Table 1.
Baseline characteristics of study participants.
| All patients (n = 88) | KTRs | Prior infection | |||||
|---|---|---|---|---|---|---|---|
| Noa (n = 69) | Yesb (n = 19) | P valuec | No (n = 59) | Yes (n = 29) | P valuec | ||
| Demographics | |||||||
| Median age in years (IQR) | 58 (51–71) | 62 (52–72) | 53 (51–58) | 0.016 | 58 (51–70) | 63 (51–72) | 0.365 |
| Sex | |||||||
| Female | 44 (50) | 37 (53.6) | 7 (36.8) | 0.300 | 29 (49.2) | 15 (51.7) | 1.000 |
| Male | 44 (50) | 32 (46.4) | 12 (63.2) | 30 (50.8) | 14 (48.3) | ||
| Cause of renal failure | |||||||
| Diabetes mellitus | 24 (27.3) | 20 (29.0) | 4 (21.1) | 0.573 | 14 (23.7) | 10 (34.5) | 0.316 |
| Hypertension | 1 (1.1) | 0 (0) | 1 (5.3) | 0.216 | 1 (1.7) | 0 (0) | 1.000 |
| Glomerulonephritis | 39 (44.3) | 29 (42.0) | 10 (52.6) | 0.444 | 29 (49.2) | 10 (34.5) | 0.255 |
| Othersd | 24 (27.3) | 20 (29.0) | 4 (21.1) | 0.573 | 15 (25.4) | 9 (31.0) | 0.616 |
| Immunosuppressant | |||||||
| Any | 39 (44.3) | 21 (30.4) | 18 (94.7) | < 0.001 | 25 (42.4) | 14 (48.3) | 0.652 |
| Prednisolone | 36 (40.9) | 20 (29.0) | 16 (84.2) | < 0.001 | 23 (39.0) | 13 (44.8) | 0.649 |
| Calcineurin inhibitors | 27 (30.7) | 10 (14.5) | 17 (89.5) | < 0.001 | 14 (23.7) | 13 (44.8) | 0.052 |
| Anti-metabolite | 18 (20.5) | 6 (8.7) | 12 (63.2) | < 0.001 | 15 (25.4) | 3 (10.3) | 0.159 |
| mTOR inhibitor | 3 (3.4) | 0 (0) | 3 (15.8) | 0.009 | 2 (3.4) | 1 (3.4) | 1.000 |
| Single Immunosuppressive drug | 7 (8) | 7 (10.1) | 0 (0) | 0.338 | 6 (10.2) | 1 (3.4) | 0.418 |
| Combination immunosuppressive drugs | 32 (36.4) | 14 (20.3) | 18 (94.7) | < 0.001 | 19 (32.2) | 13 (44.8) | 0.346 |
| KTRs | 19 (21.6) | NA | NA | NA | 12 (20.3) | 7 (24.1) | 0.784 |
| Blood test | |||||||
| Median creatinine (IQR) | 694 (131–936) | 742 (362–965) | 119 (108–158) | < 0.001 | 656 (135–937) | 694 (125–938) | 0.918 |
| Median eGFR (ml/min)e (IQR) | 8.5 (4.0–48.5) | 5.5 (4–25) | 53 (38–64) | < 0.001 | 8 (4–45) | 11 (4–48) | 0.943 |
| COVID-19 infection | |||||||
| Infected prior to blood specimen collection | 29 (33.0) | 22 (31.9) | 7 (36.8) | 0.784 | NA | NA | NA |
| Vaccine doses | |||||||
| Received at least 1 dose of COVID-19 vaccine | 80 (90.9) | 61 (88.4) | 19 (100) | 0.193 | 55 (93.2) | 25 (86.2) | 0.431 |
| Completed primary series | 75 (85.2) | 56 (81.2) | 19 (100) | 0.062 | 55 (93.2) | 20 (69.0) | 0.008 |
| Received at least 1 booster | 53 (60.2) | 35 (50.7) | 18 (94.7) | < 0.001 | 41 (69.5) | 12 (41.4) | 0.020 |
| Vaccine typee | |||||||
| CoronaVac only | 30 (37.5)f | 25 (41.0)f | 5 (26.3)f | 0.337 | 20 (36.4)f | 10 (40.0)f | 0.597 |
| BNT162b2 only | 43 (53.8)f | 30 (49.2)f | 13 (68.4)f | 29 (52.7)f,g | 14 (56.0)f,g | ||
| BNT162b2 plus CoronaVac | 7 (8.8)f | 6 (9.8)f | 1 (5.3)f | 6 (10.9)f,g | 1 (4.0)f,g | ||
| Median number of days between the last dose of vaccination or last episode of infection and specimen collectionh | 130 (84–173) | 138 (84–171) | 110 (62–196) | 0.987 | 129 (73–171) | 131 (90–174) | 0.974 |
Data are n (%) unless otherwise specified.
Abbreviations: eGFR, estimated glomerular filtration rate; IQR, interquartile range; KTRs, kidney transplant recipients.
a54 patients are dialysis dependent (29 patients with hemodialysis; 25 patients with peritoneal dialysis).
bThe median time interval since the last transplantation was 18 years (IQR: 8–26 years).
cThe P values were calculated using Mann Whitney U test for continuous variables and Fisher’s exact test for categorical variables.
dInclude polycystic kidney disease, renal angiolipomyoma, obstructive uropathy, CKD of unknown cause.
eFor the purpose of statistical analysis, a value of 91 was used if the eGFR is greater than 90.
fOnly included the 80 patients who have received at least one dose of vaccine.
gOf the 37 patients who were vaccinated with BTN162b2 but did not report infection, 2 tested positive for antibody against SARS-CoV-2 N protein and were classified as infected.
hExcluded 4 patients who were not infected and not vaccinated. For patients in which the date of infection cannot be ascertained, the date of last vaccination was used for the calculation.