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CADs Having Trouble with RBC/CBC Blood Testing

As a CAD you may find there is a disconnect in the medical community between Professional Blood testing facilities, and CAD (Cold Agglutinin Disease) Patient blood testing requirements.

You may even deal with conflict concerning your doctor.  Especially If they are not up to speed with CAD.  Or a doctor that has not treated a CAD patient that has moved through various stages of the disease.  Perhaps better referred too as the various stages of cold sensitivity?  This sensitivity changes for many CADs as time goes on.

There may be a lucky group of CADs that have low level sensitivity?  Some which their condition remains static at that level?  They lead a normal life and seem unaffected.  They may not even be aware?

For the most part we aren’t hearing that scenario, in our social media support group.   But that might simply mean the more severely affected are out there looking for information?

This article specifically pertains to when CBC/RBC blood tests start failing to result properly.  When standard blood testing protocols start becoming an issue for the CAD patient.  This would also apply to a Thermal Amplitude Blood Test.

The focus of this article is not about the disease itself, but problems a CAD will most likely encounter having a RBC/CBC  blood test done.

If you are new to CAD in general, you may also want to go to our page I was just informed I had CAD.  Now What?

Ironically the (CBC/RBC) test.  The specific blood test a CAD Patient needs to monitor their Red Blood Count/Hemoglobin levels,  and monitor to see if they are falling to anemic levels.  Is the very test that can fail to result, or result with inaccurate numbers.

It seems the worse your CAD becomes [more sensitive to the cold], the more traditional Blood drawing/testing protocols cease to provide a result, or an accurate result.

You as a CAD may experience 3 stages.   3 Phases, scale of 1 to 3,  distinct categories, a progression?  Or whatever Key word, or phrase you deem might be an appropriate way of labeling the change in process requirements.  Basically, process changes required to produce an accurate RBC/CBC for a CAD patient, depending on how cold reactive their blood is.

We want to clarify this because a select few want to split hairs on this subject and often comment there is no “progression” with CAD.  While others that have similar experience fully recognize and understand what we are attempting to communicate.

If you are one of the lucky ones that are static at a low level, and not experiencing any difficulties with blood testing [RBC/CBC].  Consider yourself lucky.  Just don’t muddy up the waters for others experiencing difficulties and needing answers.

Please do not interject on social media, there are not different levels, stages, or some apparent progression.  If you feel there isn’t, you are one of the lucky, less affected.

To our knowledge, there is not an official medical term to define what we are attempting to share with other CADs.   If there is, please email us that info.  For the sake of conversation and explanation, we are simply using the term STAGE, as our label.  So bear with us while we attempt to explain this.  If it doesn’t apply to you.  Consider yourself very fortunate.

So let us define first.

STAGE = Our label to explain testing differences

“Stage” in this case defines, a different approach that must be taken to test a CAD patients blood for a CBC/RBC.  When a  CADs Cold Sensitivity becomes more elevated or severe.  Some change in the CAD, that causes an existing working blood testing method to start failing.

This pertains to blood testing, not the disease itself.   Though, as the RBC/CBC blood testing protocol necessitate a change in testing method.  The CAD patient has most likely become more sensitive or more reactive to the cold.  So there does seem to be some type of relationship one could make.

So “stage” may also roughly represent the sensitivity level a CAD is at?

For the RBC/CBC test, there appears to be a scale from 1 to 3.  Or 3 stages.  Is there a stage beyond that?  Some 4th way of testing that might be needed?  Not to our knowledge.

This might apply to other blood tests?  But for the most part it seems to only affect the RBC/RBC and a Thermal Amplitude Blood Test. This is based on personal experience as well as input from lots of CADs via our social media forum.   We will update this article if numerous people report problems with other tests.

So remember, this is only a guide for those that are finding their CBC/RBC Tests seems to fail.


During the early stage or lease amount of Cold Sensitivity a CAD deals with. Standard Protocol blood draws & testing methods work fine and produce usable RBC/CBC test results.  This is the method that a lab uses on all normal people.  Nothing special is done.

Samples can be drawn at a satellite facility, held, shipped, and later tested without special handling or failures to result properly.

The lab can get good RBC/CBC.  It won’t fail.  You will never know  anything different unless the lab notates some type of agglutination.

In this stage, Standard Protocol uses no “Keep it Warm” techniques on the drawn blood sample.

Rewarming your specimen at the lab, to perform the test, may be successful.  A process you as a patient may never know goes on.

Though lab notes on your test results may state something like “Cold Agglutinin Detected”, “High levels of Agglutinin”, or “Clumping observed due to Agglutinins”. The CBC/RBC may still result accurately during this stage.

Note:  People that donate blood at times, will receive a notice about high or abnormal Agglutinins being identified.

