A rare case of a patient having both systemic mastocytosis (SM) and postural orthostatic tachycardia syndrome (POTS) was recently reported in the journal Heart.
Excessive mast cellMast cell A type of white blood cell produced in the bone marrow. They help defend against infections and play a key role in allergic reactions. In SM, mast cells become overactive and build up throughout the body. activity in patients with SM can produce a variety of symptoms involving several organ systems. The cardiovascular system is often affected, with a significant percentage of patients exhibiting symptoms such as low blood pressure, accelerated heart rate (tachycardia) and fainting.
Read more about SM signs and symptoms
POTS is a clinical syndrome in which patients experience symptoms such as lightheadedness, palpitations, tremulousness and generalized weakness after standing up. The syndrome is most commonly associated with nerve conduction abnormalities (polyneuropathy), low blood volume (hypovolemia) and some autoimmune conditions; however, there is limited research on its association with SM.
The authors reported a case of a 35-year-old woman with the condition, which in this case appeared to be secondary to SM.
The patient, who was 37 weeks pregnant, was referred to cardiology after her obstetrician detected an irregular pulse during a prenatal examination. Further evaluation revealed recurrent episodes of palpitations and fainting after standing.
On one occasion during examination, she exhibited extremely low blood pressure and electrocardiographic abnormalities; further tests were normal. She was initially diagnosed with orthostatic intolerance — intolerance to positional changes from sitting to standing — and was given lifestyle recommendations, including adequate salt and fluid intake.
However, she continued to experience palpitations and fainting, leading to the diagnosis of POTS and the initiation of pharmacological therapy, which did not produce significant improvement. Some time later, she presented with facial swelling, prompting suspicion of a mast cell disorder. SM was subsequently confirmed by tryptaseTryptase A protein enzyme that is primarily produced by mast cells and stored in small pockets within the cells, known as granules. High levels of tryptase are a key indicator of SM. levels and bone marrow biopsyBone marrow biopsy A procedure to collect a sample of bone marrow using a needle. Often used to examine the characteristics of mast cells and diagnose SM..
Nine years later, the patient continues to have palpitations and fainting despite pharmacological therapy.
“To our knowledge, this is the first reported case of mastocytosisMastocytosis Rare disease caused by the buildup of mast cells. Cutaneous mastocytosis primarily affects the skin and is more common in children, while systemic mastocytosis affects internal organs and is more common in adults. and POTS,” the study’s authors noted. “Mast cell disorders should be considered in recurrent syncope, and referral to Haematology can confirm the diagnosis, aiding prognosis and management of refractory syncope.”
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