Does MGUS cause red blood cells (RBCs) to drop?

Thank you for your response. I wrote down your questions and I will ask them. I go to a cancer center and my blood is drawn every six months too. The cancer PA asked me if I have night sweats, fevers, or weight loss. I don't. The PA seems knowledgeable, but should I ask for a cancer doctor. When I first went to the cancer center, I saw a doctor there, but she left. I think a lot of doctors are leaving. I have been waiting for the results of my x-ray for over two weeks which is unusual.
I have found that the general PA is willing to do referrals. He did one for my GERD. I tried to find what I call my team, which would be doctors that listen and help me with whatever problem I might have. I ran into stone walls, and wrong diagnosis. One doctor even told me not to come back because I cannot pass the breathing test. I would have thought he would want to know why I couldn't pass it, not just dismiss me.
Oh well I feel armed after our conversation and I will begin to ask more and more questions. Thank you!

I was dealing w/ low RBC and crazy WBC numbers for 2.5 yrs after having a Prostatectomy. I worked w/ a PT Pelvic Floor specialist after the surgery. Did not bounce back to my normal self, sluggish, low energy level, slept 10-14 hrs/day. She got in my face and said get to an Onc/Hematologist to get my blood checked. Saw the PCP first, who put me on Iron supplementation w/out blood analysis. Got to a Onc?Hematologist (found out later he was THE MAN), did blood draws immediately, especially for the Iron since my PCP put me on supplementation w/out blood check. Got a call 2 days later, STOP the Iron; Iron levels were fine. He mentioned that too much could cause liver damage. Did many more blood tests and upper & lower GI analysis. Nothing was coming up & my fatigue continued and RBC counts were bottom or below; WBC counts were no better-all over the place. Was seeing the Onc/Hema every 3 months at that point. He was perplexed - always got a rash of questions when I was in the office. Finally toward end of 2023, he asked if I had a certain blood test - well if it wasn’t in my record - guess not!!!! He did a different one; then called into the office w/in 2 wks. Thought I had MGUS but wanted further tests. He wanted a PET scan (full body) and then a bone marrow biopsy. Results came back positive on the bone marrow biopsy. The Doc moved to NYC and is working there. Was petrified as I had no idea if I would get a new Onc/Hema that was aware of this diagnosis. My new PCP was oblivious. Finally was told I had a schedule appt w/ new Onc/Hematologist - answer to lots of prayers. Lady has been working w/ the diagnosis for 20+ yrs and worked at The Cleveland Clinic. So, apparently it can cause the low RBC count. Never had a problem w/ counts before in my life. All the sudden since having Prostate Surgery. I now have multiple specialists I see to address all issues related to the MGUS. I still deal w/ the apprehension of it moving on - in fact I had a slight rise is my readings, but the Onc/Hematologist said she is not concerned at this time as everything else is looking good. Find yourself Docs (specialists) that will know how to take care of you. It helps decrease the apprehension & worry. I’m a 70 yr old male that was working full time, traveling, enjoying life till about 3 yrs ago when the blood counts went off. Fatigue & energy level is the worst. That is a good thing if that is all I have to deal with. The best in your hunt for Docs.

I first saw an M-Protein spike of .5 in April 2023, it has been in a range of .5 to .7 since. Three Oncologist follow-up since, most recently on October 4. RBC has always been normal. My free Kappa light chain has increased from 37.6 to 45.0 with the October 4 follow-up. my ratio is 2.56. My Oncologist who is very caring, actually moved my next follow-up to 9 months out from 6. He was not overly concerned with the free kappa light chains. What is your free kappa light chain value?

My Kappa light chain was 26.16 and ratio 1.58. I to have recheck of all the tests in 6 months. Got an appointment with my PCP and hope he will refer me to a new hematologist. Just trying to deal with the fatigue. This was diagnosed in June 2024. The oncologist I saw was contradictory, inappropriate, and dismissive. Thank you for your story. Trying to be thankful for the life I do have.

MGUS is (supposed to be) asymptomatic. My kappa is about 300 and kappa/lambda is 29 (8 years). I now have some fatigue, but it is likely due to minor remaining long covid and new (urk) chronic kidney disease (I'm 70). It would be good to get complete bloodwork and any other tests to see why you have the fatigue. Granted, the stress of being diagnosed with MGUS can cause fatigue, but if this is ongoing then finding out why is important.

@bojean, the reason my MGUS was found was because my Hb was low. My PCP stated that MGUS can cause anemia. Just like what someone else in this thread said, the overproduction of the M-proteins crowds out production of other blood cells. My Hb flitters around the low end: sometimes normal, sometimes not. But I'm also in a wait and see pattern. I asked for 3 tests, 6 months apart (my dr wanted 2). Now I'm on an annual cycle.

I'm glad to hear you are getting a follow up test. I hope they are able to help you with your RBC.