Neutrophil-lymphocyte ratio and platelet-lymphocyte ratio as an alternative to C-reactive protein in diagnostics of inflammatory state in patients with psoriasis

摘要

Background: The ratio of neutrophils to lymphocytes (NLR), the ratio of platelets to lymphocytes (PLR), the ratio of monocytes to lymphocytes (MLR), and mean platelet volume (MPV) are considered novel inflammatory markers. We stated a hypothesis that apart from C-reactive protein (CRP) level, also NLR, PLR, MLR, and MPV are higher in patients with psoriatic arthritis (PsA, where both skin and joints are involved) than in patients with psoriasis vulgaris (PsV) Material and Methods: Our study is based on a retrospective analysis. We collected laboratory data, namely CRP levels as well as a total blood count, and calculated the following additional parameters: NLR, PLR, MLR, and MPVLR (mean platelet volume/lymphocyte ratio). For all data, two groups of patients were compared: PsV with N=80 and PsA with N=80. Results: CRP levels were significantly higher in PsA patients compared with those in PsV patients (median PsV – 19.43 nmol/L vs median PsA – 37.90 nmol/L, p=0.001). Similarly, both NLR and PLR were higher in PsA patients than in PsV patients (NLR, median PsV – 2.0 vs median PsA – 2.28, p=0.030; PLR, median PsV – 111.61 vs median PsA – 121.85, p=0.027). Moreover, for patients with psoriatic arthritis a weak to moderate positive correlation between C-reactive protein levels and WBC, neutrophils count, monocytes count, platelets count, NLR, PLR, and MLR was observed. CONCLUSIONS: CRP levels are higher in patients with PsA than in patients with PsV, which can be helpful in predicting arthritis in patients with psoriasis. Furthermore, similar information can be obtained from a blood count. In particular, NLR and PLR are simple predictors which can indicate ongoing joint inflammation in patients with psoriasis, hence they can be used as an alternative to the CRP level.