Patients with cold urticaria (ColdU) and cold-induced anaphylaxis (ColdA) have the KIT p.D816V mutation, a hallmark of systemic mastocytosis (SM), at higher rates than the general population, a study in Frontiers in Immunology recently reported.
“The KIT p.D816V variant, which is considered absent in the general population, was identified in 6.6% of ColdU patients and 6.3% of those with ColdA,” the study’s authors noted.
ColdU is a condition in which exposure to cold temperatures causes symptoms such as itching and welts. Meanwhile, ColdA is a condition in which patients develop a severe allergic reaction when exposed to the cold. This allergic reaction is mediated by mast cells, which is the type of cell that is found in abnormally high levels in SM.
The authors of the study primarily sought to better characterize the relationship between basal serum tryptase (BST) and total immunoglobulin E (IgE) levels in patients with ColdU and ColdA. In addition, they sought to analyze testing for the KIT p.D1816V variant in ColdU and ColdA.
The research team enrolled patients with symptoms of ColdU who were seen at a medical center in Slovenia between May 2019 and December 2022. Participants underwent extensive laboratory assessments and clinical tests.
The team found that the most common triggers for ColdU were whole-body water immersion (72.8%) and cold air (71.7%), followed by moving from cold outdoors to warm indoors (51.1%) and contact with cold surfaces (42.4%). In ColdA, the most common triggers were whole-body water immersion and cold air.
One patient in the study fulfilled the diagnostic criteria for SM. The researchers found that in general, patients with the KIT p.D816V mutation had experienced the onset of ColdU or ColdA at an older age than patients without the mutation. They also found that the presence of the KIT p.D816V mutation did not impact the severity of symptoms in patients with ColdU.
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Raised BST levels were found in 9.8% of patients with ColdU; this was attributed to either KIT p.D816V mutation and/or hereditary α-tryptasemia (HαT).
In addition, researchers found that HαT prevalence was significantly higher among patients with ColdU or ColdA. Patients with ColdA also had higher levels of total serum IgE.
“Our findings demonstrate a higher prevalence of HαT and KIT p.D816V in ColdU and ColdA compared to the general population,” the authors of the study wrote. “These results raise the hypothesis that HαT and clonal [mast cell] disease may contribute to the pathogenesis of ColdU and ColdA in some patients.”
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