Plasma pentraxin 3 in idiopathic inflammatory myopathies: a possible new biomarker of disease activity

Clin Exp Immunol. 2023 Jun 6:uxad063. doi: 10.1093/cei/uxad063. Online ahead of print.ABSTRACTPentraxin-3 (PTX3) is a component of humoral innate immunity with essential functions both in promotion and resolution of inflammation. We aimed to study the PTX3 in the plasma and in the muscle of patients with idiopathic inflammatory myopathies (IIM) and whether PTX3 may correlate with disease activity. Plasma PTX3 levels were assessed in 20 patients with IIMs, 10 Dermatomyositis (DM) and 10 Polymyositis (PM), compared to 10 patients with rheumatoid arthritis (RA) and 10 healthy donors (HDs) aged, sex and body mass index matched. Disease activity in IIMs was assessed by Myositis Disease Activity Assessment Visual Analogue Scale (MYOACT), while disease activity score on 28 joints (DAS28) was used for RA patients. Muscle histopathology and immunohistochemical (IHC) analyses were also performed. Mean plasma PTX3 levels were significantly higher in IIM patients than HDs (518±260 pg/ml vs 275±114 pg/ml, p=0.009). Linear regression analysis adjusted for age, sex and disease duration showed a direct correlation between PTX3 and CPK levels (β: 0.590), MYOACT (β: 0.759) and physician global assessment of disease activity (β: 0.832) in IIMs. No association between PTX3 levels and DAS28 was found in RA. Global PTX3 pixel fraction was higher in IIM than HDs muscle, but a lower PTX3 expression was found in perifascicular areas of DM and in myofibers with sarcolemmal staining for membrane a...
Source: Clinical and Developmental Immunology - Category: Allergy & Immunology Authors: Source Type: research