Line blot immunoassays in idiopathic inflammatory myopathies: retrospective review of diagnostic accuracy and factors predicting true positive results

Table 2 Cases of antibody positivity by final diagnosis

IIM	42/67 (62.7%)
Only weak MSA/MAA	9 (13.4%)
Only strong MSA/MAA	27 (40.3%)
Both weak and strong MSA/MAA	6 (9.0%)
CTD without IIM	41/120 (34.2%)
Only weak MSA/MAA	13 (10.8%)
Only strong MSA/MAA	18 (15.0%)
Both weak and strong MSA/MAA	10 (8.3%)
Non-IIM/CTD	38/155 (24.5%)
Only weak MSA/MAA	22 (14.2%)
Only strong MSA/MAA	13 (8.4%)
Both weak and strong MSA/MAA	3 (1.9%)
Any positive MSA/MAA across all diagnostic groups	121 (35.4%)

IIM idiopathic inflammatory myopathy, CTD connective tissue disease, MSA myositis-specific autoantibody, MAA myositis-associated autoantibody

ISSN: 2520-1026