A cross sectional study of bone and cartilage biomarkers: correlation with structural damage in rheumatoid arthritis

Figures & data

Table 1. Baseline characteristic of the all RA cohort.

Demographic	Female patients (%)	100
	Age (years)	44 [21–59]
Clinical parameters	Disease duration (years)	2 [0.08–15]
	Tender joint	6 [1–28]
	Swollen joint	3 [0–13]
	VAS	60 [10–100]
	DAS 28	4.46 [2.65–7.36]
Biological parameters	CRP (mg/L)	13 [0.3–88]
	CTX I (ng/mL)	0.48 [0.3–1.04]
	OC (ng/mL)	14.99 [6.33–34.92]
	PINP (ng/mL)	37.9 [12.6–72.2]
	COMP (ng/mL)	10.6 [3.04–19.6]
	CTXII (ng/mL)	0.64 [023–1.25]
Radiological parameters	Erosion noted in MCP	0.5 [0–21]
	Erosion noted in Wrist	3.5 [0–30]
Treatment modalities	Methotrexate N (%)	45 (69.2%)
	Combination therapy N (%)	5 (7.69%)
	Sulfasalazine, N (%)	9 (13.84%)
	Leflunomide, N (%)	6 (9.23%)

Values expressed as median [Minimum-Maximum] or absolute value and percentage; RA: Rheumatoid arthritis; VAS: visual analogue scale for pain; CRP: C-reactive protein; DAS28: Disease activity score; CTX I: C-terminal telopeptide of type I collagen; OC: osteocalcin; PINP: N-terminal propeptide of collagen type I; COMP: Cartilage oligomeric matrix protein3; CTX II: C-telopeptide fragment of collagen II; MCP: metacarpo-phalangeal joint; N: number of patients.

Table 2. Comparison of demographic, clinical and biological characteristics of the different sub-groups of patients.

Baseline demographics, clinical and biological characteristics	Group I DAS28 ≤ 3.2	Group II 3.2< DAS28 ≤ 5.1	Group III DAS28 > 5.1	p value*
Number (%)	9 [13.8]	36 [55.4]	20 [30.8]	NS
Age (years) (median)	48 [32–54]	42.5 [21–59]	44 [31–54]	NS
Disease duration (years)	1 [0.08–7]	2.5 [0.08–10]	6 [0.08–15]	< 0.05
CRP (mg/L)	1.2 [0.3–13]	7.9 [0.5–49]	36 [5.2–88.5]	< 0.001
CTX I (ng/mL)	0.37 [0.29–0.62]	0.45 [0.3–0.83]	0.58 [0.3–1.04]	< 0.01
OC (ng/mL)	17.3 [12–34.9]	17.2 [6.9–34.5]	12.5 [6.3–29.9]	< 0.01
PINP (ng/mL)	51.4 [31.5–69.5]	41.6 [12.6–72.2]	31.6 [12.8–56]	< 0.01
COMP (ng/mL)	13 [5.1–15.3]	9.89 [3.04–19.6]	10.9 [5.1–16.5]	NS
CTX II (ng/mL)	0.63 [0.48–1.03]	0.62 [0.23–19.6]	0.65 [0.38–1.21]	NS
MCP erosion score	0 [0–3.5]	0.25 [0–6]	4.5 [0–21]	< 0.01
Wrist erosion score	0 [0–8]	3 [0–18]	14 [0–30]	< 0.01

* Kruskall-Wallis test.

Values expressed as median [Minimum-Maximum]; RA: Rheumatoid arthritis; CRP: C-reactive protein; DAS28: Disease activity score; CTX I: C-terminal telopeptide of type I collagen; OC: osteocalcin; PIPN: N-terminal propeptide of collagen type I; COMP: Cartilage oligomeric matrix protein 3; CTX II: C-telopeptide fragment of collagen II; MCP: metacarpo-phalangeal joint; NS: no significant.

Table 3. Multiple comparison of clinical, radiological and biological characteristics between RA subgroups.

Clinical, biological and radiological parameters	Multiple comparisons inter RA subgroups
	Group I vs group II	Group I vs Group III	Group II vs Group III
Disease duration (years)	NS	< 0.01	NS
CRP (mg/L)	< 0.01	< 0.001	< 0.001
CTX I (ng/mL)	NS	< 0.01	< 0.01
OC (ng/mL)	NS	< 0.01	< 0.01
PINP (ng/mL)	NS	< 0.01	< 0.01
COMP (ng/mL)	NS	NS	NS
CTX II (ng/mL)	NS	NS	NS
MCP erosion score	NS	NS	< 0.01
Wrist erosion score	NS	< 0.01	< 0.01

Mann-Whitney test.