Since Agglutinins may be low level, there may have been no warning from other notable physical symptoms.  You might not be Anemic to any degree.

This type of notice is often a shock to the donor since a previous donation went un-noticed.

Dr. follow-up is recommended.  We further suggest you keep your own copies of blood test results from this point forward.  If you can obtain a previous test result that was OK it would be beneficial to have those for a baseline reference later.  Also to know what may have transpired, health wise, from a previous good RBC/CBC, to one notating “Agglutinins”.

It is possible this is a temporary condition that will pass with time?



CADs that have become more Reactive to cold Temperatures than a stage 1  CAD.  We are grouping these CAD together as stage 2..

In this group the CBC/RBC Tests may start failing often, or fail all the time.  If your blood testing facility follows Standard Protocol.

Initially the patient may experience hit and miss tests.  Where you as a patient have to give another sample and they test again.

The blood specimen will start requiring special handling to produce consistent, accurate test results.

CADs, in this Stage 2 group, will eventually require a “Keep it Warm” process.

The specimen tubes must be pre-warmed, the drawn specimen kept warm, and the lab testing done stat.  Your particular lab may or may not be up to speed on any of this?

Satellite specimen collection where the sample is later shipped to a lab may not work for the CBC/RBC.

I must mention “keep it warm” is another CAD Patient made up term used by many.  But to my knowledge it is certainly not an official medical term.  So if you start throwing that term around at a blood testing facility or ER room, you might encounter a blank stare.   You may have to explain.  Expect to be met with doubt.

This “Keep it Warm” technique will often be talked about or recommended on CAD types of social media or support forums.  Perhaps your doctor will tell you?

Once you are in this stage 2 scenario.  It’s best to have written and signed documentation (By your Dr on their letterhead) detailing the steps to the “keep it warm” technique.  Carry this with you to present at any blood facility, ER Room etc.  Believe me, it will prove invaluable to you.  It will prevent lots of conflicts or even being disbelieved.

When this Keep it Warm process is not followed on the CADs at this cold sensitivity level, the CBC/RBC will often fail to result or have invalid numbers.

Note:  Often patients newly identified as having CAD, are already in this stage.

Some CADs may never have had any previous health symptoms to trigger any type of blood testing when they were healthy and not troubled by CAD.



Some CADs become even more sensitive and reactionary to the cold.

We group the CADs that are so cold sensitive, that “Keep it Warm” techniques fail to product a good RBC/CBC, into a group we term Stage 3.

In these CADs, clumping of the blood may occur even using “keep it warm” testing techniques.  Meaning the “Keep it warm” techniques will eventually start failing for some CADs.

This problem seems to apply to an even smaller percentage of those with CAD.  So this very small percentage of CADs are truly rare indeed. Just hope you don’t have to deal with this.

Our observation of this change occurred about 16 years after the disease was first diagnosed.   As with anything CAD related, this time line is probably all over the place from individual CAD, to CAD.  It is very well possible many CADs  will never get to this sensitivity level?

For these even more rare CAD patients, in this 3rd stage. Some have to seek out a  facility that is willing to use a Plasma/Saline Replacement Process to produce successful and accurate CBD/RBC results.

Most labs seem reluctant to accommodate in this manner.  The process is documented at the bottom of this article.  It is definitely not Standard Protocol.

The documentation we present below is not worded by us or another lay person.  Its not our opinion.

It was written by a medical professional.  The lab manager of a major hospital.  When Marilyn could no longer have her RBC/CBC run using the “keep it warm” techniques.  It was their solution for doing her RBC/CBC when she was admitted to the Emergency Room.

In our personal case this was triggered when Marilyn’s blood continuously failed to result using the stage 2 “keep it warm” techniques, time after time.

Around the same time Quest, LabCorp, and PPL all starting telling Marilyn they could no longer test her RBC/CBC.  Up until that point they too were successful if they used the “keep it warm” technique.

In Marilyn’ case, her Hematologist had to set up a special account for her at another local hospital.  A facility that normally does not do “Out Patient” type services.  That hospital was willing to make special arrangements for the testing, and the abnormal billing as an outpatient.

Even then, Marilyn always calls ahead and touches base with a lab contact so they get a heads up she is coming in.


Once you identify you are truly a CAD patient, you need to be better informed. Educate yourself, and actively be involved to ensure your Doctor, Phlebotomist, and Lab are all on board with the differences in testing.  Know what stage you are in.  Know what is required so you can speak up for yourself.

At the same time you don’t want to get all upset and demanding, if you are in the stage 1 arena.  Or you are having non-CBC/RBC tests run.  That will only ruin your credibility with the medical staff.

