The PFA-100 ® does not predict delta-granule platelet storage pool deficiencies

Area of Science:

• Hematology
• Platelet Function Analysis
• Congenital Bleeding Disorders

Background:

• Delta-granule platelet storage pool deficiencies (δ-PSPD) are common mild bleeding disorders.
• The PFA-100® is a widely used screening tool for bleeding disorders.
• Previous studies on PFA-100® in platelet disorders had limited patient numbers and diagnostic specificity.

Purpose of the Study:

• To investigate the utility of the PFA-100® in detecting δ-PSPD.
• To determine the correlation between PFA-100® results and platelet electron microscopy findings in pediatric patients with δ-PSPD.

Main Methods:

• Retrospective review of 105 pediatric patients diagnosed with δ-PSPD (2008-2010).
• Analysis of PFA-100® closure times (C-EPI and C-ADP) in 99 patients.
• Correlation analysis (Spearman's Rho) between PFA-100® results and average platelet granule counts from electron microscopy.

Main Results:

• 46% of tested patients had at least one abnormal PFA-100® closure time; 16% had both abnormal.
• No statistical correlation was found between C-EPI closure time and granule count (ρ = -0.0095, P = 0.9328).
• No statistical correlation was found between C-ADP closure time and granule count (ρ = 0.0315, P = 0.7798).

Conclusions:

• The PFA-100® does not correlate with the presence or severity of δ-PSPD.
• Platelet electron microscopy remains the gold standard for diagnosing δ-PSPD.
• PFA-100® testing alone is insufficient to rule out δ-PSPD in patients with suspected bleeding disorders.