The patients who have psoriasis often remain undiagnosed with PsA. Therefore, it becomes important to recognize the soluble biomarkers for PsA which will help screen psoriasis patients and choose suitable rheumatology referral for them. Cretu D and colleagues conducted the case-control study to analyze if the serum levels of novel markers previously determined by quantitative mass spectrometric (MS) analysis of synovial fluid and skin biopsies are superior over CRP in distinguishing PsA patients from those with PsC.

The serum samples were collected from 3 groups; 100 subjects with PsA; 100 with PsC and 100 healthy controls. PsA and PsC patients in the groups were balanced for age, sex, psoriasis duration and Psoriasis Area and Severity Index (PASI). ELISA method was used to assay four high-priority markers (M2BP, CD5L, MPO, and ITGB5) and previously discovered markers (MMP3 and CRP). Logistic regression method was used to analyze the data and receiver operating characteristic (ROC) curves were plotted.

The results depicted independent association of CD5L, ITGB5, M2BP, MPO, MMP3 with PsA when compared to controls. CD5L, M2BP and MPO were found to be independently linked to PsC alone. ITGB5, M2BP, and CRP were found to be independently associated with PsA as compared to PsC.