• autoimmune diseases
• autoantibodies
• dermatomyositis
• polymyositis
• systemic lupus erythematosus

We thank Mahler et al for their comment1 on our work in which we used hierarchical clustering on principal components to define clinically meaningful subgroups of patients with anti-Ku antibodies.2

Mahler et al argue for the use of machine learning alongside expert decision, thus relying on augmented judgement in making the final decision on patient stratification. We share this view.

In this regard, we disagree with the statement according to which the hierarchical clustering on principal components applied to 1000 observations with a multivariate normal distribution proposed by Pinal-Fernandez and Mammen3 and the hierarchical clustering on principal components applied to our observations from 42 anti-Ku patients yielded similar results.

As Mahler et al stated, clustering …