Table 1 Demographics of enrolled patients and matched comparators

Age, years, mean (SD)

68.0 (16.3)

62.8 (12.7)

0.200

Male gender, n (%)

32 (55.2)

9 (45.0)

0.450

Dialysis vintage, months, median (range)

33.5 (1–320)

66.5 (5–335)

0.168

Charlson’s comorbidity Index, mean (SD)

4.82 (1.85)

5.75 (2.53)

0.085

Frailty score, mean (SD)

3.65 (2.19)

3.35 (1.53)

0.568

Anti-SARS-CoV-2 vaccination, n (%)

44 (74.6)

18 (90.0)

0.212

Number of vaccine doses, mean (SD)

1.52 (1.07)

2.65 (1.08)

< 0.0001

Moderate COVID-19, n (%)

59 (100)

NA

Absolute total white blood cell count/mm³, mean (SD)

6625.2 (2760.6)

7204.6 (2312.5)

0.407

Absolute neutrophil blood cell count/mm³, mean (SD)

4869.1 (2562.7)

5321.4 (2562.7)

0.485

Absolute lymphocyte blood cell count/mm³, mean (SD)

988.1 (446.7)

1371.2 (673.2)

0.006

C-reactive protein, mg/l, median (range)

18.0 (0.4–261.7)

3.1 (0.5–28.0)

< 0.0001

Procalcitonin, ng/ml, median (range)

0.82 (0.14–30.40)

0.23 (0.07–0.39)

< 0.0001

Ferritin, ng/ml, median (range)

720 (27–7430)

42.5 (5.9–374.3)

< 0.0001

Urea, mg/dl mean (SD)

132.9 (45.4)

130.4 (30.9)

0.827

Creatinine, mg/dl mean (SD)

7.34 (2.56)

8.47 (1.79)

0.087

Medical history of diabetes mellitus, n (%)

27 (46.6)

8 (40.0)

0.795

Medical history of arterial hypertension, n (%)

46 (80.7)

11 (55.0)

0.037

Obesity, n (%)

12 (20.7)

5 (25.0)

0.756