The association between the lymphocyte-monocyte ratio and disease activity in rheumatoid arthritis

Abstract

The lymphocyte-monocyte ratio (LMR) is a systemic inflammatory marker for prediction of disease development, progress, and survival. Recently, a genome-wide association study identified genetic variations in ITGA4 and HLA-DRB1 that affect the LMR levels and were widely believed to be susceptibility genes for autoimmune diseases, including rheumatoid arthritis (RA). However, the role of LMR in RA patients remains unclear. The LMR level and other laboratory data of 66 RA patients, 163 osteoarthritis (OA) patients, and 131 healthy controls (HC) were compared using binary logistic regression. The correlations between LMR and disease activity and other inflammatory markers were measured using the Spearman rank test. ROC curve analyses assessed the diagnostic accuracy of LMR in RA. The LMR and lymphocyte count were significantly lower in RA patients, whereas the monocyte count was significantly higher relative to the HC group/OA patients (p < 0.01). A decreased LMR has been associated with increased disease activity (p = 0.012). In addition, the DAS28 and traditional inflammatory markers, including ESR, CRP, RDW, PLR, and NLR, and immune-related factors, such as C4, IgA, and IgM, were inversely correlated with LMR, while hemoglobin and albumin were positively correlated with LMR. The ROC curve showed that the area under the curve of LMR was 0.705 (95%CI = 0.630-0.781). The corresponding specificity and sensitivity were 82.82 and 45.45%, respectively. The present study shows that the LMR is an important inflammatory marker which could be used to identify disease activity in RA patients and to distinguish RA from OA patients.

Meta‐analysis of neutrophil‐to‐lymphocyte and platelet‐to‐lymphocyte ratio in rheumatoid arthritis

“…After a full‐text revision of 25 articles, 12 studies were excluded because they did not meet the inclusion criteria. Thus, thirteen studies were included in the meta‐analysis . The characteristics of these studies, published between 2015 and 2017, are presented in Table .…”

“…Eight studies evaluated PLR in a total of 380 RA patients (203 males and 177 females) and 305 healthy controls (149 males and 156 females). The mean ± SD age of RA patients and controls was 39.7 ± 6.8 and 37.3 ± 5.8 years, respectively.…”

“…This issue needs to be addressed in future studies evaluating haematological parameters in RA given the known influence of several immunomodulating drugs on circulating blood cells. Thirdly, the role of NLR and PLR as markers of RA disease severity (measured by Disease Activity Score‐28 joints, DAS‐28) was not investigated due to the relatively low number of relevant studies and the high heterogeneity in cut‐offs used . Lastly, the assessment of NLR and PLR according to RF and ACPA positivity was not performed for similar reasons …”

“…A P ‐value < 0.05 was considered statistically significant, and 95% confidence intervals (CIs) were reported. In one study, the median and range values were extrapolated from graphs using the Graph Data Extractor software, in three studies the mean and standard deviation values were extrapolated from the median and range as previously described, and in two other studies the mean and standard deviation values were extrapolated from the median and interquartile range (IQR) as previously reported …”

“…Recently, several reports have suggested the potential utility of the neutrophil-lymphocyte ratio (NLR) and the platelet-lymphocyte ratio (PLR), as diagnostic biomarkers in RA [6][7][8][9][10][11][12][13][14][15][16][17] and other rheumatic diseases. [18][19][20] A previous meta-analysis reported a significant association between NLR and PLR and RA.…”