A recent review takes a closer look at the complex and still-evolving relationship between hereditary alpha-tryptasemia (HαT) and 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., two conditions linked by 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. biology and the biomarker 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.. The paper, published in Current Allergy and Asthma Reports, summarizes current knowledge about how the genetic trait HαT may influence the diagnosis and clinical presentation of mast cell disorders.
Hereditary alpha-tryptasemia is a genetic trait caused by extra copies of the TPSAB1 gene. This gene produces alpha-tryptase, a protein released by mast cells. An elevated serum tryptase level is a key diagnostic marker for mast cell disorders, including systemic mastocytosis (SM).
People with HαT typically have higher-than-average levels of tryptase in their blood. While many with the genetic trait do not develop serious health problems, the elevated tryptase levels can influence how doctors evaluate possible SM.
Researchers have found that HαT appears more frequently in people with mastocytosis than in the general population. While about 5% to 7% of people overall carry the genetic trait, studies suggest that roughly 15% to 20% of those with mastocytosis may have HαT. Scientists are still working to understand why these two conditions often occur together.
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One possible explanation is related to testing. Because HαT naturally causes higher baseline tryptase levels, it can prompt additional diagnostic procedures, such as bone marrow biopsies, and increase the likelihood of detecting mastocytosis.
At the same time, genetically elevated levels may mimic mast cell diseaseMast cell disease A group of conditions in which mast cells behave abnormally by building up in excess, releasing chemicals too easily or both. Includes mastocytosis, mast cell activation syndrome and hereditary alpha-tryptasemia. or obscure signs of mast cell activationMast cell activation Describes when mast cells release histamine and other mediators into the blood stream in response to an allergen or other trigger. This leads to symptoms like fatigue, rash and, in severe cases, anaphylaxis.. This can lead to uncertainty in clinical assessment or unnecessary invasive testing.
Some studies have also suggested that HαT may influence symptoms in mast cell disorders, particularly increasing the risk of severe reactions such as anaphylaxisAnaphylaxis A severe allergic reaction that can turn fatal without treatment. Patients with SM are at a higher risk of developing anaphylaxis. in certain patients. However, findings have been inconsistent, and researchers caution that the relationship is not fully understood.
“Future population-based studies employing ultra-sensitive molecular techniques and stratified analyses are needed to elucidate the biological and clinical significance of HαT in mast cell disorders,” the researchers concluded.
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