Alternative methods for calculating percentage haemolysis of red cell concentrates in peripheral blood banks in Sri Lanka

Background

Haemolysis - one of the major limiting factors of red cell concentrate quality - must be measured as a quality-monitoring requirement. According to international quality standards, percentage haemolysis must be monitored in 1.0% of red cell concentrates produced monthly and maintained under 0.8%.

Objective

This study assessed three alternative methods for determining plasma haemoglobin concentration in peripheral blood banks that lack a plasma or low haemoglobin photometer - the gold-standard method - in Sri Lanka.

Methods

A standard haemolysate was prepared using an unexpired whole blood pack of normal haemoglobin concentration. A concentration series from 0.1 g/dL to 1.0 g/dL was prepared by diluting portions of standard haemolysate with saline. The alternative methods, namely visual haemoglobin colour scale, spectrophotometric calibration graph, and standard haemolysate capillary tube comparison, were designed using this concentration series and were used to test red cell concentrates received at the Quality Control Department of the National Blood Center, Sri Lanka, from February 2021 to May 2021.

Results

A strong correlation was observed between the haemoglobin photometer method and the alternative methods (R = ~0.9). Based on the linear regression model, the standard haemolysate capillary tube comparison method was the best of the three alternative methods (R ² = 0.974).

Conclusion

All three alternative methods are recommended for use in peripheral blood banks. The standard haemolysate capillary tube comparison method was the best model.

Factors related to allergic transfusion reactions and febrile non-haemolytic transfusion reactions in children

BACKGROUND AND OBJECTIVES

Allergic transfusion reactions (ATRs) and febrile non-haemolytic transfusion reactions (FNHTRs) are the two major types of transfusion-related adverse reactions (TRARs). Although prestorage leucocyte reduction and diversion of the first aliquot of blood (LR/D) could reduce FNHTRs and bacterial contamination in adult transfusion, ATRs are still problematic. In addition, there is little information about TRARs in paediatric population.

MATERIALS AND METHODS

We conducted a single-centre retrospective analysis of all transfusions, except washing products, and TRARs for 153 months to evaluate related factors such as delivery of treatment and the characteristics of recipients.

RESULTS

Most TRARs were FNHTRs and/or ATRs in children. In delivering blood products with LR/D, the frequencies of not only FNHTRs but also ATRs were significantly reduced with both platelet concentrates (PCs) and red cell concentrates (RCCs). TRARs of fresh-frozen plasma were infrequent in children. In addition, even after the introduction of LR/D, ATRs were significantly more frequent in patients with primary haematological and malignant diseases who received PCs and RCCs, older patients who received PCs and patients who received frequent RCCs.

CONCLUSION

These results suggest that leucocytes or mediators from leucocytes are underlying cause of ATRs in addition to FNHTRs in children. Furthermore, particular characteristics of patients would be other risk factors for ATRs.

Release of cytokines in stored whole blood and red cell concentrate: Effect of leukoreduction

Background:

Storage time of blood components plays a major role in the accumulation of cytokines causing adverse transfusion reactions.

Aims:

The aim was to study the trend in the levels of interleukin-6 (IL-6), IL-8, tumor necrosis factor-alpha (TNF-α) and regulated upon activation, normal T-cells expressed and secreted (RANTES) during storage of whole blood (WB) and red cell concentrate (RCC) and to study the effect of leukoreduction (LR).

Materials and Methods:

WB sample was taken on 0, 7, 14, 21, and between 28 and 35 days and plasma aliquots were frozen. Samples from RCC and buffy-coat depleted RCC prepared using Optipress II were collected on 0, 7, 14, 21 and between 28 and 35 days. Cytokine estimation was done using ELISA development kits. Normal range of cytokines was established using 0 day samples of WB. Statistical analysis was done using nonparametric tests.

Results and Conclusion:

The normal range of IL-6 was 0-23 pg/ml, IL-8 0-12 pg/ml, TNF-α 0-3 pg/ml, and RANTES 1200-2000 pg/ml. IL-6 was in normal range and showed a decreasing trend during storage. IL-8 levels increased significantly from 0 to 35 days. In RCC, the highest level was 480 pg/ml on 28^th day. It was in the normal range in buffy-coat depleted RCC up to 28 days. RANTES level was significantly low in buffy-coat depleted RCC compared to RCC. We conclude that WB has high levels of IL-8 and RANTES. The levels of cytokines are affected by storage period and LR. Comparison of WB and buffy-coat depleted RCC shows significantly low levels of IL-6, IL-8, and RANTES in buffy-coat depleted RCC. This study emphasizes the use of red cell components instead of WB and buffy-coat depleted RCC instead of RCC.

