Table 1.
Baseline characteristics according to response status
| Variable | All (n = 308) | Responsea (n = 112) | No response (n = 196) | p |
|---|---|---|---|---|
| Age (years) | 57.51 ± 13.84 | 53.68 ± 14.45 | 59.7 ± 13.02 | <0.001 |
| Female gender | 111 (36%) | 36 (32.1%) | 75 (38.3%) | 0.282 |
| Time from transplantation (years) | 7.08 ± 7.54 | 7.05 ± 7.17 | 7.11 ± 7.77 | 0.393 |
| Transplantation in the previous 3 months | 12 (3.9%) | 0 (0%) | 12 (6.1%) | 0.008 |
| Living donor | 234 (76%) | 91 (81.3%) | 143 (73%) | 0.101 |
| eGFR (mL/min/1.73 m2) | 62.74 ± 22.74 | 70.54 ± 24.66 | 58.28 ± 20.32 | <0.001 |
| eGFR <60 mL/min/1.73 m2 | 149 (48.4%) | 38 (33.9%) | 111 (56.6%) | <0.001 |
| Diabetes mellitus | 53 (17.2%) | 15 (13.4%) | 38 (19.4%) | 0.180 |
| Time lapsed from second vaccine dose (days) | 28.6 ± 9.49 | 28.2 ± 9.49 | 28.83 ± 9.51 | 0.576 |
| BMI (per kg/m2) | 26.91 ± 4.62 | 26.84 ± 4.38 | 26.94 ± 4.77 | 0.852 |
| No mycophenolic acid | 82 (26.6%) | 46 (41.1%) | 36 (18.4%) | <0.001 |
| Low-dose mycophenolic acidb | 26 (8.4%) | 13 (11.6%) | 13 (6.6%) | |
| Medium-dose mycophenolic acidb | 117 (38%) | 38 (33.9%) | 79 (40.3%) | |
| High-dose mycophenolic acidb | 83 (26.9%) | 15 (13.4%) | 68 (34.7%) | |
| Tacrolimus yes/no | 285 (92.5%) | 104 (92.9%) | 181 (92.3%) | 0.870 |
| Cyclosporine yes/no | 23 (7.5%) | 8 (7.1%) | 15 (7.7%) | |
| Tacrolimus level (ng/mL) | 7.76 ± 2.19 | 7.1 ± 1.61 | 8.14 ± 2.39 | <0.001 |
| Cyclosporine level (ng/mL) | 129.13 ± 55.13 | 112.63 ± 39.54 | 137.93 ± 61.29 | 0.305 |
| mTOR inhibitor | 26 (8.4%) | 10 (8.9%) | 16 (8.2%) | 0.816 |
| High calcineurin inhibitor levelc | 181 (58.8%) | 55 (49.1%) | 126 (64.3%) | 0.009 |
| High-dose CSc | 26 (8.4%) | 4 (3.6%) | 22 (11.2%) | 0.02 |
| Treatment with rituximabc | 6 (1.9%) | 0 (0%) | 6 (3.1%) | 0.149 |
| Treatment with ATGc | 14 (4.5%) | 3 (2.7%) | 11 (5.6%) | 0.234 |
Categorical variables are presented as numbers (percentage); continuous variables are presented as mean + -standard deviation. eGFR, estimated glomerular filtration rate; BMI, body mass index; mTOR, mammalian target of rapamycin; CNI, calcineurin inhibitors; ATG, antithymocyte globulin; CS, corticosteroids.
Adequate antibody response was defined as IgG ≥50 AU/mL using the SARS-CoV-2 IgG II Quant (Abbott©) assay.
Low-dose mycophenolic acid was defined as ≤360 mg/day, medium dose as 361–1079 mg/day, and high dose as ≥1080 mg/day.
High CNI level was defined as >7 ng/mL for tacrolimus and >150 ng/mL for cyclosporine; high-dose CS was defined as intravenous methyl prednisolone (at least 250 mg dose) in the previous 6 months before the first vaccine dose; treatment with rituximab or ATG was defined as any dosage in the last year before the first vaccine dose.