Hi all. I'm wondering whether FlipperTD or indeed anyone else with some technical know-how, can make sense of my blood results.
I've recently gained access to my GP records and can see that I've had low ferritin for at least 4 years. Levels have ranged from 17ng/L to 27ng/L on a range of (10 - 180).
My GP said my ferritin was 'in range' (where have we heard that before), so not low, despite it being below the 30 cited by NICE and other iron specialists (and Rexz !)
The thing is, I haven't picked this up as an issue until recently, as all my Medichecks ferritin results have ranged from 47 - 89 ug/L. This led me to believe my levels were fine - i.e. above 30.
I've then noticed the ranges for Medichecks changed recently from 13-150ug/L to 30-264ug/L. Surely, these can't be directly compared?
After upping my exercise levels in the spring, I developed classic low iron symptoms - hair loss, shortness of breath, extreme tiredness, yawning/air hunger, aches, low mood, poor concentration. See above for my latest Medichecks iron result and tracker. Iron has dropped and transferrin is below range. I've been supplementing iron, along with folate 400mg and B12 IM weekly for the last 3 weeks and am slowly improving.
I've been in touch with Medichecks, but they can't explain so far why my NHS ferritin results are consistently around half those of my Medichecks ones, when taken at the same time of day, etc.
Any info or advice on what all this means and whether I can actually trust the results I've had from Medichecks would be appreciated. 😊
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KBird01
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Ferritin is measured using an immunoassay. This means that an antibody to ferritin is required. Each manufacturer's assay kit uses an antibody, but they're all different. But they're all anti-ferritin antibodies. The method for detecting the ferritin/anti-ferritin antibody complex varies considerably by manufacturer. As a consequence, the methods involved have differing sensitivities and therefore different reference ranges. There can be quite significant sensitivities between manufacturers. All of these methods are verified, and when used in NHS laboratories, the labs participate in the Government's External Quality Assurance Scheme, 'NEQAS'. The scheme compares the users with each others in their group, and also across other system users. As you can guess, for a 'punter' [that's you], comparing a result for ferritin from Lab A to one from Lab B is fraught with difficulty. Likewise it's not even worth trying to best-guess the sensitivities of the methods, because labs using the same manufacturer's kits won't use the same reference ranges. [Or they shouldn't!]
Comparing the various bits of a full blood count is easier, but this still isn't as simple as you'd hope. Haemoglobin measurements, Red Cell Counts and Total White Cell Counts are probably as good across labs as you'll get, whereas MCV methods vary and thus don't compare as much as you'd hope. Likewise the automated differential WBC varies, due to the methods involved. If it's a differential performed on a stained blood film down the microscope, it's more comparable, but far less precise.
The samples we use aren't as stable as you'd hope either. A sample sent through the post is fine for some things, and virtually useless for others. A finger-prick sample is a challenge at the best of times.
A venepuncture, performed by a competent phlebotomist, into the correct tube, mixed as required, transported to the lab without delay, and analysed without delay, is hard to compare to a fingerprick sample, posted and analysed eventually.
NHS labs are run by competent, qualified professionals, regulated nationally. I'll say no more.
Ha! Thanks FlipperTD ! *It's complicated* I knew you were going to say that! 😄
Some of my Medichecks ones have been finger prick and others venepuncture sample, although all are then posted of course.
The NHS results have been fairly consistent - 17 - 26 ng/ml [10-180], but Medichecks less so, with a nonsensical change in range this year, that I struggle to see how they can even accommodate onto a tracker.
Also, don't see how any of this fits with the NICE guidelines of <30 ug/L ferritin being indicative of iron deficiency.
Further NHS tests are out of the question at the moment. (I don't have the energy to try explaining to my GP I think I have low ferritin, etc. - can't face going through all that again.)
Any thoughts from you or anyone else where I might get an iron panel with ferritin tests that are comparable to my NHS ones?
Thanks again btw for the insights into what seems like a straight-forward process!
My guess is that Medichecks may have changed their supplier to a different method. They may even send it off/buy it in from another lab? Who knows?
