Background: Although skin manifestations are common in systemic lupus erythematosus (SLE), there is still a lack of a diagnostic marker for cutaneous involvement. Pentraxin3 (PTX3) has been studied in SLE patients; however, it has not been investigated in relation to cutaneous manifestations.
Objective: To assess the serum PTX3 level in SLE patients, and to investigate its relationship with disease activity as well as with variable skin manifestations.
Patients and methods: Thirty-four patients with SLE (17 patients with skin manifestations and 17 without) and 30 healthy subjects were included in the study. Patients were evaluated clinically for systemic and skin manifestations of SLE. Systemic Lupus Erythematosus Disease Activity Index (SLEDAI-2k) and Cutaneous Lupus Erythematosus Activity and Severity Index (CLASI) scores were calculated. Serum level of PTX3 was measured in patients and controls using ELISA.
Results: Higher serum PTX3 level was found in SLE patients compared to controls (p < 0.001). Patients with skin manifestations showed higher SLEDAI-2k scores and had higher PTX3 level compared to those without skin manifestations (p = 0.015 and p < 0.001, respectively). PTX3 showed higher levels in association with malar rash (p < 0.001), mucosal ulcers (p < 0.001), alopecia (p < 0.001), and purpuric eruption (p = 0.002). Moreover, PTX3 level positively correlated with CLASI scores (p < 0.001).
Conclusion: Our results reinforce the important role of Pentraxin3 in SLE patients with skin manifestations, and it may be considered an interesting biomarker for the pattern and extent of cutaneous involvement in SLE.
Keywords: CLASI; Pentraxin 3; SLEDAI-2k; Systemic Lupus Erythematosus.