Alloimmunization in myelodysplastic syndrome is associated with higher healthcare costs, longer hospitalizations, and increased mortality.

BACKGROUND: Transfusion of red blood cells (RBC) is an important component of treatment for myelodysplastic syndromes (MDS). Patients receiving frequent transfusions are more likely to develop alloimmunization, an immune reaction to minor RBC antigens that increases the risk of complications including delayed hemolysis. Phenotypic matching is believed to reduce alloimmunization although rigorous evidence is lacking. This study examines the association of alloimmunization with clinical and economic outcomes and may give insight into the potential benefit of phenotypic matching in MDS. STUDY DESIGN AND METHODS: This study used data from 1054 hospitals included in the Premier hospital chargemaster dataset. Alloimmunized MDS patients (January 2015 to June 2019) were indirectly identified by ICD-10 codes (antiglobulin crossmatch and RBC antibody identification). The primary objective was assessment of the association between incremental cost per patient encounter and alloimmunization in MDS patients. Secondary objectives were assessment of the association of length of stay, intensive care unit (ICU) admission, and inpatient mortality for alloimmunized versus non-alloimmunized MDS patients. RESULTS: Worse clinical and economic outcomes were observed for the alloimmunized group. Higher costs (14%), more ICU admissions (38%), longer hospital (21%) and ICU stays (55%), and greater mortality (30%) were observed among alloimmunized MDS patients compared to non-alloimmunized (p < .0001 for all comparisons). DISCUSSION: Alloimmunization may be associated with higher costs and greater risk of ICU admission and death in patients with MDS. While further mechanistic research is needed, it seems that MDS patients may benefit substantially from practices that limit risk of alloimmunization, including providing prophylactic antigen matching.

Acute pulmonary injury in hematology patients supported with pathogen-reduced and conventional platelet components.

ABSTRACT: Patients treated with antineoplastic therapy often develop thrombocytopenia requiring platelet transfusion, which has potential to exacerbate pulmonary injury. This study tested the hypothesis that amotosalen-UVA pathogen-reduced platelet components (PRPCs) do not potentiate pulmonary dysfunction compared with conventional platelet components (CPCs). A prospective, multicenter, open-label, sequential cohort study evaluated the incidence of treatment-emergent assisted mechanical ventilation initiated for pulmonary dysfunction (TEAMV-PD). The first cohort received CPC. After the CPC cohort, each site enrolled a second cohort transfused with PRPC. Other outcomes included clinically significant pulmonary adverse events (CSPAE) and the incidence of treatment-emergent acute respiratory distress syndrome (TEARDS) diagnosed by blinded expert adjudication. The incidence of TEAMV-PD in all patients (1068 PRPC and 1223 CPC) was less for PRPC (1.7 %) than CPC (3.1%) with a treatment difference of -1.5% (95% confidence interval [CI], -2.7 to -0.2). In patients requiring ≥2 PCs, the incidence of TEAMV-PD was reduced for PRPC recipients compared with CPC recipients (treatment difference, -2.4%; 95% CI, -4.2 to -0.6). CSPAE increased with increasing PC exposure but were not significantly different between the cohorts. For patients receiving ≥2 platelet transfusions, TEARDS occurred in 1.3% PRPC and 2.6% CPC recipients (P = .086). Bayesian analysis demonstrated PRPC may be superior in reducing TEAMV-PD and TEARDS for platelet transfusion recipients compared with CPC recipients, with 99.2% and 88.8% probability, respectively. In this study, PRPC compared with CPC demonstrated high probability of reduced severe pulmonary injury requiring assisted mechanical ventilation in patients with hematology disorders dependent on platelet transfusion. This trial was registered at www.ClinicalTrials.gov as #NCT02549222.