As for the NHS lab results, well, sorry but they're the best place to get them done but that gives you a bit of a challenge. Many NHS labs do have schemes for 'Income Generation' and would do the sample for you if they had a referral from a medic. [Yes, I know that's the problem] but they're bound by protocol and ethics to only do stuff for registered practitioners, and report back the same way.
Nothing wasted with a phone call to the hospital lab, with a 'for instance' message. Give it a try, but don't mention my name. [!]
Thanks again FlipperTD . I do appreciate your input and making sense of my world. I've since seen on the thyroid forum that Medichecks changed to a different lab last year for ferritin, as the one they were using lost their licence. Not good.
I'm awaiting a response from Medichecks to my query too, so I'll post if and when I receive anything. Might give you a good laugh if nothing else! 😉
Thanks helvella . Yes, I think I'd seen your blog and posts too. The difficulty I'm having with my Medichecks results is that it consistently seems to come out almost double my NHS ones, and as a result is consistently over the 30ug/l range even when they are only a few days apart. (See chart above) I saw from some other responses on the thyroid forum they'd had this issue also.
This is concerning, as looking at my NHS results, many of my symptoms would be explained by iron deficiency, but I didn't consider this, as I didn't have full access to my NHS records at the time and my Medichecks results were showing well in range.
Thanks Curious123 . I did use Blue Horizon before for an MMA and other tests. I'm oop north though, so went to Manchester Spire hospital for that one. I think that might be an alternative perhaps. To have blood drawn for testing at a private hospital. Referring back to FlipperTD's post above, I guess I'll need to check if they test on site.
Medichecks tests active B12 oily1601 , whereas most GP's check total serum B12, which is a much higher result. Most people recommend the active one as giving the best picture, as this is the B12 that's available for your body to use. Hope that helps.
Yes we need forum experts to interpret our Medichecks ferritin results: I do the Medichecks full thyroid check 1-2 a year and get my ferritin bloods consistently in lowish 40-60 but was taken aback when Medichecks kept changing the range in 2022-3 it had shot up to 30-650 making a result that had been c.25% thru a range now under 5%. Medichecks admitted it was a different lab doing these assays, and I could ask not to use them, but it becomes impossible to compare like with like…very frustrating when I had made a very concerted effort to get my ferritin up.
Thanks for this Judithdalston . I agree, it's very frustrating. And also that as the readings themselves are so much higher, this didn't trigger any concern on my part that my levels might be too low. Not good. 😑
I have read a few of your replies but not all so sorry if this has already been mentioned and therefore repeated. Have you thought of testing via Monitor My Health?
They are finger prick tests but are run by the NHS in an NHS hospital laboratory. It is non profit making, I think the proceeds from doing some private testing goes to NHS charity but not 100% certain. On their website under the tests you want done it usually gives the reference ranges they use for comparison. I did one myself today for Active B12, Ferritin etc under their Anaemia Test. Had to resort to private testing again as my Active B12 was cancelled by my GP. Another story. MMH ref ranges might differ slightly to other hospital trusts but may be worth a look at.
Blue Horizon did have some ref ranges similar to NHS but I can't say for sure about Iron panel.
I do wonder about the finger prick tests in how accurate they are, after the blood has gone through the post etc. Although mine so far have been fairly accurate in comparison to NHS lab but they are not the gold standard for testing. Trouble as always is getting a GP to agree to do the testing, which is the big hurdle to get over!!!!
Hi Dancer57 . Thanks for this and no, I haven't heard of Monitor My Health before. Having a quick glance at the website, it says there are no ranges, just lower levels though. Have you used these and do they give you a 'score', or just that it's above or below range?
I have used them twice before. You do get a score which is also shown as plotted on a graph with 3 ranges, Low, Normal, High. Each level has figures next to it so you can see where your score falls within the cut off value.
You also get a comment. If you are looking for a more detailed iron panel then this may not be for you as it tests Ferritin and Ferritin saturation only. Also Folate, Active B12, Haemoglobin levels.
There are many other private testing companies but the reference ranges can vary quite a bit depending on who you use. The Thyroid UK community are quite knowledgeable on private testing it might be worth asking them for comparison companies to test with. My knowledge is limited.
It is a nightmare to know what to do for the best for sure.
