PIVKA-II plasma levels as markers of subclinical vitamin K deficiency in term infants

Vitamin K insufficiency and the prophylaxis strategy in term healthy infants: A multicentre study

BACKGROUND/AIM

Late vitamin K deficiency bleeding (VKDB) during early infancy is a serious problem worldwide. Vitamin K (VK) deficiency commonly occurs in newborns who are exclusively breastfed. Protein Induced by VK Absence (PIVKA-II) has been identified as an early indicator of subclinical VK deficiency in neonates, surpassing prothrombin time. To assess PIVKA-II levels at 48 h, 1 and 3 months of age in full-term newborns who were exclusively breastfed and received varying VKDB prophylaxis regimens.

METHODS

A prospective observational study was conducted in four hospitals, enrolling 105 newborns. PIVKA-II levels were measured using a sandwich-type enzyme-linked immunosorbent assay.

RESULTS

At 48 h of age, there was no significant difference in PIVKA-II concentrations between newborns who received intramuscular administration of 1 mg of phylloquinone (VK1) and those who received oral administration of 2 mg of VK1 at birth. At 1 and 3 months of life, infants who received any supplementation regimen between 2 and 14 weeks exhibited significantly lower PIVKA-II concentrations compared to infants who received only 1 mg of intramuscular VK1 at birth. The prophylaxis involving a dose of 1 mg of intramuscular VK1 at birth followed by oral administration of 150 μg/day of VK1 from the 2nd to the 14th week of life showed the lowest PIVKA-II blood concentrations.

CONCLUSIONS

Oral supplementation of VK1 after discharge significantly reduced PIVKA-II concentrations in exclusively breastfed term infants. These findings suggest the importance of oral VK1 supplementation in exclusively breastfed infants during their first 3 months of life to avoid the risk of VK insufficiency.

Characterization of Gla proteoforms and non-Gla peptides of gamma carboxylated proteins: Application to quantification of prothrombin proteoforms in human plasma

Gamma (γ) carboxylation is an essential post-translational modification in vitamin K-dependent proteins (VKDPs), involved in maintaining critical biological homeostasis. Alterations in the abundance or activity of these proteins have pharmacological and pathological consequences. Importantly, low levels of fully γ-carboxylated clotting factors increase plasma des-γ-carboxy precursors resulting in little or no biological activity. Therefore, it is important to characterize the levels of γ-carboxylation that reflect the active state of these proteins. The conventional enzyme-linked immunosorbent assay for protein induced by vitamin K absence or antagonist II (PIVKA-II) quantification uses an antibody that is not applicable to distinguish different γ-carboxylation states. Liquid chromatography-mass spectrometry (LC-MS) approaches have been utilized to distinguish different γ-carboxylated proteoforms, however, these attempts were impeded by poor sensitivity due to spontaneous neutral loss of CO2 and simultaneous cleavage of the backbone bond in the collision cell. In this study, we utilized an alkaline mobile phase in combination with polarity switching (positive and negative ionization modes) to simultaneously identify and quantify γ-carboxylated VKDPs. The method was applied to compare Gla proteomics of prothrombin (FII) in 10 μL plasma samples of healthy control and warfarin-treated adults. We also identified surrogate non-Gla peptides for seven other VKDPs to quantify total (active plus inactive) protein levels. The total protein approach (TPA) was used to quantify absolute levels of the VKDPs in human plasma.

First Comparative Evaluation of Short-Chain Fatty Acids and Vitamin-K-Dependent Proteins Levels in Mother-Newborn Pairs at Birth

BACKGROUND

The interplay between vitamin K (vitK) (as carboxylation cofactor, partially produced by the gut microbiota) and short-chain fatty acids (SCFAs), the end-product of fiber fermentation in the gut, has never been assessed in mother-newborn pairs, although newborns are considered vitK deficient and with sterile gut.

