Undiagnosed systemic mastocytosis (SM) led to bleeding complications in a patient with a severe anaphylactic reaction, according to a recently published case report in Clinical Medicine.
“Anaphylaxis, a potentially life-threatening immune response, is characterized by the rapid release of a multitude of mediators from activated mast cells and basophils,” the authors said.
What is SM?
Systemic mastocytosis (SM) is a rare hematological disease characterized by mast cells that are overactive and accumulate in different parts of the body such as the bone marrow, liver, spleen, gastrointestinal tract and lymph nodes.
The case involved a 40-year-old man with a known history of peanut allergy who sought medical attention because of accidental contact with peanuts.
Read more about SM signs and symptoms
The patient was agitated and combative as he arrived at the emergency room and entered cardiac arrest shortly after his admission. After cardiopulmonary resuscitation (CPR), epinephrine administration and intubation with mechanical ventilation, he was deemed stable enough to undergo laboratory tests.
The results showed elevated tryptase levels and profound alteration in his coagulation profile associated with a significant hemorrhage risk. Because coagulopathy is not a common complication of anaphylactic reactions, the physicians used thromboelastography to determine the cause.
The results suggested that the patient had a heparin-like anticoagulant in his bloodstream despite not receiving any such medication before or after admission. He received heparinase, and his coagulation profile normalized spontaneously the next day.
During the following days, his hemoglobin levels decreased, and further testing revealed findings suggestive of a stroke, as well as bleeding and two tumors in one kidney. In light of his tryptase levels, he underwent a bone marrow aspirate, which confirmed the SM diagnosis.
The patient recovered well and was discharged shortly after admission with pending consultations with neurology, nephrology, urology and hematology.
The findings of coagulation studies and his adequate response to heparinase suggested that the patient’s mast cells released a heparin-like mediator during the anaphylactic reaction.
Mast cells can release tissue plasminogen activator, and tryptase can activate the single-chain urinary-type plasminogen activator; both molecules have anticoagulant properties, and their excess can lead to bleeding.
