TY - JOUR
T1 - Anti-Cytosolic 5'-Nucleotidase 1A in the Diagnosis of Patients with Suspected Idiopathic Inflammatory Myopathies
T2 - An Italian Real-Life, Single-Centre Retrospective Study
AU - Porcelli, Brunetta
AU - d'Alessandro, Miriana
AU - Gupta, Latika
AU - Grazzini, Silvia
AU - Volpi, Nila
AU - Bacarelli, Maria Romana
AU - Ginanneschi, Federica
AU - Biasi, Giovanni
AU - Bellisai, Francesca
AU - Fabbroni, Marta
AU - Bennett, David
AU - Fabiani, Claudia
AU - Cantarini, Luca
AU - Bargagli, Elena
AU - Frediani, Bruno
AU - Conticini, Edoardo
N1 - Publisher Copyright:
© 2023 by the authors.
PY - 2023/7/12
Y1 - 2023/7/12
N2 - BACKGROUND: Anti-cytosolic 5'-nucleotidase 1A (anti-cN1A) antibodies were proposed as a biomarker for the diagnosis of inclusion body myositis (IBM), but conflicting specificity and sensitivity evidence limits its use. Our study aimed to assess the diagnostic accuracy of anti-cN1A in a cohort of patients who underwent a myositis line immunoassay for suspected idiopathic inflammatory myopathies (IIM). We also assessed the agreement between two testing procedures: line immunoassay (LIA) and enzyme-linked immunoassay (ELISA).MATERIALS AND METHODS: We collected retrospective clinical and serological data for 340 patients who underwent a myositis antibody assay using LIA (EUROLINE Autoimmune Inflammatory Myopathies 16 Ag et cN-1A (IgG) line immunoassay) and verification with an anti-cN1A antibody assay using ELISA (IgG) (Euroimmun Lubeck, Germany).RESULTS: The serum samples of 20 (5.88%) patients (15 females, 5 males, mean age 58.76 ± 18.31) tested positive for anti-cN1A using LIA, but only two out of twenty were diagnosed with IBM. Seventeen out of twenty tested positive for anti-cN1A using ELISA (median IQR, 2.9 (1.9-4.18)).CONCLUSIONS: Our study suggests excellent concordance between LIA and ELISA for detecting anti-cN1A antibodies. LIA may be a rapid and useful adjunct, and it could even replace ELISA for cN1A assay. However, the high prevalence of diseases other than IBM in our cohort of anti-cN1A-positive patients did not allow us to consider anti-cN1A antibodies as a specific biomarker for IBM.
AB - BACKGROUND: Anti-cytosolic 5'-nucleotidase 1A (anti-cN1A) antibodies were proposed as a biomarker for the diagnosis of inclusion body myositis (IBM), but conflicting specificity and sensitivity evidence limits its use. Our study aimed to assess the diagnostic accuracy of anti-cN1A in a cohort of patients who underwent a myositis line immunoassay for suspected idiopathic inflammatory myopathies (IIM). We also assessed the agreement between two testing procedures: line immunoassay (LIA) and enzyme-linked immunoassay (ELISA).MATERIALS AND METHODS: We collected retrospective clinical and serological data for 340 patients who underwent a myositis antibody assay using LIA (EUROLINE Autoimmune Inflammatory Myopathies 16 Ag et cN-1A (IgG) line immunoassay) and verification with an anti-cN1A antibody assay using ELISA (IgG) (Euroimmun Lubeck, Germany).RESULTS: The serum samples of 20 (5.88%) patients (15 females, 5 males, mean age 58.76 ± 18.31) tested positive for anti-cN1A using LIA, but only two out of twenty were diagnosed with IBM. Seventeen out of twenty tested positive for anti-cN1A using ELISA (median IQR, 2.9 (1.9-4.18)).CONCLUSIONS: Our study suggests excellent concordance between LIA and ELISA for detecting anti-cN1A antibodies. LIA may be a rapid and useful adjunct, and it could even replace ELISA for cN1A assay. However, the high prevalence of diseases other than IBM in our cohort of anti-cN1A-positive patients did not allow us to consider anti-cN1A antibodies as a specific biomarker for IBM.
KW - autoantibodies
KW - idiopathic inflammatory myopathies
KW - inclusion body myositis
U2 - 10.3390/biomedicines11071963
DO - 10.3390/biomedicines11071963
M3 - Article
C2 - 37509600
SN - 2227-9059
VL - 11
JO - Biomedicines
JF - Biomedicines
IS - 7
M1 - 1963
ER -