Daratumumab, isatuximab (CD38 drugs)

[SNT Gatchaman]

Polyclonal IgG levels remained unchanged, which may be explained by a subset of normal PC with reduced CD38 expression that survived during daratumumab therapy.

That is a pretty striking finding. It seems to suggest that if daratumumab has any efficacy in ME/CFS it is not due to killing plasma cells!

But IGG did go down in Fluge et al.

I wondered that. So things do not necessarily go as pear-shaped as it seemed.

That paper's cohort are patients with myeloma, and they are characterised as extensively pre-treated. Could a reduced CD38 expression on plasma cells more generally be an environmental effect (eg a precursor requirement) before you can even get to the clonal expansion seen in myeloma?

Ie is it possible this observation is not relevant to the ME/CFS context, whose plasma cells are presumptively normal, but just happen to be producing pathological immunoglobulins that we'd like to get rid of?