Cell division cycle 42 reflects disease risk, symptoms, Th1/Th2 disproportion, and its short‐term variation indicates symptom amelioration after treatment in allergic rhinitis patients

BACKGROUND: Cell division cycle 42 (CDC42) modulates the pathogenesis of allergic rhinitis (AR) through regulating immunity, allergic response, and T‐helper (Th)1/Th2 imbalance. This study aimed to evaluate the potential of CDC42 to reflect disease risk, symptom scores, and Th1/Th2 axis of AR and the correlation of its vertical change with symptom amelioration after treatment. METHODS: CDC42, Th1 cells, and Th2 cells in the peripheral blood mononuclear cells (PBMCs) and interferon‐γ and interleukin‐4 in the serum were determined in 200 AR patients. Simultaneously, PBMC CDC42 was detected in 50 non‐atopic obstructive snoring patients [as disease controls (DCs)] and 50 healthy controls (HCs). RESULTS: CDC42 was increased in AR patients compared with DCs and HCs (both p < 0.001) but showed no difference between DCs and HCs (p = 0.054). In AR patients, CDC42 was positively linked to rhinorrhea, itching, sneezing, and total nasal symptom scores (TNSS) (all p < 0.05), but not congestion score (p = 0.052). Meanwhile, CDC42 showed positive correlations with Th2 cells (p < 0.001) and interleukin‐4 (p = 0.005), a negative correlation with Th1/Th2 axis (p = 0.001), but no correlation with Th1 cells (p = 0.095) or interferon‐γ (p = 0.174). Notably, CDC42 at week 4 after treatment (W4) was reduced compared with that at enrollment (W0) (p < 0.001) and positively correlated with TNSS at W4 (p < 0.001); from W0 to W4, CDC42 change also positively correlated with TNSS change (p = 0.004). CONCLUSION: CDC42 is elevated and positively correlates with symptom scores and Th2 cells, whose short‐term reduction reflects symptom alleviation in AR patients.