Overview of Arthritis, Disease Markers, and Inflammation Blood Tests

[ITYFIALMCTT]

Dr Ronan Kavanagh's nicely readable overview of diagnosing arthritis and the role of disease markers and blood tests for inflammation levels. This is a nice compilation for anyone wondering about seronegative blood test results or curious about some statistics for various classifications.

"The ESR or CRP may also be normal in patients newly presenting with rheumatoid arthritis. In a large study of RA patients from Finland and US, between 45-47% of patients had a normal ESR, 44-58% had normal CRP at presentation. BOTH were normal in 33% and 42% of patients**. When a rheumatoid factor test was included, 14-15% of patients had no abnormalities in all 3 tests."

ronankavanagh.ie/blog/arthr...

Seronegative stuff is a pest but I confess to being curious about it. I should state that although I'm being evaluated for psoriatic arthritis (waiting on some further tests and imaging) I have no indication of inflammation in my blood work. Not in a single test nor the more recently researched ratios such as neutrophils:lymphocytes. The only hint that something is odd is that I have a high cholesterol level (particularly LDL) that is at complete odds with my overall blood work etc. - and I only mention this because it is known to co-occur with inflammatory osteoarthritis (aka erosive osteoarthritis) which is a differential diagnosis for PsA.

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Neutrophil to lymphocyte ratio (NLR) is used as a marker of subclinical inflammation. It is calculated by dividing the number of neutrophils by number of lymphocytes (these are usually given in any CBC). "We have identified that the normal NLR values in an adult, non-geriatric, population in good health are between 0.78 and 3.53. These data will help to define the normal values of the NLR." (Taken from following link.) My value is 0.73 FWIW.

Full text of clinical paper about NLR (free): ncbi.nlm.nih.gov/pmc/articl...

Full text of clinical paper on neutrophils:lymphocytes ratio and CVD risk (free download): researchgate.net/profile/Ne...

FAO: richardmax98 who might find this relevant.

[Talmalmo]

Thank you for the information. Looking forward to having a good read through.

[Hidden]

Very interesting thanks. I have been wondering if I might have PsA for years now but so far I'm diagnosed with pSjogrens and OA.

I'm in the opposite camp where my inflammatory bloods are invariably high. My connective tissue doctor explains that this is due to my high IgG levels which he says are common to those with Sjögren's - and lead to uniquely concentrated blood which never thins out - so my high levels are my normal apparently. He says this is why the fatigue of nearly all Sjögren's sufferers is so unremitting and why it's untreatable compared to other rheumatic diseases.

I checked this with a fellow Sjögren's sufferers on a FB page but it doesn't seem to be born out I have to say. But then many of these are self diagnosed seronegative people whereas I do have a confirmed diagnosis - for which I am very thankful.

With Sjögren's you have to be lip biopsy positive to be seronegative - similarly with Lupus you have to be ANA positive to be classed as seronegative by most doctors. RA and of course, PsA, seem to be the only exceptions where you can be negative for all bloods but still diagnosed on clinical signs and symptoms alone.

[ITYFIALMCTT in reply to Hidden]

I wonder if anything would shift my CRP or ESR levels I had an episode of sinusitis earlier this year and I still have a swollen submaxillary lymph node several months later. I had it when I had my last lot of blood tests and yet you'd not know it by my serum results - no sign of inflammation nor infection.

I know the same discordance has shown up in previous years (before the ?PsA manifested) because my serum inflammation markers were the usual low levels altho' MRIs showed a fair amount of bursitis in both of my shoulders as well as bone oedema (same for the knees).

And, yes - there seems to be little rhyme nor reason to how some auto-immune diagnoses are completely dependent on blood work but others can be made from clinical observation and symptoms.

[Hidden in reply to ITYFIALMCTT]

I had a CRP of 160 twice when I had a pancreatic reaction to Azathioprine - diagnosed at the time as a UTI Sepsis. After a week in hospital on IV antibiotics it went down to 2.5. I've learnt from this that my normal of 14 is just me!

[Simba1992]

Hello AARA,

Just a thought. High cholesterol is one symptom that points at thyroid dysfunction. Have you had a compleate thyroid panel done. One that also shows T3? I have understood that NHS seldom oks other than a very superficial thyroid analysis. If you have subclinical inflammation this may be an idea to check.xxSimba

[ITYFIALMCTT in reply to Simba1992]

Hi Simba1992 - if you meant to write to AARA then your link isn't live (different thread).

If you meant to respond to me (as the OP), I don't have subclinical inflammation (I'm below the range given in the clinical paper) - so, apart from the pain and stiffness in my hands (possibly other sites) I don't manifest inflammation at all (except for the LDL - and yes, there are associations there with hypothyroidism etc.).

[Simba1992 in reply to ITYFIALMCTT]

Sorry, my mistake! But actually was responding to you😊It's really interesting the connection so often to thyroid function when joint symptoms. How is your temperature, high or low? Low temp another symptom of thyroid dysfunction.