Fabio R. Kerbauy

Hematopoietic cell transplantation from HLA-identical sibling donors after low-dose radiation-based conditioning for treatment of CML

A total of 24 patients (median age 58; range, 27–71 years) with chronic myeloid leukemia (CML) in first chronic (CP1) (n=14), second chronic (n=4), or accelerated phase (n=6) who were not candidates for conventional hematopoietic cell transplantation (HCT), received nonmyeloablative HCT from HLA-matched siblings a median of 28.5 (range, 11–271) months after diagnosis. They were conditioned with 2 Gy total body irradiation (TBI) alone (n=8) or combined with fludarabine, 90 mg/m2 (n=16). Postgrafting immunosuppression included cyclosporine and mycophenolate mofetil. All patients initially engrafted. However, 4 of 8 patients not given fludarabine experienced nonfatal rejection while all others had sustained engraftment. With a median follow-up of 36 (range, 4–49) months, 13 of 24 patients (54%) were alive and in complete remission. There were five (21%) deaths from nonrelapse mortality, one (4%) during the first 100 days after transplant. The proportions of grade II, III, and IV acute GVHD were 38, 4, and 8%, respectively. The 2-year estimate of chronic GVHD was 32%. The 2-year survival estimates for patients in CP1 (n=14) and beyond CP1 (n=10) were 70 and 56%, respectively. This study shows encouraging remission rates for patients with CML not eligible for conventional allografting.

Dog leukocyte antigen-haploidentical stem cell allografts after anti-CD44 therapy and nonmyeloablative conditioning in a preclinical canine model

Background. We previously described a reduced-intensity hematopoietic cell transplantation (HCT) regimen in dog leukocyte antigen (DLA)-haploidentical littermate recipients consisting of 450 cGy total body irradiation (TBI) and anti-CD44 monoclonal antibody (mAb) S5 before and mycophenolate mofetil (MMF)/cyclosporine (CSP) after HCT. Methods. We tested a nonmyeloablative regimen of mAb S5 and 200 cGy TBI with postgrafting MMF/CSP in 44 DLA-haploidentical recipients using eight different regimens. Ten dogs also received escalating doses of donor lymphocyte infusion (DLI) alone or with pentostatin to convert to complete donor chimerism. Results. All dogs achieved initial engraftment between one to two weeks after HCT with peripheral blood mononuclear cell (PBMC) donor chimerism ranging from 2% to 98% (median 37%) on day +35. Twenty-five (57%) dogs rejected their donor grafts at a median of seven (range; 1–19) weeks after HCT. Low levels of PBMC donor chimerism at three weeks predicted graft rejection. DLI neither facilitated conversion to full donor chimerism after HCT nor prevented rejection. Higher total nucleated cells, CD4+, CD8+, and CD14+ cell subset numbers in the PBMC graft were associated with stable full donor engraftment. Dogs given higher cell subset doses of infused PBMC achieved longer duration of mixed chimerism. Conclusions. Nonmyeloablative conditioning with 200 cGy TBI and anti-CD44 mAb was sufficient for initial uniform engraftment across DLA haplotype-mismatched barriers. However, sustained donor engraftment was seen in only 43% of recipients. Graft composition and donor-dominant chimerism early after HCT may be the most important factors for sustained donor engraftment.

Haploidentical bone marrow transplantation with post transplant cyclophosphamide for patients with X-linked adrenoleukodystrophy: a suitable choice in an urgent situation

