D-Dimer Elevation at Time of Admission is Associated with Need for Ventilator Support among Pediatric Patients with COVID-19 Infection.

BACKGROUND: This study aims to determine if coagulation abnormalities at presentation are associated with clinical severity of pediatric COVID-19 infection. METHODS: We retrospectively reviewed admission coagulation studies (D-dimer, prothrombin time (PT), partial thromboplastin time with hepzyme, fibrinogen, and platelet count) with disease severity defined by need for ICU admission, ventilator support, and length of stay (LOS). RESULTS: There were 110 pediatric patients (0.5 months to 18 years) who had coagulation studies collected within 24 hours of admission. Patients who required ICU admission and ventilation support had significantly higher D-dimer and PT values at presentation compared to patients who required neither. In addition, D-dimer showed moderate correlation with LOS. CONCLUSIONS: Elevated D-dimer correlated significantly with severity of disease and LOS, while prolonged PT only correlated with disease severity. Our data suggest that D-dimer at presentation may predict a pediatric patient's need for ICU care or ventilator support.

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.

Transfusion support for a patient with McLeod phenotype without chronic granulomatous disease and with antibodies to Kx and Km.

BACKGROUND AND OBJECTIVES: Kell antigens are encoded by the KEL gene on the long arm of chromosome 7. Kx antigen is encoded by the XK gene on the short arm of the X chromosome. Kell and Kx proteins in the red cell membrane are covalently linked by a disulphide bond. The McLeod phenotype is characterized by weakened expression of antigens in the Kell blood group system, absence of Km and Kx antigens, and acanthocytosis. It has an X-linked mode of inheritance with transmission through carrier females. Some males with the McLeod syndrome also have chronic granulomatous disease (CGD). It is generally believed that patients with non-CGD McLeod may develop anti-Km but not anti-Kx, but that those with CGD McLeod can develop both anti-Km and anti-Kx. MATERIALS AND METHODS: We present serological data, DNA genotyping and gene sequencing, monocyte monolayer assay and neutrophil oxidative burst test from a patient with the McLeod phenotype without clinical evidence of CGD. RESULTS: We report here the second example of a patient with non-CGD McLeod who developed anti-Kx in addition to anti-Km. Sequencing of our patient's XK gene confirmed the presence of a mutation resulting in a premature stop codon and lack of Kx protein in the red cell membrane, which is consistent with the diagnosis of McLeod syndrome. Neutrophil oxidative burst test was normal, indicating that our patient did not have CGD. The challenge of providing 10 compatible blood units for multiple surgeries was met. CONCLUSION: The second case of a rare entity, a patient with non-CGD McLeod who developed anti-Kx and anti-Km, was managed successfully with a combination of autologous donations and procurement of compatible units from national and international sources.