Streamlined panel of agonists with interpretative notes for diagnosing platelet function defects
| Agonist . | Concentration . | % of maximal aggregation, mean ± SD . | Expected . | Abnormal pattern and further testing . |
|---|---|---|---|---|
| ADP* | 10μM | 59.8% ± 12.5% | Maximal, sustained aggregation and secretion | Reduced or transient aggregation and absent secretion: use 30μM |
| Adrenaline* | 10μM | 70.3% ± 13.7% | Biphasic aggregation with secretion coincident with second phase | Reduced or absent primary wave and absent secretion: use 30μM |
| Arachidonic acid | 1mM | 71.0% ± 8.5% | Maximal, sustained aggregation and secretion | Absent or delayed/reduced aggregation and secretion: use U46619 (3μM) |
| PAR-1 receptor–specific peptide (SFLLRN) | 100μM | 73.8% ± 11.1% | Maximal, sustained aggregation and marked secretion | Transient aggregation and reduced secretion: use PAR-4 receptor–specific peptide (AYPGKF; 500μM). |
| Collagen* | 1 μg/mL | 50.4% ± 22.5% | Sustained aggregation and secretion | Reversible aggregation and absent secretion: use 3 μg/mL and collagen-related peptide (CRP; 3 μg/mL) or convulxin |
| Ristocetin | 1.5 mg/mL | 70.8% ± 16.1% | Maximal sustained aggregation (often biphasic) and secretion | Reduced or absent aggregation and secretion |
| Agonist . | Concentration . | % of maximal aggregation, mean ± SD . | Expected . | Abnormal pattern and further testing . |
|---|---|---|---|---|
| ADP* | 10μM | 59.8% ± 12.5% | Maximal, sustained aggregation and secretion | Reduced or transient aggregation and absent secretion: use 30μM |
| Adrenaline* | 10μM | 70.3% ± 13.7% | Biphasic aggregation with secretion coincident with second phase | Reduced or absent primary wave and absent secretion: use 30μM |
| Arachidonic acid | 1mM | 71.0% ± 8.5% | Maximal, sustained aggregation and secretion | Absent or delayed/reduced aggregation and secretion: use U46619 (3μM) |
| PAR-1 receptor–specific peptide (SFLLRN) | 100μM | 73.8% ± 11.1% | Maximal, sustained aggregation and marked secretion | Transient aggregation and reduced secretion: use PAR-4 receptor–specific peptide (AYPGKF; 500μM). |
| Collagen* | 1 μg/mL | 50.4% ± 22.5% | Sustained aggregation and secretion | Reversible aggregation and absent secretion: use 3 μg/mL and collagen-related peptide (CRP; 3 μg/mL) or convulxin |
| Ristocetin | 1.5 mg/mL | 70.8% ± 16.1% | Maximal sustained aggregation (often biphasic) and secretion | Reduced or absent aggregation and secretion |
Different concentrations of agonists with the percentage of maximal aggregation ± SD are shown.
ATP secretion from dense granules should be measured for the following agonist concentrations: ADP (30μM), adrenaline (30μM), arachidonic acid (1mM), PAR-1–specific peptide (100μM), and collagen (3 μg/mL).