My Dad is an 86 year old male who had been checked for all types of cancer and blood diseases. He’s had intermittent low grade fevers every few days for at least 8 month, anemic blood levels, requiring infusions, and an elevated white blood count. He had little appetite, and has lost a lot of weight. All of these symptoms tend to wax and wane throughout the course of a week. What is it ? Rheumatoid arthritis????