P30: Serum PTX3 in systemic lupus erythematosus: a potential indicator of cutaneous disease activity

Sahar Ismail,¹ Rania Abdel-motaal,¹ Nevin Hammam,^1,2 Safaa Hussein¹ and Sara Awad¹

¹Faculty of Medicine Assiut University, Assiut, Egypt; and ²University of California San Francisco (UCSF), San Francisco, CA, USA

Cutaneous manifestations are common in systemic lupus erythematosus (SLE); however, there is still an unmet need for a valuable diagnostic and prognostic marker for the cutaneous involvement. Pentraxin 3 (PTX3) has been investigated in patients with SLE but not yet in relation to the cutaneous manifestations. We aimed to evaluate serum PTX3 level in patients with SLE, and to assess its relationship with disease activity and with skin involvement in SLE. Thirty-four patients with SLE (17 with skin manifestations and 17 without skin manifestations) and 30 healthy controls were included. Patients were examined for systemic and cutaneous manifestations of SLE. Systemic Lupus Erythematosus Disease Activity Index (SLEDIA-2k) and Cutaneous Lupus Erythematosus Activity and Severity Index (CLASI) scores were calculated. Serum PTX3 level was measured by enzyme-linked immunosorbent assay in patients and controls. Of the patients, 31 (91%) were female, with a mean (SD) age of 29.8 (9.5) years, and a mean (SD) disease duration of 6.6 (4.3) years. Serum PTX3 level was higher in patients with SLE vs. healthy controls (P < 0.001). Patients with skin manifestations had higher SLEDIA-2k scores and higher PTX3 levels than those with no skin manifestations (P = 0.015 and P < 0.001, respectively). Higher PTX3 levels were observed for patients with malar rash (P < 0.001), alopecia (P < 0.001), mucosal ulcers (P < 0.001) and purpuric eruption (P = 0.002). Serum PTX3 level correlated positively with CLASI scores (P < 0.001). PTX3 level was elevated in patients with SLE with skin manifestations. Serum PTX3 may be a useful biomarker of the pattern and extent of skin involvement in patients with SLE.