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.