Glucose and haemolysis as a rapid screen for contamination of red blood cells with Yersinia and Serratia

Prevalence of G6PD deficiency in Thai blood donors, the characteristics of G6PD deficient blood, and the efficacy of fluorescent spot test to screen for G6PD deficiency in a hospital blood bank setting

BACKGROUND

Transfusion of blood from glucose-6-phosphate dehydrogenase (G6PD) enzyme deficient donors could cause a potentially unfavorable outcome, especially in newborns and those with hemoglobinopathies.

AIMS

To determine the prevalence of G6PD deficiency in Thai blood donors, the characteristics of G6PD deficient blood, and the efficacy of fluorescent spot test (FST) to screen for G6PD deficiency in a hospital blood bank setting.

METHODS

Blood samples were obtained from 514 Thai blood donors who donated blood at Siriraj Hospital (Bangkok, Thailand) during December 2020-February 2021. G6PD deficiency status was screened using FST, and in vitro hemolysis of red blood cell parameters of G6PD deficient blood units was compared with those of normal control units at different time points during 35 days of refrigerated storage.

RESULTS

The prevalence of G6PD deficiency was 7.59% (35 [8.73%] males, 4 [3.54%] females). The sensitivity of FST was 100% (95% confidence interval [CI]: 90.97-100%), and the specificity was 99.58% (95%CI: 98.49-99.95%). In vitro hemolysis was not significantly different between G6PD deficiency and normal controls.

CONCLUSION

The prevalence of G6PD deficiency in this study was 7.59%. FST was demonstrated to be an effective and reliable method for G6PD deficiency screening among Thai blood donors in a hospital blood bank setting.

Feasibility of photoacoustic imaging for the non-invasive quality management of stored blood bags

BACKGROUND AND OBJECTIVES

During the in vitro storage of red blood cells (RBCs), unfavourable changes (storage lesions) cause a rapid consumption of intracellular diphosphoglycerate. The latter deregulates the oxygen-haemoglobin binding potential, subsequently increasing oxygen saturation (SO₂ ) and membrane degradation, transforming RBCs from biconcave discs to rigid spherical bodies (spheroechinocytes). Current laboratory techniques invasively extract RBC samples to assess the quality of red cell concentrate (RCC) units. Optical technologies could provide a means of assessing quality non-invasively.

MATERIALS AND METHODS

A photoacoustic (PA) imaging technique was developed for acquiring the SO₂ of blood bags non-invasively. Seven RCC units were monitored every 3-5 days until expiry (6 weeks). Measurements were validated against a conventional blood gas analyzer (BGA). Using an image flow cytometry assay, morphological profile trends were compared against the SO₂ trends during blood bag storage.

RESULTS

A strong correlation (r²  ≥ 0·95) was found when comparing temporal data between PA and BGA SO₂ measurements. Inter-sample PA variability was found to be similar to that produced by BGA (±0·8%). A strong correlation was found to exist between the temporal changes in SO₂ and relative spheroechinocyte population (0·79 ≤ r²  ≤ 0·97).

CONCLUSION

This study suggests that PA imaging can non-invasively track the SO₂ of stored RBCs non-invasively. By longitudinally monitoring the change in SO₂ , it is possible to infer the effects of the storage lesion on RBC morphology. This non-invasive monitoring technique allows for the assessment of blood bags, without compromising sterility pre-transfusion.

Preliminary evaluation of optical glucose sensing in red cell concentrations using near-infrared diffuse-reflectance spectroscopy

Bacterial contamination of blood products is one of the most frequent infectious complications of transfusion. Since glucose levels in blood supplies decrease as bacteria proliferate, it should be possible to detect the presence of bacterial contamination by measuring the glucose concentrations in the blood components. Hence this study is aimed to serve as a preliminary study for the nondestructive measurement of glucose level in transfusion blood. The glucose concentrations in red blood cell (RBC) samples were predicted using near-infrared diffuse-reflectance spectroscopy in the 1350 to 1850 nm wavelength region. Furthermore, the effects of donor, hematocrit level, and temperature variations among the RBC samples were observed. Results showed that the prediction performance of a dataset which contained samples that differed in all three parameters had a standard error of 29.3 mg/dL. Multiplicative scatter correction (MSC) preprocessing method was also found to be effective in minimizing the variations in scattering patterns created by various sample properties. The results suggest that the diffuse-reflectance spectroscopy may provide another avenue for the detection of bacterial contamination in red cell concentrations (RCC) products.

Bacterial contamination of blood components

Blood for transfusion is a potential source of infection by a variety of known and unknown transmissible agents. Over the last 20 years, astounding reductions in the risk of viral infection via allogeneic blood have been achieved. As a result of this success, bacterial contamination of blood products has emerged as the greatest residual source of transfusion-transmitted disease. This paper summarizes the current status of detection, prevention, and elimination of bacteria in blood products for transfusion.