Antineutrophil cytoplasmic antibodies (ANCA) - their role in pathogenesis, diagnosis, and treatment monitoring of ANCA-associated vasculitis

Granulomatosis with polyangiitis: clinical characteristics and updates in diagnosis

Granulomatosis with polyangiitis (GPA) is a rare systemic disease characterized by granulomatous inflammation of the respiratory tract and necrotizing vasculitis of small and medium vessels often associated with the production of anti-neutrophil cytoplasmic antibodies (ANCA) directed mainly against leukocyte proteinase 3 (PR3). Usually, it involves upper airways, lungs, and kidneys, however any organ may be affected. The diagnosis is based on clinical, radiological, and serological findings. Biopsies, although strongly recommended, are not always feasible and often provides non-specific features. ANCA plays a crucial role in the diagnosis of GPA; nevertheless, ANCA detection is not a substitute for biopsy, which plays an important role in suspected cases, particularly when histological confirmation cannot be obtained. Significant advances have been made in classification criteria and phenotyping of the disease, particularly in determining the nuances between PR3-ANCA and myeloperoxidase (MPO)-ANCA vasculitis. This has led to better characterization of patients and the development of targeted treatment in the future. In addition, better identification of cytokine and immunological profiles may result in immuno-phenotyping becoming a new approach to identify patients with ANCA-associated vasculitis (AAV). Due to the chronic relapsing-remitting nature, strict follow-up of GPA is necessary to provide appropriate management. The search for the accurate marker of disease activity and to predict relapse is still ongoing and no predictor has been found to reliably guide therapeutic decision-making.

Chemokine expression in sera of patients with microscopic polyangiitis and granulomatosis with polyangiitis

We evaluated chemokine expression and its correlation with disease activity in patients with microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) (MPA/GPA). Serum CCL2, CCL4, CCL19, CXCL1, CXCL2, and CX3CL1 level in 80 patients were analysed using multiple enzyme-linked immunosorbent assays. Correlations between variables were investigated using Pearson's correlation analysis, and receiver operator curve analysis was performed to identify optimal CX3CL1 values in determining active disease. Multivariate logistic regression analysis was done to evaluate predictors of active disease. CCL4 (r = 0.251, p = 0.025), CXCL1 (r = 0.270, p = 0.015), and CX3CL1 (r = 0.295, p = 0.008) significantly correlated with BVAS, while CX3CL1 was associated with five-factor score (r =  - 0.290, p = 0.009). Correlations were revealed between CCL2 and CCL4 (r = 0.267, p = 0.017), CCL4 and CXCL1 (r = 0.368, p < 0.001), CCL4 and CXCL2 (r = 0.436, p < 0.001), and CXCL1 and CXCL2 (r = 0.518, p < 0.001). Multivariate analysis revealed serum CX3CL1 levels > 2408.92 pg/mL could predict active disease (odds ratio, 27.401, p < 0.001). Serum chemokine levels of CCL4, CXCL1, and CX3CL1 showed association with disease activity and especially, CX3CL1 > 2408.92 pg/mL showed potential in predicting active MPA/GPA.

New Biomarkers for Systemic Necrotizing Vasculitides

Systemic necrotising vasculitides (SNVs) pose significant challenges due to their diverse clinical manifestations and variable outcomes. Therefore, identifying reliable biomarkers holds promise for improving precision medicine in SNVs. This review explores emerging biomarkers aiming to enhance diagnostic accuracy, prognostic assessment, and disease monitoring. We discuss recent advances in immunological biomarkers, inflammatory indicators, and other parameters that exhibit potential diagnostic and prognostic utility. A comprehensive understanding of these biomarkers may facilitate earlier and more accurate SNV detection, aiding in timely intervention and personalized treatment strategies. Furthermore, we highlight the evolving landscape of disease monitoring through innovative biomarkers, shedding light on their dynamic roles in reflecting disease activity and treatment response. Integrating these novel biomarkers into clinical practice can revolutionize the management of SNVs, ultimately improving patient outcomes and quality of life.

Evaluation of prognostic factors for patients with eosinophilic granulomatosis with polyangiitis recruited at the pneumonological centre and mainly ANCA negativity: A retrospective analysis of a single cohort in Poland

OBJECTIVES

The aim was to investigate the risk factors for relapse and death in patients with eosinophilic granulomatosis with polyangiitis (EGPA) recruited at the pneumonological centre and mainly antineutrophil cytoplasmic antibody negativity.

METHODS

We retrospectively recruited 86 patients. Relapse was defined as the recurrence or appearance of new organ symptoms. The study end-point included the final examination.

