A patient presents with a platelet count of 223x10^9/L with an abnormal PFA most possibly suggest:

A patient presents with a platelet count of 223x10^9/L with an abnormal PFA most possibly suggest:

• A. Decreased platelet production
• B. Defective platelet function
• C. Increased platelet production
• D. Increased platelet destruction

Answer: (B)

This question tests how to distinguish a qualitative platelet problem from a quantitative one using the PFA. When the platelet count is normal but the PFA is abnormal, it points to defective platelet function rather than an issue with how many platelets are present. The PFA measures how well platelets adhere and aggregate to form a plug; a prolonged or abnormal result means the platelets aren’t functioning properly even though there are enough of them. If production were decreased, the count would be low; if destruction were increased, the count would typically drop as well; and increased production would raise the count. So the abnormal PFA with a normal count best indicates defective platelet function.

This question tests how to distinguish a qualitative platelet problem from a quantitative one using the PFA. When the platelet count is normal but the PFA is abnormal, it points to defective platelet function rather than an issue with how many platelets are present. The PFA measures how well platelets adhere and aggregate to form a plug; a prolonged or abnormal result means the platelets aren’t functioning properly even though there are enough of them. If production were decreased, the count would be low; if destruction were increased, the count would typically drop as well; and increased production would raise the count. So the abnormal PFA with a normal count best indicates defective platelet function.