Pathogenesis Of Polyarteritis Nodosa Research Articles

Imbalanced expression of dysfunctional regulatory T cells and T-helper cells relates to immunopathogenesis in polyarteritis nodosa

Objectives: We investigated the characteristics of circulating T-helper (Th) cells and CD4+ regulatory T cells (Tregs) in polyarteritis nodosa (PAN).Methods: Peripheral blood samples were obtained from 14 patients with PAN. Nine patients having granulomatosis with polyangiitis (GPA) and 11 healthy individuals (HC) were enrolled as controls. Th cells and Tregs were analyzed by flow cytometry. Suppression assay of Tregs was simultaneously performed by evaluating the proliferation of conventional CD4+ T cells cocultured with Tregs.Results: The frequencies of Th cells were significantly higher in PAN than in HC. In comparison with GPA, the expression of Th1 cells was higher but that of Th17 cells was lower. Additionally, significant increase in Tregs was observed in PAN, which was correlated with the expression of Th1 cells; however, defects in suppressive ability and CTLA-4 expression were observed. The Th1-cell frequency was significantly decreased after immunosuppressive therapy in PAN; however, there were no improvements in other phenotypes or in Treg function.Conclusion: T-helper cell expansion and Treg dysfunction are thought to be associated with the pathogenesis of PAN. Th1 cells show a response to immunosuppressive therapy; however, the persistent immune abnormalities may interfere with complete recovery in patients with PAN.

Increased serum levels of interleukin-8 in polyarteritis nodosa and Behçet's disease.

The pathogenesis of Behçet's disease (BD) and polyarteritis nodosa (PAN) is not yet well established. Endothelial cells have been shown to express chemokines that are involved in inflammatory processes. Interleukin-8 (IL-8) is a potent chemoattractant and activator of neutrophils. We evaluated serum IL-8 levels in patients with PAN and BD. We measured serum IL-8 levels in 21 patients with BD and 16 with PAN. Sera from 30 age-matched healthy blood donors were used as normal controls. Serum IL-8 levels were measured by an enzyme-linked immunosorbent assay (ELISA). The mean serum IL-8 level of the active BD (1522.31 pg/ml) and that of the active PAN (654.8 pg/ml) was significantly higher than that of the normal controls (40.39 pg/ml, P <0.05). There was no difference in mean serum IL-8 levels between patients with inactive disease and normal controls. We found higher serum levels of IL-8 in those patients with more severe disease. These results suggest that IL-8 may play a role in the pathogenesis of PAN and/or BD. Our study also suggests a possible relation between serum IL-8 levels and the severity of these diseases.

Pathogenesis of polyarteritis nodosa in hypertensive rats.

The pathogenesis of the vascular lesions of polyarteritis nodosa found in young rats with experimental renal hypertension is described. The panarteritic lesion was a product of the combination of renal injury and feeding sodium chloride. It began with a fibrinoid necrosis of the intima and media which was followed by an extensive inflammatory reaction with subsequent fibrosis of all layers of the vessel wall.