MGUS and Infections
 

Hello - Hoping someone there might have information about MGUS and infections. Diagnosed with MGUS in 2014, I received 3 out of 4 rituximab treatments, but cancelled the last one as it seemed to be making my PN go into overdrive. In 2015, had 2 out of 4 treatments and stopped for the same reason. My IgM levels are quite low (0.2g/dL at last blood test) but SGPG levels are whopping, leading to nerve demyelination and quite severe sensory and motor neuropathy.

Beyond this concern (which of course is huge and exhausting), I have been having recurring UTIs for over a year. They are particularly wearing, largely due to the companion courses of antibiotics. My urologist has recommended prophylactic antibiotics at a low dose, but I would much prefer to avoid that. Still, given the past 8-10 months, on ab for a week nearly every month, perhaps it is worth some investigation and thought.

At any rate, does anyone know if the B-cell depletion by rituximab could have left me somewhat susceptible to infections? I am a 65 year old female. Very recently, I cut my working hours from 40/wk to 24/wk and am hoping this might reduce my stress; allow me more time/energy to put into attempting to recover some functionality, and perhaps improve my body's ability to fight infections. Poor wee hen works so hard!

I am open to suggestions or advice if anyone out there has any knowledge of this problem. Many thanks in advance!

There is evidence that MGUS is a risk factor for both bacterial and viral infections Monoclonal gammopathy of undetermined significance and risk of infections: a population-based study. This may have been exacerbated by your Rituximab treatment.

This is just a comment (I am not intending to second-guess your health care team), but I am surprised that they recommended Rituximab treatment.

Usually MGUS is just monitored with no treatment. It can progress to multiple myeloma or a similar lymphoproliferative disorder but this is rare (about 1% per year) - regular monitoring should pick this up.

Thank you, Kiwi. It definitely mystifies me why my body “chose” this particular symptom given that some people with much higher M protein levels never have any problems.

My baffling neuropathic symptoms had been increasing for two years before I finally went to a neurologist, who found the M protein and sent me to the oncologist. A bone marrow biopsy revealed a 5.8% level of abnormal B-cells, leading to the diagnosis of MGUS as opposed to Waldenstrom Macroglobulinemia, which requires a 10% level of abnormal cells. By that time the neuropathy had gotten quite bad, so we collectively decided on the rituximab treatment, as it has shown some success in helping MGUS neuropathy. Though the oncologist would have preferred to add bendamustine or cytoxin to the treatment mix (SCCA in Seattle treats rather aggressively), I convinced him to try rituximab alone. My thought was, why add a toxic chemotherapeutic, as it might lead to worse problems in the future? My blood work was excellent, except for the M protein and SGPG levels. The oncologist said, “If it weren’t for your neuropathy, we wouldn’t be sitting here”. Unfortunately, I had what he called an “idiosyncratic reaction” to the drug. While it ultimately seemed to lower my M protein levels, it made the predominant symptom worse.

Plasmapheresis is massively expensive, and has not shown much success with MGUS neuropathy. We need some kind of chelating agent to lock onto the auto-antibodies and flush them out of the body, but to my knowledge, it doesn’t exist.

When I went through a round of rituxin my doctor told me that I should avoid things like changing a cat litter box, changing baby diapers, because the b cell depletion from rituxin can increase the risk of bacterial infections.

Thuja, do you know if the monoclonal IgG in your MGUS is specific for SGPG?

This should be easy to establish; purify some of the monoclonal IgG from your serum and then run it against SGPG in an immunoassay - maybe in an ELISA, maybe in an immunoblot.

If that turns out to be the case (doing the experiment is the only way to find out) then more aggressive treatment of your MGUS may be indicated.

Your health care team should be able to help with this.

Hi, Kiwi - My body produces monoclonal IgM, not IgG. Other immunoglobulins are depressed.

And Northerngal - Thanks for your input. Fortunately, I don't have either a cat or a baby! But good to know others have gotten the advice to be careful due to B-cell depletion. Did your doc tell you how long this would be the case?

If she did, I can't remember how long it was----it's been several years since I tried the rituxin. My IGG and IGM were high, well above the levels for normal. The rituxin decreased them, but it did not help my neuropathy.

Sounds all too familiar! Have you found anything that does help your neuropathy?