Protein C and S levels in acute leukemia

Area of Science:

• Hematology
• Oncology
• Thrombosis Research

Background:

• Venous thrombosis occurs in acute leukemia patients during chemotherapy, even with low platelets.
• The role of natural anticoagulants in this phenomenon is unclear.

Purpose of the Study:

• To prospectively investigate levels of protein C and protein S in acute leukemia patients undergoing remission induction chemotherapy.
• To determine if altered anticoagulant levels correlate with thrombosis risk.

Main Methods:

• Measured plasma levels of protein C (antigen and function) and protein S (total and free) in 50 adult acute leukemia patients (34 AML, 16 ALL).
• Analyzed C4b binding protein (C4bBP) levels.
• Compared levels between active disease, remission, and control groups.

Main Results:

• Significantly lower immunologic and functional protein C levels in active AML patients compared to controls and remission patients.
• Significantly decreased free protein S levels in active AML patients.
• Normal protein C and free protein S levels were observed in acute lymphocytic leukemia (ALL) patients.
• Decreased free protein S in AML was not linked to liver disease, white cell count, or elevated C4bBP.

Conclusions:

• Reduced levels of protein C and free protein S in active AML patients may contribute to their risk of venous thrombosis.
• These findings offer a potential explanation for unexplained thrombosis in AML patients undergoing chemotherapy.