Inflammatory and Hematological Biomarkers as Indicators of Psoriatic Arthritis in Patients Attending Dermatology Clinic

Abstract

Background: Psoriatic arthritis (PsA), a heterogeneous inflammatory arthropathy where inflammatory biomarkers such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) show normal levels in over half of cases in spite of having clinically active disease. Hemoglobin, a readily available parameter, remains a largely underexplored surrogate of systemic inflammatory burden in PsA. Methods: Consecutive sampling was used to enroll 132 PsA patients (CASPAR criteria) attending the Dermatology Outpatient Clinics of Al Yarmouk Hospital via a cross-sectional study. Disease activity was stratified based on the Disease Activity Index for PsA (DAPSA) into low (≤13), moderate (14–27), and high (>27). Demographic and lab tests, hematological and inflammatory (full blood count, CRP, and ESR), were measured for all. Anemia was defined by WHO sex-specific thresholds. Results: mean age of enrolled cases (46.3±14.3 years; 61.4% female). High disease activity was reported in 58.4% of patients. All hematological and inflammatory indicators show significant differences across DAPSA strata. Hemoglobin fell negatively with rising disease activity (12.80±1.95g/dL in moderate vs. 11.30±1.6g/dL in high activity). Anemia (56.1%) was independently associated with higher DAPSA scores (51.9±39.2 vs. 35.4±40.2; p<0.001), increased acute-phase reactants, and female gender. Psoriasis duration correlated negatively with hemoglobin (r= −0.28, p=0.001) but not with CRP or ESR. Conclusions: Hemoglobin is a cost-free, available, and clinically meaningful biomarker that matches DAPSA-defined disease activity in PsA more reliably than CRP or ESR in real-world practice.