Infectious profile in inpatients with ANCA-associated vasculitis: a single-center retrospective study from Southern China

Clinical features and outcomes of small airway disease in ANCA-associated vasculitis

BACKGROUND AND OBJECTIVE

To clarify the prevalence, features and outcomes of small airway disease (SAD) in a Chinese cohort with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) related pulmonary involvement.

METHODS

SAD was recorded when the manifestations of either centrilobular nodules or air trapping were observed according to CT scans, except for infection or other airway-related comorbidities. Baseline and follow-up data were collected retrospectively.

RESULTS

Of the 359 newly diagnosed AAV patients with pulmonary involvement, 92 (25.6%) had SAD, including 79 (85.9%) cases of anti-MPO-ANCA positive, 9 (9.8%) cases of anti-PR3-ANCA positive and 2 (2.2%) cases of double positive. Patients with SAD were more likely to be younger, female, non-smokers, have more ear-nose-throat (ENT) involvement, and have higher baseline Birmingham Vasculitis Activity Score (BVAS) compared to patients without SAD. Several AAV-related SAD patients have improved lung function and CT scans after immunosuppressive therapy. Patients with SAD had a better prognosis compared to those without SAD. When dividing all patients into three groups: isolated SAD (only small airway involvements), SAD with other lower airway involvements, and non-SAD, patients in the SAD with other lower airway involvements group had the highest risk of infection, while patients in the non-SAD group had the worst long-term outcomes. Similar results were observed in anti-MPO-ANCA positive patients when performing subgroup analyses.

CONCLUSION

SAD is a unique manifestation of AAV-related lung involvement and exhibits distinct clinical features. It is vital to focus on SAD because of its association with prognosis and infection in AAV patients, especially in anti-MPO-ANCA positive patients. Moreover, SAD might represent a better response to immunosuppressors.

T lymphocyte subsets and immunoglobulin and complement levels are associated with the infection status of patients with antineutrophil cytoplasmic antibody-associated vasculitis

BACKGROUND

Infection is the leading cause of death in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV). The aim of this study was to characterize the immunological features of infectious events occurring in patients with newly diagnosed AAV and to identify possible risk factors associated with infection.

METHODS

The T lymphocyte subsets, immunoglobulin, and complement levels of the groups were compared between infected group and the noninfected group. Further, regression analysis was conducted to determine the association of each variable with the risk of infection.

RESULTS

280 patients with newly diagnosed AAV were enrolled. The average levels of CD3+ T cells (720.0 vs. 920.5, P < 0.001), CD3+CD4+ T cells (392.0 vs. 547.0, P < 0.001), and CD3+CD8+ T cells (248.0 vs. 335.0, P = 0.001), serum IgG (11.66 g/L vs. 13.59 g/L, P = 0.002), IgA (1.70 g/L vs. 2.44 g/L, P < 0.001), C3 (1.03 g/L vs. 1.09 g/L, P = 0.015), and C4 (0.24 g/L vs. 0.27 g/L, P < 0.001) were significantly lower in the infected group than in the noninfected group. The levels of CD3+CD4+ T cells (adjusted OR 0.997, P = 0.018), IgG (adjusted OR 0.804, P = 0.004), and C4 (adjusted OR 0.001, P = 0.013) were found independently associated with infection.

CONCLUSIONS

Patients of infected AAV and those without infection differ in T lymphocyte subsets and immunoglobulin and complement levels. Furthermore, CD3+CD4+ T cells counts and serum IgG and C4 levels were independent risk factors with infection in patients with newly diagnosed AAV.

Systematic literature review informing the 2022 update of the EULAR recommendations for the management of ANCA-associated vasculitis (AAV): part 1-treatment of granulomatosis with polyangiitis and microscopic polyangiitis

OBJECTIVE

To summarise and update evidence to inform the 2022 update of the EULAR recommendations for the management of antineutrophil cytoplasm antibody-associated vasculitis (AAV).

METHODS

A systematic literature review (SLR) was performed to identify current evidence regarding treatment of AAV. PubMed, EMBASE and the Cochrane library were searched from 1 February 2015 to 25 February 2022. The evidence presented here is focused on the treatment of granulomatosis with polyangiitis and microscopic polyangiitis.

RESULTS

3517 articles were screened and 175 assessed by full-text review. Ninety articles were included in the final evidence synthesis. Cyclophosphamide and rituximab (RTX) show similar efficacy for remission induction (level of evidence (LoE) 1a) but RTX is more effective in relapsing disease (LoE 1b). Glucocorticoid (GC) protocols with faster tapering result in similar remission rates but lower rates of serious infections (LoE 1b). Avacopan can be used to rapidly taper and replace GC (LoE 1b). Data on plasma exchange are inconsistent depending on the analysed trial populations but meta-analyses based on randomised controlled trials demonstrate a reduction of the risk of end-stage kidney disease at 1 year but not during long-term follow-up (LoE 1a). Use of RTX for maintenance of remission is associated with lower relapse rates compared with azathioprine (AZA, LoE 1b). Prolonged maintenance treatment results in lower relapse rates for both, AZA (LoE 1b) and RTX (LoE 1b).

CONCLUSION

This SLR provides current evidence to inform the 2022 update of the EULAR recommendations for the management of AAV.

Early infectious risk in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis according to remission-induction therapy

OBJECTIVE

Few comparative data exist on early infections secondary to remission-induction therapy (RIT) with rituximab (RTX) versus cyclophosphamide (CYC) in newly diagnosed anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) patients. We compared and analysed the rates and predictors of severe infection in such patients within the first 6 months following RIT.

METHOD

From the Caen University Hospital databases, we included all consecutive adults newly diagnosed with ANCA-positive granulomatosis with polyangiitis or microscopic polyangiitis between January 2006 and December 2019. We compared rates of survival without severe infection and survival without infections of any severity within 6 months of RIT and used a multivariate Cox analysis to identify predictors of infection.