METHODS

We collected venous blood from 45 healthy mothers with uncomplicated term pregnancies and umbilical cord blood from their newborns at birth. The concentrations of total SCFAs and hepatic/extra-hepatic vitK-dependent proteins (VKDPs), as proxies of vitK status were assayed: undercarboxylated and total matrix Gla protein (ucMGP and tMGP), undercarboxylated osteocalcin (ucOC), undercarboxylated Gla-rich protein (ucGRP), and protein induced by vitK absence II (PIVKA-II).

RESULTS

We found significantly higher ucOC (18.6-fold), ucMGP (9.2-fold), and PIVKA-II (5.6-fold) levels in newborns, while tMGP (5.1-fold) and SCFAs (2.4-fold) were higher in mothers, and ucGRP was insignificantly modified. In mother-newborn pairs, only ucGRP (r = 0.746, p < 0.01) and SCFAs (r = 0.428, p = 0.01) levels were correlated. Conclusions: We report for the first time the presence of SCFAs in humans at birth, probably transferred through the placenta to the fetus. The increased circulating undercarboxylated VKDPSs in newborns revealed a higher vitamin K deficiency at the extrahepatic level compared to liver VKDPs.

Hemorrhagic Disease of the Newborn: A Case Series Illustrating Preventable Harm

Newborns are susceptible to postnatal Vitamin K deficiencies from limited placental transfer, gastrointestinal absorption, and bioavailability in breast milk and formula preparations. For over 50 years, the American Academy of Pediatrics has recommended prophylactic vitamin K to prevent hemorrhagic disease in newborns. Yet, public skepticism contributes to increasing refusal rates. We present three cases of vitamin K-dependent bleeding following parental refusal of postnatal prophylaxis. Two patients experienced intracranial hemorrhage with resultant neurological devastation and mortality, respectively. The third child presented with symptomatic hematuria. Perinatal providers must partner with families and advocate vitamin K prophylaxis to limit unnecessary morbidity and mortality.

Three Different Regimens for Vitamin K Birth Prophylaxis in Infants Born Preterm: A Randomized Clinical Trial

OBJECTIVE

To study the efficacy of 3 different vitamin K birth prophylaxis regimens in infants born premature.

STUDY DESIGN

This was an open-label, parallel-group, randomized clinical trial conducted in a tertiary neonatal care unit in India. Infants born very preterm (≤32 weeks) and/or with very low birth weight (≤1500 g) were included. In each arm, 25 babies were enrolled. Babies were randomized to receive 1.0 mg, 0.5 mg, or 0.3 mg intramuscular (IM) vitamin K1 at birth. Protein induced by vitamin K absence - II (PIVKA-II) levels were assessed at birth, and on days 5 and 28, along with the frequency of death, bleeding manifestations, intraventricular hemorrhage, necrotizing enterocolitis, bilirubin levels, and duration of phototherapy. The primary outcome was comparison of PIVKA-II levels on day 5 of life.

RESULTS

All the 3 regimens resulted in similar proportion of vitamin K subclinical sufficiency (PIVKA-II < 0.028 AU/mL) infants on day 5 (1 mg - 100%; 0.5 mg - 91.7%; 0.3 mg - 91.7%, P = .347), with no significant difference in median (IQR) PIVKA-II levels (AU/mL): 1 mg 0.006 (0.004, 0.009); 0.5 mg 0.008 (0.004, 0.009); 0.3 mg 0.006 (0.003, 0.009), P = .301. However, on day 28, there was a significant decrease in the proportion of vitamin K-sufficient infants in the 0.3-mg IM group (72.7%) compared with the 1.0-mg (100%) or 0.5-mg (91.3) groups. The 1.0-mg group had significantly greater bilirubin levels and duration of phototherapy. None of the other clinical outcomes were statistically different.

CONCLUSIONS

Both 1-mg and 0.5-mg IM vitamin K birth prophylaxis resulted in high sufficiency on follow-up, compared with 0.3 mg. The current recommendation of 0.5-1 mg IM vitamin K birth prophylaxis for infants born preterm, needs to be continued.

TRIAL REGISTRATION

CTRI/2022/02/040396.

