Low Incidence and severity of Graft-Versus-host disease after outpatient allogeneic Peripheral Blood Stem Cell Transplantation employing a Reduced-Intensity Conditioning

Graft-versus-host disease (GVHD) is the most common complication of allogeneic hematopoietic cell transplantation (alloHCT) and may affect the transplant outcome. Its incidence is higher when the preparative regimen used is a non-myeloablative and the stem cell's source is peripheral blood after mobilization.

Demonstrate the 10 years incidence of GVHD in 2 Mexican transplant centers using peripheral hematopoietic stem cell transplantation (PHSCT) in related donors after non-myeloablative conditioning.

Three hundred and four patients with hematological and non-hematological malignancies that underwent outpatient PHSCT after non-myeloablative conditioning between October 1998 and July 2008 were included. The age ranged between 1 and 71 years (median of 30.5). One hundred and eighty-five patients were men and 119 women. The median of cells CD34+ infused was 4.9 × 10⁶/kg (0.23-17.70).They received cyclosporine 4mg/kg per day and intramuscular methotrexate 5mg/ m2 in days +1, +3, +5 and +11 for GVHD prophylaxis.

Two hundred thirty-nine (80%) patients were successfully engrafted. The conditioning regimen was delivered as an outpatient procedure in all individuals. One hundred and fifty-four patients (64%) developed acute and/or chronic GVHD. Sixty four patients (26.7%) developed acute GVHD, 50 (20.9%) developed chronic GVHD, and 40 (16.7%) with acute GVHD progressed to chronic. Twenty seven (26%) patients who developed acute GVHD were grade III or IV, and 30 (33.2%) of chronic GVHD patients presented in the extensive way. GVHD was the cause of dead in 40 patients; 24 of acute GVHD and 16 of chronic GVHD, even when immunosuppressive therapy (high dose steroids and rituximab) was used. Last death was 24 months ago; subsequently, alemtuzumab was included in GVHD treatment. The cumulative incidence of acute GVHD was 37.6%.

The higher incidence of GVHD reported in other studies after PBSC transplant seems to decrease if non-myeloablative conditioning regimens are used. We suggest that the combination of a reduced-intensity conditioning transplant and the outpatient procedure is the responsible for the low incidence of GVHD in our patients.

No relevant conflicts of interest to declare.