Table 1.
Characteristics of the two groups of patients: “responders” (anti-Spike receptor-binding domain IgGs equal or above 30 binding antibody units/ml) and “nonresponders” (anti-Spike receptor-binding domain IgGs below 30 binding antibody units/ml)
| Parameter | Anti-Spike Protein Humoral Response | |||||
|---|---|---|---|---|---|---|
| Total | Responders, ≥30 U/ml | Nonresponders, <30 U/ml | P Value | |||
| Parameter | Missing Values, n/% | Parameter | Missing Values, n/% | |||
| N, % | 75 (100) | 63 (84) | 0 | 12 (16) | 0 | |
| Age, yr | 75 (65–81) | 75 (66–82) | 0 | 70 (62–80) | 0 | NS |
| Men, % | 44 (59) | 37 (59) | 0 | 7 (58) | 0 | NS |
| Mean eGFR, ml/min per 1.73 m2 | 20 (15–26) | 20 (15–26) | 0 | 19 (15–28) | 0 | NS |
| Time between first and second mRNA vaccine injections, d | 28 (26–28) | 28 (26–28) | 0 | 28 (24–28) | 0 | NS |
| Time between second mRNA vaccine injection and serology, d | 31 (31–37) | 31 (29–34) | 0 | 31 (28–35) | 0 | NS |
| Anti-Spike RBD IgGs 1 mo after second vaccine dose, BAU/ml | 243 (243–243) | 243 (243–243) | 0 | 0.8 (0–6) | 0 | <0.001a |
| CKD etiology, n (%) | 0 | NS | 0 | |||
| Vasculitis/SLE | 9 (12) | 5 (8) | 4 (33) | |||
| Vascular disease: HN, diabetes | 26 (35) | 25 (40) | 1 (8) | |||
| Genetic disorder, including ADPKD and Alport syndrome | 9 (12) | 8 (13) | 1 (8) | |||
| Urinary tract disorders | 11 (15) | 9 (14) | 2 (17) | |||
| Others: glomerulopathies, toxic, interstitial nephritis | 20 (27) | 16 (25) | 4 (33) | |||
| Biologic data | ||||||
| Leukocytes count-serology, d | 25 (22–32) | 25 (12–40) | 2 (3) | 19 (1–47) | 1 (8) | NS |
| Leucocytes/mm3 | 6030 (5085–7790) | 6030 (5250–7790) | 2 (3) | 6140 (4527–7513) | 1 (8) | NS |
| Lymphocytes/mm3 | 1480 (1229–1980) | 1570 (1310–2025) | 2 (3) | 1100 (770–1390) | 1 (8) | 0.003a |
| Hemoglobin, g/dl | 11.7 (11.3–12.0) | 11.7 (10.9–12.6) | 2 (3) | 11.0 (10.5–12.2) | 1 (8) | NS |
| Platelets/mm3 | 228,000 (182,000–270,000) | 228,000 (183,000–270,000) | 2 (3) | 245,000 (174,000–272,500) | 1 (8) | NS |
| Albumin, g/dl | 4.1 (3.7–4.3) | 4.1 (3.7–4.3) | 22 (35) | 4.2 (3.8–4.4) | 0 | NS |
| PTH, pg/ml | 121 (84–197) | 124 (83–177) | 10 (16) | 114 (93–271) | 1 (8) | NS |
| Chronic immunosuppressive therapy | ||||||
| Immunosuppressive therapy | 10 (13) | 3 (5) | 0 | 7 (58) | 0 | <0.001a |
| Steroids | 3 (5) | 3 (25) | ||||
| Calcineurin inhibitor | 0 (0) | 4 (33) | ||||
| Mycophenolate mofetil | 2 (3) | 3 (25) | ||||
| Rituximab within past 6 mo | 0 (0) | 3 (25) | ||||
Biologic assessment was collected at the closest time to the monitoring of the anti-Spike protein humoral response, with a cutoff of 90 days except for albumin and PTH assessment, which was collected during the past year before severe acute respiratory syndrome coronavirus 2 serology. Results of quantitative variables are expressed as medians (interquartile ranges). Comparability between groups was evaluated by the nonparametric Wilcoxon test. Results of qualitative variables are expressed with the number of patients/percentage. Comparability between groups was evaluated by Fisher exact test. NS, nonsignificant; RBD, receptor-binding domain; BAU, binding antibody units; HN, hypertensive nephrosclerosis; ADPKD, autosomal dominant polycystic kidney disease; PTH, serum parathormone.
P≤0.05 was considered significant.