Evidence based recommendations for an optimal prenatal supplement for women in the US: vitamins and related nutrients

The blood levels of most vitamins decrease during pregnancy if un-supplemented, including vitamins A, C, D, K, B1, B3, B5, B6, folate, biotin, and B12. Sub-optimal intake of vitamins from preconception through pregnancy increases the risk of many pregnancy complications and infant health problems. In the U.S., dietary intake of vitamins is often below recommended intakes, especially for vitamin D, choline and DHA. Many studies suggest that insufficient vitamin intake is associated with a wide range of pregnancy complications (anemia, Cesarean section, depression, gestational diabetes, hypertension, infertility, preeclampsia, and premature rupture of membranes) and infant health problems (asthma/wheeze, autism, low birth weight, congenital heart defects, intellectual development, intrauterine growth restriction, miscarriage, neural tube defects, orofacial defects, and preterm birth). The primary goal of this paper is to review the research literature and propose evidence-based recommendations for the optimal level of prenatal supplementation for each vitamin for most women in the United States. A secondary goal was to compare these new recommendations with the levels of vitamins in over 180 commercial prenatal supplements. The analysis found that prenatal supplements vary widely in content, often contained only a subset of essential vitamins, and the levels were often below our recommendations. This suggests that increasing prenatal vitamin supplementation to the levels recommended here may reduce the incidence of many pregnancy complications and infant health problems which currently occur.

Vitamin K2 Needs an RDI Separate from Vitamin K1

Vitamin K and its essential role in coagulation (vitamin K [Koagulation]) have been well established and accepted the world over. Many countries have a Recommended Daily Intake (RDI) for vitamin K based on early research, and its necessary role in the activation of vitamin K-dependent coagulation proteins is known. In the past few decades, the role of vitamin K-dependent proteins in processes beyond coagulation has been discovered. Various isoforms of vitamin K have been identified, and vitamin K2 specifically has been highlighted for its long half-life and extrahepatic activity, whereas the dietary form vitamin K1 has a shorter half-life. In this review, we highlight the specific activity of vitamin K2 based upon proposed frameworks necessary for a bioactive substance to be recommended for an RDI. Vitamin K2 meets all these criteria and should be considered for a specific dietary recommendation intake.

A Novel LC-MS/MS Assay for Quantification of Des-carboxy Prothrombin and Characterization of Warfarin-Induced Changes

Warfarin is a narrow therapeutic index anticoagulant drug and its use is associated with infrequent but significant adverse bleeding events. The international normalized ratio (INR) is the most commonly used biomarker to monitor and titrate warfarin therapy. However, INR is derived from a functional assay, which determines clotting efficiency at the time of measurement and is susceptible to technical variability. Protein induced by vitamin K antagonist-II (PIVKA-II) has been suggested as a biomarker of long-term vitamin K status, providing mechanistic insights about variation in the functional assay. However, the currently available antibody-based PIVKA-II assay does not inform on the position and number of des-carboxylation sites in prothrombin. The assay presented in this paper provides simultaneous quantification of carboxy and des-carboxy prothrombin that are essential for monitoring early changes in INR and, thus, serves as the superior tool for managing warfarin therapy. Additionally, this assay permits the quantification of total prothrombin level, which is affected by warfarin treatment. Prothrombin recovery from plasma was 95% and the liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay was linear (r²  = 0.98) with a dynamic range of 1-100 µg/mL. The assay interday precision was within 20%. A des-carboxy peptide of prothrombin (GNLER) was negatively correlated with active prothrombin (Pearson r = 0.99, P < 0.0001), whereas its association was positively linked with INR values (Pearson r = 0.75, P < 0.015). This novel LC-MS/MS assay for active and inactive prothrombin quantification can be applied to titrate anticoagulant therapy and to monitor the impact of diseases, such as hepatocellular carcinoma on clotting physiology.

