Experiences with Haploidentical Allogeneic Blood STEM CELL Transplantation for High-Risk Hematologic Disease in a Colombian Reference Center

BACKGROUND:

The scarce of unrelated donors and high costs hamper this treatment modality in Colombia. Alternative donors, such as related haploidentical donors, might contribute to a desired increase in transplant activity.

OBJECTIVE:

Describe sociodemographic and clinical characteristics of patients taken to haploidentical hematopoietic stem cell transplantation (HHSCT) in Fundación Oftalmológica de Santander (FOSCAL), Santander Colombia and report de early outcomes for overall survival (OS) at 100 days and 1 year of follow up.

METHODS:

We reviewed 11 patients taken to (HHSCT) at our institution between January 2014 and April 2016. Patients were eligible for (HHSCT) if they did not have an HLA matched related or 10/10 matched unrelated donor (MUD). Conditioning therapy included a thiotepa, fludarabine and busulfan, Graft-versus-host disease (GVHD) prophylaxis was with post-transplantation cyclophosphamide, calcineurin inhibitor and mycophenolate. OS was estimated at 100 days and at 1 year of follow up.

RESULTS:

Since January 2014 we have conducted eleven haploidentical T-cell repleted transplants. The median age was 25 (range 16-57) years with a HCT-CI score of 0 in 9/11 (81%) of patients and score 1 in 2/11 (19%). The ECOG performance status was 0 in 9/11 (81%) and 2/11 (status 1-2). Seven patients (63%) were male and 4 (37%) were female. Conditioning therapy with thiotepa, fludarabine, busulfan was utilized in 10/11 (90%) of patients and fludarabine, busulfan without thiotepa was utilized in 1/11 (10%) patient. The majority of patients had acute lymphoblastic leukemia 7 (63%), followed by acute myeloid leukemia 2 (18%), myelodysplastic syndrome 1 (9%) and 1 patient (9%) had acute leukemia mixed phenotype and the other one Hodgkin disease. At the time of transplant 10 patients (90%) were in complete remission, whereas 1 patient (9%) with myelodysplastic syndrome was treated with intent to achive remission, but no complete remission was achived.

The majority of patients (90%) achieved 100% donor chimerism at day +28. The median time to neutrophil ≥ 0,5 x 109/L was 18 days (range 13-29) and platelets ≥ 20 x 109/L was 22 (range 10-110). Acute GVHD was seen in seven patients. Five were classified as grade II, one patient as grade I and other one as grade III. Chronic GVHD of mild severity was observed in five patients. The major post transplant complication causing significant morbidity and prolonged hospitalization was hemorrhagic cystitis (HC). It appeared as complicated grade III disease in two patients and both had evidence of co-infection with polyomavirus, adenovirus and CMV. Evidence of CMV reactivation was detected in 7 patients successfully eradicated. Evidence of EBV viremia/reactivation was found in 6 patients of whom three patients were treated with rituximab (Table 1). The OS within a median follow up of 12 months was 100%. Two patients with B-ALL and Hodgkin disease relapsed, 13 and 10,7 months post-transplantation respectively.

CONCLUSION

Although few patients, this type of transplant is an alternative for our patients without HLA-matched donor available, with low mortality and similar complications and outcomes to those using other donor types in high-risk hematologic disease.