Table 2 Characteristics of congenital and acquired Protein C deficits

Congenital deficiencies

 I

Quantitative or true deficiency

(75% of patients)

↓

↓

↓

 II

Qualitative or dysfunctional

(IIa 23,75% and IIb 1.25% of patients)

N

↓ (IIa)

N (IIb)

↓

 II

Quantitative and qualitative

↓

↓↓

↓↓

Acquired deficiencies

Liver diseases

Vitamin K deficiency

AVK treatment

DIC

Sepsis

Chemotherapy with L-asparaginase

Nephrotic syndrome

Solid malignancies

Reduced synthesis/increased clearance

↓

↓

↓

Antibodies against PC

Mainly inhibitors

N

↓

↓

Factors potentially interfering with results

 Pregnancy

–

↑

(early)

–

 DOAC

–

-

False ↑

 Clotted/activated samples

–

False ↑

False ↓

 Lupus anticoagulant (aPTT-based, not dRVVt)

–

–

False ↑

 Factor V Leiden/Factor VIII > 200%

–

–

False ↓

(with aPTT-based assays)

 Increased FVIII activity > 200%

–

False ↓

(with aPTT-based assays)