LIGHT CHAIN QUESTIONS

But I continue to have so many questions about my abnormal light chain result.

1. Can the blood test itself be off? As the doctors have stated many times, blood tests are not always perfection. The numbers can vary from blood draw to blood draw.  They look for an over all pattern not a particular one time result.  My change in the ratio is a small one. Could it simply be a blood test fluctuation that will go back to normal? I wish I could find some hard data on this. 

2. Could it be due to donating blood? In October I donated a blood for research. I was told I could not give blood again for 8 weeks. Yet, my free light chains were tested after about 6 weeks from the blood donation. Without my knowledge. My ratio is off due to a drop in my lambda free light chains. My Kappa light chains hardly moved.  Does that suggest that perhaps the blood draw threw off the light chains and it had not properly recovered yet? 

3. Assuming it is not from blood donation... why would the lambada light chains be so substantially lower? From everything I read, you normally have more of the involved light chain. So people who have a lambada involved cell.. will see their ratio go down. While those with a kappa involved cell will see their ratio go up.  I have kappa, why did my lambada go down? 

4. Can the change in ratio be caused by something other than the mugs? As noted in the last post, it seems that light chains are related to immunoglobulin. Well, those can changed based on non clonal cell issues. Cold, virus. etc. Though of course the ratio typically can be normal... can it change on for reasons unrelated to MGUS. After all free light chains are not typically tested for unless you have a clonal cell issue.   By taking a blood test snapshot can it be misleading? From Wikipedia: Increased levels of free Ig light chains have also been detected in various inflammatory diseases. It is important to note that, in contrast to increased levels in lymphoma patients, these Ig light chains are polyclonal.  So if I had inflammation and Ig light chains made my light chains change, how would I know what the reason was?  The free light chain measurement just measures all light chains. So how do know if it is an issue of IGM?  In January my doctor mistakenly ran an IGM immunoglobulin test and unlike November, it had decreased. From 290 to 260. Does that give me a hint that my free chains will be down? Also, I had been taking turmeric and fasting, both shown to reduce inflammation,  will that reduce my light chains?

5. How much exactly is dangerous to have in terms of just kappa or lambda? Right now both my kappa and lambda results are normal. But assuming they go out of wack, when should I be concerned about their volume?

If anyone has any answers feel free to comment. 

FRUSTRATED ABOUT LIGHT CHAINS

I just find it so hard to get good information about MGUS. When I was first diagnosed with MGUS my light chain ratio was normal.  This made me happy as it seemed to place me in a low risk category. In fact, at that time..., almost everything was good. Everything was normal but for the M-spike. Which actually went down at the first subsequent blood test.  From .5 to .3. 

But then, only 4 months after that test. 

- my M-spike went up (though just back to where it was when I got diagnosed).

- my IGM immunoglobulin went up... normal but still at the top of the range.

- my light free chain ratio went up to abnormal. From 1.5 to 1.9. (end of normal is 1.65).

This really upset me. I now have moved into a much more risk prone situation. I have both IGM (more risk for progression) and abnormal light free chains. All of this happening just one year after I was diagnosed. To me suggesting I have an aggressive problem. But my doctors seem completely unconcerned. 

What I have managed to learn. 

The ratio itself isn't that bad. Ultimately a lot of people with an abnormal ratio have a much grater ratio than I have. Some people have 17 to 20 or greater and are still MGUS. In fact, typically they won't treat you until you reach 100.  If you calculate the increase in light chains that I had in about 1 year you will see that it is about....25%. 

Light chains themselves are sort of a waste product of the immunoglobulins.  So the over producing clonal cell secretes (in my case) IGM immunoglobulins. And if you are having an excess of clonal cells and IGM immunoglobulins then you are necessarily likely to have an increase in the light chains (in my case likely Kappa) since I am IGM kappa - throwing your ratio off. 

In addition, the light chains in your blood are a function of the kidney. Your kidneys clear the light chains.  So the only thing that my specialist at Dana Farber told me to do was to drink water. Now I think very much the case could have been that drinking water helps clear the light chains and keep kidney's functioning well.  So does your hydration status play a role in your result?  I think so. From Wikipedia in normal individuals, free light chains are rapidly cleared from the blood and catabolised by the kidneys. Monomeric free light chains (kappa) are cleared in 2–4 hours, and dimeric (lambda) light chains in 3–6 hours. Removal may be prolonged to 2–3 days in people with complete renal failure. So can your hydration and also your status make a slight change? Possibly.  In my case I was not expecting at all to get my blood tests for this so I have no idea if I was dehydrated etc. 

So it seems clear that light chains, antibodies and the M spike are all closely related. With the M spike being one of the last things to move.