[A proposed decision-making algorithm for discrepancies between red blood cell (Beth-Vincent) and serum (Simonin) tests in ABO blood typing at the Immunology Laboratory of Bouaké University Hospital (Côte d'Ivoire)].

INTRODUCTION

ABO blood typing relies on two complementary tests: the red blood cell test (Beth-Vincent) and the serum test (Simonin-Michon). Concordance between these tests is essential for transfusion safety. Persistent discrepancies, though rare, are critical and require thorough investigation.

METHODS AND CASE PRESENTATION: Thirteen patients (aged 6-73) were examined for persistent ABO discordance. We performed parallel Beth-Vincent and Simonin tests. In the event of discordance, we triple washed the red blood cells in saline solution. Auto-, allo-, and ABO controls were systematically performed. The clinical contexts included trauma, anemia, and preoperative and prenatal assessments. Most patients had no history of previous transfusion. Most cases presented a positive auto control, suggesting the presence of autoantibodies, and/or a positive AB control, indicating polyagglutinability. Discrepancies mainly concerned conflicts between direct and inverse ABO phenotypes (AB/O, A/O, and B/O). These results demonstrate the value of controls in guiding diagnosis and the need for complementary approaches.

CONCLUSION

This series illustrates the decision-making algorithm proposed for cases with persistent discrepancies between red blood cell and serum tests during ABO blood typing.