Adhesion characteristics of RBCs from patients with SCD
| Marker/parameter assayed . | HbAA controls (n = 10) . | SCD-1 low PS/low CD36 (n = 19) . | SCD-2 high PS/high CD36 (n = 45) . | SCD-3 low PS/high CD36 (n = 10) . | SCD-4 high PS/low CD36 (n = 13) . |
|---|---|---|---|---|---|
| PS+erythrocytes | 0.78% ± 0.60% | 1.44% ± 0.42% | 5.59% ± 2.30%* | 1.76% ± 0.35%† | 4.38% ± 1.56%* |
| (0.59%, 0.31%, 1.12%) | (1.49%, 1.03%, 1.81%) | (5.05%, 3.71%, 7.60%) | (1.93%, 1.38%, 2.06%) | (3.96%, 3.41%, 4.97%) | |
| CD36+erythrocytes | 0.06% ± 0.07% | 0.23% ± 0.16% | 2.22% ± 1.69%* | 2.12% ± 1.73%* | 0.30% ± 0.15%† |
| (0.02%, 0.00%, 0.11%) | (0.24%, 0.08%, 0.30%) | (1.33%, 0.94%, 3.39%) | (1.53%, 1.01%, 2.82%) | (0.30%, 0.15%, 0.38%) | |
| VLA-4+erythrocytes | 0.05% ± 0.05% | 0.05% ± 0.08% | 0.23% ± 0.30%* | 0.33% ± 0.64%* | 0.05% ± 0.11%† |
| (0.04%, 0.00%, 0.11%) | (0.03%, 0.00%, 0.07%) | (0.14%, 0.05%, 0.30%) | (0.09%, 0.04%, 0.22%) | (0.00%, 0.00%, 0.04%) | |
| Erythrocytes positive | ND | 0.10% ± 0.09% | 1.18% ± 0.83%* | 0.96% ± 0.54%* | 0.10% ± 0.06%† |
| for both PS and CD36 | (0.07%, 0.03%, 0.14%) | (0.93%, 0.64%, 1.18%) | (0.79%, 0.60%, 1.36%) | (0.09%, 0.06%, 0.15%) | |
| Plasma-induced | 1.18 ± 0.46 | 2.20 ± 1.36 | 6.49 ± 4.10* | 2.08 ± 1.47† | 6.39 ± 1.8* |
| adhesion | (1.07, 0.91, 1.40) | (1.90, 1.20, 2.73) | (5.92, 3.03, 9.88) | (1.38, 1.22, 2.35) | (6.80, 5.30, 7.90) |
| Marker/parameter assayed . | HbAA controls (n = 10) . | SCD-1 low PS/low CD36 (n = 19) . | SCD-2 high PS/high CD36 (n = 45) . | SCD-3 low PS/high CD36 (n = 10) . | SCD-4 high PS/low CD36 (n = 13) . |
|---|---|---|---|---|---|
| PS+erythrocytes | 0.78% ± 0.60% | 1.44% ± 0.42% | 5.59% ± 2.30%* | 1.76% ± 0.35%† | 4.38% ± 1.56%* |
| (0.59%, 0.31%, 1.12%) | (1.49%, 1.03%, 1.81%) | (5.05%, 3.71%, 7.60%) | (1.93%, 1.38%, 2.06%) | (3.96%, 3.41%, 4.97%) | |
| CD36+erythrocytes | 0.06% ± 0.07% | 0.23% ± 0.16% | 2.22% ± 1.69%* | 2.12% ± 1.73%* | 0.30% ± 0.15%† |
| (0.02%, 0.00%, 0.11%) | (0.24%, 0.08%, 0.30%) | (1.33%, 0.94%, 3.39%) | (1.53%, 1.01%, 2.82%) | (0.30%, 0.15%, 0.38%) | |
| VLA-4+erythrocytes | 0.05% ± 0.05% | 0.05% ± 0.08% | 0.23% ± 0.30%* | 0.33% ± 0.64%* | 0.05% ± 0.11%† |
| (0.04%, 0.00%, 0.11%) | (0.03%, 0.00%, 0.07%) | (0.14%, 0.05%, 0.30%) | (0.09%, 0.04%, 0.22%) | (0.00%, 0.00%, 0.04%) | |
| Erythrocytes positive | ND | 0.10% ± 0.09% | 1.18% ± 0.83%* | 0.96% ± 0.54%* | 0.10% ± 0.06%† |
| for both PS and CD36 | (0.07%, 0.03%, 0.14%) | (0.93%, 0.64%, 1.18%) | (0.79%, 0.60%, 1.36%) | (0.09%, 0.06%, 0.15%) | |
| Plasma-induced | 1.18 ± 0.46 | 2.20 ± 1.36 | 6.49 ± 4.10* | 2.08 ± 1.47† | 6.39 ± 1.8* |
| adhesion | (1.07, 0.91, 1.40) | (1.90, 1.20, 2.73) | (5.92, 3.03, 9.88) | (1.38, 1.22, 2.35) | (6.80, 5.30, 7.90) |
Values presented are the mean ± SD from 10 to 45 donors as indicated. Corresponding median, 25th and 75th percentile values are shown in the parentheses. Marker levels from either the SCD-1 (low PS/low CD36) or SCD-2 (high PS/high CD36) group were compared to the other 3 patient groups. For comparison, marker levels from HbAA control donors are also shown. Adhesion is the ratio of test erythrocyte adhesion in the presence of plasma to HbAA control RBC adhesion performed in the absence of plasma to retinal microendothelium. F cells (erythrocytes containing HbF) in SCD-2 and SCD-4 with the highest adhesion ratios were not significantly different from values in SCD-1. Number of control HbAA RBCs (measured as 51Cr radioactivity) adhered to retinal capillary microendothelium in the absence and the presence of plasma ranged from 30 to 90 cpm/well, equivalent to 50 to 150 RBCs/mm2 (calculated from a specific radioactivity of 1700 cpm/1 × 106 RBCs).
ND indicates measurements not done.
Indicates values significantly different from SCD-1 atP < .05 to .0001.
Indicates values significantly different from SCD-2 atP < .0001.