Infection is associated with increased risk of MPO- but not PR3-ANCA-associated vasculitis

Autoantibody Profiling and Anti-Kinesin Reactivity in ANCA-Associated Vasculitis

ANCA-associated vasculitides (AAV) are rare autoimmune diseases causing inflammation and damage to small blood vessels. New autoantibody biomarkers are needed to improve the diagnosis and treatment of AAV patients. In this study, we aimed to profile the autoantibody repertoire of AAV patients using in-house developed antigen arrays to identify previously unreported antibodies linked to the disease per se, clinical subgroups, or clinical activity. A total of 1743 protein fragments representing 1561 unique proteins were screened in 229 serum samples collected from 137 AAV patients at presentation, remission, and relapse. Additionally, serum samples from healthy individuals and patients with other type of vasculitis and autoimmune-inflammatory conditions were included to evaluate the specificity of the autoantibodies identified in AAV. Autoreactivity against members of the kinesin protein family were identified in AAV patients, healthy volunteers, and disease controls. Anti-KIF4A antibodies were significantly more prevalent in AAV. We also observed possible associations between anti-kinesin antibodies and clinically relevant features within AAV patients. Further verification studies will be needed to confirm these findings.

An unsuspected histopathological finding -concomitant IgA nephropathy in a patient with ANCA-associated vasculitis: a case report and literature review

Although associations of IgA nephropathy (IgAN) and ANCA-associated vasculitis (AAV) have been described, this coexistence scarcely occurs and requires multidisciplinary management. Herein, we discuss a course of treatment introduced in a patient with two exacerbations. Furthermore, alterations in histopathological images between two kidney biopsies are presented. The applicability of traditional inflammatory markers, e.g., CRP, in monitoring disease severity in AAV and IgAN is limited. Based on our patient and current literature, we suggest ANCA testing in patients with rapidly progressing IgAN for therapeutic and prognostic purposes. As regards the therapy of IgAN associated with AAV, aggressive immunosuppressive regimens with methylprednisolone and cyclophosphamide are recommended. Alternatively, methylprednisolone with rituximab, plasma exchange, mycophenolate mofetil, and intravenous immunoglobulin (IVIG) could also be considered.

Plasma exchange as an adjunctive therapy in anti-neutrophil cytoplasm antibody-associated vasculitis

INTRODUCTION

We summarize evidence for the role of therapeutic plasma exchange (TPE) in the treatment of anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV). TPE rapidly removes ANCA IgG, complement and coagulation factors important in the pathogenesis of AAV. TPE has been used in patients with rapidly deteriorating renal function to achieve early disease control, allowing time for immunosuppressive agents to prevent resynthesis of ANCA. The PEXIVAS trial challenged the utility of TPE in AAV, as it did not show benefit of adjunctive TPE on a combined end point of end stage kidney disease (ESKD) and death.

AREAS COVERED

We analyze data from PEXIVAS and other trials of TPE in AAV, an up-to-date meta-analysis, and recently published large cohort studies.

EXPERT OPINION

There remains a role for the use of TPE in AAV in certain groups of patients, in particular those with severe renal involvement (Cr >500 μmol/L or dialysis-dependent). It should be considered in patients with Cr >300 μmol/L and rapidly deteriorating function, or with life-threatening pulmonary hemorrhage. A separate indication is patients double positive for anti-GBM antibodies and ANCA. TPE may have the greatest benefit as part of steroid-sparing immunosuppressive treatment strategies.

Stable incidence but increase in prevalence of ANCA-associated vasculitis in southern Sweden: a 23-year study

OBJECTIVE

To update the epidemiology of anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) in a defined geographical area of southern Sweden.

METHODS

The study area comprised 14 municipalities with a combined adult population (≥18 years) of 623 872 in 2019. All cases diagnosed with AAV in 1997-2019 in the study area were included in the estimate of incidence. Diagnosis of AAV was verified by case record review, and cases were classified using the European Medicines Agency algorithm. Point prevalence was estimated on 01 January 2020.

