Table 6.
Correlation between FcγRIIa H131R genotype and S. aureus-induced platelet aggregation, activation and S. aureus–platelet binding using blood from selected healthy volunteers.
| Agonist | FcγRIIa H131R genotype |
P valuea | ||
|---|---|---|---|---|
| H/H | H/R | R/R | ||
| Platelet-rich plasma (n = 88) | ||||
| Lag time, min | ||||
| Newman, stationary | 1.82 ± 0.58 | 1.94 ± 0.68 | 2.02 ± 0.69 | 0.384 |
| 209, stationary | 8.02 ± 3.69 | 8.31 ± 3.85 | 9.91 ± 4.00 | 0.287 |
| Newman, exponential | 5.90 ± 1.61 | 6.67 ± 1.29 | 5.92 ± 1.07 | 0.077 |
| 207, exponential | 9.28 ± 3.64 | 9.18 ± 3.60 | 8.87 ± 3.23 | 0.765 |
| 209, exponential | 1.86 ± 0.51 | 1.92 ± 0.64 | 2.16 ± 1.01 | 0.401 |
| Platelet aggregation, % | ||||
| Newman, stationary | 69 ± 9 | 68 ± 8 | 65 ± 10 | 0.351 |
| 209, stationary | 68 ± 9 | 67 ± 10 | 64 ± 14 | 0.611 |
| Newman, exponential | 70 ± 14 | 65 ± 17 | 66 ± 9 | 0.285 |
| 207, exponential | 69 ± 10 | 64 ± 17 | 66 ± 13 | 0.576 |
| 209, exponential | 65 ± 6 | 65 ± 8 | 57 ± 15 | 0.043 |
| ADP | 73 ± 11 | 70 ± 13 | 69 ± 11 | 0.206 |
| SFLLRN–NH2 | 65 ± 15 | 70 ± 12 | 68 ± 9 | 0.275 |
| Washed platelets (n = 31) | ||||
| Lag time, min | ||||
| Newman, stationary | 3.26 ± 0.66 | 3.19 ± 1.18 | 5.42 ± 7.96 | 0.949 |
| 209, stationary | 9.00 ± 8.18 | 9.59 ± 8.13 | 12.81 ± 10.31 | 0.948 |
| Newman, exponential | 11.98 ± 10.44 | 8.74 ± 8.19 | 12.61 ± 10.42 | 0.328 |
| 207, exponential | 23.62 ± 3.38 | 22.85 ± 5.98 | 22.82 ± 6.18 | 0.536 |
| 209, exponential | 9.57 ± 7.90 | 9.29 ± 7.23 | 8.68 ± 7.26 | 0.332 |
| Platelet aggregation, % | ||||
| Newman, stationary | 81 ± 3 | 79 ± 5 | 85 ± 4 | 0.066 |
| 209, stationary | 75 ± 6 | 73 ± 14 | 77 ± 8 | 0.385 |
| Newman, exponential | 69 ± 5 | 75 ± 5 | 56 ± 22 | 0.207 |
| 209, exponential | 76 ± 3 | 69 ± 13 | 74 ± 5 | 0.251 |
| ADP | 33 ± 31 | 29 ± 16 | 26 ± 19 | 0.877 |
| SFLLRN–NH2 | 75 ± 7 | 71 ± 7 | 68 ± 18 | 0.622 |
| Agonist-induced platelet activation, % (n = 31) | ||||
| Newman, stationary | 64 ± 29 | 54 ± 27 | 40 ± 25 | 0.294 |
| 209, stationary | 27 ± 12 | 22 ± 12 | 23 ± 9 | 0.834 |
| Newman, exponential | 49 ± 24 | 38 ± 16 | 25 ± 15 | 0.059 |
| 207, exponential | 31 ± 22 | 19 ± 11 | 22 ± 10 | 0.450 |
| 209, exponential | 34 ± 23 | 23 ± 14 | 21 ± 6 | 0.410 |
| SFLLRN–NH2 | 78 ± 23 | 84 ± 6 | 79 ± 11 | 0.473 |
| Percentage of platelets bound to S. aureus, % (n = 31) | ||||
| Newman, stationary | 87 ± 23 | 87 ± 18 | 80 ± 26 | 0.456 |
| 209, stationary | 84 ± 28 | 90 ± 16 | 82 ± 25 | 0.544 |
| Newman, exponential | 56 ± 30 | 60 ± 29 | 57 ± 34 | 0.964 |
| 207, exponential | 75 ± 31 | 81 ± 21 | 70 ± 27 | 0.476 |
| 209, exponential | 51 ± 27 | 59 ± 23 | 51 ± 30 | 0.730 |
| Percentage of S. aureus cells bound to platelets, % (n = 31) | ||||
| Newman, stationary | 52 ± 9 | 48 ± 13 | 47 ± 14 | 0.768 |
| 209, stationary | 47 ± 13 | 42 ± 12 | 40 ± 12 | 0.550 |
| Newman, exponential | 21 ± 6 | 22 ± 14 | 19 ± 9 | 0.896 |
| 207, exponential | 20 ± 6 | 25 ± 10 | 22 ± 7 | 0.699 |
| 209, exponential | 17 ± 1 | 18 ± 11 | 15 ± 5 | 0.591 |
Percentage platelet aggregation in response to strain 207 grown to exponential phase could not be analyzed when using washed platelets, as aggregation was only observed with platelets isolated from 2 subjects. Data for S. aureus strain 207 at stationary phase of growth were not analyzed as platelet aggregation was not observed in response to this agonist.
a
P values were determined using the Kruskal–Wallis test.