TY - JOUR T1 - Clinical Features and Perforin A91V Gene Analysis in 31 Patients with Macrophage Activation Syndrome and Systemic Juvenile Idiopathic Arthritis in China JF - The Journal of Rheumatology JO - J Rheumatol SP - 1238 LP - 1239 DO - 10.3899/jrheum.121040 VL - 40 IS - 7 AU - ZENG HUASONG AU - WEI PING AU - CHEN XIANGYUAN AU - WEI YANDAN Y1 - 2013/07/01 UR - http://www.jrheum.org/content/40/7/1238.abstract N2 - To the Editor:Macrophage activation syndrome (MAS) is a severe, potentially fatal complication of rheumatoid disease, especially in systemic juvenile idiopathic arthritis (sJIA). MAS has been considered reactive familial hemophagocytic lymphohistiocytosis (FHLH), and the perforin gene mutations have been identified in some patients diagnosed with the FHLH1,2,3. Vastert, et al4 have found that the mutation rate of perforin gene A91V was significantly higher in MAS than in sJIA. Perforin deficiency may increase macrophage activation because of an increased production of interferon-γ and … Address correspondence to Dr. Huasong; E-mail: huasongz{at}gmail.com. ER -