Fig. 3

Reactivity of anti-Jo1 autoantibodies towards HisRS variant and domains decreases over time but remains high against HisRS-FL. A Reactivity against HisRS-FL, HisRS splice variant (SV), and HisRS domains (WHEP, CD, and ABD) displayed by total IgG purified from the first available anti-Jo1⁺ sera close to diagnosis (T = −0.25–0 years), T = 0.1–1, T = 1.1–2, and T = 2.1–3 years after diagnosis. Additional graphs displaying anti-Jo1 reactivity against HisRS-FL, variant, and domains are displayed in Supplementary Fig. 7 upper panel. B Anti-Jo1 reactivity of 6 anti-Jo1⁺ patients (P2, P6, P7, P11, P16, P17) displayed by total IgG purified from sera collected longitudinally. The Y-axis represents anti-Jo1 antibody levels against HisRS, measured in the total IgG fraction isolated from anti-Jo1⁺ IIM/ASSD sera. The X-axis represents disease duration in years. Gray italic sentences provide information on interstitial lung disease outcome during follow-up. Improvement, stabilization, or worsening of ILD was based on the comparison of spirometry test results (5–10% absolute increase or decline of predicted FVC and/or 10–15% increase or decline of DLCO) and of HRCT reports made by experienced thorax radiologists at the different time points. Concentration (ng/mL) of anti-Jo1 antibodies was calculated based on a standard curve derived from anti-Jo1 IgG isolated from a sera pool of 38 anti-Jo1⁺ IIM/ASSD individuals, and titers were measured in the linear range between 5 and 100 ng/mL (Supplementary Fig. 3B [32]). The letter P (Patient) followed by a number in each graph represents an anti-Jo1⁺ IIM/ASSD individual. Friedman’s tests corrected for multiple comparisons by Dunn’s test was applied in A. No significant differences were denoted