Relationship between serum bilirubin and coagulation test results in 1-month-old infants.

OBJECTIVE: Although the connection between cholestasis and conjugated hyperbilirubinemia is well known, mild hepatic dysfunction or cholestasis may also be associated with unconjugated hyperbilirubinemia in some infants with prolonged jaundice. The aim of this study was to investigate the relationship between serum bilirubin levels and alanine aminotransferase levels, aspartate aminotransferase levels, prothrombin time, activated partial thromboplastin time, and international normalization ratio findings in a group of infants. METHODS: The study included 77 healthy, term, breast-fed infants with jaundice and 56 age-matched, healthy, term, non-jaundiced controls. The 133 babies were divided into three subgroups according to their total bilirubin levels [group I (controls) < 50 micromol/L, group II = 50-100 micromol/L, and group III > 100 micromol/L, and the findings for the noted parameters were compared]. RESULTS: The mean conjugated bilirubin level was significantly higher, and the mean activated partial thromboplastin time significantly longer in group III than in group I. A significant positive correlation was found between bilirubin levels and PT and APTT results. CONCLUSION: Clinical vitamin K deficiency appeared unlikely to develop in this group of infants with prolonged unconjugated hyperbilirubinemia. However, a significant positive correlation between bilirubin levels and PT and APTT suggest that a higher bilirubin load to the liver may cause some degree of vitamin K deficiency due to mild cholestasis. The importance of this finding, and the possible benefits of vitamin K supplementation in 1-month-old breast-fed infants with bilirubin levels higher than 100 micromol/L require further investigation.

Inherited Vitamin K Deficiency: Case Report and Review of Literature

Vitamin K is the cofactor for the hepatic carboxylation of glutamic acid residues in a number of proteins including the procoagulants factors ll, Vll, lX, and X. The role of vitamin K in normal bone function is not fully understood. Inherited deficiency of vitamin K dependent coagulation factors is a rare bleeding disorder reported only in a few patients. Here we present an 18-month old child who presented with osteopeni due to inherited vitamin K deficiency. While the patient had high bone specific alkaline phosphatase and parathyroid hormone levels and low osteocalcin and bone mineral density values, with the regular supplementation of vitamin K all the mentioned parameters returned to normal values.

Vitamin K deficiency.

Vitamin K (phylloquinone, K1; menaquinone, K2) functions as an essential cofactor for the synthesis of the coagulation protein factors II, VII, IX, X and protein C and S by promoting a unique post-translational modification of specific glutamic acid residues to gamma-carboxylglutamic acid, thus mediating calcium binding to phospholipid surfaces. Vitamin K deficiency results in a depletion of liver stores of phylloquinone, decreased plasma levels of vitamin K1, increased levels of K1 epoxide, appearance of noncarboxylated protein (PIVKA), decreased levels of functioning vitamin K-dependent clotting factors and prolongation of the APTT, PT and thrombotest. When the progression of deficiency leads to abnormal clotting tests a generalized bleeding tendency occurs. Noncarboxylated prothrombin (PIVKA-II) determinations are a sensitive indicator of vitamin K deficiency. Although Vitamin K deficiency can occur at any age (warfarin, fasting, antibiotic therapy, malabsorption syndromes) the major public health problem is related to prevention of early, classic and late hemorrhagic disease of the newborn (HDN). A single dose of oral or parenteral vitamin K prevents classic HDN but the most effective way to prevent early HDN is by giving large doses to the mother prior to delivery (2 weeks). Late HDN in breastfed infant occurs with a prevalence of about 20 per 100,000 live births when no neonatal prophylaxis is given. Parenteral (1 mg) K1 prevents late HDN and single or repeated doses of oral vitamin K reduces the incidence but does not eliminate all late HDN. The optimal (cost, feasibility, effective) mode of neonatal prophylaxis remains to be determined.