As our friend MaryAnn indicates, there is no direct link between RA and PV. there is an indirect link in that both conditions are inflammatory in nature. Since the JAK2 mutation causes the overproduction of inflammatory cytokines, there can be exacerbation of inflammatory symptoms. Controlling systemic inflammation is an important part of treating both conditions.

Rheumatoid arthritis and polycythemia vera are not related at all, except that often PV patients will have gout with joint pain, especially involving the big toe, and the doctor will put RA on the differential diagnosis meaning there are things on the list to check out because of similar symptoms. However, rheumatoid arthritis is totally different. It is an autoimmune disease meaning the body's immune system attacks its owns cells and causes a lot of inflammatory reactions. Polycythemia vera as you know is a type of blood cancer with the body making too many red blood cells. There is nothing to connect the two diagnoses at all.

I knew you would come through with an important addition, Steve. Thanks. I think that about covers the often puzzling comparisons.

Pain in fingers joints may be either due to high serum uric acid levels or blood viscosity issues. Higher levels of uric acid increase the risk of developing gout in the joints.