Anti-neutrophil cytoplasmic autoantibodies (ANCA) and vasculitis

Granulomatosis with polyangiitis and cardio vascular co-morbidity in Denmark. A registry-based study of 21 years of follow-up

OBJECTIVES

To describe the epidemiology of granulomatosis with polyangiitis (GPA) in Denmark. To investigate if cardiovascular (CV) related comorbidity and death were increased among Danish AAV patients registered with a diagnosis of granulomatosis with polyangiitis (GPA) in Denmark. To investigate if there was a temporal relation between diagnosis of GPA and CV disease and death.

METHODS

A population-based cohort study was performed using the Danish Civil Registration System, the Danish National Patient Registry and the Danish Cause of Death Register in the period January 1, 1995, to December 31, 2015. Patients registered twice or more with a diagnosis of GPA were included. Annual incidence rate (IR), point prevalence (PP) and standardized mortality rate (SMR) were calculated. The entire adult population in Denmark served as control population. CV morbidity and death caused by CV disease was registered.

RESULTS

We identified 1829 individuals with GPA. The median annual IR was 20.5/1,000,000 and PP increased from 64 to 277/1,000,000 in 2015. Overall SMR was 2.14. Among patients with GPA 171 had a hospital diagnosis of acute myocardial infarction (AMI). Compared to the control population, the hazard ratio (HR) of AMI was 2.47 (95% CI 1.24-4.94) during the first 3 months after the GPA diagnosis. From 3 months to one year declining to 1.41 (95%CI 0.80-2.49) and after 10 years the HR was still slightly increased to 1.64 (95%CI 1.20-2.23). The risk of a diagnosis of heart failure (HF) was markedly increased with a HR at 7.22 (95% CI 4.55-11.46) during the first 3 months after a GPA diagnosis, after three months up to one year 2.94 (95%CI 1.87-4.69), and 2.07 (95% CI 1.54-2.78) after 10 years. The total number of CV deaths in the GPA cohort was 307. During the first three months after a GPA diagnosis, the HR was increased to 9.51 (95%CI 7.12-12.70) declining to 2.51 (95% CI 1.77-3.58) after one year, but still increased to 1.56 (95% CI 1.23-1.98) after 10 years. Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation.

CONCLUSION

In a population-based study on GPA, we found stable incidence, increasing prevalence and an overall increased SMR. The risk of CV comorbidity and of CV death among patients with a register diagnosis of GPA was increased.

IFN-γ licenses CD11b(+) cells to induce progression of systemic lupus erythematosus

Autoantibodies are a hallmark of autoimmune diseases, such as rheumatoid arthritis, autoimmune hepatitis, and systemic lupus erythematosus (SLE). High titers of anti-nuclear antibodies are used as surrogate marker for SLE, however their contribution to pathogenesis remains unclear. Using murine model of SLE and human samples, we studied the effect of immune stimulation on relapsing of SLE. Although autoantibodies bound to target cells in vivo, only additional activation of CD8(+) T cells converted this silent autoimmunity into overt disease. In mice as well as in humans CD8(+) T cells derived IFN-γ enhanced expression of Fc-receptors on CD11b(+) cells. High expression of Fc-receptors allowed CD11b(+) cells to bind to antibody covered target cells and to destroy them in vivo. We found that autoantibodies induce clinically relevant disease when adaptive immunity, specific for disease non-related antigen, is activated.