Unanswered Questions Remain in Optimal Management of RBC Transfusions in MDS

Patients with myelodysplastic syndromes (MDS) almost universally develop anemia, leading to a need for extended periods of red blood cell (RBC) or platelet transfusion support. With lingering questions about optimal transfusion management, particularly in the outpatient setting, a pair of researchers recently examined current evidence and areas for future research.

For instance, one of the unknowns are appropriate hemoglobin and platelet thresholds for transfusions, according to the researchers, who noted that few transfusion trials have focused on patients with hematological malignancies, and none have looked at hemoglobin threshold or outcomes studies for patients receiving transfusion chronically.

“Although nearly 20,000 patients have been enrolled in randomized trials comparing different hemoglobin thresholds, these have been almost exclusively in the acute anemia setting, most often in critical care or cardiac surgery, and often aimed at addressing primary outcomes of short-term (eg, in hospital) mortality,” said the researchers. “It is inappropriate to extrapolate the results from these trials to recommend a “restrictive” policy in transfusion-dependent MDS.”

Recently, an international group responded to this unmet need and conducted the Red Blood Cell Transfusion Schedule in Myelodysplastic Syndromes pilot trial that included transfusion-dependent patients with MDS. Patients included in the trial received either a restrictive (Hb 80 g/L, to maintain hemoglobin 85 to 100 g/L) or liberal (Hb 105 g/L, maintaining 110 to 125 g/L) threshold for RBC transfusion.

According to the researchers, patients receiving the liberal transfusion threshold receiving nearly twice as many RBCs as patients receiving the restrictive threshold and also had a shorter duration between transfusions. The researchers say these findings of a need for more visits and blood have implications for both patients and transfusion services.

“A post hoc exploratory analysis suggested that the 5 main [quality of life] domains were improved for participants in the liberal arm, supporting the need for additional research to elucidate the impact of different RBC transfusion policies,” added the researchers.

Research has also focused on determining the main objective of RBC transfusions for these patients, with quality of life [QoL] coming to the forefront. However, when and how should this be measured? Unfortunately, many trials focused on RBC transfusions have set short-term mortality as the primary outcome, but the researchers caveat that there have been some trials assessed QoL and functional outcomes.

In particular, the RETRO study included patients with a range of hematologic/oncologic conditions, including MDS, and found that RBC transfusions were associated with improvement in some outcomes like fatigue and distance walked while it fell short of improving other outcomes like dyspnea.

Other considerations highlighted by the researchers include identifying and managing transfusion reactions in the outpatient setting, alloimmunization to RBC antigens, iron overload, and iron chelation.

Reference

Wood E, McQuilten Z. Outpatient transfusions for myelodysplastic syndromes. Hematology Am Soc Hematol Educ Program. 2020;2020(1):167-174.