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only treatment that enhances survival and stabilizes neurologic symptoms in X-linked adrenoleukodystrophy (X-ALD) with cerebral involvement, a severe demyelinating disease of childhood. Patients with X-ALD who lack a well-matched HLA donor need a rapid alternative. Haploidentical HSCT using post transplant cyclophosphamide (PT/Cy) has been performed in patients with malignant and nonmalignant diseases showing similar outcomes compared to other alternative sources. We describe the outcomes of transplants performed for nine X-ALD patients using haploidentical donors and PT/Cy. Patients received conditioning regimen with fludarabine 150 mg/m2, cyclophosphamide 29 mg/kg and 2 Gy total body irradiation (TBI) with or without antithymocyte globulin. Graft-vs.-host disease prophylaxis consisted of cyclophosphamide 50 mg/kg/day on days +3 and +4, tacrolimus or cyclosporine A and mycophenolate mofetil. One patient had a primary graft failure and was not eligible for a second transplant. Three patients had secondary graft failure and were successfully rescued with second haploidentical transplants. Trying to improve engraftment, conditioning regimen was changed, substituting 2 Gy TBI for 4 Gy total lymphoid irradiation. Eight patients are alive and engrafted (17–37 months after transplant). Haploidentical HSCT with PT/Cy is a feasible alternative for X-ALD patients lacking a suitable matched donor. Graft failure has to be addressed in further studies.

Extracorporeal photopheresis combined with pentostatin in the conditioning regimen for canine hematopoietic cell transplantation does not prevent GVHD

Extracorporeal photopheresis (ECP) and the purine analog pentostatin exert potent immunomodulatory effects. We evaluated the use of these treatment modalities to prevent GVHD in a canine model of unrelated dog leukocyte Ag-mismatched hematopoietic cell transplantation, after conditioning with 920 cGy TBI. We have shown previously in this model that 36/40 dogs given MTX alone as postgrafting immunosuppression engrafted and that 25 of 40 dogs had severe GVHD and median survival of 21 days. In the current study, nine dogs received conditioning with 920 cGy TBI and postgrafting MTX either with ECP on days −2 to −1 alone (n=5) or ECP on days −6 and −5 combined with two doses of pentostatin (days −4 to −3) (n=4). Seven of nine dogs achieved engraftment. Six dogs developed severe acute GVHD (four in the group with ECP alone and two with pentostatin and ECP). We failed to demonstrate a positive impact of ECP and pentostatin for the prevention of GVHD compared with historical control dogs.

Extracorporeal Photopheresis in Addition to Pentostatin in Conditioning for Canine Hematopoietic Cell Transplantation: Role in Engraftment

Extracorporeal photopheresis (ECP) and the purine analog pentostatin exert potent immunomodulatory effects, but have not been evaluated for their ability to enhance engraftment of hematopoietic stem cells. We evaluated, in a canine model of dog leukocyte antigen (DLA)-identical hematopoietic cell transplantation (HCT), whether ECP in combination with pentostatin could enhance engraftment using a nonmyeloablative regimen consisting of 100 cGy TBI and postgrafting immunosuppression with mycophenolate mofetil and CYA. We have shown previously that with 100 cGy TBI alone as conditioning, all of the six dogs rejected their grafts 2–12 weeks after HCT. With the addition of pentostatin to 100 cGy TBI, 6 of 10 dogs rejected their graft. We now tested the additional use of ECP alone (n=2) or ECP and 3–6 doses of pentostatin (n=7) before 100 cGy TBI and HCT. Eight out of nine dogs rejected their grafts within 6–11 weeks after HCT. Compared with data without ECP, we failed to demonstrate a positive impact of the use of either ECP or pentostatin for prevention of rejection.

Brazilian guidelines on hematopoietic stem cell transplantation in acute myeloid leukemia

Acute myeloid leukemia (AML) accounts for 90% of all cases of acute leukemia in adults. In Brazil, the mortality from myeloid leukemia is 1.74/100 000 men and 1.37/100 000 women. Our aim was to review and update guidelines of the Brazilian Society of Bone Marrow Transplantation on indications of hematopoietic stem cell transplantation (HSCT) for the treatment AML.

