(P-TS-107) Transfusion Reactions in Patients with Sickle Cell Disease: Are Hemolytic Reactions Being Underreported?

Hemolytic transfusion reactions (HTR) to red blood cells (RBCs) may be under recognized and under reported in patients with sickle cell disease (SCD) due to differences in definitional criteria and/or similarity to manifestations of clinical disease. While the Centers for Disease Control National Healthcare Safety Network (CDC/NHSN) hemovigilance definition requires a drop in hemoglobin with a positive direct antiglobulin test (DAT) and/or identification of a new alloantibody (Ab), the American Society of Hematology (ASH) criteria requires one or more of the following in addition to a significant drop in hemoglobin (Hb): hemoglobinuria, increase in hemoglobin S% (HbS)/decrease in hemoglobin A% (HbA), reticulocytopenia/reticulocytosis, increase in lactate dehydrogenase (LDH), or a new Ab.  Reported transfusion reactions (TR) in 2020 were reviewed at a high-volume center to identify patients without a new Ab that would have met ASH criteria for HTR.

Study

Design/Methods:

A retrospective, single-center study evaluated clinically suspected TR to RBCs in patients with SCD reported from 1/1/2020 to 12/31/2020. Patient demographic, clinical, transfusion, and laboratory data were manually captured from the electronic health record, laboratory information system, and quality assurance datasets. Criteria for HTR utilized both CDC/NHSN and ASH definitions to classify reactions. Allergic TR were excluded from analysis.

Results/Findings:

Thirty-one TR were reported in 27 SCD patients (median age 37 years [interquartile range 29-49 years]) of whom 41% (n=11/27) were male and 48% (n=13/27) were previously alloimmunized. Reactions were classified as febrile nonhemolytic TR (FNHTR) (32%, n=10/31), delayed serologic TR (DSTR) (6%, n=2/31), delayed hemolytic TR (DHTR) (3%, n=1/31) or no evidence of TR (58%, n=18/31) using CDC/NHSN criteria. No acute hemolytic TR were reported.  Of those with no evidence of TR, 28% (n=5/18) met ASH criteria for HTR including 11% (n=2/18) with hyperhemolysis (Table 1). A positive antibody detection test was noted in 2 patients that met ASH criteria for HTR, however, the identified Ab was previously known to the patient and antigen negative RBCs were provided for transfusion. Additionally, all 5 patients had compatible post transfusion crossmatches and IgG-negative DATs.

Conclusions: In this study, 5 additional patients would have been classified as having had DHTR if ASH criteria were applied. HTR may be missed due to symptom overlap with vaso-occlusive crises especially in the absence of a new alloantibody or positive DAT. Antibody-negative suspected HTRs in patients with SCD remain a challenge for diagnosis and transfusion management.