The following is a summary of “Disease correlates and clinical relevance of hereditary α-tryptasemia in patients with systemic mastocytosis,” published in the FEBRUARY 2023 issue of Allergy & Immunology by Sordi, et al.
Systemic mastocytosis (SM) is a diverse collection of clonal illnesses characterized by aberrant growth of mast cells (MCs). Several genetic variations have been identified as predisposing to the onset of the disease and impacting its clinical presentation, in addition to KIT and other genes frequently altered in myeloid neoplasms. Hereditary α-tryptasemia (HαT) was a cause of nonclonal high tryptasemia and is characterized by variations of the TPSAB1 gene with increased copy numbers. HαT is also elevated in SM patients, which may impact the prevalence of symptoms linked to mediators. For a study, researchers sought to examine the clinical correlations of germline TPSAB1 copy number increases in a multicenter data collection of 444 patients with MC diseases.
To check for the existence of HαT, digital droplet PCR was used in each case. In addition, analysis was done on the clinical history, blood results, and bone marrow test.
We found that patients with mastocytosis had a greater incidence of HαT+ cases than the overall population (n = 59, 13.3% vs. 5%). Higher levels of tryptase and a decreased burden of MC-associated illness were characteristics of HαT+ patients. In addition, several disease-related factors, such as bone marrow MC infiltration and MC-related histopathologic features, were consistent with the pattern. These factors also explained why HαT+ (10.2%) patients were more likely to experience clonal MC activation syndrome than HαT– patients (3.4%; P =.029). Additionally, they found that HαT+ carriers had a considerably greater anaphylactic frequency, with no discernible changes in other clinical symptoms.
The results from a sizable patient series confirmed and supplemented earlier findings, and they implied that understanding the HαT status may help treat SM patients individually.
Reference: jacionline.org/article/S0091-6749(22)01424-5/fulltext