Survival and relapses assessment in patients with Wegener’s granulomatosis and predominant renal involvement

Introduction. Wegener’s granulomatosis (WG) is a potentially fatal condition with remissions and high relapses rates. Objectives. Assessment of survival and relapses in a population based cohort of patients with WG with predominant renal involvement. Patients and methods. A prospective cohort study including 60 patients – median age of 42 years with different dynamics and clinical presentation. Patients were divided into 3 groups (group 1, group 2 and group 3 respectively, and subgroups: 3.1,3.2,.3.3): group 1 – WG patients without renal involvement, group 2 – WG patients with abnormalities in urinary sediment, group 3.1 – WG patients with chronic renal failure, group 3.2 – WG patients with diffuse alveloar hemorrhage (DAH) and rapid progressive glomerulonephritis (RPGN), and group 3.3 – WG patients with RPGN. The clinical analysis has been conducted using the disease extent index (DEI) only and Birmingham Vasculitis Activity Score-Wegener’s granulomatosis (BVAS- -WG) disease activity questionnaire. Logistic regression analysis and the Wilcoxon test were used. Survival time and death risk were assessed using the Kaplan-Meier estimator and Cox proportional hazard model. Results. Eighty-eight percent of patients survived the first year follow-up since the diagnosis, while 84% of patients remained alive after the second year of observation. Life expectancy was 67.1 ±4.4 months. During the first year of observation 9.8% of patients died, after 2 years death hazard amounted to 3.7% per year, and after 4 years 2.6% per year (p <0.05). Death risk was 1.3-fold higher in group 2 and 3.3-fold higher in group 3 compared to group 1 (p >0.05). Mortality in patients from group 3.1 was 6-fold lower than in patients from group 3.2 (p <0.03) and in group 3.3 was more than 4-fold lower than in patients from group 3.2 (p <0.04). Relapse risk after first the year of follow-up was 20% per year and minimally changed after 3 years of observation, then decreased to 6% after 5 years. Relapse hazard ratio in group 2 was significantly lower in comparison with group 1 (HR1/3.6, p <0.04). Conclusions. We found significant differences in survival and relapses in various subpopulations of WG patients.