RESULTS

Relapses occurred in 34.9% of the patients, while 9.3% died. Immunosuppressive therapy (P = 0.042), prolonged low-dose corticosteroid treatments (mainly for asthma) (P = 0.006), and longer follow-up duration (P = 0.004) were associated with a higher relapse risk, while advanced EGPA severity (P = 0.0015) and activity (P = 0.044), older age of onset (P = 0.030), symptomatic cardiac involvement (P = 0.007), and postinflammatory cardiac fibrosis (P = 0.038) were associated with a higher risk of death. Sinusitis (P = 0.028) and prolonged low-dose corticosteroid treatments (P = 0.025) correlated with a better prognosis. Relapses did not have an impact on the mortality (P = 0.693).

CONCLUSIONS

Relapses in EGPA remain frequent, although they do not impact mortality. Cardiac involvement is common, but clinically symptomatic cardiomyopathy is associated with a higher risk of death. Asthma requiring chronic corticosteroid treatments is associated with a lower risk of death, although the risk of EGPA recurrence is significantly higher.

Elevated plasma FXII is associated with disease activity in ANCA-associated vasculitis: A Retrospective Cross-Sectional Study in Western China

This study examined whether plasma FXII levels reflect disease activity in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Plasma FXII levels were detected by ELISA in 127 patients with AAV, and their associations with disease activity and plasma myeloperoxidase (MPO)-ANCA titre were examined. Immunofluorescent co-staining of FXII and neutrophils was performed on the renal tissues of patients with AAV. MPO expression in renal biopsy tissues was determined by immunohistochemical staining. The association between plasma FXII levels and histological activity was assessed in 82 patients who underwent kidney biopsy. Plasma FXII levels were considerably increased in patients with clinically active AAV compared to those in clinical remission and healthy individuals. Plasma FXII levels correlated positively with creatinine (r = 0.377), CRP (r = 0.222), urine red blood cell (r = 0.203), serum MPO-ANCA titer (r = 0.353), white blood cell (r = 0.194), percentage of glomeruli with crescents (P = 0.001), capillary breaks (P = 0.001), interstitial inflammation (P < 0.001) and fibrinoid necrosis (p < 0.001) on kidney biopsy. The plasma FXII optimal cut-off value for evaluating AAV activity was 24.5 μg/mL (sensitivity = 0.81, specificity = 0.82, P = 0.0001), which was superior to that achieved using conventional serologic biomarkers. Co-expression of FXII and neutrophils was higher, with increased MPO expression, in renal tissue with pathologically active AAV than that observed in pathologically inactive tissues. In conclusion, elevated plasma FXII levels reflect AAV clinical and histologic activity, and can serve as markers of active AAV.

False-Positive Myeloperoxidase-Antineutrophil Cytoplasmic Antibody in a Patient with Rheumatoid Arthritis

BACKGROUND Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a form of vasculitis predominantly affecting small blood vessels and systemic organs, including the lungs and kidneys. The serum ANCA is an important diagnostic marker for AAV. However, ANCA levels can be nonspecifically elevated in autoimmune diseases like rheumatoid arthritis (RA) and some infectious diseases. Furthermore, RA and AAV can occur together. Therefore, when ANCA is detected in patients with RA, interpretation of the results is often difficult. CASE REPORT A 71-year-old woman with a 15-year history of RA was admitted to our hospital with a fever and anorexia. She was treated with prednisolone 5 mg/day and iguratimod 50 mg/day for the RA. She presented with bilateral frosted glass shadows in the lungs, acute kidney injury, positive myeloperoxidase (MPO)-ANCA results, and elevated ß-D-glucan levels, suggesting AAV or pneumocystis pneumonia. A renal biopsy and bronchoalveolar lavage ruled out AAV. A polymerase chain reaction of the bronchoalveolar lavage fluid was positive for Pneumocystis jirovecii DNA, leading to a diagnosis of pneumocystis pneumonia. After admission, the patient continued to receive intravenous supplemental fluids, and renal function improved. Based on her pathological test results and clinical course, acute kidney injury was diagnosed as prerenal failure due to dehydration in the background of chronic kidney disease. CONCLUSIONS Even if MPO-ANCA is positive in patients with RA, it is important to consider the possibility of a false-positive result and perform a thorough and aggressive examination.

