Severe congenital vs. acquired protein C deficiency
Causes of Protein C (PC) deficiency
Making the distinction between congenital and acquired PC deficiency is often challenging particularly in the setting of acute thrombosis. Genetic testing is often useful in confirming the actual diagnosis.1 Shown below are the different types of causes.
Homozygous pc defiency
- Type 1
- Type 2
COMPOUND HETEROZYGOUS PC DEFIENCY
- Type 1
- Type 2
Type 1 – Reduction in both PC antigen concentration and activity3
Type 2 – Normal antigen concentration but with reduction in activity3
Severe Congenital PC deficiency (SCPCD) is a rare, autosomal recessive disorder that mainly presents in neonates. One of the main symptoms is purpura fulminans. There are two genotypes that are associated with this disorder, homozygous and compound heterozygous.
In SCPCD, PC levels are nearly nonexistent [PC < 1 IU/dL].1
Infants with SCPCD usually present within hours of birth with rapidly progressive purpura fulminans and DIC.1
Increased consumption of PC
- Sepsis/Severe infection without overt Disseminated Intravascular Coagulation (DIC), e.g. Group streptococcus infection
- Overt DIC
- Antiphospholipid antibodies
- Cardiac bypass
Decreased synthesis of PC
- Severe hepatic dysfunction
- Severe congenital heart disease
- Warfarin therapy
- Complications of prematurity
Acquired PC deficiency is a result of the consumption of PC levels due to the above factors or the following:2
- Vitamin K deficiency also contributes to PC deficiency.3 Vitamin K is necessary for coagulation factors, as well as PC and protein S.4
- Liver disease, such as chronic hepatitis C, has also been demonstrated to be associated with Protein C deficiency.3,5
Goldenberg N, Manco-Johnson M. Protein C Deficiency. Haemophilia. 2008;14(6):1214-1221.
Price VE, et al. Diagnosis and management of neonatal purpura fulminans. Semin Fetal Neonatal Med. 2011;16:318-322.
Kottke-Marchant K, Comp P. Laboratory issues in diagnosing abnormalities of protein C, thrombomodulin, and endothelial cell protein C receptor. Arch Pathol Lab Med. 2002;126:1337–1348.
Bovill EG, et al. Vitamin K1 metabolism and the production of des-carboxy prothrombin and protein C in the term and premature neonate. Blood. 1993;81(1):77–83.
Saray A, et al. Protein C Deficiency in Chronic Hepatitis C: Correlation With Histological Extent of Liver Fibrosis. Clin Appl Thromb Hemost. 2017;23(1):72-77.