RESULTS

We included 145 patients, 27 in the RTX and 118 in the CYC group. Patients in the RTX group more frequently had pneumococcal vaccination (p < 0.01) and creatinine < 150 µmol/L; other characteristics were comparable between the two groups. Overall, 37 severe infections and 65 infections of any severity were recorded. Rates of survival without severe infection were similar in both groups (p = 0.69), but survival without infections of any severity was lower in the RTX group (p = 0.005). In multivariate analysis, risk factors at diagnosis for severe infections included chronic urinary tract disease, dialysis, and absence of trimethoprim-sulfamethoxazole prophylaxis (p < 0.01 each).

CONCLUSIONS

Within 6 months of RIT, rates of survival without severe infection were similar in newly diagnosed ANCA-positive AAV patients treated with RTX or CYC, but survival rates without infections of any severity appeared to be lower with RTX treatment.

Clinical features and markers to identify pulmonary lesions caused by infection or vasculitis in AAV patients

OBJECTIVES

Pulmonary lesion is frequently seen in ANCA-associated vasculitis (AAV) patients primarily due to AAV lung involvement or infection, which are hard to differentiate due to their high similarity in clinical manifestations. We aimed to analyze the clinical features of pulmonary lesions consequent to AAV involvement or infection in AAV patients and further identify the markers for differential diagnosis.

METHODS

140 AAV patients who admitted to the Renmin Hospital of Wuhan University from January 2016 to July 2021 were included in this study. According to the nature of lung conditions, these patients were divided into the non-pulmonary lesion group, the lung infection group and the non-pulmonary infection group, and their demographics, clinical symptoms, imaging features, as well as laboratory findings were compared. A receiver operating characteristic (ROC) curve was drawn, and the diagnostic efficacy of single biomarker and composite biomarkers on pulmonary infection was then evaluated.

RESULTS

The patients in the lung infection group were significantly older than those in the no lesion group (63.19 ± 14.55 vs 54.82 ± 15.08, p = 0.022). Patients in the lung infection group presented more frequent symptoms and more obvious pulmonary image findings. Compared with patients in the non-pulmonary infection group, patients in the lung infection group showed a higher symptom incidence of fever, chest tightness, cough and expectoration, and hemoptysis (52.94% vs 16.00%, 61.76% vs 40.00%, 72.06% vs 46.00%, 27.94% vs 8.00%, p < 0.05, respectively), and more changes in pulmonary CT scanning images in terms of patched/striped compact opacity, alveolar hemorrhage, bronchiectasis, pleural effusion, as well as mediastinal lymphadenopathy (89.71% vs 52.00%, 11.76% vs 2.00%, 22.06% vs 8.00%, 50.00% vs 20.00%, 48.53% vs 24.00%, p < 0.05, respectively). In addition, patients in the lung infection group had significantly higher levels of serum pro-calcitonin (PCT), C-reactive protein (CRP), amyloid A (SAA), blood neutrophil-to-lymphocyte ratio (NLCR), erythrocyte sedimentation rate (ESR), as well as Birmingham vasculitis activity score (BVAS) than patients in the other two groups (p < 0.05). Among all biomarkers, PCT exhibited the highest diagnostic efficacy (0.928; 95%CI 0.89-0.97) for pulmonary infected AAV patients at a cut-off score of 0.235 ng/ml with 85.3% sensitivity and 84% specificity. Moreover, the composite biomarker of PCT-CRP-NLCR showed more diagnostic efficacy (0.979; 95% CI 0.95-1.00) in distinguishing the infectious and non-infectious lung injuries in AAV patients.

CONCLUSIONS

AAV patients with lung infection manifested more clinical symptoms and prominent lung image changes. The PCT and composite biomarker PCT-CRP-NLCR showed high diagnostic efficacy for a lung infection in AAV patients. Pulmonary lesion caused by either infection or AAV involvement is commonly seen and difficult to distinguish. We aim to identify the biomarkers that can be applied in the differentiation diagnosis of pulmonary lesions in AAV patients.

Severe infections in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis: a retrospective cohort study with a clinical phenotype approach

Severe infections are common in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). We aimed to describe the characteristics of patients with AAV and severe infections according to clinical phenotype. Retrospective cohort study including patients with granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA). Baseline characteristics were compared between patients with and without at least one severe infection. Demographics, comorbidities, clinical characteristics, laboratory and treatment were retrieved at diagnosis and at every infectious event. One hundred and eight patients were included (57 with and 51 without infections). Patients with an infection had received more frequently methylprednisolone boluses at AAV diagnosis than patients without infections (OR 2.6, 95% CI 1.1-5.9, p = 0.01). There were a total of 108 severe infections in 57 patients (median follow-up 18 months). Thirty-two patients (56%) had an infectious complication within the first year of AAV diagnosis, 43 (75%) had pulmonary involvement during the first infection. The most frequent type of infection was pneumonia. Phenotypes were: Non-severe AAV (n = 11), severe PR3-AAV (n = 30), severe MPO-AAV (n = 9); the number of infectious events in each group was 11, 69, 18, respectively. Patients with severe MPO phenotype were older and required more frequently ICU stay compared to other phenotypes. Positive correlation was found between total of infections and pulmonary infiltrates due to vasculitis (ρ = 0.40, p = 0.003), endobronchial involvement (ρ = 0.40, p = 0.003), and alveolar hemorrhage (ρ = 0.34, p = 0.015). Severe infections, most commonly pneumonia, were frequent in this cohort, especially during the first year after diagnosis, in patients with pulmonary involvement and severe PR3 phenotype who received methylprednisolone boluses.