Trasplante de médula ósea en pacientes con anemia falciforme. Experiencia en un centro

Matched sibling donor stem cell transplantation for sickle cell disease: Results from the Spanish group for bone marrow transplantation in children

OBJECTIVES

The prevalence of sickle cell disease (SCD) in Spain is markedly inferior compared with other European and Mediterranean countries. However, the diagnosis of new patients with SCD is expected to increase. In this multicenter retrospective study, we analyze the hematopoietic stem cell transplantation (HSCT) results obtained in Spain.

METHODS

Forty-five patients who underwent a matched sibling donor (MSD) HSCT between 1999 and 2018 were included. Primary endpoint was event-free survival (EFS), and secondary endpoints included acute and chronic graft-versus-host disease (GvHD) and overall survival (OS).

RESULTS

Bone marrow was the most frequent stem cell source (93.3%). Most patients received a conditioning regimen based on busulfan and cyclophosphamide (69%). Cumulative incidence of grade III-IV acute GvHD and chronic GvHD was 6.8% (95% CI: 2.3%-20.1%) and 5.4% (95% CI: 1.38%-19.9%), respectively. EFS and overall survival (OS) at 3 years post-HSCT were 89.4% (95% CI: 73.9%-95.9%) and 92.1% (95% CI: 77.2%-97.4%), respectively. All patients aged ≤ 5 presented 100% EFS and OS.

CONCLUSIONS

An early referral to HSCT centers should be proposed early in life, before severe complications occur. MSD HSCT should be considered a curative option for all patients aged ≤ 5 years and for older pediatric patients who present complications derived from the disease.

Systematic Review/Meta-Analysis on Efficacy of Allogeneic Hematopoietic Cell Transplantation in Sickle Cell Disease: An International Effort on Behalf of the Pediatric Diseases Working Party of European Society for Blood and Marrow Transplantation and the Sickle Cell Transplantation International Consortium

Sickle cell disease (SCD) affects more than 300,000 children annually worldwide. Despite improved supportive care, long-term prognosis remains poor. Allogeneic hematopoietic cell transplantation (allo-HCT) is the sole validated curative option, resulting in sustained resolution of the clinical phenotype. The medical literature on allo-HCT for SCD is largely limited to children. Recent studies have evaluated allo-HCT efficacy in adults. Here, we conducted a systematic review/meta-analysis to assess the totality of evidence on the efficacy, or lack thereof, of allo-HCT in treating SCD. We performed a comprehensive literature search using PubMed/Medline, Embase, and Cochrane library databases on November 13, 2019. Four authors independently extracted data on clinical outcomes related to benefits (overall survival [OS] and disease-free survival [DFS]) and harms (acute graft-versus-host disease [aGVHD], chronic graft-versus-host disease [cGVHD], nonrelapse mortality [NRM], and graft failure [GF]). Our search identified a total of 1906 references. Only 33 studies (n= 2853 patients) met our inclusion criteria. We also performed a subset analysis by age. Analyses of all-age groups showed pooled rates of 96% for OS, 90% for DFS, 20% for aGVHD, 10% for cGVHD, 4% for NRM, and 5% for GF. In the pediatric population, pooled rates for OS, DFS, aGVHD, cGVHD, NRM, and GF were 97%, 91%, 26%, 11%, 5%, and 3%, respectively. In adults, pooled rates for OS, DFS, aGVHD, cGVHD, NRM, and GF were 98%, 90%, 7%, 1%, 0%, and 14%, respectively. Our data show that allo-HCT is safe and effective, yielding pooled OS rates exceeding 90%. The high GF rate of 14% in adults is concerning and emphasizes the need to evaluate new strategies.

Toward dual hematopoietic stem-cell transplantation and solid-organ transplantation for sickle-cell disease

Sickle-cell disease (SCD) leads to recurrent vaso-occlusive crises, chronic end-organ damage, and resultant physical, psychological, and social disabilities. Although hematopoietic stem-cell transplantation (HSCT) is potentially curative for SCD, this procedure is associated with well-recognized morbidity and mortality and thus is ideally offered only to patients at high risk of significant complications. However, it is difficult to identify patients at high risk before significant complications have occurred, and once patients experience significant organ damage, they are considered poor candidates for HSCT. In turn, patients who have experienced long-term organ toxicity from SCD such as renal or liver failure may be candidates for solid-organ transplantation (SOT); however, the transplanted organs are at risk of damage by the original disease. Thus, dual HSCT and organ transplantation could simultaneously replace the failing organ and eliminate the underlying disease process. Advances in HSCT conditioning such as reduced-intensity regimens and alternative donor selection may expand both the feasibility of and potential donor pool for transplantation. This review summarizes the current state of HSCT and organ transplantation in SCD and discusses future directions and the clinical feasibility of dual HSCT/SOT.

Allogeneic stem cell transplantation for sickle cell disease

PURPOSE OF REVIEW

As the safety and availability of allogeneic hematopoietic stem cell transplantation (HSCT) have improved, this procedure is becoming a viable option for nonmalignant conditions such as sickle cell disease (SCD). There are very few treatment options available for SCD, and even with optimal care SCD patients still suffer from a myriad of comorbidities to multiple organ systems and have a decreased life span. In this review, we will summarize results from trials of HSCT for children or adults with SCD using a variety of graft sources as well as conditioning and graft-versus-host disease prophylaxis regimens, and discuss the unique challenges that arise in these patients.

RECENT FINDINGS

AlloHSCT for SCD has been performed on small numbers of patients at multiple centers around the world using several different transplant platforms, and early outcomes are encouraging. Overall survival is excellent, although graft failure remains a challenge.

SUMMARY

As alloHSCT becomes safer and more widely available, the procedure should be considered for patients with severe disease phenotypes in whom the potential benefits of transplantation outweigh the complications from the disease. AlloHSCT has been shown to reverse or at least halt the progression of end-organ damage secondary to SCD. More research is needed to understand the mechanisms underlying graft failure in SCD recipients, as well as to understand the biopsychosocial underpinnings of persistent pain in the posttransplant period to maximize the benefit from the transplant procedure.