Implications of CD45RA and CD45RO T cell subsets in patients of chronic rhinosinusitis with nasal polyposis infected with Aspergillus flavus.

T cell subsets (CD4 and CD8) play a prominent role in the development of chronic rhinosinusitis with nasal polyposis (CRSwNP). Colonization with Aspergillus flavus is recognized as a trigger for the growth of nasal polyps. The fungal proteins initiate the recruitment of T cells into the nasal mucosa, which contributes to the progression of nasal polyps. The study included 50 cases of CRSwNP and 50 healthy controls. Biopsies were subjected to KOH and culture for mycological investigation. We examined the changes in T helper (CD4+) and T cytotoxic (CD8+) in total T cells (CD3+) and expression of naive (CD45RA) and memory (CD45RO) cell markers in T cell subsets in peripheral blood mononuclear cells (PBMCs) challenged by A. flavus antigens in cases before and after treatment and in healthy controls by flow cytometry. Predominantly, A. flavus (86%) identified in nasal polyp biopsies of patients. An increased percentage of CD3+CD4+ T cells observed after A. flavus stimulation in patients when compared with healthy controls. The expression of CD4+CD45RA+ cells was significantly (P < .05) reduced in patients and increased CD4+CD45RO+ was observed upon stimulation with A. flavus in patients when compared with healthy control. Continuous exposure to inhaled fungal spores may induce aberrant immune responses to A. flavus spores, causing an allergic immunological reaction with high CD4+T cell responses, resulting in an unfavourable outcome. Elevated CD4+CD45RO+ T cells may transform the pathogenic response and highlight the chances of A. flavus reactive T cells involvement in prompting inflammation in CRSwNP.