“There are no randomized control trials for some of the questions we had,” explained Dr Chou. “To address those questions, we used cohort studies or even, in some cases, case series and case reports. We then combined and interpreted all of that evidence to make the recommendations.”
The researchers noted that many of the recommendations are consistent with those of other societies, including the 2014 National Heart, Lung, and Blood Institute Expert Panel Report of the Evidence-Based Management of Sickle Cell Disease,2 the 2018 Standard for Clinical Care of Adults with Sickle Cell Disease in the United Kingdom,3 the 2018 International Collaboration for Transfusion Medicine Guidelines on Red Blood Cell Specifications for Patients with Hemoglobinopathies,4 and the 2019 Guidelines on the use of Therapeutic Apheresis in Clinical Practice.5 However, they also highlighted some key differences.
“We analyzed the data for prophylactic Rh and K matching for patients with SCD by looking at the incidence of alloantibodies produced per unit transfused, rather than just looking at prevalence,” said Dr Chou. “When we did that, we saw a large effect of providing prophylactically matched red cells and were able to formulate a strong recommendation that differs from previous guidelines in which it has always been a conditional recommendation.”
She continued, “This is already practiced at most large centers that care for many patients with SCD, but not uniformly, and not at smaller centers. We hope that with a strong recommendation, it will be even more widely practiced.”
In addition to the strong recommendation for prophylactic Rh- and K-matched red cells for patients with SCD, the panel also included unique recommendations on the mode of transfusion for chronically transfused patients with SCD (simple vs RCE), the use of IHD-RCE, and the use of immunosuppressive therapy for prevention or treatment of acute and delayed HTRs.
The panel acknowledged the limitations of these guidelines; most importantly, for many of the questions, much of the identified evidence was of low or very low certainty. Additionally, the studies did not included measures of the potential burden of blood transfusion for the patient, including emotional distress, loss of transfusion-associated time and income, and patient concerns about the procedures.
Lastly, the panel acknowledged that some of the recommendations may be associated with “moderate resource implications” due to the cost of transfusion and the recommendation for exchange transfusion under certain scenarios.
The panel included a reminder that the guidelines are not intended to serve or be construed as a standard of care; instead, they are intended to help clinicians make decisions about diagnostic and treatment alternatives, to inform policy, education and advocacy, and to state future research needs.
The panel advised against publishing the recommendations without their accompanying remarks. To read the detailed recommendations with the qualifying remarks, readers should consult the full publication by Dr Chou and colleagues in Blood Advances.
1. Chou ST, Alsawas M, Fasano RM, et al. American Society of Hematology 2020 guidelines for sickle cell disease: transfusion support. Blood Adv. 2020;4:327-355.
2. National Heart, Lung, and Blood Institute. Evidence-Based management of sickle cell disease: expert panel report, 2014. Published September 2014. Accessed February 24, 2020.
3. The Sickle Cell Society. Standard for clinical care of adults with sickle cell disease in the United Kingdom-2018. Published May 2, 2018. Accessed February 24 2020.
4. Compernolle V, Chou ST, Tanael S, et al. . Red blood cell specifications for patients with hemoglobinopathies: a systematic review and guideline. Transfusion. 2018;58:1555-1566.
5. Padmanabhan A, Connelly‐Smith L, Aqui N, et al. Guidelines on the use of therapeutic apheresis in clinical practice – evidence‐based approach from the writing committee of the american society for apheresis: the eighth special issue. J Clin Apher. 2019;34:171-354.