Subclinical microvascular changes in ANCA-vasculitides: the role of optical coherence tomography angiography and nailfold capillaroscopy in the detection of disease-related damage

BACKGROUND

Both cardiovascular and complement-mediated disorders might lead to microvascular damages in anti-neutrophil cytoplasm autoantibodies (ANCA)-associated vasculitides (AAV). We aimed at investigating, for the first time, subclinical microvascular abnormalities with non-invasive techniques in AAV patients by analyzing both retinal and nailfold capillary changes. Retinal plexi were investigated using optical coherence tomography angiography (OCT-A), while nailfold capillary changes by video-capillaroscopy (NVC). Potential correlations between microvessels' abnormalities and disease damage were also explored.

METHODS

An observational study was conducted on consecutive patients who met the inclusion criteria of defined diagnosis of eosinophilic granulomatosis with polyangiitis (EGPA), granulomatosis with polyangiitis (GPA), and microscopic polyangiitis (MPA), age ≥ 18 ≤ 75 yrs, and no ophthalmological disorders. Disease activity was assessed by Birmingham Vasculitis Activity Score (BVAS), damage by Vasculitis Damage Index (VDI), and poorer prognosis by the Five Factor Score (FFS). Quantitative analysis of vessel density (VD) was performed by OCT-A in both superficial and deep capillary plexi. Figures and detailed analysis from NVC were performed for all subjects in the study.

RESULTS

Included AAV patients (n = 23) were compared with 20 age/sex-matched healthy controls (HC). Retinal VD in superficial whole and parafoveal plexi resulted significantly decreased in AAV compared to HC (P = 0.02 and P = 0.01, respectively). Furthermore, deep whole and parafoveal vessel density was strongly reduced in AAV than HC (P ≤ 0.0001 for both). In AAV patients, significant inverse correlations occurred between VDI and OCTA-VD in both superficial (parafoveal, P = 0.03) and deep plexi (whole, P = 0.003, and parafoveal P = 0.02). Non-specific NVC pattern abnormalities occurred in 82% of AAV patients with a similar prevalence (75%) in HC. In AAV, common abnormalities were edema and tortuosity in a comparable distribution with HC. Correlations between NVC changes and OCT-A abnormalities have not been described.

CONCLUSION

Subclinical microvascular retinal changes occur in patients with AAV and correlate with the disease-related damage. In this context, the OCT-A can represent a useful tool in the early detection of vascular damage. AAV patients present microvascular abnormalities at NVC, whose clinical relevance requires further studies.

Physicians' perceptions about antineutrophil cytoplasmic antibody-associated vasculitis: an online survey report in the time of the COVID-19 pandemic

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) are characterized by necrotizing inflammation of small and medium-size vessels that often manifest with devastating multi-organ effects. They present with a myriad of systemic features and require potent immunosuppression. Since they are uncommonly encountered in clinical practice, it is necessary to understand physicians' knowledge and perceptions about this group of diseases. An online questionnaire was designed featuring 28 questions based on relevant global practice guidelines, recommendations, and previous online surveys on AAV. The questionnaire was validated by a core group of specialists with an interest in AAV. It was shared via social networking sites and entries were restricted to physicians. Only completed entries were analyzed with descriptive statistics. A total of 113 respondents from 21 different countries responded of whom the commonest were rheumatologists, internists, and general practitioners. Forty-five (40%) ran clinics dedicated to AAV patients as a part of their practice. They commented on organs involved in AAV; vasculitis secondary to infections, drugs or other rheumatic diseases; various tests useful for AAV diagnosis; and drug choices for induction and maintenance. They mentioned their experience regarding COVID-19 in AAV patients as well as vasculitic manifestations of COVID-19. Various methods to mitigate cardiovascular risks in AAV were mentioned. Finally, the respondents indicated how medical education needed to be strengthened to increase awareness and knowledge regarding AAV. This survey helped to inform about various perceptions regarding AAV across countries, including current practices and recent evolution of management. It also provided information on treatment of the COVID-19 in AAV patients. This survey showed that there is still a lack in understanding the prevalent definitions and there is gap between guidelines and current practice. Key Points • Perception about ANCA-associated vasculitis differ across countries. • The number of cases encountered across 21 different countries are limited implying a need for multi-national cooperation to study this disease further. • The COVID-19 pandemic has changed the approach towards ANCA-associated vasculitis by the various clinicians.

