Oral estrogen leads to falsely low concentrations of estradiol in a common immunoassayhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC8859944/Cirrincione LR, Crews BO, Dickerson JA, Krasowski MD, Rongitsch J, Imborek KL, Goldstein Z, Greene DN.
Oral estrogen leads to falsely low concentrations of estradiol in a common immunoassay. Endocr Connect. 2022 Feb 9;11(2):e210550. doi: 10.1530/EC-21-0550. PMID: 35015702; PMCID: PMC8859944.
Published online 2022 Jan 11.
"Recently, an estradiol immunoassay manufacturer (Beckman Coulter, USA) issued an 'important product notice' alerting clinical laboratories that their assay (Access Sensitive Estradiol) was not indicated for patients undergoing exogenous estradiol treatment."
"The New BC assay had the largest magnitude overall bias (median: −34%) and was −40%, −22%, and −10%, among participants receiving tablet, patch, or injection preparations, respectively."
"We observed the greatest magnitude of bias within the tablet subgroup (n = 51, median: −40%) relative to the patch or injection subgroups (n = 9, −22% and n = 29, −10%, respectively)."
"Conclusions
"Immunoassay measurement of estradiol in transgender women may lead to falsely decreased concentrations that have the potential to affect management. A multidisciplinary health care approach is needed to ensure if appropriate analytical methods are available."------
I recently had two lab results for my estradiol come back very low. Previously, the VA sent my samples to Quest Labs back East. The turn-around was about ten days. Lately, my labs have been processed in-house in our local lab and they have returned unbelievable results.
In August 2023, my estradiol was reported to be 38. My doctor ordered a retest and the sample was sent to a different lab. That result returned at 118. Earlier this month (Feb 5th) my lab results returned my estradiol at 22. My baseline level from 2019 pre-transition was 28. I asked my doctor how I can be taking any medication as prescribed and my estradiol level drops lower than it has ever been in recorded history. So I did what I do and went looking for answers.
As a patient, we do not have access to our lab technicians or equipment. Even your prescriber may not have access to the lab scientists that actually perform the tests. We don't know what type of equipment is being used, or what protocols are being followed. Even if the lab is aware of the issue and their software is updated, the patient and the prescriber are not notified. The danger is when a level is reported too low, and the prescriber unnecessarily raises the patient's dosage.
As the cited article points out, if a patient is taking exogenous estrogen (i.e. from outside the body and not from ovaries), this particular test should not be used. The Beckman Coulter was reporting results up to 40% too low for oral estrogen, 22% too low for the patch, and 10% too low for injection. Prescribers must have accurate lab results so that they can accurately adjust our dosage to optimum levels.
Because the VA is using an in-house lab, my doctor can walk over and talk to the lab technicians and ask them if they are using this equipment. [She is doing that today.] Then on future lab orders, she can specify to not use this test, or request they send the sample to a different lab.
Be your own best advocate. Ask questions. Sometimes the question you ask may get your doctor to think along other avenues to find a solution.
