I'm curious to know what labs are taken and looked into prior to next round of Rituximab (or b-cell depleting medication in general)?

Here is My Question:
Hello,
I'm curious to know what labs are taken and looked into prior to next round of Rituximab (or b-cell depleting medication in general)? What is normal/concerning? What is tested? What will be something that would post pone infusion? Etc.

I hope I'm making sense. Thanks in advance

Answer:
Excellent question. The FDA approved package insert only requires labs prior to the first infusion and includes a Hepatitis B serological profile and immunoglobulin levels. Since we know that treatment may cause immunoglobulin deficiency and other abnormalities in blood cell profiles and these deficiencies increase the risk of infection, most centers routinely obtain a complete blood count and differential (CBC with diff) and Immunoglobulin levels before each infusion. 

Most centers also check total CD19+ B cell counts before every treatment, although this is probably only necessary prior to the first treatment if you plan to receive infusions every 6 months according to the FDA approved dosing interval. If you plan to shift to extended interval dosing, an increasingly common practice to avoid prolonged B cell suppression, then you should get B cell counts or better yet, complete B cell subsets, prior to every infusion. This could then be used to guide when to repeat infusions.
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So to recap, minimal labs prior to every infusion are CBC with diff and Immunoglobulin levels, particularly IgG levels.

Revere P (Rip) Kinkel, MDProfessor of Neurosciences
Director of the Multiple Sclerosis Program
University of California San Diego