Numbers indicate p values; CRP: C-reactive protein; MCP: metacarpo-phalangeal joint; CTX I: C-terminal telopeptide of type I collagen; OC: osteocalcin; PINP: N-terminal propeptide of collagen type I; COMP: Cartilage oligomeric matrix protein 3; CTX II: C-telopeptide fragment of collagen II; Group I: DAS28 ≤ 3.2, Group II: 3.2< DAS28 ≤ 5.1, Group III: DAS28 > 5.1; NS: no significant.

Table 4. Comparison of demographic, clinical, biological and radiological characteristics between very active RA group and the other sub group of patients.

Demographic, clinical, biological and radiological parameters	Group I (N = 45)	Group II (N = 20) Das28>	p value **
	Das28 ≤ 5.1	Das 28 > 5.1
Age (years)	43 [21–59]	44 [31–54]	NS
RA duration (years)	2 [0–10]	6 [0–15]	NS
CRP (mg/L)	7 [3–49]	36 [5.2–88.5]	< 0.001
CTX I (ng/mL)	0.44 [0.29–0.83]	0.58 [0.3–1]	< 0.01
OC (ng/mL)	17.3 [6.9–34.9]	12.5 [6.3–29.9]	< 0.01
PINP (ng/mL)	43.3 [12.6–72.2]	31.6 [12.8–56)	< 0.01
COMP (ng/mL)	10.2 [3–19.6]	10.9 [5.1–16.5]	NS
CTX II (ng/mL)	0.63 [0.23–1.25]	0.65 [0.38–1.21]	NS
MCP erosion score	0 [0–6]	4.5 [0–21]	< 0.01
Wrist erosion score	2 [0–18]	14 [0–30]	< 0.01

** Mann-Whitney test.

Values as median [Minimum-Maximum]; RA: Rheumatoid arthritis; CRP: C-reactive protein, DAS28: Disease activity score; CTX I: C-terminal telopeptide of type I collagen; OC: Osteocalcin; PINP: N-terminal propeptide of collagen type I; COMP: Cartilage oligomeric matrix protein 3; CTX II: C-telopeptide fragment of collagen II; NS: no significant; Group I: DAS 28 ≤ 5.1; Group II: DAS 28 > 5.1.

Table 5. Correlation values between CT erosion scores and others parameters.

	r values between CT scores and other parameters
Variables	Wrist erosion CT score		MCP erosion CT score
Age	0.064	NS	0.173	NS
Disease duration (Years?)	0.228	NS	0.214	NS
DAS 28	0.41	p < 0.01	0.38	p < 0.01
CRP	0.35	P < 0.01	0.37	P < 0.01
CTX I	0.43	P < 0.001	0.42	P < 0.001
OC	−0.39	P < 0.01	−0.38	P < 0.01
PINP	−0.32	P < 0.01	−026	P < 0.05
COMP	0.196	NS	0.202	NS
CTXI I	0.061	NS	0.050	NS

r: Spearman correlation value; NS: non-significant; CRP: C-reactive protein; DAS28: Disease activity score; CTX I: C-terminal telopeptide of type I collagen; OC: osteocalcin; PINP: N-terminal propeptide of collagen type I; COMP: Cartilage oligomeric matrix protein3; CTX II: C-telopeptide fragment of collagen II.

Table 6. Correlation values between DAS28 score and others parameters.

	r values between DAS28 scores and other parameters
Variables	DAS 28	p
Age	0.048	NS
Disease duration	0.27	< 0.05
CRP	0.73	< 0.001
CTX I	0.46	< 0.001
OC	−0.40	< 0.01
PINP	−0.46	< 0.001
COMP	0.17	NS
CTX II	0.03	NS
MCP erosion score	0.38	< 0.01
Wrist erosion score	0.41	< 0.01

r: Spearman correlation value; NS: no significant; CRP: C-reactive protein; DAS28: Disease activity score; CTX I: C-terminal telopeptide of type I collagen; OC: osteocalcin; PINP: N-terminal propeptide of collagen type I; COMP: Cartilage oligomeric matrix protein3; CTX II: C-telopeptide fragment of collagen II; MCP: metacarpo-phalangeal joint.