Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Felty's syndrome ?
    ### Response:
    Felty's syndrome is a rare, potentially serious disorder that is defined by the presence of three conditions: rheumatoid arthritis (RA), an enlarged spleen (splenomegaly) and a decreased white blood cell count (neutropenia), which causes repeated infections.
    