Avise Touch from Exagen - Test your levels of Plaquenil? I didn't even know you could do that!

A few weeks ago,  I received a press release about Exagen's new AVISE Touch - a new, non‐invasive blood collection method that requires a single drop of blood, similar to a prick test for diabetes, as opposed to volume blood collection. 

What caught my eye is that one of the first applications of AVISE Touch is AVISE HCQ, or "an advanced drug monitoring test that provides accurate measurement of Hydrochloroquine (HCQ) levels in whole blood to help physicians assess their patients' exposure to HCQ therapy."

I didn't even know you could or should test the levels of this drug in your blood!

I read (and re-read) the press release, but I found I had additional questions before I posted. (I like to be fully informed before sharing information.) So I put in a request for some answers, and I got a personal phone call from Exagen, answering every last one of my questions, and then some.

I'm thankful for the time and consideration the company allowed, and am happy to share my findings. Here's a list of my pertinent questions, and most importantly, the answers:

Is the testing of HCQ levels in a patient's blood a new thing? 

Yes and no. It has been available, and in fact, lupologist Dr. Michelle Petri has been a big advocate of testing HCQ levels. But there's been an increased awareness based on recent developments in understanding blood circulation, and how one patient might circulate the drug therapy differently then another.

Is this an oversight by our doctors for not running the test in the past? 

No. This test, which eliminates volume collection (because it simply requires a drop of blood), offers whole blood testing, which is more accurate than plasma or serum testing, which is how HCQ toxitity has typically been tested. Thus, this new test allows for more accurate readings, which may encourage doctors to administer the test because the results will be more conclusive. Past variability (due to the plasma/serum testing) may have contributed to the reluctance to do HCQ testing.

Why should the test be administered? 

It is estimated that as few as 50% of patients on HCQ actually achieve beneficial circulating levels of the drug. HCQ is a mainstay drug for many lupus patients, serving as a relatively safe, long-term part of their treatment regimen, and one that may control lupus flares over time, Thus, it is essential that a patient's HCQ levels be tested to ensure that they're actually getting the full benefit of the drug. (I asked if patients like me, who have experienced a concerning level (although typically reversible) of retinal changes due to HCQ, would be particularly good candidates for this kind of testing. The answer seemed to be yes, but the conclusion was that most patients would benefit.)

What would contribute to a patient not receiving full benefit from HCQ? 

Primarily adherence, but also the understanding that Patient A may process, say, a 400mg dose of plaquenil, differently than Patient B. It is now believed that the way HCQ is circulated throughout the bloodstream may vary patient to patient. (There appears to have been a previous assumption that 400mg had the same effect on both Patient A and B, though, in contradiction, there are still dosing guidelines that most doctors follow for prescribing the drug.)

All that said, it's important to give proper attention to the first reason - that of drug adherence. If a doctor instructs a patient to take 400mg of plaquenil daily, but that patient a) forgets a dose, b) chooses to skip a day here or there, or c) can't afford to maintain that treatment regimen, then the efficacy of the medication treatment will be eroded.  The medicine won't work in the way it's intended, and the level of disease activity may increase. If the communication between patient and doctor isn't open and honest, then the doctor is working on false information, and stronger drugs may be prescribed, when a simple blood test will indicate that HCQ isn't being utilized to its fullest potential to begin with.

Simply put - the blood levels from an AVISE HCQ test won't lie. If you're not following doctor's orders (whatever your reason, which should be discussed openly and honestly with your doctor to determine other alternatives), then the AVISE HCQ will reflect this.

AVISE Touch is available for both patient and doctor. What is the intended use? 

Down the road, the intention of AVISE Touch is to increase dialogue between patient and doctor, to decrease the unnecessary back and forth to the lab for volume testing, and  prevent excessive doctor's appointments for disease management. Additionally, it may empower the patient to take increased ownership of their drug regimen - practicing strict adherence so that the disease can be evaluated accurately, rather than on false assumptions.

You can read bits of the press release below, or click here to learn more:


Exagen Diagnostics, a specialized medical laboratory with offices in Vista, CA and Albuquerque, NM has released the first test using this method to identify levels of hydroxychloroquine (HCQ), brand name Plaquenil. An estimated 750,000 Americans are presently taking HCQ as part of their long‐term treatment regimen for chronic rheumatic diseases such as rheumatoid arthritis and lupus. This immunomodulatory drug is considered one of the safest and most cost‐effective drugs available.
Unfortunately, it is estimated that as few as 50% of patients on HCQ actually achieve beneficial
circulating levels of the drug. Physicians and their patients can now work together to achieve drug
levels that are associated with improved health and better outcomes, all without ever waiting to
have a traditional blood draw.

According to Ron Rocca, President and CEO of Exagen Diagnostics, “The AVISE Touch collection
method ushers in a new era of access to information for patients suffering from autoimmune
rheumatic diseases. Gone are the days of physicians and their patients not knowing if medications
are actually contributing to management of a given condition. We are delighted to be advancing
laboratory science and doing so in a way that adds convenience for the patient.”

Unlike other “Micro” or “Nano” sample methods this new approach called AVISE Touch™ has
been scientifically validated to demonstrate equivalence of fingerstick blood collection to traditional
venipuncture blood collection, making the test available throughout the contiguous US.


You can read more about AVISE Touch here, watch a how-to video here, and be sure to read this handy HCQ guide from Johns Hopkins. It may give you a new appreciation of those little white, oblong HCQ pills, too!

(Note - this information is patient provided, and should be used to spark conversation with your doctor, not take the place of the valuable information that your medical professional can provide.)


Nicole said…
Thank you so much for the great information! After trying to cut down to 300 mg/day from 400, and needing to go back up, but worried about retinal effects long-term, I will ask for this test.
Sara Gorman said…
You're welcom! Definitely a good conversation starter between patient and doctor. Thx for stopping by.

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