Consider yourself lucky, the longer you remain in the group of stage 1 CADs.  But quite frankly the bulk of CADs seem to be in the Stage 2 group.

Once you know you have moved into the second stage, many CAD patients, on their own, attempt to work with their blood testing facilities.  Making attempts to educate those they come into contact with.

Many have found help from other CAD Patients that have blazed the trail and provided information.  Having printed material along with you certainly helps.

If your requirements are written by your doctor on their letterhead, so much the better.  This is truly the way to go.

If it is a facility that has dealt with other CAD patients, feel fortunate.  Everything might simply be routine for them.

In the early stages and as the disease progresses [as cold sensitivity increases]  some patients and medical facilities have found they have to use the “warming’ techniques we touched on above. The blood needs tested quickly, while still at body temperature.  Simply rewarming in the lab may or may not work.  It will depend on how cold sensitive you are.

Sure there is a variety of blood tests that result just fine without special handling. But the CBC/RBC is one that starts not resulting properly.  The Thermal Amplitude Blood Test may also fail for a CAD if not drawn and processed properly using warming methods.

With normal non-CAD patients, the lab does not have to follow these steps and pre-cautions. They can process blood specimens that have been delayed, those that sit around, or those that have cooled for hours.  They operate using “Standard Protocol”.

There is also a big problem with CAD patients that encounter new facilities or medical personnel.   Such as being transported to an ER room, treated by First Responders, etc.  Often they will admit they have no knowledge of CAD.

While on this subject, most CAD patients (depends on the CADs temperature sensitivity) always need IV infused fluids run through a warmer. i.e. Blood Transfusions, Saline, etc.

This does not apply to some IV Pharmaceuticals such as Rituxan though…..just in case that comes up.

Your loved ones/advocates need to know this info. Your medical ID bracelet should state it. Your medical records, should state this. All in case you are unconscious or unable to speak. A serious traffic accident would be a prime example situation. Your advocate might not be around.

The “keep it warm” and test it “STAT”, technique in our case eventually required blood draws done right at the Lab. Sitting in the Lab or Lab doorway, with all medical personnel involved in the collection and testing chain, brought up to speed first. The Blood needed drawn into warmed tubes, then immediately handed off to the lab tech, and tested right then. Processed and Tested “STAT”.

That normally involved finding who the lab manager was beforehand. Having a discussion with the manager, and often times providing our own written documentation to help “educate”. That document is best when written by your Dr. on their letter head and signed. But alas some doctors are not even up to speed on this if you are their first CAD. Then they are often too busy to take the time to do this for you.

Make paper copies to present and/or have attached to your chart. Then it is best to arrange a special blood draw appointment, when the informed lab manager or supervisor is present, and involved. Or at least agreeable you have to be handled/tested differently then instruct their staff.

Some of our worst experiences are when admitted to an ER. You are basically trapped and some medical staff personnel are very close minded to a patient that has some rare condition. Guessing you are written off as another complaining unrealistic patient. Sorry, but we have encountered this way too often.

Surgeries are another concern.  Again sensitivity level may dictate special considerations.  But that is material for another entire discussion.

I can’t stress enough that you better have paper copies of your Dr’s blood draw instructions for the ER, and your chart. If you are admitted after hours all of this often turns into a giant conflict…especially if they can’t reach your doctor.

If you are admitted because you know you have low blood counts, and not thinking clearly it makes matters worse. You definitely need an advocate that is aware of your condition, have written documentation along, and be somewhat educated on blood result numbers and what they mean.

Stick to your guns when approached by a Tech that you know does not know the “Keep it Warm” process [If you are in that stage].  I must say here that this is no official term any facility uses.  You have to feel the tech out by starting….I have Cold Agglutinin Disease.  Are you prepared to keep  my specimen warm?  Is the lab on board?  Are you getting a blank stare???

Stick to your guns about having Saline IV’s run through warmers too.  Especially concerning is emergency first responders that may  have no training concerning CAD, then attempt to infuse you with cold saline while on the way to the ER.

We generally flag down an “In Charge” nurse before this ever comes up.   It helps avoid a tech walking up to you, then getting blindsided when you start throwing questions.

A good indicator the tech is not on board is they have no means of warming the tubes.  [Again, if you are in the “keep it warm” stage]

As the disease progresses the patient may experience failed or erroneous results, unless the blood is kept warm the entire process.  You will know when that point in time arrives.  That is when your conflicts will most likely begin.

In our experiences some hospitals and labs dealing with CAD patients have become more aware the drawing tubes must be pre-warmed, warmed the entire time the blood is in transit to the lab, and the lab must keep it warm and tested STAT.  But you have to make it clear you are CAD.

