Effects of Spectral Interfering Substances on Light Transmission Platelet Aggregation Using Infrared Based...

Area of Science:

• Hematology
• Clinical Chemistry
• Diagnostic Assays

Background:

• Platelet aggregation (PA) is a critical indicator of hemostasis.
• Hemolyzed, icteric, or lipemic (HIL) samples can interfere with various laboratory tests.
• The TA-8 V aggregometer utilizes a near-infrared light source to mitigate HIL interference.

Purpose of the Study:

• To evaluate the impact of HIL interference on PA testing using the TA-8 V aggregometer.
• To determine the interference thresholds for hemolysis, icterus, and lipemia in PA assays.

Main Methods:

• Platelet-Rich-Plasma (PRP) samples were spiked with varying concentrations of red blood cell hemolysate (RBCH), bilirubin, and Intralipid.
• Maximal intensity (MaxInt) and velocity (Vel) of platelet aggregation were measured in response to ADP and collagen.
• The effect of apyrase on RBCH interference was also investigated.

Main Results:

• Spontaneous platelet aggregation occurred at RBCH concentrations above 0.6 g/L.
• Apyrase treatment of RBCH prevented spontaneous aggregation and reduced interindividual variability.
• Increased RBCH concentrations significantly decreased MaxInt and Vel in response to ADP and collagen.
• Bilirubin did not affect MaxInt or Vel.
• Lipids significantly increased MaxInt at concentrations of 0.5 g/L and above.

Conclusions:

• The TA-8 V aggregometer is not significantly affected by icterus or hyperlipidemia within tested ranges in healthy individuals.
• Grossly hemolyzed samples (>0.6 g/L) interfere with PA testing due to released ADP and should be rejected.
• Further studies are needed to validate these findings in patients with platelet dysfunction.