Patients with ANCA-associated vasculitis treated with conventional regimens are at increased risk of death compared with an age- and sex-matched population.

Cancer rates for AAV patients treated with conventional immunosuppressive therapy exceeded those expected for the general population. This cancer excess was largely driven by an increased incidence of NMSC. The smaller cancer risk magnitude in this cohort, compared with previous studies, might reflect less extensive use of cyclophosphamide in current treatment protocols. Longer follow-up data are warranted to appraise the risk of developing cancers later during the course of AAV.

During vasculitis, activation of the kinin system induces inflammation, whereby the kinin B1-receptor is expressed and activated after ligand binding. Additionally, activated blood cells release microvesicles into the circulation. Here we determined whether leukocyte-derived microvesicles bear B1-kinin receptors during vasculitis, and if microvesicles transfer functional B1-receptors to recipient cells, thus promoting inflammation. By flow cytometry, plasma from patients with vasculitis were found to contain high levels of leukocyte-derived microvesicles bearing B1-receptors. Importantly, renal biopsies from two patients with vasculitis showed leukocyte-derived microvesicles bearing B1-receptors docking on glomerular endothelial cells providing in vivo relevance. Microvesicles derived from B1-receptor-transfected human embryonic kidney cells transferred B1-receptors to wild-type human embryonic kidney cells, lacking the receptor, and to glomerular endothelial cells. The transferred B1-receptors induced calcium influx after B1-receptor agonist stimulation: a response abrogated by a specific B1-receptor antagonist. Microvesicles derived from neutrophils also transferred B1-receptors to wild-type human embryonic kidney cells and induced calcium influx after stimulation. Thus, we found a novel mechanism by which microvesicles transfer functional receptors and promote kinin-associated inflammation.

No abstract

The kinin system is activated during vasculitis and may contribute to chronic inflammation. C1-inhibitor is the main inhibitor of the kinin system. In this study, we investigated the presence of the kinin B1 receptor on endothelial microvesicles and its contribution to the inflammatory process. Compared with controls (=15), patients with acute vasculitis (=12) had markedly higher levels of circulating endothelial microvesicles, identified by flow cytometry analysis, and significantly more microvesicles that were positive for the kinin B1 receptor (<0.001). Compared with microvesicles from wild-type cells, B1 receptor-positive microvesicles derived from transfected human embryonic kidney cells induced a significant neutrophil chemotactic effect, and a B1 receptor antagonist blocked this effect. Likewise, patient plasma induced neutrophil chemotaxis, an effect decreased by reduction of microvesicle levels and by blocking the B1 receptor. We used a perfusion system to study the effect of patient plasma (=6) and control plasma (=6) on the release of microvesicles from glomerular endothelial cells. Patient samples induced the release of significantly more B1 receptor-positive endothelial microvesicles than control samples, an effect abrogated by reduction of the microvesicles in the perfused samples. Perfusion of C1-inhibitor-depleted plasma over glomerular endothelial cells promoted excessive release of B1 receptor-positive endothelial microvesicles compared with normal plasma, an effect significantly decreased by addition of C1-inhibitor or B1 receptor-antagonist. Thus, B1 receptor-positive endothelial microvesicles may contribute to chronic inflammation by inducing neutrophil chemotaxis, and the reduction of these microvesicles by C1-inhibitor should be explored as a potential treatment for neutrophil-induced inflammation.

