Correlations between serum 25-hydroxyvitamin D levels and nailfold microvascular changes in psoriatic arthritis patients with distal interphalangeal arthritis treated with TNF inhibitors.

BACKGROUND/OBJECTIVES: The role of microvascular abnormalities in the pathophysiology of Psoriatic Arthritis (PsA) has gained increasing attention. Previous studies have identified significant differences in capillary density and morphology in patients with PsA compared to healthy controls. METHODS: This retrospective observational study included 75 female patients-40 with psoriatic arthritis with distal interphalangeal joint involvement and 35 with biopsy-confirmed cutaneous psoriasis (PsO). Data were extracted from patients' medical records at two time points-baseline and six months after bDMARDs initiation-with strict inclusion and exclusion criteria applied to reduce selection bias. RESULTS: Using nailfold videocapillaroscopy (NVC), we observed capillary alterations that correlate with the severity of distal interphalangeal joint involvement. In PsA, improvements in capillary parameters likely reflect the effects of biologic therapy combined with vitamin D supplementation, while in PsO, correcting vitamin D levels appears to be the main factor driving vascular improvement. These findings suggest that microvascular alterations may serve as a potential biomarker for disease activity and severity, particularly in patients with predominant distal interphalangeal involvement. In association with ultrasonography, NVC facilitates early detection of pathophysiological alterations, which could influence symptomatology and disease progression and support more targeted and personalized therapeutic strategies. This integrated approach may allow for timely modifications to therapeutic strategies. Moreover, the study explored the association between 25-hydroxyvitamin D (25-OH vitamin D) status and capillary abnormalities. DISCUSSIONS/CONCLUSIONS: Our results demonstrate that NVC is a valuable non-invasive tool for monitoring microvascular changes in patients with distal interphalangeal-predominant PsA undergoing TNF inhibitor therapy. Moreover, they suggest a potential therapeutic impact of TNF inhibitors on vascular health and support the use of NVC as a complementary method in clinical assessment.