Germinal Centers in Diagnostic Biopsies of Patients With Primary Sjögren's Syndrome Are Not a Risk Factor for Non‐Hodgkin's Lymphoma but a Reflection of High Disease Activity: Comment on the Article by Sène et al. Issue 1 (24th November 2018) - Haacke, Erlin A.; van der Vegt, Bert; Vissink, Arjan; Spijkervet, Fred K. L.; Bootsma, Hendrika; Kroese, Frans G. M.