Preparation of red blood cell concentrates and plasma units from whole blood held overnight using a hollow-fibre separation system

BACKGROUND

The ErySep system represents an alternative to centrifuge-based whole blood (WB) separation, using gravity and filtration through hollow-fibres (0·2 µm pore size) to produce red blood cell (RBC) and plasma components. The aim of this study was to characterise the quality of ErySep RBC and plasma units compared with standard products from WB held overnight.

METHODS/MATERIALS

Two ABO-compatible WB units (n = 24) were pooled and split to produce matched products. One of the WB units was separated into components using the ErySep system (ErySep; n = 12), whereas the other units were separated by centrifugation (control; n = 12). RBC units were stored at 2-6 °C and assessed for in vitro quality over 42 days of storage. Plasma was frozen at -30 °C and tested upon thawing.

RESULTS

Processing WB with the ErySep system took longer than controls. The ErySep RBC units were of an appropriate volume (307 ± 17 mL) and contained sufficient Hb (50 ± 2 g unit(-1) ). ErySep RBC components contained more microparticles relative to controls at expiry. The plasma volume, total protein, coagulation factor activity (fibrinogen, FV, FVIII) and number of microparticles was lower in the ErySep units compared with controls.

CONCLUSION

Following overnight hold of WB, the ErySep system was capable of producing RBC components that met specifications. However, the ErySep plasma components did not meet quality specifications.

Overview of blood components and their preparation

The whole blood which is a mixture of cells, colloids and crystalloids can be separated into different blood components namely packed red blood cell (PRBC) concentrate, platelet concentrate, fresh frozen plasma and cryoprecipitate. Each blood component is used for a different indication; thus the component separation has maximized the utility of one whole blood unit. Different components need different storage conditions and temperature requirements for therapeutic efficacy. A variety of equipments to maintain suitable ambient conditions during storage and transportation are in vogue. The blood components being foreign to a patient may produce adverse effects that may range from mild allergic manifestations to fatal reactions. Such reactions are usually caused by plasma proteins, leucocytes, red cell antigens, plasma and other pathogens. To avoid and reduce such complications, blood products are modified as leukoreduced products, irradiated products, volume reduced products, saline washed products and pathogen inactivated products. The maintenance of blood inventory forms a major concern of blood banking particularly of rare blood groups routinely and common blood groups during disasters. PRBCs can be stored for years using cryopreservation techniques. New researches in red cell cultures and blood substitutes herald new era in blood banking.

Evaluation of single unit red cell transfusions given to adults during surgery

BACKGROUND AND OBJECTIVE

The ready availability of blood in Surat city has resulted in its liberal use. Surat Raktadan Kendra and Research Centre (SRKRC) is 30 years old blood bank having license to supply blood components. In spite of publishing quarterly bulletin and organizing seminars to update clinicians' knowledge still we have not achieved rational use of blood. Present study has evaluated the use of single unit as well as whole blood transfusion for adult surgery cases.

MATERIALS AND METHODS

A total of 8470 surgery cases in the age group of 19 years to 95 years receiving 13070 units of whole blood and 3761 units of red cell concentrate (RCC) during surgery were analyzed on the basis of incidence of single unit and whole blood transfusions, sex and Hb values using Microsoft Excel.

RESULTS

Analysis revealed that 38.9% cases received single unit and 77.7% whole blood transfusions. Females more frequently received single unit transfusion than males (p< 0.001). The highest incidence of single unit (62.2%) and whole blood transfusion (95.2%) was observed for urogenital surgeries. The lowest incidence (22.9%) of single unit transfusion was for cancer surgeries. There was no significant difference in the mean Hb level at which male and female cases, received single unit transfusion (p>0.5). Mean Hb concentration was about 10.0 g/dl for patients receiving single unit of whole blood and 8 g/dl for those who received single unit of RCC.

CONCLUSION

Surgery patients are receiving inappropriate transfusions. Continuous awareness programmes are needed to achieve judicious use of blood.