You’re correct, I forgot to specify: my mom has both, but her osteoarthritis has practically been “paused” for two years after getting the rheumatoid arthritis in check. Her specialist is not sure why that is. And this is years after she stopped to southern climates during the winter months which used to be her only relief and help. They’re doing regular check ups to keep it observed.
Osteoarthritis is not an immune disorder.