12803
A 52 year - old male patient diagnosed of ankylosing spondylitis presented with an iron deficiency anemia after a ten - month treatment of methotrexate .
 iron deficiency anemia, methotrexate
Please list all entity pairs containing a certain relationship in the given options.Output format is "word1, word2; word3, word4". 
Option: adverse effect 
Text: {0} 
Answer:
 iron deficiency anemia, methotrexate