Has anyone here had a bad reaction to ritux, like serum sickness?

My brother noticed last week after his infusuion that his right thumb was swollen and painful, but not terrible. It was written off. Then last night, his entire right wrist became very swollen & very painful and he was readmitted into the hospital. He is on lots of steroids & pain meds to get it under control. Right now they're thinking it may be serum sickness... his last ritux infusion is supposed to be today. We're not sure if he'll be able to do it.

Does anyone have any experience with this? And if cytox has failed for you as well as ritux, whats the next med to try?