11453
BACKGROUND : The aim of this study was to determine and compare interleukin - 6 ( IL - 6 ) levels in gingival crevicular fluid ( GCF ) and clinical periodontal findings in patients with rheumatoid arthritis ( RA ) and adult periodontitis ( AP ) .
 interleukin - 6, IL - 6
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 interleukin - 6, IL - 6