Antibodies to domain I of β-2-glycoprotein I and IgA antiphospholipid antibodies in patients with ‘seronegative’ antiphospholipid syndrome

being highly correlated to disease activity: CXCL10, TNFR2 and Galectin-9. 5 We measured these proteins before and at different time points after aSCT to determine kinetics and correlation to disease activity in the context of this intervention.Values of creatine kinase were not elevated in the weeks before aSCT and did not change after, indicating low correlation with actual disease activity.CXCL10, TNFR2 and Galectin-9 were elevated in the patients prior to the conditioning regimen, irrespective of maintenance treatment (figure 1A).After aSCT, these three markers decreased over time in patients 1 and 2 with the most pronounced reduction in levels of Galectin-9 and CXCL10.These levels remained low, even after full reconstitution of the immune system.In parallel, clinical scores improved over time as shown in figure 1B.Pre-existent severe calcinosis disappeared completely in patient 2 after aSCT 4 but is still persisting in patient 3. Importantly, only in this patient, CXCL10 and Galectin-9 levels remained elevated after aSCT.In contrast to TNFR2, CXCL-10 and Galectin-9 are produced by immune and non-immune cells under inflammatory conditions. [6]7][8][9] As circulating immune cells are largely depleted during aSCT, our data suggest that CXCL10 and Galectin-9 are mainly produced by tissue cells or tissue infiltrating cells.Therefore, even during profound immunosuppression these markers may reveal ongoing disease activity in the tissues.This is also supported by the observation that CXCL10 and Galectin-9 levels dropped very gradually following aSCT in patients 1 and 2 and mirrored clinical disease improvement.In conclusion these data demonstrate that aSCT can induce prolonged drug-free disease remission in refractory patients with JDM with regards to the myositis.Furthermore, we show that the proinflammatory signature as measured by TNFR2, CXCL-10 and Galectin-9 leads to a differentiated response after aSCT, with a marked decrease in the two patients with inactive disease but persistent elevation in a patient with skin involvement.