TY - JOUR T1 - Dr. Ludvigsson, <em>et al</em> reply JF - The Journal of Rheumatology JO - J Rheumatol SP - 1619 LP - 1619 DO - 10.3899/jrheum.130623 VL - 40 IS - 9 AU - JONAS F. LUDVIGSSON AU - ALBERTO RUBIO-TAPIA AU - VAIDEHI CHOWDHARY AU - JOSEPH A. MURRAY AU - JULIA F. SIMARD Y1 - 2013/09/01 UR - http://www.jrheum.org/content/40/9/1619.2.abstract N2 - To the Editor:We thank Park, et al for their interest1 in our report2. We agree that the association between SLE and celiac disease (CD) is multifactorial, at both genetic and environmental levels, and merits further study. Interleukin 21 (IL-21), an important cytokine for B cell growth and differentiation, needs to be examined in systemic lupus erythematosus (SLE) … Address correspondence to Dr. J.F. Ludvigsson, Department of Pediatrics, Örebro University Hospital, 701 85 Örebro, Sweden. E-mail: jonasludvigsson{at}yahoo.com ER -