In a nonpregnant state, protein S deficiency is indicated by a free protein S antigen level of:

In a nonpregnant state, protein S deficiency is indicated by a free protein S antigen level of:

• A. Less than 30%
• B. Less than 50%
• C. Less than 55%
• D. Less than 70%

Answer: (C)

In a nonpregnant state, a free protein S antigen level of less than 55% is considered indicative of protein S deficiency. Protein S is a crucial anticoagulant protein that plays a key role in the regulation of coagulation by serving as a cofactor to protein C in the inactivation of factors Va and VIIIa. When protein S levels drop below the threshold of 55%, it suggests an increased risk of venous thromboembolism due to diminished anticoagulant activity. In clinical practice, evaluating protein S levels helps in diagnosing thrombophilic states when patients present with thromboembolic events. The reference ranges for free protein S antigen can vary, but a level under 55% is generally accepted as a marker for potential deficiency and carries clinical significance. Understanding these thresholds assists healthcare professionals in making informed decisions regarding the management of patients who may be at risk for thrombosis.

In a nonpregnant state, a free protein S antigen level of less than 55% is considered indicative of protein S deficiency. Protein S is a crucial anticoagulant protein that plays a key role in the regulation of coagulation by serving as a cofactor to protein C in the inactivation of factors Va and VIIIa. When protein S levels drop below the threshold of 55%, it suggests an increased risk of venous thromboembolism due to diminished anticoagulant activity.

In clinical practice, evaluating protein S levels helps in diagnosing thrombophilic states when patients present with thromboembolic events. The reference ranges for free protein S antigen can vary, but a level under 55% is generally accepted as a marker for potential deficiency and carries clinical significance. Understanding these thresholds assists healthcare professionals in making informed decisions regarding the management of patients who may be at risk for thrombosis.