In a subset of psoriasis (PsO) and psoriatic arthritis (PsA) patients, the skin and/or joint lesions appear to generate biologically significant systemic inflammation. Red cell distribution width (RDW) and mean platelet volume (MPV) are readily available clinical tests that reflect responses of the bone marrow and/or plasma thrombogenicity (e.g., inflammation), and can be markers for major adverse cardiac events (MACE). We aimed to evaluate if RDW and MPV may be employed as inexpensive, routinely obtained biomarkers in predicting myocardial infarction (MI), atrial fibrillation (AF), and chronic heart failure (CHF) in psoriatic and psoriatic arthritis patients. The study was divided into two parts: (a) case control study employing big data (Explorys) to assess MPV and RDW in psoriasis, psoriatic arthritis and control cohorts; (b) a clinical observational study to validate the predictive value of RDW and to evaluate RDW response to anti-psoriatic therapies. We used Explorys, an aggregate electronic database, to identify psoriatic patients with available MPV and RDW data and compared them to gender and age matched controls. The incidence of myocardial infarction (MI), atrial fibrillation (AF), and chronic heart failure (CHF) was highest among patients with both elevated RDW and MPV, followed by patients with high RDW and normal MPV. RDW elevation among PsA patients was associated with an increased risk of MI, AF, and CHF. In a local clinical cohort, high RDWs were concentrated in a subset of patients who also had elevated circulating resistin levels. Among a small subset of participants who were treated with various systemic and biologic therapies, and observed over a year, and in whom RDW was elevated at baseline, a sustained response to therapy was associated with a decrease in RDW. RDW and MPV, tests commonly contained within routine complete blood count (CBC), may be a cost-effective manner to identify PsO and PsA patients at increased risk of MACE.
Keywords: MACE; Psoriasis; endotypes; mean platelet volume (MPV); precision medicine; psoriatic arthritis; red cell distribution width (RDW).