Thrombin Generation in Preterm Newborns With Intestinal Failure-Associated Liver Disease

Background and Aim: Intestinal failure-associated liver disease (IFALD) affects one-fifth of neonates receiving parenteral nutrition (PN) for more than 2 weeks. We aimed to define the effect of IFALD on hemostasis of preterm infants. Methods: This is an ancillary analysis of a prospective study aimed at defining coagulation in preterm infants. We included neonates exposed to PN (at least 14 days), in full-enteral feeding. We compared thrombin generation in the presence of thrombomodulin, defined as endogenous thrombin potential-ETP, PT, aPTT between infants with IFALD vs. those without (controls), at birth, and after 30 days. IFALD was defined as conjugated bilirubin ≥1 mg/dl. Results: We enrolled 92 preterm infants (32 IFALD; 60 controls). Cholestatic patients had a lower birthweight, longer exposure to PN, and longer hospitalization. Infants with IFALD showed longer median PT (12.8-vs.-12 sec; p = 0.02) and aPTT (39.2-vs.-36.5 sec; p = 0.04) than controls, with no difference in ETP. Conclusions: Despite prolonged PTs and aPTTs infants with IFALD had similar ETP than those without.

Congenital Combined Deficiency of the Vitamin K-dependent Clotting Factors (VKCFD): A Novel Gamma-glutamyl Carboxylase (GGCX) Mutation

Congenital combined vitamin K-dependent clotting factors deficiency (VKCFD) is a very rare autosomal recessive bleeding disorder. Here we report a case of a girl with novel variant in the gamma-glutamyl carboxylase (GGCX) gene leading to VKCFD. A 3-month-old girl presented to our hospital with a history of bleeding from puncture site. Laboratory evaluation showed markedly prolonged partial thromboplastin time and activated partial thromboplastin time. Activities of vitamin K-dependent factors were all low. Genetic analysis revealed a homozygous currently unreported variant in the GGCX gene further supporting a diagnosis of VKCFD type 1. VKCFD due to GGCX mutation has an overall good prognosis.

The Effects of Parenteral K1 Administration in Pseudoxanthoma Elasticum Patients Versus Controls. A Pilot Study

Introduction

Pseudoxanthoma elasticum (PXE) is a rare disease caused by mutations in the ABCC6 gene. Vitamin K1 is involved in the posttranslational carboxylation of some proteins related to inhibition of the calcification process. Our aim was to investigate, in patients affected by PXE, baseline levels of vitamin K₁-dependent proteins and -metabolites and whether parenteral administration of phytomenadione was effective in modulating their levels.

Methods

We included eight PXE patients with typical clinical symptoms (skin, retina, and vascular calcification) and two ABCC6 causative mutations; 13 clinically unaffected first-degree patients’ relatives (9 carrying one ABCC6 mutation and 4 non-carriers). We assessed urinary vitamin K1 metabolites and serum Glu- and Gla-OC, Gas6 and undercaboxylated prothrombin (PIVKA-II), at baseline and after 1 and 6 weeks after a single intramuscular injection of 10 mg vitamin K1.

Results

Comparison of PXE patients, heterozygous, and non-carriers revealed differences in baseline levels of serum MK-4 and of urinary vitamin K metabolites. The response to phytomenadione administration on vitamin K-dependent proteins was similar in all groups.

Conclusion

The physiological axis between vitamin K₁ and vitamin K-dependent proteins is preserved; however, differences in the concentration of vitamin K metabolites and of MK-4 suggest that vitamin K1 metabolism/catabolism could be altered in PXE patients.

Roles of Vitamins D and K, Nutrition, and Lifestyle in Low-Energy Bone Fractures in Children and Young Adults

