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Studies on vitamin K-dependent factor deficiency during early childhood with special reference to prothrombin
Insights
This study identifies abnormal prothrombin, termed PIVKA-II, in infants with vitamin K deficiency. PIVKA-II is linked to congenital bile duct atresia and severe hemorrhagic tendencies in breast-fed infants.
Area of Science:
- Biochemistry
- Pediatric Hematology
- Nutritional Science
Background:
- Vitamin K-dependent factor deficiency can cause severe bleeding in infants.
- Congenital bile duct atresia and exclusive breastfeeding are risk factors for vitamin K deficiency.
- Understanding the specific nature of prothrombin abnormalities is crucial for diagnosis and management.
Purpose of the Study:
- To investigate prothrombin activity and antigen levels in young infants with vitamin K-dependent factor deficiency.
- To characterize the abnormal prothrombin antigen found in infants with congenital bile duct atresia and severe hemorrhagic tendencies.
- To determine if the abnormal prothrombin antigen is PIVKA-II.
Main Methods:
- Studied 8 infants (14 days to 5 months) with vitamin K-dependent factor deficiency.
- Assessed prothrombin activity and antigen levels.
- Utilized crossed immunoelectrophoresis to analyze prothrombin antigen.
- Evaluated prothrombin antigen behavior after plasma recalcification and BaSO4 absorption.
- Observed the effect of vitamin K administration on abnormal prothrombin antigen levels.
Main Results:
- Infants with congenital bile duct atresia and/or breastfeeding showed a significantly reduced ratio of prothrombin activity to antigen (<0.1).
- Crossed immunoelectrophoresis revealed an abnormal prothrombin antigen with a faster anodal shift in affected infants.
- This abnormal prothrombin antigen was resistant to recalcification and poorly absorbed by BaSO4.
- Parenteral vitamin K administration led to the disappearance of the abnormal prothrombin antigen.
Conclusions:
- The abnormal prothrombin antigen identified in these infants is likely PIVKA-II (Protein Induced by Vitamin K Absence or Antagonism II).
- PIVKA-II is a marker for vitamin K deficiency in infants, particularly those with bile duct atresia or exclusively breastfed.
- These findings highlight the importance of vitamin K assessment in infants presenting with hemorrhagic tendencies.
Abstract:
8 young infants aged 14 days to 5 months with vitamin K-dependent factor deficiency were studied with special reference to prothrombin activity and antigen level. Among them, 3 infants had congenital bile duct atresia and 5 were breast-fed babies with severe hemorrhagic tendency of unknown cause. In the patients with both congenital bile duct atresia and breast feeding the ratio of prothrombin activity to prothrombin antigen was lower than 0.1. Furthermore, the arc of prothrombin antigen in these patients demonstrated a faster anodal shift than did normal prothrombin antigen on crossed immunoelectrophoresis. This abnormal prothrombin antigen was not consumed after recalcification of patient plasma, and absorbed poorly on BaSO4. In addition, the abnormal prothrombin antigen disappeared from the patient plasma within a few days after parenteral administration of vitamin K. These results suggest that this abnormal prothrombin is PIVKA-II.