Transplantation of allogeneic CD34+ blood cells in leukemia or lymphoma patients at high risk of GVHD

Peripheral Blood Stem Cell Transplantation and Graft-versus-Host Disease: A Case Study

Peripheral blood stem cell transplantation is an acceptable treatment option for children with hematologic malignancies that are refractory to traditional treatments. Reports in the literature suggest that acute graft-verus-host disease (aGVHD), a common complication of peripheral blood stem cell transplantation, is associated with significant morbidity and mortality. aGVHD, a complex immunologic response, is reported in allogeneic transplants in which there is antigen presentation and activation of the donor T cell. The release of cytokines from the activated lymphocytes results in host cell death. This article reports on a 3-year-old child with a hematologic malignancy who, upon relapse, had received an identically matched allogeneic stem cell transplant from a sibling. Prophylaxis against aGVHD included several immunosuppressive agents. The dosage and serum levels of mycophenolate mofetil and tacrolimus were carefully monitored; however, the aGVHD progressed to include the liver and gut. As the child continued to deteriorate the aggressive treatment against aGVHD continued without success. A review of this case of aGVHD will provide nurses a knowledge base that is necessary to provide optimal care to the patient and family members alike.

Decreased RBCTs after reduced intensity conditioning allogeneic stem cell transplantation: predictive value of prior Hb level

BACKGROUND

RBCT (RBCT) requirements of stem cell transplant (SCT) recipients are often substantial and may be related to transplant type.

STUDY DESIGN AND METHODS

An analysis was done of RBCT requirements and Hb recovery kinetic in the first 60 days after HLA-identical sibling allogeneic SCT in a series of 110 consecutive patients treated for various malignant diagnoses. Patients were prepared with either an antithymocyte globulin (ATG) and reduced intensity chemotherapy-based conditioning (RIC) (n=64) or a myeloablative conditioning regimens (MAC; n=46). Patients received marrow (n=64) or PBPCs (n=46).

RESULTS

Overall, intensity of conditioning regimen (RIC vs. MAC; p=0.0005) and graft source (PBPC vs. marrow; p<0.0001) independently predicted RBCT requirements. Hb recovery was accelerated after RIC when compared to MAC allo-SCT (p=0.02). In RIC patients, RBCTs were inversely correlated to Hb level before conditioning (p<0.0001) and the dose of ATG (p=0.009). Moreover, Hb level before allo-SCT significantly influenced Hb recovery kinetic after RIC but had no impact on RBCT requirements and Hb recovery after MAC.

CONCLUSION

Thus, RIC conditioning creates a different pattern of erythropoiesis recovery as compared to a MAC regimen and suggest a need for studies aimed at further reducing RBCT and accelerating Hb recovery.

Survey of early disapearance of BCR/ABL fusion transcript after allogeneic or autologous stem cell transplantation for chronic myelogenous leukemia

The detection of BCR-ABL specific RNA by RT-PCR has been shown to predict relapse when positive 6 months after allogeneic stem cell transplantation (SCT) for chronic myelogenous leukemia (CML). In the present study, the focus was on evaluation of residual disease during the first weeks following SCT. In this study, 177 blood or marrow samples were obtained from 33 patients who received allogeneic (20 patients) or autologous (13 patients) SCT on day 0, day 30 and every 3 months for 1 year. T-cell depletion (TCD) was performed in 4 cases. On day 0 (day of graft infusion), 10/30 evaluable patients had negative RT-PCR (33%) regardless of pretransplant characteristics. On day 30, 14/18 patients (77%) from the allogeneic group had negative RT-PCR versus 0% in the autologous group. 2/4 patients who received TCD allogeneic grafts had day 30-positive PCR. Five patients in the allogeneic group had at least one positive RT-PCR sample between day 30 and day 90: 3 of them subsequently relapsed suggesting possible correlation between early positivity and relapse. Our results show that disappearance of MRD can be achieved within 3 months after transplantation in the majority of patients treated with allogeneic but not after autologous SCT. This suggests that the GVL effect might be operational early during the first weeks following transplantation.

Allogeneic hematopoietic transplantation of CD34+ selected cells from an HLA haplo-identical related donor. A long-term follow-up of 135 patients and a comparison of stem cell source between the bone marrow and the peripheral blood

We studied the outcome of allogeneic transplants in 135 patients who received selected BM and/or PBSC CD34+ cells from HLA haplo-identical related donors. Donor engraftment was achieved in 108 of 128 evaluable transplants. Engraftment failure occurred more often in non-malignant than in malignant diseases (10 of 25 vs 17 of 103, P = 0.010). The CD34+ cell dose was associated with the speed of neutrophil and platelet recovery, but the cell source was not. Acute GVHD (> or = grade II) developed in 21.0 +/- 3.7%. Chronic GVHD occurred more frequently in malignancies than in non-malignancies (44.1 +/- 7.6% vs 0.0%, P = 0.0075), and more in PBSC recipients than in BM recipients (53.6 +/- 9.4% vs 17.4 +/- 9.3%, P = 0.0054). Relapse rate was higher in high risk patients than in standard risk patients (78.7 +/- 7.1% vs 22.1 +/- 10.0%, P = 0.0001). Probabilities of disease-free survival (DFS) were 14.2 +/- 3.5% in malignancies and 25.7 +/- 9.2% in non-malignancies. Probabilities of DFS in standard and high risk patients were 39.4 +/- 9.2% and 5.7 +/- 2.8% (P = 0.0001). A high incidence of graft failure, infection and relapse was observed and resulted in high mortality.

Tolerance and hematopoietic stem cell transplantation 50 years after Burnet's theory

OBJECTIVE

In 1949, the original formulation of Burnet's theory on the mechanisms responsible for the capacity of the immune system to discriminate between foreign antigens (i.e., the "non-self") and the cells of its own body (i.e., the "self") was published. Since then, further refinements and reconsiderations of the basic concepts underlying the achievement of a state of tolerance toward a certain antigen have been reported. Here, we attempt to analyze critically new clinical and experimental strategies aimed at inducing alloantigen-specific unresponsiveness.

DATA SOURCES

The data discussed in this review are drawn from articles and abstracts published in journals covered by the Science Citation Index and Medline.

STATE OF THE ART

Induction of tolerance toward alloantigens still remains one of the most elusive goals of clinical immunology. Until now, nonspecific immunosuppressive drugs have been used to successfully perform both solid organ and hematopoietic stem cell transplantation. However, using this approach, patients given an allograft are exposed to the threat of infections, tumors, and other side effects. Moreover, in solid organ transplant recipients, permanent tolerance toward the graft's alloantigens is never achieved. Recently, considerable progress has been made in expanding our knowledge of transplant tolerance. The traditional model of central tolerance, derived from Burnet's concept, has been complemented by knowledge of mechanisms of peripheral tolerance.

CONCLUSIONS

New experimental and therapeutic trials based on the blockade of costimulatory molecules, as well as on generation and infusion of either regulatory or nonimmunogenic cells, have been recently proposed for inducing alloantigen-specific tolerance.The achievements obtained in understanding the mechanisms of unresponsiveness toward non-self antigens are fundamental prerequisites for successful allogeneic transplants, and they could open a new exciting era of specific, immunosuppressive therapies.