Instruct: Identify the main category of Medrxiv papers based on the titles and abstracts
Query: SIGLEC1 enables straightforward assessment of type I interferon activity in idiopathic inflammatory myopathies ObjectiveTo evaluate SIGLEC1 expression on monocytes by flow cytometry as a type I interferon biomarker in idiopathic inflammatory myopathies (IIM).

MethodsWe performed a retrospective analysis of adult and pediatric patients with the diagnosis of IIM. SIGLEC1 expression was assessed by flow cytometry and was compared with Physician Global Assessment (PGA) or Childhood Myositis Assessment Scale (CMAS) disease activity scores. Mann Whitney-U test and receiver operating characteristic (ROC) curves were used for cross-sectional data analysis (n=96), two-level mixed-effects linear regression model for longitudinal analyses (n=26, 110 visits). Response to treatment was analyzed in 14 patients within 12 months, using Wilcoxon test. SIGLEC1 was compared to ISG15/MxA status by immunohistochemical staining of muscle biopsies (n=17).

Results96 patients with adult (a) and juvenile (j) dermatomyositis (DM, n=38), antisynthetase syndrome (AS, n=19), immune-mediated necrotizing myopathy (IMNM, n=8), inclusion body myositis (IBM, n=9), and overlap myositis (n=22) were included. SIGLEC1 distinguished significantly between active and inactive disease with an area under the curve (AUC) of 0.92 (95% CI: 0.83-1) in DM and correlated with disease activity longitudinally (aDM: standardized beta=0.54, p<0.001; jDM: standardized beta=-0.70, p<0.001). Response to treatment in DM was associated with a decreasing SIGLEC1 (p<0.01, Wilcoxon test). A positive ISG15/MxA stain was highly associated with a SIGLEC1 upregulation. SIGLEC1 was found upregulated in AS (42.1%) and IBM (22,2%) and not in IMNM.

ConclusionSIGLEC1 is a candidate biomarker to assess type I interferon activity in IIM and proved useful for monitoring disease activity and response to treatment in juvenile and adult DM.

Key messagesO_ST_ABSWhat is already known about this subject?C_ST_ABSO_LIThere is an unmet need for routine clinical biomarkers to assess type I interferon activity in rheumatic musculoskeletal diseases
C_LIO_LISIGLEC1 is part of the type I interferon signature and transcripts were found to be upregulated in various autoimmune diseases such as systemic lupus erythematosus (SLE), Sjoegren syndrome and dermatomyositis.
C_LIO_LISIGLEC1 is expressed on the surface of monocytes and thus is easily assessable by flow cytometry, which enables straightforward monitoring of type I interferon activity
C_LI

What does this study add?O_LIAn activation of the type I interferon system in IIM can be identified by flow cytometry analysing SIGLEC1 expression. SIGLEC1 correlated to disease activity and improvement under therapy in juvenile and adult dermatomyositis.
C_LI

How might this impact on clinical practice or future developments?O_LISIGLEC1 expression is a suitable biomarker for monitoring type I interferon activation in rheumatic musculoskeletal diseases, which has clinical implications for patient stratification and treatment decision making especially in the context of interferon inhibitory therapies.
C_LI
21
The categories of this paper are: psychology
11
The categories of this paper are: policy
54
The categories of this paper are: gynecology
42
The categories of this paper are: occupational
12
The categories of this paper are: genomic
31
The categories of this paper are: imaging
23
The categories of this paper are: gastroenterology
16
The categories of this paper are: immunology
70
The categories of this paper are: otolaryngology
61
The categories of this paper are: dermatology
27
The categories of this paper are: quality
22
The categories of this paper are: clinical
60
The categories of this paper are: addiction
28
The categories of this paper are: nutrition
25
The categories of this paper are: improvement
72
The categories of this paper are: urology