10/03/2025
New research from University of Toledo, funded by Dysautonomia International, found that a majority of pre-COVID POTS patients and Long COVID POTS patients have platelet dense (delta) storage pool deficiency (deltaSPD)
DeltaSPD is associated with increased tendencies for bruising and bleeding, and is characterized by a deficiency in the dense granules (delta granules) within platelets. These granules contain essential clotting factors, such as adenosine diphosphate, serotonin, and calcium. Platelets are an important mediator of both the innate and adaptive immune systems, and when there is a vascular injury, the delta granules are released from the "activated" platelet to help with coagulation and healing of the vascular injury.
Paradoxically, while deltaSPD is considered a bleeding disorder, it can also be associated with an increased risk of blood clots in some patients. Importantly, there has been prior research in POTS and in Long COVID documenting an increased risk of blood clots, and an increased in pro-thrombotic and inflammatory proteins in the blood that contribute to blood clot risk.
DeltaSPD can present as a rare genetic disorder, or as an acquired form that is associated with chronic inflammation and autoimmune diseases. Since deltaSPD is so common in POTS and there is abundant other research documenting inflammation and autoimmunity in POTS patients, researchers believe the deltaSPD seen in POTS is the more common acquired form associated with inflammation and autoimmunity.
The University of Toledo researchers note that one of the treatments for deltaSPD, desmopressin, is also used to treat POTS. Desmopressin is a synthetic form of the natural hormone vasopressin (also known as antidiuretic hormone or ADH). It acts on the kidneys to help regulate the amount of water and salt in the body to expand blood volume, and is also used to treat deltaSPD and other bleeding disorders because it increases certain coagulation factors. Other POTS clinics have noted, anecdotally, that vasopressin is often low in POTS patients, and they have had success in reducing POTS symptoms by treating those patients with desmopressin.
A link to the journal article is in the comments.
We need additional research to explore whether desmopressin can safely be used to treat deltaSPD and low blood volume in POTS patients, and a lot of other research on coagulation factors and inflammation in POTS.
This research was funded by Dysautonomia International, thanks to contributions from our community. You can support more POTS, other dysautonomia, and Long COVID research by making a contribution at CureDys.org
