For a study, researchers sought to determine if combining the passive mast cell activation (pMAT) with CHX-specific IgE (sIgE) allowed us to display effector cell degranulation in response to alexidine (ALX) octenidine (OCT) and polyhexamethylene biguanide (PHMB), which could have indicated CHX cross-reactivity. The research contained the serum of 10 CHX-allergic patients, 9 persons with an isolated sIgE CHX, and 5 healthy controls. Before and after sensitization, human cultured mast cells (MCs) were exposed to CHX, ALX, OCT, or PHMB. The up-regulation of CD63 was used to quantify degranulation. Furthermore, 4/10 and 3/10 of the sera of CHX-allergic individuals showed MC reactivity to ALX and OCT, respectively. Degranulation percentages ranged from 12-34% for ALX reactive MCs to 4-22% for OCT reactive MCs. When sera from people with an isolated sIgE CHX or healthy controls were tested, no reaction to ALX or OCT was determined. Unlike CHX, ALX, and OCT, PHMB was discovered to be a direct MC activator via MRGPRX2 occupancy. PHMB-reactive sIgEs were detected in some patients with an isolated sIgE CHX, but they could have not caused degranulation in MRGPRX2 knock-down MCs. MCs were a useful technique for investigating cross-reactivity between structurally related molecules. The pMAT could have increased the understanding of sIgE cross-reactivity patterns, including assessment of molecules not yet approved for human use and identifying safe options for the individual patient.
Source:onlinelibrary.wiley.com/doi/10.1111/cea.14129
