Neutrophil/lymphocyte and platelet/lymphocyte ratios as potential markers of disease activity in patients with Ankylosing spondylitis: a case-control study

Abstract Background: The neutrophil/ lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR) have the potential to be inflammatory markers that reflect the activity of many inflammatory diseases. The aim of this study was to evaluate the NLR and PLR as potential markers of disease activity in patients with ankylosing spondylitis. Methods: The study involved 132 patients with ankylosing spondylitis and 81 healthy controls matched in terms of age and gender. Their sociodemographic data, disease activity scores using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), erythrocyte sedimentation rate (ESR), and white blood cell, neutrophil, lymphocyte and platelet counts were recorded. The patients with ankylosing spondylitis were further divided according to their BASDAI scores into patients with inactive disease (BASDAI < 4) and patients with active disease (BASDAI ≥4). The correlations between the NLR, PLR and disease activity were analysed. Results: There was a statistically significant difference in the NLR and PLR between the active and inactive ankylosing spondylitis patients (2.31 ± 1.23 vs. 1.77 ± 0.73, p = 0.002), (142.04 ± 70.98 vs. 119.24 ± 32.49, p < 0.001, respectively). However, there was no significant difference in both the NLR and PLR between the healthy control group and ankylosing spondylitis patients (p > 0.05). In addition, the PLR was significantly higher in both the active and inactive groups compared to those in the healthy control group (142.04 ± 70.98 vs. 99.32 ± 33.97, p = 0.014), (119.24 ± 32.49 vs. 99.32 ± 33.97, p = 0.019). The BASDAI scores were positively correlated with the PLR (r = 0.219, p = 0.012) and the NLR, but they were not statistically significant with the later (r = 0.170, p = 0.051). Based on the ROC curve, the best NLR cut-off value for predicting severe disease activity in ankylosing spondylitis patients was 1.66, with a sensitivity of 61.8% and a specificity of 50.6%, whereas the best PLR cut-off value was 95.9, with a sensitivity of 70.9% and a specificity of 55.5%. Conclusion: The PLR may be used as a useful marker in the assessment and monitoring of disease activity in AS together with acute phase reactants such as the ESR.

Correlation analysis of platelet-lymphocyte ratio with system involvement and disease activity in rheumatoid arthritis / 医学研究生学报

ObjectiveIt is very important to monitor the disease activity and complications of patients in the treatment of rheumatoid arthritis (RA). In this paper, we evaluated the level of platelet-lymphocyte ratio (PLR) of peripheral blood in patients with rheumatoid arthritis and discussed the relationship between PLR and the system involvement, laboratory indexes, and disease activity in patients with rheumatoid arthritis.MethodsFrom September 2013 to May 2017, 123 patients with rheumatoid arthritis who were first diagnosed in the General Hospital of Eastern Theater Command were analyzed retrospectively. 123 healthy persons(healthy control group) and 123 patients with other autoimmune diseases(disease control group) were matched according to the sex and age in a ratio of 1:1. According to the disease activity score 28 joints C-reactive protein (DAS28-CRP), RA patients were divided into the high activity group and the low activity group, and the PLR levels of high-activity and low-activity patients, healthy control group and disease control group were compared, respectively. To evaluate the relationship between system involvement and PLR level in RA patients; to analyze the correlation between PLR and DAS28-CRP and traditional inflammatory indexes by Spearman; to evaluate the application effect of receiver operating characteristic curve(ROC) in the diagnosis of RA and the differentiation of disease activity of RA patients.ResultsThe PLR level of RA patients was significantly higher than that of healthy people [133.63 (103.17, 140.99)] and disease control group [159.83(104.22, 203.55)], and the difference was statistically significant(P0.05]. There was a significant positive correlation between PLR and DAS28 CRP, C-reactive protein (CRP), ESR (r=0.433, 0.501, 0.592, P all <0.01）. The AUC of PLR in diagnosing RA and evaluating RA was 0.68 and 0.73 respectively. When cut off value was 134.47 and 147.61 respectively, sensitivity was 74.8% and 77.5%, specificity was 56.5% and 63.2%.ConclusionThe level of PLR of peripheral blood in patients with RA is increased, especially in patients with circulatory system involvement, infectious diseases or RF positive, and related to disease activity. PLR is expected to be an effective supplement for RA disease diagnosis and disease activity assessment and has potential application value.