Assessment Of Red Blood Cell Distribution Width In Patients With Psoriatic Arthritis And Psoriasis Vulgaris-only

Objective:Psoriatic arthritis(Ps A)is an inflammatory arthropathy that causes pain and joint damage and eventually results in disability.Currently,elevated levels of biomarkers for inflammation in psoriasis have been demonstrated to aid in the diagnosis and monitoring of disease severity in clinical practice.We aimed to investigate the differences of red cell distribution width(RDW)values in patients with Ps A,psoriasis and normal subjects.Methods:This retrospective study was performed in the First Hospital of Jilin University between March 2014 and September 2016.After exclusion,74 psoriasis vulgaris(Ps V)patients,49 Ps A patients and 80 healthy subjects as controls were enrolled to the current study.Haematological and inflammatory parameters including RDW,high sensitivity C-reactive proteins(hs-CRP),platelet to lymphocyte ratio(PLR),neutrophil to lymphocyte ratio(NLR),mean platelet volume(MPV)and erythrocyte sedimentation rate(ESR)were examined in Ps A,psoriasis vulgaris-only(Ps V)and healthy controls.Results:Data from 123 patients with psoriasis(49 Ps A and 74 Ps V)and 80 controls were analyzed.Compared with healthy controls,the NLR,PLR and RDW were remarkably higher in both Ps A and Ps V,while MPV was significantly lower.Moreover,when these parameters were compared between Ps V and Ps A,only RDW was significantly increased in Ps A,similar to hs-CRP and ESR.There was no difference between both the two groups(Controls vs Ps V,Controls vs Ps A)with regard to gender and age.However,there are more male patients in Ps A group compared with Ps V group.Independently related parameters associated with Ps A were detected by univariate logistic regression analysis.RDW(odds ratio [OR]: 1.711,95% confidence interval [CI]: 1.041-2.812,P: 0.034)and ESR(OR: 1.077,95% CI: 1.001-1.159,P: 0.047)are determinant in predicting Ps A among psoriasis.Furthermore,in multivariate regression,RDW remained an independent predicting factor of Ps A in psoriasis(OR: 3.043,95% CI: 1.181-7.841,P: 0.021)and was superior to the other serum inflammatory markers(NLR,MPV,hs-CRP,PLR and ESR).Additionally,a RDW level of 13.550 was determined as the best cut-off value by ROC analysis(sensitivity 51.4%,specificity 85.2%,the area under the ROC curve 0.616).Conclusions:RDW was elevated in Ps A patients as compared to Ps V patients.RDW may be a reliable,cost-effective and novel potential parameter to help identify potential Ps A in psoriasis.