Once alerted, some medical facilities are prepared and use “baby heel warmer” wrapped tubes, or beakers of warm water. If they arrive for collection without it and you know you are at the point it is necessary, it is time to say “stop”.

Start the discussion. Not with that tech, but a supervisor, “In Charge, or attending Dr. You will more than likely have to make waves.  Because if they aren’t on board, neither is the lab.

Unfortunately many facilities, Doctors, and staff, are entirely clueless concerning this “warming” technique or the Lab handoff/testing STAT.

We have encountered honest Doctors and Techs will admit they know no special protocol. Never heard of such a thing,  Most have no exposure dealing with a CAD patient.  Some I suspect won’t even believe you if they don’t research it.

We still carry paper documents when a trip to the ER is necessary.

In our case, after some years, things progressed even beyond the “keep it warm” technique. In some patients that even fails to work. They and their Doctor will have to really work with a facility to move into testing using a non-standard testing Protocol.

We have had several facilities refuse to alter their protocol. With test after test failing at their lab, we were finally told to go somewhere else.  Quest, LabCorp, and PCL have all told my wife they could no longer test her blood.  They stated they would not alter their standard protocol to accommodate her once the “Keep it Warm’ process started consistently failing.

That is great if you have insurance that will let you go anywhere else you please. With things the way they are with our insurance we are limited to specific labs. You know…. the lowest bidder it seems.  The ones that won’t work outside the box.  We are not sure what others are encountering with socialized medicine?

Sure we can go other places and pay the bill!  We have PPL insurance and we are getting this. I can only image what HMO or managed health care patients are dealing with?

We had an in house Hospital Lab manager providing a testing procedure they are now using to produce accurate blood test numbers on such a patient. The type of patient that “keep it warm” no longer works.

Unfortunately they will not take Marilyn on an out patient basis.  To do a CBC/RBC through an ER visit (which she has done on occasion) costs thousands of dollars.  We have had to go that route on two occasions.

Her Hematologist used the same information (Plasma Replacement Process) at a second hospital that set up a special outpatient account so Marilyn could walk in as an out-patient for a blood test.  Why this is so difficult is way beyond me.

Whether you can convince your Doctor, or your Lab, or some Hospital to follow the process. Will really depend on how open minded they are. We dealt with numerous failed tests for 3 years.  Some ER bills approaching $5000 to basically run a RBC/CBC.

Someone is finally just now listening and taking the time to get involved. Things shouldn’t be this way. But it sometimes takes that special person, or special doctor to perhaps open that door for you.

It would be nice if some professional(s) in the medical community would pick up the torch on all of this. Have the protocols altered nationally (Globally) for CAD patients.  To produce accurate and consistent test results, regardless of their cold reactive-ness.

Many do not understand CADs.  Many CADs often live on the edge of being anemic.  Often even below the average acceptable range of a healthy person.    Common colds can often tip that fragile balance.

That is the trouble with us Lay people that do not have the technical or medical knowledge, or influence, to change any of this. We just see the waste and delay, and have to deal with the frustration.

Forward Updates to: Rick Beach
Loved one of a CAD patient. With nearly 20 years (as of 2019) observing and living as an advocate for a CAD patient.

I have experienced the blind mentality patients and loved ones experience at the hands of some uncaring Doctors, Hospitals, and medical team personnel.

Yet have also seen the rare and compassionate professional that takes the time to go above and beyond, and get involved. The later are truly the few and far between these days.  They are truly appreciated.  Real hero’s to CADs.
The below document is verbatim from our written document from a Hospital Laboratory Manager. When Marilyn is in this hospital a copy of the below document must be presented at each blood draw.

The wording is not that of a lay person, but a medical professional, a lab supervisor, of major hospital.

We are reluctant to post the name of the person or Facility fearing they may no longer be willing to work with us should people start contacting them.

We do hope this may help others that experience the same Blood Testing failures Marilyn eventually did.


To Print only the below info rather than this entire article click PRINTABLE FORM ONLY

Date 11/19/16
Subject: Strong Cold Agglutinin for
(omitted patient name)

The CBC for (omitted patient name) will require special handling. Tube must be prewarmed using infant heel warmers and tube needs to be kept warm after collection and delivery straight to the lab.

Heme tech: Put CBC tube in 37 degree heat block. Have blood Bank put saline in 37 degree water bath for 1 hour. Perform plasma replacement technique on separate CBC tube with prewarmed saline. Return to CBC tube to 37 degree heat block for 1 hour. Run well mixed tube on hematology analyzer in manual mode, do not allow results to autoverify.

Report results with documentation of steps taken. Report whether hemolysis is observed in the supernatant while processing.

A Copy of these Written Instructions must accompany tube to lab department.

Thank You

(Omitted Lab Manager Name & Facility)


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