Circulating DNA in rheumatoid arthritis: pathological changes and association with clinically used serological markers

Table 2 Median concentrations of nuclear and mitochondrial circulating DNA and cell surface-bound DNA as well as C-reactive protein and autoantibodies in blood from patients with rheumatoid arthritis and healthy subjects

	n-cirDNA^a	n-csbDNA^a	m-cirDNA^b	m-csbDNA^b	RF^c (U/ml)	ACPA^c (U/ml)	CRP^c (mg/L)
HS	8.4 (1.6–115.2)	50.8 (4–368.4)	0.34 × 10⁶ (0.06–1.34) × 10⁶	0.58 × 10⁶ (0.14–0.24) × 10⁶	6.8 (2.6–13.9)	15 (2–32)	2.6 (0.9–8.1)
Patients with RA^d	12.0 (0.4–183.2)	24.0 (1.8–290.8)	0.38 × 10⁶ (0.006–3.38) × 10⁶	1.44 × 10⁶ (0.06–9.36) × 10⁶	16.1 (0.4–169)	1725 (4–3254)	21.4 (0.4–169)
HS versus RA	p < 0.05	p < 0.01	p > 0.05	p < 0.01	p < 0.01	p < 0.01	p < 0.01
RA activity classes I–II (subgroup 1)	10.4 (2.8–32.8)	21.6 (1.8– 160.0)	0.32 × 10⁶ (0.08–1.68) × 10⁶	0.96 × 10⁶ (0.068–5.18) × 10⁶	10 (4.1–130)	1370 (4 – 2942)	11.9 (1.4–139)
RA activity class III (subgroup 2)	14.0 (0.4–183.2)	25.6 (2.8–290.8)	0.42 × 10⁶ (0.06–3.4) × 10⁶	1.54 × 10⁶ (0.26–9.36) × 10⁶	16.3 (0.4–169)	1945 (10 – 3254)	27.6 (1.6–147.1)
Subgroup 1 versus subgroup 2	p < 0.05	p > 0.05	p > 0.05	p > 0.05	p > 0.05	p > 0.05	p < 0.05

Abbreviations: ACPA Anticitrullinated protein/peptide antibodies, CRP C-reactive protein, HS Healthy subjects, m-cirDNA Cell-free mitochondrial circulating DNA, m-csbDNA Mitochondrial cell surface-bound DNA, n-cirDNA Cell-free nuclear circulating DNA, n-csbDNA Nuclear cell surface-bound DNA, RA Rheumatoid arthritis, RF Rheumatoid factor
^an-cirDNA and n-csbDNA concentrations in nanograms per milliliter of blood
^bm-cirDNA and m-csbDNA concentrations in copies per milliliter of blood
^cRF, ACPA, and CRP concentrations in units per milliliter of blood plasma; median values are presented with range in parentheses
^dRA group 1 (n = 74) (see Table 1)

ISSN: 1478-6362