AB1378 Clinical comparison of new criteria for inflammatory myopathy in a colombian cohort

Abstract

BackgroundIdiopathic inflammatory Myopathies are a group of diseases characterised by weakness due to muscle inflammation, with or without dermatological involvement, that classically includes pathognomonic findings like Gottron sign. There have been different criteria used to classify these diseases, being Peter and Bohan the most used in time, but recently the ARC/EULAR group proposed a new wat to approach the classification.ObjectivesTo compare ACR/EULAR 2017 versus Peter and Bohan criteria for Idiopathic Inflammatory Myopathy in a Colombian cohortMethodsA cross-section retrospective research was done with data collected between 2014 and 2017 from a population diagnosed with Idiopathic Myopathy according to Peter and Bohan criteria and followed up for at least six months. The new ACR/EULAR criteria were applied to each individual using the online tool (hhtp://www.imm.ki.se/biosatistics/calculators/iim). Both sets of criteria were compared using Cohen’s kappa coefficient and concordance was evaluated.ResultsData of 149 patients were obtained. Anti-Jo1 results were not available for 75% of the patients. Biopsy was available in 44,3% of patients. Biopsy results were compatible with inflammatory myopathy in 66,7% and non-compatible in 33,3%. According to Peter and Bohan criteria the diagnosis of idiopathic inflammatory myopathy was definite in 63,1% of the patients, and probable in 27,5%. Using ACR/EULAR 2017 criteria instead the diagnosis was definite in 63,1%, probable 10,1% and non-possible in 20,8%. According to the new criteria, 31 patients had polymyositis, 47 dematomyositis, 4 amyopathic dermatomyositis, 35 juvenile myositis and 1 inclusion body myositis. The concordance analysis between the two sets of criteria showed agreement of 54% (kappa 0,22 p<0,001) in the whole group, 59% (kappa 0,21 p<0,001) in adults, 32% (kappa 0,18 p=0,05) in children, 44% (kappa 0,05 p=0,3) in polymyositis and 42% (kappa 0,16 p=0,1) in dermatomyositis.ConclusionsData of 149 patients were obtained. Anti-Jo1 results were not available for 75% of the patients. Biopsy was available in 44,3% of patients. Biopsy results were compatible with inflammatory myopathy in 66,7% and non-compatible in 33,3%. According to Peter and Bohan criteria the diagnosis of idiopathic inflammatory myopathy was definite in 63,1% of the patients, and probable in 27,5%. Using ACR/EULAR 2017 criteria instead the diagnosis was definite in 63,1%, probable 10,1% and non-possible in 20,8%. According to the new criteria, 31 patients had polymyositis, 47 dematomyositis, 4 amyopathic dermatomyositis, 35 juvenile myositis and 1 inclusion body myositis. The concordance analysis between the two sets of criteria showed agreement of 54% (kappa 0,22 p<0,001) in the whole group, 59% (kappa 0,21 p<0,001) in adults, 32% (kappa 0,18 p=0,05) in children, 44% (kappa 0,05 p=0,3) in polymyositis and 42% (kappa 0,16 p=0,1) in dermatomyositis.Reference[1] I. Lundberg, et al. 2017European League Against Rheumatism/American College of Rheumatology classification criteria for adult an...

Performance of the 2017 EULAR/ACR Classification Criteria for adult and juvenile idiopathic inflammatory myopathies and their major subgroups: a scoping review

“…The majority of the studies were single-centre studies (n=19; 59.4%), while data were collected from multiple centres in 10 studies (11, 18-20, 23, 29-33). Three studies did not specify the number of centres (34)(35)(36). The gold standard used for IIM diagnosis was based on physician assessment or expert consensus in the majority of the studies (24 out of 30 studies with reported gold standard, 80%).…”

“…The gold standard used for IIM diagnosis was based on physician assessment or expert consensus in the majority of the studies (24 out of 30 studies with reported gold standard, 80%). Remaining studies used Bohan-Peter, ENMC or Sontheimer criteria as the gold standard for IIM diagnosis (2,3,28,29,(35)(36)(37)(38).…”

“…After excluding the studies that used Bohan-Peter criteria as a gold standard (28,29,(35)(36)(37)(38), did not specify definite/probable/possible case classification (12)(13)(14)39) or did not report sensitivity/specificity information (32), 21 studies were identified that reported the performance of the EULAR-ACR criteria for IIM classification. The majority of the studies (n=15) assessed the performance of the criteria in patients with IIM with one study specifically focusing on anti-aminoacyl-tRNA synthetase (ARS) autoantibody positive IIM (31), one study on non-Jo-1-MSA positive IIM cases (40) and one study on MSA positive and negative IIM (11).…”

“…For PM, the EULAR/ACR criteria achieved a modestly lower sensitivity but a higher specificity than the Bohan-Peter criteria (21,26,42). Concordance rates between the EULAR/ACR and Bohan-Peter criteria were 54-89.5% for IIM, 42-83.7% for DM and 44-95.8% for PM (32, 33, Performance of the 2017 Myositis Classification Criteria / D. Saygin et al 35,36,38). For JDM, the EULAR-ACR criteria had a higher sensitivity and similar specificity to the Bohan-Peter criteria (17,18).…”