Objectives To evaluate the cytokine profile in patients with localized and generalized forms of granulomatosis with polyangiitis (GPA).
Methods We enrolled in our study patients with GPA that complied with the ACR criteria and the CHCC-2012 definitions. Group with localized form of GPA consisted of 25 patients with upper and/or lower respiratory tract disease. 33 patients had generalized form of GPA - renal vasculitis with serum creatinine <500 μmol/L or/and imminent vital organ failure.
Cytokines genes expression was studied in blood by reverse transcription polymerase chain reaction. We evaluated mRNA for the following cytokines: interferon (IFN)-α, IFN-γ, interleukin (IL)-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-18, tumor necrosis factor (TNF)-α production. Control group consisted of 40 healthy volunteers.
Results There were 58 patients with GPA aged from 18 to 77 years (19 male and 39 female). Majority of them were positive for ANCA (87%), mostly to proteinase-3, and had biopsy-proven diagnosis (64%).
Patients with generalized and localized forms of GPA had higher proportion of blood samples expressing IFN-α mRNA and lower proportion of samples expressing IL-12 and TNF-α mRNA as compared with controls (table).
As compared with controls, expression of IL-2 and IL-8 mRNA occurred more frequently only in patients with generalized GPA, whereas expression of IFN-γ mRNA occurred less frequently only in patients with localized GPA. The differences between patients with generalized and localized GPA were insignificant.
Conclusions GPA is associated with different changes in cytokines genes expression. Patients with generalized GPA more frequently showed expression of mRNA of IL-2 (stimulates B-cell increase and immunoglobulin production) and Il-8 (regulates immune cells migration). These data warrant further studies of aforementioned cytokines as possible markers of GPA generalization.
Disclosure of Interest None declared