Introduction
The mechanisms associated with immunomodulation after red blood cell transfusion are not completely understood, possibly due to methodological biases in the clinical studies and presence of comorbidities such as sepsis. Therefore, a controlled animal model of blood cell transfusion may be a more appropriate approach to minimize these issues. We designed this pilot study in order to validate in vitro and in vivo the survival of swine erythrocytes stored for 13 days.
Methods
Blood was collected from one Agroceres® swine and stored in 2 units of red blood cells (RBC). The following measurements were performed at baseline and after 13 days of storage: volume, hemoglobin and hematocrit, hemolysis index, potassium, sodium, glucose and pH. In vivo validation and hemolysis evaluation were performed by labeling the cells with Na251CrO4 and recovering viable erythrocytes up to 24 hours after transfusion in one autologous material and four homologous animals. A splenectomy was performed after death to evaluate splenic sequestration of RBC.
Results
In vitro validation of the samples is demonstrated in Table 1. The mean RBC recovery value after 24 hours of injection of labeled RBC was 97.5 ± 19%, demonstrating a good viability of the samples. The evaluation of splenic hemolysis was negative.
Table 1.
| Unit | Period | Volume (ml) | HT (%) | Hb (g/dl) | Hemolysis index (%) | K+ (mEq/l) | Na+ (mEq/l) | pH | Glucose (mg/dl) |
|---|---|---|---|---|---|---|---|---|---|
| Unit 1 | Baseline | 196.3 | 68.8 | 22.5 | 0.07 | 3.5 | 144 | 7.09 | 333 |
| 13-day storage | 187.1 | 67.9 | 22.3 | 0.09 | 32.8 | 118 | 6.90 | 362 | |
| Unit 2 | Baseline | 163 | 67.9 | 22.3 | 0.02 | 3.2 | 145 | 6.96 | 362 |
| 13-day storage | 144.7 | 67.2 | 22 | 0.1 | 31.3 | 120 | 6.90 | 370 |
Conclusion
Erythrocytes from pigs stored under human standardized conditions for up to 13 days may be used for experimental transfusion studies. This controlled animal model may be useful to study pathogenetic mechanisms related to adverse effects of RBC transfusion.
Acknowledgements
Supported by Research and Education Institute, Hospital Sírio-Libanês.