The research on skeletal system health in children and young adults, while recognizing the important role of calcium and vitamin D, goes beyond these nutritional standards. This review focuses on the role of vitamin K in combination with vitamin D and other factors in bone health. The current understanding is that maintaining bone health and prevention of low-energy fractures in any pediatric population includes nutritional factors combined with an active lifestyle. Calcium, vitamin D, and vitamin K supplementation contribute independently and collectively to bone health. The beneficial role of vitamin K, particularly vitamin K2 as menaquinone-7 (MK-7), in bone and cardiovascular health is reasonably well supported scientifically, with several preclinical, epidemiological, and clinical studies published over the last decade. Osteocalcin and matrix-Gla (glutamate-containing) protein (MGP) exemplify vitamin K-dependent proteins involved in building bone matrix and keeping calcium from accumulating in the arterial walls, respectively. An important part of the mechanism of vitamin K involves carboxylation and posttranslational activation of the family of vitamin K-dependent proteins, which prevent expression of pro-inflammatory factors and support improvement in bone mineral concentration, bone mineral density, and the quality of bone matrix. Understanding the combined approach to a healthy skeletal system in children and young adults, including the roles of vitamins D and K, calcium, healthy diet, and exercise, is particularly important in view of reports of subclinical insufficiency of vitamins D and K in otherwise healthy pediatric populations with low-energy bone fractures.

Coagulative safety of epidural catheters after major upper gastrointestinal surgery: advanced and routine coagulation analysis in 38 patients

BACKGROUND

The risk of spinal haematoma in patients receiving epidural catheters is estimated using routine coagulation tests, but guidelines are inconsistent in their recommendations on what to do when results indicate slight hypocoagulation. Postoperative patients are prone to thrombosis, and thromboelastometry has previously shown hypercoagulation in this setting. We aimed to better understand perioperative haemostasis by comparing results from routine and advanced tests, hypothesizing that patients undergoing major upper gastrointestinal surgery would be deficient in vitamin K-dependent coagulation factors because of malnutrition, or hypocoagulative because of accumulation of low molecular weight heparin (LMWH).

METHODS

Thirty-eight patients receiving epidural analgesia for major upper gastrointestinal surgery were included. We took blood at the time of preoperative epidural catheterization and at catheter withdrawal. Prothrombin time-international normalized ratio (PT-INR), activated partial thromboplastin time (aPTT) and platelet count (Plc) were analysed, and also albumin, proteins induced by vitamin K absence (PIVKA-II), rotational thromboelastometry (ROTEM®), multiple electrode aggregometry (Multiplate®) and activities of factors II, VII, IX, X, XI, XII and XIII.

RESULTS

Postoperative coagulation was characterized by thrombocytosis and hyperfibrinogenaemia. Mean PT-INR increased significantly from 1.0 ± 0.1 to 1.2 ± 0.2 and mean aPTT increased significantly from 27 ± 3 to 30 ± 4 s. Activity of vitamin K-dependent factors did not decrease significantly: FIX and FX activity increased. FXII and FXIII decreased significantly. Mean Plc increased from 213 ± 153 × 10⁶/L while all mean ROTEM-MCFs (maximal clot firmnesses) especially FIBTEM-MCF increased significantly to above the reference interval. All mean ROTEM® clotting times were within their reference intervals both before and after surgery. ROTEM® (HEPTEM minus INTEM) results were spread around 0. There were significant correlations between routine tests and the expected coagulation factors, but not any of the viscoelastic parameters or PIVKA-II. Multiplate® area under curve and EXTEM-MCF correlated significantly to Plc as did EXTEM-MCF to fibrinogen, FIX, FX and FXIII; and FIBTEM-MCF to Plc, FII, FXI and FXIII.

CONCLUSIONS

The increase in PT-INR may be caused by decreased postoperative FVII while the elevated aPTT may be caused by low FXII. The mild postoperative hypocoagulation indicated by routine tests is not consistent with thromboelastometry. The relevance of ROTEM® and Multiplate® in the context of moderately increased routine tests remains unclear. Trial registration number is not applicable since this is not a clinical trial.

PIVKA-II correlates with INR but not protein C or protein S concentrations in cord blood among newborns

BACKGROUND

Protein induced by vitamin K absence (PIVKA)-II, inactive precursor of prothrombin, is elevated in vitamin K (VK) deficiency. Our aims were to find the prevalence of VK deficiency in neonates, assess the utility of international normalized ratio (INR) as a screening tool, and explore the relationship between PIVKA-II, activated partial thromboplastin time (aPTT) and VK dependent anticoagulants.

