Frequency and Implications of Severe Neonatal Protein C Deficiency

Abstract

The newborn infant has a physiologically low level of protein C which rises very slowly in postnatal life. The frequency and significance of severe neonatal protein C deficiency has not been reported. In this study, protein C levels were measured in 110 newborn infants at the time of birth using functional (amidolytic, Cact) and immunologic (Laurell rocket, Cag) assays. The protein C levels were compared with a marker of thrombin activation (D-dimer fragment of fibrin, +D-D) and infants were subsequently followed for signs and symptoms of thrombosis. Results are summarized below (protein C levels are expressed as U/ml).Thirteen infants had protein C levels compatible with the homozygous deficiency state. Extremely low levels of protein C (<0.20 U/ml) were not found in well term infants and were rarely noted in stable preterm infants. D-D were infrequently present and no thrombosis occurred. Near term infants born with fetal distress frequently showed +D-D but rarely demonstrated extremely low levels of protein C. None of these infants required indwelling arterial catheters and no thromboses occurred. Preterm infants with severe respiratory distress showed lower protein C levels at birth (p <0.01). Although 71% had +D-D, thromboses in these infants were all related to invasive catheterizations. In contrast, the study population of twins demonstrated a high frequency of severe protein C deficiency with negative D-D and frequent thromboses, three of which occurred in the absence of instrumentation. In summary, severe protein C deficiency and thrombin activation are common in sick preterm infants with the risk of thrombosis increased by intravascular catheterization. In contrast, twins with severe protein C deficiency may manifest a thrombotic risk which is independent of thrombin activation or catheterization.

Reasons for admission to emergency services of the patients with hemophilia

“…Diğer bir seçenek ise kanama olmadan profilaktik faktör tedavisi verilmesidir [4]. Hastalara ve ailelerine hemofili kanamaların önlenmesi konusunda eğitim verilmesi kanama sayısını ve şiddetini azaltabilmektedir [2,5].…”