Enhanced mRNA expression of plasminogen activator inhibitor-1 in livedoid vasculopathy lesions

Abstract

Aim: Thrombosis and inflammation play an important role in pathophysiology of livedoid vasculopathy (LV). Plasminogen activator inhibitor-1 (PAI-1) is the main physiological inhibitor of fibrinolysis and is a pivotal modulator in a broad range of biological processes.

Method: The study specimens were retrospectively selected from archives of pathology department. We investigated PAI-1 mRNA expression in the paraffin blocks of patients with biopsy-proven LV and controls. We analyzed the presence of thrombus, fibrinoid necrosis, ulcer, and epidermal atrophy in study samples. The correlation between histologic findings and PAI-1 expression was investigated.

Results: Analyses were performed in 14 LV patients (mean age 31±20, 79% female) and 4 controls (mean age 64±19, 50% female). PAI-1 gene expression was significantly higher in LV compared to the control group (median 7.74 (Iqr:13.94) vs 1.0 (0.31)), P=.011. Histological analysis displayed that fibrinoid necrosis was present on all patients with LV, 61.5% displayed thrombus, 46.2% displayed ulcer, and 15.4% displayed epidermal atrophy. Overall, we did not observe any discerning difference in PAI-1 expression between the LV blocks with or without thrombus, fibrinoid necrosis, or epidermal atrophy, yet the LV specimens that displayed ulcer histologically had higher PAI-1 mRNA expression compared to those without ulcer (median 13.98 (Iqr:19.21) vs 2.86 (5.59)), (P=.046).

Conclusion: PAI-1 mRNA expression is significantly increased in cutaneous lesions of patients with LV. Histological finding of ulcer is associated with increased PAI-1 expression in LV specimen. In the current era of PAI-1 inhibitors, enhanced local PAI-1 expression can form a novel and local therapeutic target in LV.

Keywords: Fibrinolysis; Plasminogen activator inhibitor 1; Plasminogen inactivators; Thrombosis; Topical administration; Vascular diseases.