Methotrexate polyglutamates in erythrocytes are associated with lower disease activity in patients with rheumatoid arthritis

Maurits C.F.J. De Rotte, Ethan Den Boer, Pascal H.P. De Jong, Saskia M.F. Pluijm, Maja Bulatović Ćalasan, Angelique E. Weel, A. Margriet Huisman, Andreas H. Gerards, Barbara Van Schaeybroeck, Nico M. Wulffraat, Jan Lindemans, Johanna M.W. Hazes, Robert De Jonge