This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Musculoskeletal  disorders, Subject name: Pediatrics
Which of the following is false regarding systemic juvenile idiopathic ahritis (sJIA)? 
Select and explain. 
A. RA factor positive, B. High fever with rash, C. Hepatosplenomegaly, D. Elevated ESR
A: RA factor positive
Answer: A: RA factor positive 
Explanation: Rheumatoid ahritis (RA) factor is negative in systemic-onset JIA ; it is positive in polyahritic type of JIA. Ref: Nelson textbook of pediatrics 21st edition. Pgno: 1260