Endoscopy Biopsy in Different Sites for the Diagnosis of Lower and Upper Gastrointestinal Graft-Versus-Host Disease

Cell dose is a major criterion for cord blood unit (CBU) selection for allogeneic stem cell transplantation (allo-SCT). The aim of this study was the characterization of CBU cellular composition after thaw, and comparisonwith corresponding values at cryopreservation as reported by cord blood (CB) banks. The study included 87 CBUs, that were thawed for infusion in the context of single (n1⁄43) or dual-unit (n1⁄442) allo-SCT in adults with hematologic malignancies, from 8/2006 to 6/2013. Upon thawing, the cryoprotective solution (DMSO 10%) was either removed by centrifugation/washing (38 CBUs) or diluted in a less hypertonic solution of Dextran 40/Human Albumin 2.5% (49 CBUs). Total nucleated cells (TNC) were measured with a hematology analyzer, while enumeration of CD34+ stem cells was performed by singleplatform flow cytometry, according to ISHAGE guidelines. In 49 units, TNC and CD34+ cell viability was evaluated by addition of 7-AAD dye and sequential Boolean gating strategy. TNC counts after thawing were lower compared to their values at freezing (Wilcoxon test, p <10-4), and the difference was more pronounced in the units that were washed prior to infusion (Tables 1 and 2). Total cell viability was low (mean value, 42.6%), but this was mainly due to neutrophils. Regarding CD34+ cells, there was a significant difference between absolute counts at cryopreservation and at thaw (p<10-4). Despite reduction postthaw, the counts of both TNC and CD34+ cells did correlate with the corresponding values at cryopreservation by Spearman’s analysis. Of note, washing seemed slightly advantageous in terms of CD34+ recovery (Tables 1 and 2). CD34+ cells retained high viability after thaw, with 90% of CBUs (44 out of 49 tested) demonstrating CD34+ viability 80%. Viability of <50% was noticed in only one CBU that failed to engraft. In conclusion, CB cellular content and especially the CD34+ cell count is frequently shown to be inferior at thaw compared to cryopreservation. This probably reflects both the lack of standardization of CD34+ cell measurement and the effect of thawing procedure. Therefore, CD34+ cell viability may be a more meaningful marker for determining CBU quality. GVH/GVL

Hematopoietic stem cell transplantation in elderly patients with myelodisplastic syndrome and acute myelogenous leukemia: Use of busulfan/fludarabine for conditioning

Myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) are, typically, diseases of the elderly, with a 5–15% long-term survival rate and a prognosis that worsens beyond 60 years of age. The survival rate is low, regardless of the chemotherapy regimen used. Bone marrow transplantation was traditionally not used in this age group, because of the high mortality rate due to the conditioning regimen. However, survival and leukemia-free survival with lower recurrence rates can be improved with immune therapy provided by reduced-intensity and reduced-toxicity preparative allogeneic bone marrow transplantation regimens, with encouraging results in studies using busulfan and fludarabine. The effective antileukemic effect provided by cytoreduction, together with the immunological graft versus leukemia effect, with long-term disease control, leads us to believe that a myeloablative regimen without significant toxicity could be successfully used in selected elderly patients.

Autologous stem-cell transplantation for multiple myeloma: a Brazilian institution experience in 15 years of follow-up.

OBJECTIVE To determine the 5-year post-transplant survival of patients with multiple myeloma. METHODS A retrospective study in patients diagnosed with multiple myeloma submitted to autologous bone marrow transplantation at a Brazilian institution, during the period of 1993 to 2007. RESULTS Seventy-three patients were evaluated with a median age of 55 years. Survival in 5 years was 75% (2.4 to 60 months). Statistical analysis demonstrated statistical significance for the applied grade of response prior to treatment with autologous bone marrow transplantation (p = 0.01). There was no statistical significance for clinical staging or time of diagnosis (before or after the year 2000). CONCLUSION Experience in autologous bone marrow transplantation for multiple myeloma at a Brazilian institution demonstrated an evolution consistent with that of medical literature and highlighted the importance of a response to treatment prior to transplantation in the survival of these patients.