METHODS

INR, aPTT, PIVKA-II, and proteins C and S activities were measured in neonatal cord blood prior to VK administration.

RESULTS

We found 45% of neonates had subclinical VK deficiency based on PIVKA-II levels and 7% based on INR. Receiver operating characteristic (ROC) analysis assessed the utility of INR in detecting >4 ng/mL of PIVKA-II and ROC of the area under the curve was 0.70 (95% CI 0.46-0.92, p = 0.07). Proteins C and S activities were normal for age and did not correlate with PIVKA-II [(r = 0.40, p = 0.14) and (r = 0.29, p = 0.29), respectively]. There was no association between aPTT and PIVKA-II (p = 0.83).

CONCLUSION

PIVKA-II seems to be a sensitive indicator of mild VK deficiency. Further studies are needed to investigate the lack of relationship between PIVKA-II and functional protein C or S levels.

Biological Systems of Vitamin K: A Plasma Nutriproteomics Study of Subclinical Vitamin K Deficiency in 500 Nepalese Children

Vitamin K (VK) is a fat-soluble vitamin whose deficiency disrupts coagulation and may disturb bone and cardiovascular health. However, the scale and systems affected by VK deficiency in pediatric populations remains unclear. We conducted a study of the plasma proteome of 500 Nepalese children 6–8 years of age (male/female ratio = 0.99) to identify proteins associated with VK status. We measured the concentrations of plasma lipids and protein induced by VK absence-II (PIVKA-II) and correlated relative abundance of proteins quantified by mass spectrometry with PIVKA-II. VK deficiency (PIVKA-II >2 μg/L) was associated with a higher abundance of low-density lipoproteins, total cholesterol, and triglyceride concentrations (p < 0.01). Among 978 proteins observed in >10% of the children, five proteins were associated with PIVKA-II and seven proteins were differentially abundant between VK deficient versus sufficient children, including coagulation factor-II, hemoglobin, and vascular endothelial cadherin, passing a false discovery rate (FDR) threshold of 10% (q < 0.10). Among 27 proteins associated with PIVKA-II or VK deficiency at a less stringent FDR (q < 0.20), a network comprised of hemoglobin subunits and erythrocyte anti-oxidative enzymes were highly and positively correlated each other (all r > 0.7). Untargeted proteomics offers a novel systems approach to elucidating biological processes of coagulation, vascularization, and erythrocyte oxidative stress related to VK status. The results may help elucidate subclinical metabolic disturbances related to VK deficiency in populations.

Early vitamin K deficiency bleeding in a neonate associated with maternal Crohn's disease

We report herein a case of early vitamin K deficiency bleeding (VKDB) in a neonate associated with maternal Crohn's disease. A female neonate was born at 37 weeks' gestation and weighed 2778 g. She developed broad purpura on her back on day 1. Laboratory data showed anemia, prolonged coagulation time and elevated protein induced by vitamin K absence or antagonist-II. Early VKDB has not been reported in a neonate born from mother with active Crohn's disease. It is essential to give vitamin K selectively as soon as possible after birth to prevent early VKDB in neonates.

Coagulation assays and anticoagulant monitoring

Anticoagulant therapy, including conventional agents and a variety of new oral, fast-acting drugs, is prescribed for millions of patients annually. Each anticoagulant varies in its effect on routine and specialty coagulation assays and each drug may require distinct laboratory assay(s) to measure drug concentration or activity. This review provides an overview of the assorted assays that can measure anticoagulant drug concentration or activity and includes key assay interferences. The effect of these conventional and new anticoagulant agents on specialty coagulation assays used to evaluate for bleeding or clotting disorders, and whether this impact is physiological or factitious, is included. Also provided is a short review of superwarfarin poisoning and features distinguishing this from warfarin overdose. Knowledge of clinically significant pearls and pitfalls pertinent to coagulation assays in relation to anticoagulant therapy are important to optimize patient care.