Table 2.
Frequency of HLA-matched transplantation for individual HLAsa
| Non-viremia (n = 896) | Viremiab (n = 102) | P-value | |
|---|---|---|---|
| HLA-A1 match | 117 (13.1%) | 9 (8.8%) | 0.22 |
| A2 | 276 (30.8%) | 21 (20.6%) | 0.033 |
| A3 | 69 (7.7%) | 7 (6.9%) | 0.76 |
| B7 | 82 (9.2%) | 7 (6.9%) | 0.44 |
| B8 | 84 (9.4%) | 10 (9.8%) | 0.89 |
| B44c | 98 (10.2%) | 3 (2.9%) | 0.011 |
| C3 | 51 (6.2%) | 4 (4.8%) | 0.59 |
| C4 | 61 (7.5%) | 8 (9.5%) | 0.50 |
| C6 | 42 (5.2%) | 0 (0.0%) | 0.033 |
| C7 | 254 (31.1%) | 30 (35.7%) | 0.39 |
| DQ2 | 190 (21.7%) | 18 (18.6%) | 0.48 |
| DQ3 | 27 (3.1%) | 1 (1.0%) | 0.25 |
| DQ6 | 78 (8.9%) | 4 (4.1%) | 0.11 |
| DQ7 | 99 (11.3%) | 18 (18.6%) | 0.037 |
| DR4 | 142 (15.6%) | 14 (13.7%) | 0.58 |
| DR7 | 88 (9.8%) | 3 (2.9%) | 0.022 |
| DR11 | 79 (8.8%) | 11 (10.8%) | 0.51 |
| DR13 | 68 (7.6%) | 11 (10.8%) | 0.26 |
| DR15 | 85 (9.5%) | 3 (2.9%) | 0.027 |
| DR17 | 93 (10.4%) | 11 (10.8%) | 0.90 |
| DR51 | 93 (10.4%) | 3 (3.0%) | 0.017 |
| DR52 | 367 (41.0%) | 45 (44.6%) | 0.49 |
| DR53 | 249 (27.7%) | 20 (19.8%) | 0.086 |
All P-values correspond to the HLA in the corresponding row. Those further corroborated by Cox regression analysis are indicated in Table 3.
aData of HLA-C and DQ were not available in 96 and 24 transplants, respectively.
bFor the purposes of this table, even a single positive test in plasma was sufficient to include a patient in the viremia category. If analysis was restricted to the 93 patients who had sustained viremia (defined as two or more positive tests), P-values associated with DQ7 and DR15 fell to 0.064 and 0.092, respectively. Statistical significance of the remaining HLAs was not affected.
cAmong the 102 viremic patients, we identified a subset of 20 patients where the plasma level load exceeded 10 000 copies/mL, since some studies regard this viral load as a surrogate marker of BKV nephropathy. The frequency of B44 match in patients with viremia <10 000 versus >10 000 was 3.7 and 0.0%, respectively (P = 0.036). Thus, an association between B44 and lower risk of viremia remained statistically significant. Associations of HLA-DR7 and HLA-DQ7 with, respectively, lower and higher incidence of viremia became marginally significant (P = 0.064 and 0.058, respectively). Observed associations with other HLAs were lost, presumable because of the marked reduction in the number of observations available for analysis.