Serum RANKL levels associate with anti- citrullinated protein antibodies in early untreated rheumatoid arthritis and are modulated following methotrexate

Table 2 Linear regression models showed unadjusted and adjusted association between RANKL concentration and ACPA

	Least square mean of RANKL pmol/L		Coefficient	p value	R²
	(95% CI)				(adj R²)
	ACPA-	ACPA-
	positive	negative
Model A. (n = 59)	290	130			0.21
Model A. (n = 59)	(201–417)	(106–160)			(0.19)
ACPA			0.35	<0.001
(positive vs. negative)			0.35	<0.001
Intercept			2.12
Model B. (n = 59)	232	140			0.36
Model B. (n = 59)	(155–346)	(114–171)			(0.31)
ACPA			0.22	0.04
(positive vs. negative)			0.22	0.04
Age			-0.005	0.17
(per 1-year increase)			-0.005	0.17
DAS28-ESR			0.07	0.06
BMI			-0.02	0.04
Intercept			2.53

R²: proportion of variance explained by the variables in the statistical model
adj R²: adjusted R², similar to R² but takes into account the number of variables in the model
RANKL receptor activator of nuclear factor kappa B ligand, ACPA anti-citrullinated protein antibodies, DAS28 disease activity score 28, ESR erythrocyte sedimentation rate, BMI body mass index

ISSN: 1478-6362