Prognostic potential of creatinine and Cystatin C in COVID-19 – a retrospective cohort study from Karolinska University Hospital

Figures & data

Table 1. Clinical characteristics on admittance of 286 COVID-19 patients.

Variables	ICU 164 patients	Non-ICU 122 patients	All 286 patients
Median age, years (IQR)	59 (52–65)	56 (45–66)	59 (49–65)
19–39 years of age	14 (9)	15 (12)	29 (10)
40–69 years of age	128 (78)	90 (74)	218 (76)
70–81 years of age	22 (13)	17 (14)	39 (14)
Women	30 (18)	41 (34)	71 (25)
Median BMI (IQR)	29 (26–32)	28 (26–33)	29 (26–32)
Hypertension	69 (42)	41 (34)	110 (38)
Diabetes mellitus type 2	48 (29)	25 (20)	73 (26)
Chronic obstructive pulmonary disease	28 (17)	19 (16)	47 (16)
Preexisting kidney disease	10 (6)	5 (4)	15 (5)
Median days from first symptom to admittance (IQR))	8 (6–11)	8 (5–11)	8 (6–11)

Note: Whereas all data are presented as count and percentage (%) unless otherwise noted.

Table 2. Clinical routine laboratory characteristics of 286 patients with severe COVID-19.

Variables	Median at admittance (IQR)	Hospital day 7
Creatinine (µmol/L)	77 (65–94)	79 (61–138)
Cystatin-C (mg/L)	1.11 (0.92–1.41)^a	1.54 (1.22 − 2.64)
eGFRCR	80 (68–93)	77 (34–94)
eGFRCYS	64 (48–83)^a	44 (22–60)
CRP (mg/L)	114 (55–188)	166 (57–310)
Interleukin 6 (ng/L)	95 (51–219)	139 (48–409)
Procalcitonin (µg/L)	0.27 (0.14–0.55)	0.65 (0.21–1.95)
Lymphocyte count (× 10^9/L)	0.9 (0.7–1.1)	1.0 (0.7–1.4)
Neutrophil count (× 10^9/L)	5.4 (3.8–7.9)	7.1 (5.2–9.8)
Neutrophil/lymphocyte ratio	6.4 (3.9–9.5)	8.2 (4.6–12.5)
eGFRCYS / eGFRCR ratio	0.86 (0.73–1.0)	0.68 (0.56–0.81)

Note: All data are presented as median levels and interquartile range.

^aMissing data, only 34 patients had Cystatin-C results at admission.

Table 3. Clinical outcome characteristics of 286 patients with severe COVID-19.

Variables	ICU 164 patients	Non-ICU 122 patients	All 286 patients
Acute kidney injury	95 (58)	13 (11)	108 (38)
Stage 1	28 (17)	11 (85)	39 (36)
Stage 2	21 (13)	1 (8)	22 (20)
Stage 3	46 (28)	1 (8)	47 (44)
Thrombosis	49 (30)	3 (2)	52(18)
In-hospital death	54 (33)	0	54 (19)
Median days for in-hospital stay (IQR)	21.5 (15–38)	8 (5–12)	14 (8–25)
Mechanical ventilation	144 (88)	0	144 (50)
Dialysis requiring AKI	43 (26)	0	43 (15)
Median days from admittance to ICU care (IQR)	1 (1–3)	N/A	N/A

Note: Whereas all data are presented as count and percent (%) unless otherwise noted.

Figure 1. Median plasma creatinine (left upper plot) and creatinine based eGFR (right upper lot), median plasma Cystatin-C (left lower plot) and Cystatin-C based eGFR (right lower plot) divided in groups of ICU deceased (black line with dots), ICU survivors (black whole line) and non-ICU patients (broken black line).

Figure 2. Left panel: median creatinine based eGFR (broken black line) and Cystatin-C based eGFR (black line) over time. Right panel: eGFR_CYS/eGFR_CR ratio (grey line) over time.

Table 4. Discrepant eGFR in patients with severe COVID-19.

Time period:	Patients with an eGFRCYS/eGFRCR ratio <0.6
	ICU patients	Non-ICU patients
Day 0–2	13/94 (14)	2/22 (9)
Day 3–5	32/138 (23)	4/32 (12.5)
Day 6–8	62/149 (42)	6/40 (15)
Day 9–11	94/157 (60)	6/40 (15)
Day 12–21	109/161 (66)	7/40 (17.5)

Note: Data presented as number of positive patients/total number of patients, and (%), in each group (non-ICU or ICU) for each time period.