Clinical effects of different types of red cell concentrates in patients with thalassemia and sickle cell disease

Transfusion efficacy of leucoreduced packed red blood cells prepared by two different methods: A randomized controlled trial in transfusion-dependent thalassaemia patients (FUEL trial)

BACKGROUND AND OBJECTIVES

Great variations may be observed in the haemoglobin (Hb) content of packed red blood cell (PRBC) units prepared by different methods. This study aimed to assess the Hb increment in thalassaemia major patients transfused with leucoreduced PRBCs (LPRBCs) prepared by two different methods: (i) standard leucoreduced PRBCs (SLPRBCs) and (ii) leucoreduced PRBCs prepared by a new method where leucoreduction of whole blood is done first (NLPRBCs).

MATERIALS AND METHODS

This prospective, randomized, controlled trial included 80 adult thalassaemia major patients who were randomized into two groups of 40 each. Group I patients received SLPRBC and those of Group II received NLPRBC transfusions for 3 months.

RESULTS

SLPRBCs had a mean (±SD) volume of 275.50 ± 17.07 mL, while it was 316.46 ± 1.42 mL for NLPRBCs (p < 0.001). The mean Hb content of SLPRBCs was 50.60 ± 5.12 g, while that of NLPRBCs was 56.98 ± 5.92 g (p < 0.001). The mean Hb increment in Group I patients was 2.11 ± 0.89 g/dL, while that of Group II patients was 2.48 ± 0.88 g/dL (p < 0.001). The mean transfusion interval for Group I patients was 20.30 ± 3.75 days, while it was 21.34 ± 5.13 days for Group II patients (p < 0.045). A significant positive correlation was observed between the Hb dose transfused and the Hb increment with both SLPRBC (ρ = 0.4, p < 0.001) and NLPRBC (ρ = 0.19, p = 0.011) transfusions.

CONCLUSION

NLPRBCs had significantly higher Hb content than the SLPRBCs, leading to a better Hb increment post transfusion, which may potentially prolong the transfusion interval in thalassaemia major patients.

Comparison of Two Alternative Procedures to Obtain Packed Red Blood Cells for β-Thalassemia Major Transfusion Therapy

β-thalassemia major (βTM) patients require frequent blood transfusions, with consequences that span from allogenic reactions to iron overload. To minimize these effects, βTM patients periodically receive leucodepleted packed red blood cells (P-RBCs) stored for maximum 14 days. The aim of this study was to compare two alternative routine procedures to prepare the optimal P-RBCs product, in order to identify differences in their content that may somehow affect patients’ health and quality of life (QoL). In method 1, blood was leucodepleted and then separated to obtain P-RBCs, while in method 2 blood was separated and leucodepleted after removal of plasma and buffycoat. Forty blood donors were enrolled in two independent centers; couples of phenotypically matched whole blood units were pooled, divided in two identical bags and processed in parallel following the two methods. Biochemical properties, electrolytes and metabolic composition were tested after 2, 7 and 14 days of storage. Units prepared with both methods were confirmed to have all the requirements necessary for βTM transfusion therapy. Nevertheless, RBCs count and Hb content were found to be higher in method-1, while P-RBCs obtained with method 2 contained less K⁺, iron and storage lesions markers. Based on these results, both methods should be tested in a clinical perspective study to determine a possible reduction of transfusion-related complications, improving the QoL of βTM patients, which often need transfusions for the entire lifespan.

Impact of the preparation method of red cell concentrates on transfusion indices in thalassemia patients: A randomized crossover clinical trial

BACKGROUND

The average hemoglobin content of red cell concentrates (RCC) varies depending on the method of preparation. Surprisingly less data are available concerning the clinical impact of those differences.

STUDY DESIGN AND METHODS

The effects of two types of RCC (RCC-A, RCC-B) on transfusion regime were compared in a non-blinded, prospective, randomized, two-period, and crossover clinical trial. RCC-A was obtained by whole blood leukoreduction and subsequent plasma removal, RCC-B removing plasma and buffy coat first, followed by leukoreduction. Eligible patients were adult, with transfusion-dependent thalassemia (TDT).

RESULTS

RCC-A contained 63.9 (60.3-67.8) grams of hemoglobin per unit (median with 1st and 3rd quartile), RCC-B 54.5 (51.0-58.2) g/unit. Fifty-one patients completed the study. With RCC-B, the average pre-transfusion hemoglobin concentration was 9.3 ± 0.5 g/dl (mean ± SD), the average transfusion interval 14.2 (13.7-16.3) days, the number of RCC units transfused per year 39.3 (35.4-47.3), and the transfusion power index (a composite index) 258 ± 49. With RCC-A, the average pre-transfusion hemoglobin concentration was 9.6 ± 0.5 g/dl (+2.7%, effect size 0.792), the average transfusion interval 14.8 (14.0-18.5) days (+4.1%, effect size 0.800), the number of RCC units transfused per year 34.8 (32.1-42.5) (-11.4%, effect size -1.609), and the transfusion power index 272 ± 61 (+14.1%, effect size 0.997). All differences were statistically highly significant (p < .00001). The frequency of transfusion reactions was 0.59% with RCC-A and 0.56% with RCC-B (p = 1.000).

CONCLUSION

To reduce the number of RCC units consumed per year and the number of transfusion episodes, TDT patients should receive RCC with the highest average hemoglobin content.

Infections in thalassemia and hemoglobinopathies: focus on therapy-related complications

The clinical approach to thalassemia and hemoglobinopathies, specifically Sickle Cell Disease (SCD), based on transfusions, iron chelation and bone marrow transplantation has ameliorated their prognosis. Nevertheless, infections still may cause serious complications in these patients. The susceptibility to infections in thalassemia and SCD arises both from a large spectrum of immunological abnormalities and from exposure to specific infectious agents. Four fundamental issues will be focused upon as central causes of immune dysfunction: the diseases themselves; iron overload, transfusion therapy and the role of the spleen. Thalassemia and SCD differ in their pathogenesis and clinical course. It will be outlined how these differences affect immune dysfunction, the risk of infections and the types of most frequent infections in each disease. Moreover, since transfusions are a fundamental tool for treating these patients, their safety is paramount in reducing the risks of infections. In recent years, careful surveillance worldwide and improvements in laboratory tests reduced greatly transfusion transmitted infections, but the problem is not completely resolved. Finally, selected topics will be discussed regarding Parvovirus B19 and transfusion transmitted infections as well as the prevention of infectious risk postsplenectomy or in presence of functional asplenia.