Anti-MDA5 autoantibodies in juvenile dermatomyositis identify a distinct clinical phenotype: a prospective cohort study

Table 3 Outcome at 2 and >4 years post diagnosis for affected children with and without anti-MDA5 antibodies

	Two years post diagnosis		More than four years post diagnosis^a
	Anti-MDA5 present	Anti-MDA5 absent	Anti-MDA5 present	Anti-MDA5 absent
Inactive disease	6 (50%)^b	30 (22%)	6 (66.6%)	59 (46%)
Active disease	6 (50%)^b	109 (78%)	3 (33.3%)	68 (54%)
PRINTO inactive disease	7 (87%)^b	44 (43%)	4 (100%)	51 (71%)
PRINTO active disease	1 (13%)^b	59 (57%)	0 (0%)	21 (29%)

Results are presented as number of patients (%). ^aAverage 7.1 years anti-MDA5-positive and 7.9 years in anti-MDA5-negative; ^bP <0.05. Inactive disease is defined as childhood myositis assessment score (CMAS) >48, absent skin disease and physician global assessment score (PGAS) <1. Paediatric Rheumatology International Trials Organisation (PRINTO) criteria for inactivity is defined as at least three of the following; creatinine kinase (CK) ≤150, CMAS ≥48, manual muscle testing score ≥78 and PGAS ≤0.2. Patients with anti-MDA5 were more likely to have inactive disease at the time points analysed. This was statistically significant at 2 years post diagnosis.

ISSN: 1478-6362