RESULTS

Three hundred and seventy-four patients (median age 67.5 years, 47% female) were diagnosed with new-onset AAV during the study period. One hundred and ninety-two were classified as granulomatosis with polyangiitis (GPA), 159 as microscopic polyangiitis (MPA) and 23 as EGPA. The average annual incidence/million adults was 30.1 (95% CI 27.0 to 33.1) for AAV: 15.4 (95% CI 13.3 to 17.6) for GPA, 12.8 (95% CI 10.8 to 14.8) for MPA and 1.8 (95% CI 1.1 to 2.6) for eosinophilic GPA (EGPA). Incidence was stable during the study period, 30.3/million 1997-2003, 30.4/million 2004-2011 and 29.5/million 2012-2019. The incidence increased with age and was highest in age group 70-84 years (96/million adults). On 1 January 2020, the prevalence was 428/million adults and was higher in males than in females (480 vs 378/million).

CONCLUSIONS

The incidence of AAV in southern Sweden was found stable over the course of 23 years; while the prevalence has increased, which might indicate better management and treatment of AAV resulting in improved survival.

Classification and epidemiology of vasculitis: Emerging concepts

The recent publication of the American College of Rheumatology (ACR)-European Alliance of Associations for Rheumatology (EULAR) classification criteria for large vessel vasculitis and anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAVs) has provided modern criteria for the classification of these conditions, which incorporate contemporary methods of investigation and diagnosis. Further validation is required in independent cohorts, especially from populations that were not well represented in the development cohort. Studies of the occurrence of large vessel vasculitis report that Takayasu arteritis is a rare disease in most populations, and giant cell arteritis is the most common vasculitis in older populations. The incidence of AAV appears to have plateaued, but the prevalence is increasing as a result of lower mortality. The new classification criteria may affect the reported incidence and prevalence, and studies will be needed to confirm this. The impact of COVID-19 on the occurrence of the vasculitides is not completely known, but there is evidence of reduced occurrence of Kawasaki disease and IgA-associated vasculitis following lockdowns with reduced transmission of possible trigger infectious agents.

Utility of the neutrophil-to-lymphocyte ratio in the prediction of anti-neutrophil cytoplasmic antibody-associated vasculitis with infection

OBJECTIVE

This study aimed to evaluate the predictive value of the neutrophil-to-lymphocyte ratio (NLR) for infection in patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).

METHODS

Newly onset patients with AAV in China were included, and their laboratory tests and disease activity were analyzed. Based on infection, patients were divided into the infection group (A-I) and the non-infection group (A-NI). Univariable and multivariable logistic regression analyses were used to investigate variables that are independently associated with infection.

RESULTS

In total, 418 patients were enrolled. Significantly higher white blood cell count (WBC, p < 0.001), neutrophils (p < 0.001), NLR (p < 0.001), platelet-to-lymphocyte ratio (p < 0.001), monocyte-to-lymphocyte ratio (MLR, p < 0.001), erythrocyte sedimentation rate (ESR, p = 0.032), C-reactive protein (CRP, p < 0.001), procalcitonin (PCT, p < 0.001), and Birmingham vasculitis activity score (BVAS, p = 0.005) were observed in the A-I group than in the A-NI group. It was detected that NLR (ρ = 0.273, p < 0.001), MLR (ρ = 0.153, p = 0.011), ESR (ρ = 0.143, p = 0.020), and PCT (ρ = 0.391, p < 0.001) were positively correlated with BVAS. Furthermore, NLR was not only an independent predictor of infection (adjusted OR: 1.144, 95% CI: 1.059-1.236, p = 0.001), but with the largest area under ROC curve, of which value was 0.750. Notably, the optimal cut-off value of NLR for infection was 6.01, with sensitivity of 70.07% and specificity of 71.68%.

CONCLUSION

Our study demonstrated that in addition to WBC, CRP, ESR, and PCT, NLR should also be used as a beneficial inflammatory indicator to differentiate infection in newly diagnosed AAV. Key Points • NLR was a helpful inflammatory marker in differentiating infection in newly diagnosed AAV.