Author Affiliations: Department of Allergy, Immunology and Rheumatology, Guangzhou Children's Hospital, Guangzhou 510120, China (Zeng HS, Xiong XY, Wei YD); Pediatric Department, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China (Wang HW, Luo XP)

Corresponding Author: Hua-Song Zeng, Department of Allergy, Immunology and Rheumatology, Guangzhou Children's Hospital, Guangzhou 510120, China (huasongz@gmail.com)

Background: Macrophage activation syndrome (MAS) is a severe, potentially life-threatening condition induced by chronic rheumatic diseases, especially systemic-onset juvenile idiopathic arthritis (SoJIA) in childhood. This study aimed to analyze the clinical and laboratory characteristics of systemic-onset juvenile idiopathic arthritis (SoJIA) with macrophage activation syndrome (MAS) in 13 patients.

Methods: Clinical and laboratory data of 13 SoJIA patients with MAS treated in our hospital from January 2003 to October 2007 were analyzed.

Results: In the 13 patients, 9 were boys and 4 girls aged from 5 months to 12 years. Clinical manifestations were of no typical characteristics including persistent fever, anemia, arthritis, hepatosplenomegaly, lymph-adenopathy, dysfunction of the liver, abnormal fat metabolism, and hemophagocytic cells in the bone marrow. Two patients experienced acute respiratory distress syndrome, two had mutiorgan failure, and three died. The perforin A91V (NCBI:SNP rs35947132) gene in 6 patients was normal. Glucocorticoid and immunoimpressive therapy were effective in all patients and plasmapheresis used in one severe patient was also effective.

Conclusions: MAS is a serious complication of JIA, especially systemic-onset juvenile idiopathic arthritis. It is essentially important to recognize and treat MAS earlier in order to lower the mortality.

Key words: juvenile idiopathic arthritis; macrophage activation syndrome

                  World J Pediatr 2008;4(2):97-101