Platelet-to-lymphocyte ratios as a haematological marker of synovitis in rheumatoid arthritis with normal acute phase reactant level

Figures & data

Table

Grade 0: normal joint with no synovial hypertrophy

Grade 1: synovial hypertrophy up to the level of the horizontal line connecting the bone surfaces of an examined joint

Grade 2: synovial hypertrophy extending beyond the joint line but with the upper surface flat to the underlying bones

Grade 3: synovial hypertrophy extending beyond the joint line but with the upper surface convex to the underlying bones

Table

Grade 0: no Doppler activity

Grade 1: up to three single Doppler spots, or up to one confluent spot and two single spots, or up to two confluent spots

Grade 2: greater than grade 1 but <50% Doppler signals in the total GS background

Grade 3: greater than grade 2 and >50% Doppler signals of the GS background

Table 1. Demographic and clinical characteristics in RA patients.

	All patients (n = 135)
Female, n (%)	117 (86.7)
Age, years, median (IQR)	58 (51, 66)
DAS28-ESR, median (IQR)	2.89 (2.18–4.30)
DAS28-CRP, median (IQR)	2.89 (1.76–3.99)
Ultrasound of the hand joints, n (%)	88 (65.2)
Joint effusions, n (%)	72 (53.3)
GS synovitis, n (%)	67 (49.6)
Grade 1, n (%)	13 (9.6)
Grade 2, n (%)	14 (10.4)
Grade 3, n (%)	12 (8.8)
PD signals, n (%)	57 (42.2)
Grade 1, n (%)	20 (14.8)
Grade 2, n (%)	17 (12.6)
Grade 3, n (%)	13 (9.6)
Bone erosion, n (%)	56 (41.5)
RDW, median (IQR)	13.8 (13.2–14.5)
NLR, median (IQR)	2.00 (1.42–3.00)
LMR, median (IQR)	3.00 (2.16–4.00)
PLR, median (IQR)	138.26 (107.40–182.32)

DAS28: Disease Activity Score-28 joints; GS: grey scale; PD: power Doppler; NLR: neutrophil-to-lymphocyte ratio; LMR: lymphocyte-to-monocyte ratio; PLR: platelet-to-lymphocyte ratio.

Table 2. Correlations of haematological makers with ultrasound parameters and DAS-28 scores.

	NLR	LMR	PLR
Joint effusion p Value	0.031	0.003	−0.026
	0.766	0.979	0.799
GS synovitis (grade 0–3) p Value	0.213	−0.185	0.419
	0.105	0.164	0.001
PD signals (grade 0–3) p Value	0.103	−0.205	0.363
	0.358	0.069	0.001
Bone erosion p Value	0.13	0.089	0.252
	0.215	0.401	0.015
DAS28-ESR p Value	0.015	0.161	0.002
	0.867	0.08	0.985
DAS28-CRP p Value	0.024	0.069	−0.015
	0.793	0.459	0.872

GS: grey scale; PD: power Doppler; NLR: neutrophil-to-lymphocyte ratio; LMR: lymphocyte-to-monocyte ratio; PLR: platelet-to-lymphocyte ratio; DAS-28: Disease Activity Score-28 joints.

Table 3. Results of ordinal logistic regression analysis of haematological makers with GS grades.

Variables	B	Standard error	Wald	p	Odds ratio	95% confidence interval
NLR	−0.380	0.196	2.376	.052	0.684	0.466	1.003
LMR	−0.064	0.115	0.128	.580	0.938	0.748	1.176
PLR	0.009	0.004	15.208	.024	1.009	1.001	1.018

GS: grey scale; PD: power Doppler; NLR: neutrophil-to-lymphocyte ratio; LMR: lymphocyte-to-monocyte ratio; PLR: platelet-to-lymphocyte ratio; B: β coefficient.

Statistically significant correlations (p < .05) are highlighted by bold font.

Table 4. Results of ordinal logistic regression analysis of haematological makers with PD grades.

Variables	B	Standard error	Wald	p	Odds ratio	95% confidence interval
NLR	−0.282	0.183	3.782	.123	0.755	0.528	1.079
LMR	−0.044	0.123	0.307	.721	0.957	0.752	1.218
PLR	0.018	0.005	5.117	.001	1.019	1.009	1.028

GS: grey scale; PD: power Doppler; NLR: neutrophil-to-lymphocyte ratio; LMR: lymphocyte-to-monocyte ratio; PLR: platelet-to-lymphocyte ratio; B: β coefficient.

Statistically significant correlations (p < .05) are highlighted by bold font.

Figure 1. Receiver operating characteristic (ROC) curve of PLR to predict moderate to severe synovitis.

Table 5. Clinical characteristics of RA patients in different groups.

	PLR ≤ 166.1 (n = 80)	PLR > 166.1 (n = 36)	p Value
Age, median (IQR), years	61 (5367)	53 (44)	.015
Female, n (%)	69 (86.3)	33 (91.7)	.603
Disease duration, median (IQR), months	120 (48–228)	90 (27–186)	.353
DAS28-ESR, median (IQR)	2.96 (2.21–4.38)	3.09(2.25–4.06)	.69
DAS28-CRP, median (IQR)	2.89 (1.69–4.08)	2.86 (1.72–4.05)	.617
Rheumatoid nodules, n (%)	1 (1.3)	4 (11.1)	.032
Pleurisy/pericarditis, n (%)	3 (3.8)	2 (5.6)	.495
Interstitial lung disease, n (%)	34 (42.5)	12 (27.8)	.192
Number of comorbidities, median (IQR)	4 (2–5)	2 (1–4)	.001
Ultrasound parameters
Bone erosion, n (%)	32 (40.0)	19 (52.7)	.036
PD grade ≥2, n (%)	12 (15.0)	18 (50.0)	<.001
GS grade ≥2, n (%)	10 (12.5)	16 (44.4)	<.001

Comorbidities included osteoporosis, hypothyroidism, hyperthyroidism, diabetes, coronary heart disease, hypertension, hyperlipidaemia, peripheral atherosclerosis, hyperuricaemia, cataracts, cerebral haemorrhage, cerebral infarction, renal insufficiency, hepatic insufficiency, chronic gastrointestinal diseases, thrombosis and malignant tumor.

Data availability statement

The authors confirm that data supporting the findings of this study are available within the article.