Response to: ‘Performance of the systemic lupus erythematosus disease activity score (SLE-DAS) in a Latin American population’, by Rodríguez-González et al

It was with great interest that we read the letter ‘Performance of the Systemic Lupus Erythematosus Disease Activity Score (SLE-DAS) in a Latin American population’.1 Rodriguez-Gonzalez et al commented on our recent manuscript reporting the derivation and validation of Systemic Lupus Erythematosus Disease Activity Score (SLE-DAS),2 which demonstrated a much higher performance to detect clinical meaningful changes of SLE disease activity, as compared with SLE Disease Activity Index 2000 (SLEDAI-2K).3 In their letter, Rodriguez-Gonzalez et al reported a cross-sectional monocentric cohort study of 227 Mexican Mestizo SLE patients, in which they found a very high positive correlation between the SLE-DAS and the SLEDAI-2K (rho=0.92, p<0.0001). These results are consistent with our published data in which we identified a very strong correlation between the SLE-DAS and the SLEDAI-2K in both the derivation and the external validation cohorts (rho=0.940 and 0.943, respectively, p<0.0005 for both).2 Moreover, Rodriguez-Gonzalez et al analysed the correlation of SLE-DAS and SLEDAI-2K in subgroups of patients defined according to the severity of disease …