Thanks for the reply Dawn! Our daughter is receiving high dose IVIG and it was 8 weeks between infusions. Her next, third, HD/IVIG is scheduled 8 weeks from her second IVIG and will take place in June. This was Dr. B's recommendation. I've been wondering if she should possibly do them every 6 weeks or, alternatively, if we continue to see a worsening of symptoms maybe PEX is the way to go. I don't know.