withdrawal of immunosuppressive drugs in 16 of 22 matched patients without rejection episodes or kidney disease recurrence with up to 5 years follow up thereafter. One patient is in the midst of withdrawal and five are on maintenance drugs. Persistent mixed chimerism was achieved in some haplotype matched patients for at least 12 months by increasing the dose of T cells and CD34(+) cells infused as compared to matched recipients in a dose escalation study. Success of drug withdrawal in chimeric mismatched patients remains to be determined. None of the 38 patients had kidney graft loss or graft versus host disease with up to 14 years of observation. In conclusion, complete immunosuppressive drug withdrawal could be achieved thus far with the tolerance induction regimen in HLA matched patients with uniform long-term graft survival in all patients.

Percutaneous transluminal balloon valvuloplasty for pulmonary valve stenosis: report on six cases

Percutaneous transluminal baloon valvuloplasty is currently the treatment of choice for most cases of pulmonary valve stenosis. In the first series of cases performed at Kenyatta National Hospital, six patients aged 4 to 24 years with severe pulmonary valve stenosis and no other associated cardiac lesions were selected for the procedure. Immediately following baloon valvuloplasty, the pressure gradients across pulmonary valve measured by both echo-Doppler technique and cardiac catheterisation dropped very significantly (P < 0.001). Catheterisation peak systolic gradients (psg) dropped from 162.5 +/- 23.7 to 56.5 +/- 19.0 while echo-Doppler pressure gradients dropped from 112.0 +/- 11.9 to 42.8 +/- 16.0. No complications occurred during or after the procedure. This initial short-term experience in our set-up confirms the safety and effectiveness of this procedure. Furthermore, this procedure is much cheaper and technically easier to perform than cardiac surgery.