At what absolute lymphocyte count do you consider alternative/discontinuing DMT in a patient with MS on fingolimod (or other S1P modulator)?

I have asked this question for a long time, and get different answers. When a patient is hovering below 500, I start to wonder if it’s worth the long term risk/benefit. If they aren’t having infections and are young/healthy I usually leave them alone. If they’re getting older (50s and up) we have th...