Allogeneic stem cell transplant in myelodysplastic syndrome-factors impacting survival

Association between the pre-transplantation serum ferritin level and outcomes of hematopoietic stem cell transplantation: A systematic review and meta-analysis

Background

Iron overload, as indicated by evaluated serum ferritin (SF) level, occurs commonly in patients with hematological diseases. To evaluate the association between pre-transplant SF level and outcomes of hematopoietic stem cell transplantation (HSCT), we performed this systematic review and meta-analysis.

Methods

PubMed, Embase, Web of Science and the Cochrane Library electronic database were searched from inception to August 2023, and 56 studies with 14149 patients were found to be eligible.

Results

An elevated pre-transplantation SF level was associated with inferior overall survival (hazard ratio [HR],1.77; 95 % confidence interval [CI],1.61-1.96) and disease-free survival (HR, 1.86; 95 % CI, 1.58-2.19), and increased risk of non-relapse mortality (HR, 1.73; 95 % CI, 1.49-2.02), and relapse (HR, 1.46; 95 % CI, 1.29-1.65). However, no meaningful association was observed between SF levels and acute graft-versus-host disease (GVHD) (risk ratio [RR], 1.09; 95 % CI, 0.96-1.24), or chronic GVHD (RR, 0.95; 95 % CI, 0.79-1.16). Furthermore, an elevated pre-transplantation SF level was associated with a higher risk of fungal infection (RR, 1.56; 95 % CI, 1.16-2.10), but not with bacterial infection (RR, 1.09; 95 % CI, 0.80-1.50). Moreover, an elevated pre-transplantation SF level was related to a higher risk of death due to relapse/disease progression (RR, 1.72; 95 % CI, 1.33-2.23) and infection (RR, 2.21; 95 % CI, 1.55-3.15), but not death due to GVHD (RR, 1.18; 95 % CI, 0.79-1.77).

Conclusions

A higher pre-transplantation SF level was significantly associated with a higher risk of relapse/disease progression and infections, which contributed to worse survival in patients undergoing HSCT. In particular, a higher SF level was related to a higher risk of fungal infection, indicating that patients with a higher pre-transplantation SF level require more attention regarding the risk of fungal infection after HSCT.

A Systematic Literature Review of the Relationship between Serum Ferritin and Outcomes in Myelodysplastic Syndromes

Anemia is the most common form of cytopenia in patients with myelodysplastic syndromes (MDS), who require chronic red blood cell transfusions and may present high serum ferritin (SF) levels as a result of iron overload. To better understand the potential effects of high SF levels, we conducted a systematic literature review (SLR) to identify evidence on the relationship between SF levels and clinical, economic, or humanistic outcomes in adult patients with MDS. Of 267 references identified, 21 were included. No studies assessing SF levels and their relationship with humanistic or economic outcomes were identified. Increased SF levels were an indicator of worse overall survival and other worsened outcomes; however, the association was not consistently significant. SF levels were a significant prognostic factor for relapse incidence of MDS and showed a significant positive correlation with number of blood units transfused but were not associated with progression to acute myeloid leukemia or the time to transformation. Higher SF levels were also an indicator of a lower likelihood of leukemia-free survival, relapse-free survival, and event-free survival. The SLR suggests that SF levels are associated with clinical outcomes in MDS, with higher levels correlated with number of blood units transfused, frequently indicating worse outcomes.

Prognostic factors affecting the outcome after allogeneic haematopoietic stem cell transplantation for myelodysplastic syndrome

In the present study, we retrospectively analysed the results of HSCT in 47 consecutive patients with MDS diagnosed at our department between 2002 and 2019, with a focus on possible predictive factors influencing overall survival (OS), the development of relapse, infections, and the occurrence of graft versus host disease (GvHD). In a univariate analysis, the pre-transplantation value of blasts in the marrow < 5% (p = 0.006), the revised International Prognostic Scoring System (IPSS-R) (p = 0.041), and karyotype (p = 0.009) were predictive of OS. Neither the elevation of serum ferritin (> 1000 ug/ml) nor increased C-reactive protein (CRP) (> 5 mg/l) was associated with shorter OS. In contrast, elevated serum lactate dehydrogenase (LDH) (> 213 U/l) was associated with shorter OS (p = 0.04).

Following in the footsteps of acute myeloid leukemia: are we witnessing the start of a therapeutic revolution for higher-risk myelodysplastic syndromes?

For most patients with higher-risk myelodysplastic syndromes (HR-MDS) the hypomethylating agents (HMA) azacitidine and decitabine remain the mainstay of therapy. However, the prognosis mostly remains poor and aside from allogeneic hematopoietic stem cell transplantation no curative treatment options exist. Unlike acute myeloid leukemia, which has seen a dramatic expansion of available therapies recently, no new agents have been approved for MDS in the United States since 2006. However, various novel HMAs, HMA in combination with venetoclax, immune checkpoint inhibitors, and targeted therapies for genetically defined patient subgroups such as APR-246 or IDH inhibitors, have shown promising results in early stages of clinical testing. Furthermore, the wider availability of genetic testing is going to allow for a more individualized treatment of MDS patients. Herein, we review the current treatment approach for HR-MDS and discuss recent therapeutic advances and the implications of genetic testing on management of HR-MDS.

Iron overload and its impact on outcome of patients with hematological diseases

Systemic iron overload (SIO) is a common challenge in patients with hematological diseases and develops as a result of ineffective erythropoiesis, multiple red blood cell (RBC) transfusions and disease-specific therapies. Iron homeostasis is tightly regulated as there is no physiological pathway to excrete iron from the body. Excess iron is, therefore, stored in tissues like liver, heart and bone marrow and can lead to progressive organ damage. The presence of free iron in the form of non-transferrin bound iron (NTBI) is especially detrimental. Reactive oxygen species can also cause stromal damage in the bone marrow and promote leukemic cell growth in vitro. In acute leukemias and myelodysplastic syndromes outcome is worse in patients with SIO compared to patients without. Especially in patients undergoing allogeneic HSCT presence of NTBI before or during transplant has been shown to negatively affect non-relapse mortality and overall survival. Although the mechanisms, of how these effects are mediated by SIO are not very well understood monitoring of iron status by serum markers and imaging techniques is, therefore, mandatory especially in these patients. Whether peri-interventional iron chelation may improve outcome of these patients is part of current clinical research.