Persisting alterations of iron homeostasis in COVID-19 are associated with non-resolving lung pathologies and poor patients’ performance: a prospective observational cohort study

Table 2 Serum biomarkers in post-acute COVID-19 according to disease severity

Disease severity	Mild (N = 22)	Moderate (N = 34)	Severe (N = 53)	p value
Markers of iron homeostasis
Iron, µmol/L	18 ± 6	16 ± 6	15 ± 6	0.174
Transferrin saturation, %	27 ± 11	26 ± 9	24 ± 10	0.434
Ferritin, µg/L	139 ± 118	260 ± 183	317 ± 271	0.001
Soluble transferrin receptor, mg/L	2.9 ± 0.8	3.2 ± 0.9	3.8 ± 1.3	< 0.001
sTFRF index, (mg/L)/(µg/L)	1.5 ± 0.5	1.4 ± 0.5	1.7 ± 0.9	0.295
Hepcidin-25, µg/L	14 ± 10	22 ± 14	20 ± 13	0.073
Hematological parameters
Hemoglobin, g/L	139 ± 12	138 ± 13	139 ± 17	0.650
Leucocytes, 10⁹ cells/L	5.7 ± 1.6	6.1 ± 2.2	6.4 ± 2.1	0.253
Thrombocytes, 10⁹ cells/L	251 ± 47	254 ± 60	259 ± 78	0.998
Markers of inflammation
Interleukin 6, ng/L	1.45 ± 2.1	1.96 ± 1.9	4.43 ± 6.6	0.017
C-reactive protein, mg/dL	0.2 ± 0.3	0.2 ± 0.2	0.4 ± 0.6	0.067
Pro-calcitonin, µg/L	0.03 ± 0.03	0.03 ± 0.03	0.04 ± 0.04	0.332

Data are presented as mean ± 1 SD. Disease severity was categorized according to the need of medical treatment: mild, outward treatment, moderate, inward treatment, severe, inward treatment respiratory support (oxygen supply or mechanical ventilation). p values depict significant differences between severity groups
sTFRF index soluble transferrin receptor/log ferritin index

ISSN: 1465-993X