The Beauty of the SED Rate

Not too long ago, I mentioned the SED rate in a post (link).  I'd heard about it for ages but for some reason it never REALLY made it to my radar.

What I've found interesting is that I've had these tests done - and didn't know it because so many tests are run on me.  My rheumy told me that when I've had fibromyalgia flares the SED rate came back normal. However, when I've had CFIDS/ME/CFS flares, characterized by fevers, sweats and swollen lymph nodes - common occurrences with me across the board - the SED rate numbers were often mildly to moderately elevated, only to fall back to normal when the above hallmarks of infection went away.  

But one fine day, while talking to my rheumy, he said something that made me go "whoa"!  Sayeth my rheumy, "If I had to choose only one test to use for the rest of my career, it would without a doubt be the SED rate."  Well blow me over!  It's just THAT good and useful?

So the follow-up question was, what exactly IS a SED rate?  I had a good idea of it: that is, it was a blood test and involved inflammation and I knew it was crucial for lupus, but didn't understand it well enough to explain it to anyone.

But my lovelies, I'm here to explain the test now!  It's a simple blood test which has been around since 1897, invented by Polish physician Edmund Biermackego  - in some parts of the world it is still referred to as "Biemacki's Reaction" - and then "rediscovered" in 1918 by two Swedish physicians, pathologist Robert Sanno Fahraeus and Alf Vilhelm Albertsson Westergren.  (Sorry about the butchering of the names!)  The two Swedes are remembered by this test with the name "Fahraeus-Westergren Test" (FW) and in the UK as the "Westergren test."  But I digress...

I find it incredible that the SED rate is performed in every hospital in this country.  It doesn't need to be sent out to a special lab and results are ready within an hour and a half.  Furthermore, it's not very expensive! (There's finally a break for us after all!)

Continuing: the SED rate (Erythrocyte Sedimentation Rate) is a measurement of inflammation in an individual. It's a simple measurement of how far a column of red blood cells (erythrocytes) fall in one hour. The further the cells fall, the higher the SED rate and the more serious the inflammatory problem. In fact, the red cells tend to clump when measured in the test tube and these clumps - due to inflammation - tend to make them heavier, thus the fast fall.  The rate is measured in millimeters.  For example:

• An infection such as Tuberculosis (TB) or severe pneumonia would have a high SED rate, usually above 50 mm.  
• Other medical problems such as tension headache, fibromyalgia and osteoarthritis would be represented by a normal SED rate, usually less than 20 mm. 
• The really bad, life-threatening conditions such as rheumatoid vasculitis and giant cell arteritis have extremely high SED rates, typically over 100 mm.

I guess you can see where we're going here!  A normal SED rate helps the doctor rule out a huge number of conditions, typically inflammatory or infectious.  If, however, the SED rate is abnormal, the doctor must figure out why since the SED rate is not specific for any one disease but it is extremely sensitive.  In other words, if you have a bad infection or have severe inflammation the SED rate will pick it up but it won't tell you which disease you actually have.  

Some examples of how my rheumy uses the SED rate are: 

• Distinguishing between fibro (normal SED rate) and polymyalgia rheumatica (high SED rate).
• Helping to determine if the patient has osteoarthritis (normal SED rate) or rheumatoid arthritis (high SED rate). 
• Determining whether the patient's chest pain and abnormal EKG is due to atherosclerotic coronary artery disease (normal SED rate) or coronary angiitis (high SED rate). 
• Monitoring therapy.  When a vasculitis (high SED rate) is being treated successfully, the SED rate should tend to go back down to normal.  If that doesn't happen the doctor should rethink his treatment decision and perhaps raise the dose of cortisone, as an example, to get the inflammation under control.  
• Reassuring the patient whose Sed Rate is normal that he/she does not have a life-threatening case of Wegener's Granulomatosus (because the Internet strikes again, putting fear into us where there shouldn't be any), despite the patient's insistence that he/she does in fact have this dreaded disease.  
• Tracking the course of a patient's disease. For example, a lupus patient might not need to take medication such as cortisone which can have a myriad of side-effects if the SED rate is consistently normal and the lupus mainly affects the skin and a few joints. However, if there is a spike in the SED rate there could be major organ damage if the lupus flare is not addressed.  
• Figuring out if the new patient who has just walked into a doctor's office with a complaint of headache needs immediate intervention to prevent blindness or stroke as one would fear with Giant Cell Arteritis  (very high SED rate) or can be treated using medications to only ease the symptom, as in tension headache, migraine headache or mixed headache disorder (normal SED rate).  

My rheumy (thank you, kind sir!) stressed to me that any doctor, regardless of specialty, can use the SED rate to his advantage in treating a whole variety of conditions.

As always, hoping everyone is doing their best, only better.  Ciao and paka! 


(Did you enjoy this article?  Please subscribe to my blog and you'll never miss anything.  It's easy: see the directions on the right hand corner of this page.  And BTW: I'll never sell, share or rent your contact information.  I don't even know where to find it, so it's a firm promise!)