Protein C deficiency

Last revised by Abenezer Zinaye on 9 Sep 2022

Citation, DOI, disclosures and article data

Citation:

Weerakkody Y, Zinaye A, Smith H, Protein C deficiency. Reference article, Radiopaedia.org (Accessed on 19 Apr 2024) https://doi.org/10.53347/rID-60775

DOI:

https://doi.org/10.53347/rID-60775

Permalink:

https://radiopaedia.org/articles/60775

rID:

60775

Article created:

2 Jun 2018, Yuranga Weerakkody ◉

Disclosures:

At the time the article was created Yuranga Weerakkody had no recorded disclosures.

View Yuranga Weerakkody's current disclosures

Last revised:

9 Sep 2022, Abenezer Zinaye

Disclosures:

At the time the article was last revised Abenezer Zinaye had no financial relationships to ineligible companies to disclose.

View Abenezer Zinaye's current disclosures

Revisions:

3 times, by 3 contributors - see full revision history and disclosures

Systems:

Vascular, Haematology

Protein C deficiency is a hypercoagulable state due to reduced activity or an absolute deficiency of protein C, an anticoagulant protein. Protein C deficiency increases the risk of venous thrombosis.

Homozygous cases usually present in neonates with purpura fulminans. Presentation in heterozygous cases is variable and can range from varying degree of venous thromboembolism to embolic complications. The risk of venous thromboembolism in heterozygotes is seven times higher than in the general population ⁶.

Arterial thrombotic complications have been very rarely reported ³.

Pathology

Protein C is converted to activated protein C by thrombin. Activated protein C then cleaves and inactivates activated factor VIII and V protein therefore inhibiting factor X activation and further thrombin formation. The presence of the cofactor protein S is also important for protein C activation ⁷.

Most cases are genetic however some may be due to an acquired deficiency from:

warfarin use
liver disease
disseminated intravascular coagulation
vitamin K deficiency

Genetics

Type I deficiency

quantitative deficiency of protein C
variable phenotypic presentation ranging from recurrent thromboembolism to asymptomatic
autosomal inheritance usually
due to mutations in PROC gene which encodes protein C
Estimated penetrance of protein C deficiency can vary from as low as 20-30% to as high as 75%

Type II deficiency

decreased functional activity of protein C but normal levels

Radiographic features

No specific radiographic features while imaging is mainly around evaluating thomrobotic and embolic complications.

Treatment and prognosis

Treatment depends on the severity of the protein C deficiency. In severe cases of protein C deficiency, protein C concentrate and fresh frozen plasma have historically been used. However, some cases are now treated with novel oral anticoagulants (e.g. rivaroxaban) ⁵.