The Impact of ABO and RhD Blood Groups on Laboratory Parameters in Children

Developmental differences exist that impact laboratory reference intervals in children. Variances exist in ABO antigen expression and isohaemagglutinins through childhood. The impact of ABO and RhD blood group on laboratory parameters in children is unknown.

The Harmonising Age Pathology Parameters in (HAPPI) Kids study is a prospective, cross-sectional study, aiming to establish normative data for age-appropriate reference intervals for laboratory parameters in healthy children. This study explores blood group-related differences in laboratory parameters.

2012 children had blood group testing. Haemoglobin was higher in group B compared with A (median difference 3.56 g/L [0.98-6.14]) (p = 0.01) and red cell count (RCC) was higher in B compared with group A (0.23 × 10¹²/L [0.10-0.35]) (p < 0.001) and O (0.19 × 10¹²/L [0.07-0.32]) (p = 0.003). Haemoglobin and RCC were higher in B compared with non-B. Group O had statistically lower Factor VIII levels than A (-0.40 IU/mL [-0.59 to -0.20]) (p < 0.001), AB (-0.55 IU/mL [-0.73 to -0.36]) (p < 0.001) and B (-0.45 [-0.81 to -0.10]) (p = 0.027). VWF:Ag levels were lower in group O than A (-0.22 U/mL [-0.39 to -0.05]) (p = 0.023) and B (-0.34 U/mL [-0.59 to -0.08]) (p = 0.02). VWF:RCo was lower in group O than A (-0.34 U/mL [-0.50 to -0.17]) (p < 0.001). Group O compared with non-O had longer APTTs, lower FVIII and VWF parameters. No difference was found between RhD blood group and any parameter.

This is the first study to explore whether ABO and RhD blood group impact routine laboratory parameters in children. Further studies are required to confirm the blood group-related associations found and understand if ABO blood group impacts paediatric disease pathogenesis.