Not wishing to muddy what may already be muddy waters, I had a full set of bloods to identify an ongoing (20 years and 3 sets of loading doses later!) B12 deficiency. Regarding Serum Ferritin my NHS scale was between 20 - 501 ng/mL and my score was 244 ng/mL, (normal) so again a totally different range scale. Why cannot the NHS deliver standardised reporting levels. I tested 160 ng/mL for B12 and was told that was "in range" until I argued to the contrary. Having had the 6 loading doses finish 3 weeks ago I have been advised that I will need another blood test to check levels before any further injections will be made! Again, with gritted teeth I argued that after receiving 6 loading doses I would expect my levels to be "high" so whats the point of the blood test. I advised GP that revised NICE guidelines are to treat symptoms and not numbers but he looked at me with such distain daring to question him or voice some medical knowledge. I told GP I was not prepared to only get the B12 injections after I had crashed or symptoms had returned and if he didnt agree with this then to give me the name to whom I could complain. I await the next blood test on 11/7 with some energy to continue the battle for what I know I need and deserve.The general level of B12D / PA understanding in NHS is derisory and needs to be addressed through the good work of PA and B12 Societies.
Well done you for sticking to your guns. You're so right - what on earth is the sense from a financial point of view to letting people crash again before treating them, never mind the ethics!
I hadn't realised until I opened this particular can of worms and FlipperTD shared their knowledge, just how varied these ranges can be. It's just impossible to judge whether we're in or out of range on these things. I just keep having to have a word myself to continue the self treatment I know is working. I admire your energy for the scrap. Tbh I just don't have that right now, so I'll continue to do my own thing. Good luck! 😊
Hope that you regain some zest and energy!! I am amazed that GPs seem to dole out anti biotics and anti depressants, statins and BP meds like smarties but prove difficult in agreeing a vitamin jab! Taking charge of oneself seems to be the requirement, even in the face of a difficult GP.
I’m sorry I have nothing useful to say for you KBird01, was interested in your post as thinking of having some more private blood tests in this crazy Is it or isn’t it B12 nhs world! But good luck anyway.
Just wanted to say well done to you Sailing63 for standing up to your GP! I’m failing miserably at this, I think I need some assertiveness training! I hate to say this, but most of them really don’t take being questioned well at all.
OK everyone - I have a reply from Medichecks. Hmm... Whilst the info seems to align with what you posted FlipperTD , they don't seem to have answered the questions I posed, or considered the info I provided. I see no explanation why their results are consistently almost double those of my NHS test results.
The new range is supposedly to align the lower range with NICE guidelines and for women 50-60 yrs, but whilst the results dashboard tracker is seemingly adjusted to accommodate the new range, this still reads well above 30, but on the same level as my first result from them. This was in the same week I scored 24 with my NHS test. (19&22/3/19)
Here's the screenshot of what I sent them. See their reply (abridged) below:
'Lab reference ranges are determined internally and there can be significant differences in reference ranges between labs, especially when it comes to ferritin levels. In recognition of this issue, Medichecks performed an internal review of >25000 ferritin results over a 5 year period to determine our own reference ranges. We believe this is the largest ferritin reference range study to date. From this we have derived a new set of reference ranges that differ slightly depending on age and sex.
Perhaps it would be also helpful if we explain some general concepts about blood testing and result differences between laboratories, which is commonplace.
Regarding the laboratories that we use, our partner laboratories are fully accredited and are committed to the highest clinical standards by internal quality control (IQC) and external quality assurance... [...etc]
Next, regarding why Medichecks results may differ from those your doctor performed, there are several factors that affect blood test results which can be summarised as follows:
Biological variation (intra-individual variation)
In any individual, there are biological (diurnal) cycles that may affect blood results... [Gives examples of how cortisol and testosterone levels vary through the day]
With respect to ferritin in particular. Although this is a measure of iron stores it is also a marker which goes up if there is any level of infection or inflammation occurring within the body and hence we often see a variation in results as it does not solely reflect the iron stores.
This still doesn't explain why they are consistently almost double the NHS results. My concern remains that as these consistently read above 30, I did not pick up the fact I had a long-standing ferritin deficiency as per NICE guidelines.
They then provide info and a link to this web page.
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