Post rituximab drop in immunoglobulins

[timmay111]

I had severe platelet and neutrophil levels at diagnosis, and they did not recover until 4 days of high-dose dexamethasone after my eighth rituximab infusion. I am now back in mild neutropenia and my immunoglobulins have dropped below the lower limit of normal. Have othes seen this?

[Neonkittie17]

Yet it’s often the way for Rtx to lower igG and igM. The rheumys want you to stay above 6 on the blood test range for igG as going under 6 is mild hypergammaglobulinemia. Your igG can fluctuate up and down in this area around 6 and the rheumy will monitor it. What I found is when it drops to 6 you tend to get repeated infections (especially respiratory) as igG is the immunoglobulin which does so much to fight infections and igG is the most prolific antibody in your blood. It remembers the germs your body has been exposed to. IgG is made from plasma B cells so if Rtx is depleting those B cells, it’s hard for igG to remain stable in many patients.

Not all Rtx patients are affected severely with their igG going low but after 5 years of it being good at around 14, it started to drop slowly over the last 3-4 years for me. I can’t comment on the Dexamethasone as I’ve never taken it. I do know oral steroids can reduce your igG by 20 percent I was told but hopefully that can increase again once the steroids have stopped. Rtx can deplete the B cells for a long, long time even after you’ve stopped having it. Hope yours stays steady.