['Inter-assay variability is a well-known problem in antiphospholipid antibody testing, due to the lack of standardization. Inter-lab reproducibility for a same assay is similarly important.', 'Testing repeatability and reproducibility of HemosIL', 'In this observational study, out of 420 samples from the thrombophilia centers of Ghent and Geneva, 100 samples were randomly selected and successively analyzed in three centers: Ghent (C1, in duplicate for repeatability evaluation), Geneva (C2) and Frankfurt (C3).', 'Results from 99 samples were available, including 25 from patients with antiphospholipid syndrome (APS) and 74 from non-APS patients. The intra-center repeatability expressed as intra-class correlation coefficient (ICC) was higher than 0.99 for each parameter. Differences between two measurements rarely exceeded 1 U/ml for values below 100 U/ml, except for aβ2IgG where differences varied from -4 to 4 U/ml. The inter-centers ICC were higher than 0.99 except for aCL IgM (ICC = 0.961). These ICC remained high even when considering values below 100 U/ml (0.943, 0.964 and 0.977 for aCL IgG, aCL gM and aβ2GPI IgM, respectively), except for aβ2GPI IgG (ICC = 0.652). Qualitative comparison showed less than 5% of discordant classification between centers, with somewhat more discordant results for aβ2GPI IgG.'] Does a multicenter study to assess the reproducibility of antiphospholipid antibody result produced by an automated system?