ObjectivesPatients with antineutrophil cytoplasmatic antibodies-associated vasculitides (AAV) exhibit higher mortality than the general population. In the current study, we assessed whether cluster affiliation based on clinical presentation might predict mortality.MethodsWith case record review, the outcomes for a population-based cohort of patients diagnosed with AAV in southern Sweden (catchment area of 0.7 million inhabitants) between 1997 and 2010 were assessed. Based on organ involvement at presentation, the cohort was stratified into the following clusters: gastrointestinal, cardiovascular, non-renal, renal with proteinase 3 (PR3) and renal without PR3. Cluster affiliation, demographics, clinical and laboratory values at entry were tested as prognostic factors for survival in multivariable models.Results195 patients (98 female) with a median age of 69 years (IQR 55–77) at diagnosis were included in the cohort. The median time of follow-up was 4 years for the 98 patients (50%) who died during follow-up and 11 years for those alive at end of follow-up. The 1-year, 2-year, 5-year and 10-year survival was 87%, 82%, 70% and 55%, respectively. Prognostic factors for survival were sex, age, renal function and cluster affiliation. The mortality of patients with AAV was significantly increased compared with the general population except in the non-renal cluster. The cardiovascular and gastrointestinal clusters showed the highest mortality.ConclusionEven though the mortality in patients with AAV is increased compared with the general population this does not apply to patients without gastrointestinal, cardiovascular or renal involvement at diagnosis. We suggest that the initial clinical presentation is an important predictor for survival.

Objective Patients with ANCA-associated vasculitides (AAV) exhibit higher rates of malignancy than the general population. We assessed whether the cancer risk is increased in a well-characterized population-based cohort of AAV in southern Sweden, followed for a median time of 8 years. Methods With case record review, the outcomes and malignancy development in a cohort of 195 patients with AAV [granulomatosis with polyangiitis (GPA), microscopic polyangiitis, and eosinophilic GPA] diagnosed between 1997 and 2010 were assessed. The patients were followed until death or December 31, 2015. The age- and sex-standardized incidence ratios (SIR) were estimated using the Swedish population data as a reference. Results During the observation period of about 1500 person-years, we found 60 cancers in 52 of the 195 patients. SIR (95% CI) was 2.8 (2.1–3.6) for cancers at all sites, 1.8 (1.3–2.5) for all cancers excluding squamous cell carcinoma (SCC), 12.9 (8.4–18.8) for SCC, 4.3 (1.4–10.0) for bladder cancer, and 7.0 (1.4–20.5) for pancreatic cancer. Cumulative doses of cyclophosphamide (CYC) < 10 g were not associated with higher incidence of cancers other than SCC (SIR 1.63, 95% CI 0.8–2.9). Conclusion In contrast to previous publications assessing malignancy risk in patients with AAV, we show in this population-based cohort of patients a persistent increased risk for overall malignancy, bladder cancer, and pancreatic cancer as well as a markedly increased risk for SCC. There was no increase in incidence of cancers other than SCC for those treated with < 10 g CYC.

Background Preterm birth and fetal growth restriction (FGR) are associated with structural and functional kidney changes, increasing long-term risk for chronic kidney disease and hypertension. However, recent studies in preterm children are conflicting, indicating structural changes but normal kidney function. This study therefore assessed kidney structure and function in a cohort of adolescents born very preterm with and without verified FGR. Methods Adolescents born very preterm with FGR and two groups with appropriate birthweight (AGA) were included; one matched for gestational week at birth and one born at term. Cortical and medullary kidney volumes and T1 and T2* mapping values were assessed by magnetic resonance imaging. Biochemical markers of kidney function and renin–angiotensin–aldosterone system (RAAS) activation were analyzed. Results Sixty-four adolescents were included (13–16 years; 48% girls). Very preterm birth with FGR showed smaller total (66 vs. 75 ml/m2; p = 0.01) and medullary volume (19 vs. 24 ml/m2; p < 0.0001) compared to term AGA. Corticomedullary volume ratio decreased from preterm FGR (2.4) to preterm AGA (2.2) to term AGA (1.9; p = 0.004). There were no differences in T1 or T2* values (all p ≥ 0.34) or in biochemical markers (all p ≥ 0.12) between groups. Conclusions FGR with abnormal fetal blood flow followed by very preterm birth is associated with smaller total kidney and medullary kidney volumes, but not with markers of kidney dysfunction or RAAS activation in adolescence. Decreased total kidney and medullary volumes may still precede a long-term decrease in kidney function, and potentially be used as a prognostic marker. Graphical abstract