Pulmonary and Intestinal Involvement in a Patient with Myeloperoxidase-specific Antineutrophil Cytoplasmic Antibody-positive Hermansky-Pudlak Syndrome

A 26-year-old Japanese woman was admitted with a 1-month history of diarrhea, a high fever for a few days, and exacerbation of dyspnea. She was treated with an antifibrotic drug and long-term oxygen therapy for Hermansky-Pudlak syndrome-related pulmonary fibrosis. New ground-glass attenuation appeared on chest computed tomography (CT), and a colon biopsy showed an inflammatory cell accumulation with a high titer of myeloperoxidase (MPO)-specific anti-neutrophil cytoplasmic antibodies (ANCA). Systemic inflammation related to MPO-ANCA titer elevation was suspected. Steroid pulse therapy and intravenous cyclophosphamide improved chest CT findings and diarrhea. Therefore, immunosuppressant treatment should be considered for systemic inflammation related to MPO-ANCA.

Clinical patterns and risk factors in scleritis: a multicentric study in Colombia

PURPOSE

This study aims to describe the clinical characteristics of scleritis in a large cohort of Colombian patients and identify factors associated with the clinical presentation.

METHODS

Retrospective case series of patients with scleritis from 2015 to 2020. Clinical records were obtained from seven uveitis referral centers in Colombia. Patients with a diagnosis of episcleritis were excluded.

RESULTS

We evaluated 389 patients with scleritis (509 eyes). There was a female predominance (75.6%) with a mean age of 51 ± 15 years. Most cases were noninfectious (94.8%) and unilateral (69.2%). The most frequent type of inflammation was diffuse anterior scleritis (41.7%), followed by nodular scleritis (31.9%) and necrotizing scleritis (12.3%). Systemic autoimmune diseases were found in 41.3% of patients, the most common being rheumatoid arthritis (18.5%) and granulomatosis with polyangiitis (5.9%). Polyautoimmunity was found in 10.4% of those with a systemic autoimmune disease. The most frequent treatment was systemic steroids (50.9%), followed by systemic NSAIDs (32.4%). Steroid-sparing immunosuppression was required in 49.1% of patients. Systemic autoimmune diseases were more common in patients with necrotizing scleritis and those older than 40 years of age. Best-corrected visual acuity of 20/80 or worse at presentation was more common in necrotizing scleritis and subjects with associated uveitis, ocular hypertension, or who were over 40 years of age.

CONCLUSIONS

This is the first study in Colombia and the largest in Latin America describing the clinical characteristics and presentation patterns of scleritis. The most common presentation was in females, with unilateral, anterior diffuse noninfectious scleritis. Systemic autoimmune diseases and polyautoimmunity were frequent, as was the need for steroid-sparing immunosuppression. Age over 40 and necrotizing scleritis were associated with higher odds of having a systemic autoimmune disease and worse visual acuity at presentation.

Increased frequency of IgD-CD27hiCD38hi B cells and its association with the renal involvement in ANCA-associated vasculitis

Background

B cells have been highlighted in the pathogenesis of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) by the identification of activated B cells in granulomatous lesions and the efficacy of B cell depletion in treatment of AAV patients in the current study; we aimed to investigate the frequency of a specific B cell subset, IgD-CD27^hiCD38^hi B cells in AAV patients, and its association with the disease severity of AAV.

Methods

Blood samples of patients with AAV in active stage and in remission were collected. The frequency of IgD-CD27^hiCD38^hi B cells was detected by flow cytometry, and its correlation with clinicopathological parameters was analyzed.

Results

Our results showed a significant increase of circulating IgD-CD27^hiCD38^hi B cells in AAV patients in active stage compared with patients in remission and healthy donors, and the frequency of IgD-CD27^hiCD38^hi B cells correlated with the severity of renal involvement, including serum creatinine, estimated glomerular filtration rate, and percentages of total crescents in renal biopsies.

Conclusions

The results indicated that IgD-CD27^hiCD38^hi B cells could reflect disease severity of renal involvement in AAV.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02796-9.

Rare Overlap of Granulomatosis With Polyangiitis in a Patient With Rheumatoid Arthritis

Granulomatosis with polyangiitis (GPA) is a systemic small/medium-sized vessel vasculitis, which is a member of the family of antineutrophil cytoplasmic auto-antibody-associated vasculitides. This disorder affects multiple organs as it is a systemic disease, but overlapping with rheumatoid arthritis is extremely rare, with few cases reported in the medical literature. We report a case of a 55-year-old female with a history of rheumatoid arthritis who presented with recurrent upper/lower respiratory tract symptoms that responded poorly to antibiotics. The patient had elevated antiproteinase antibodies, ANCA IgG titer with a cytoplasmic staining pattern, proteinuria, hematuria, chest imaging showing cavitating and non-cavitating masses, and biopsies of lung and nasal tissue confirming the diagnosis of GPA. Our patient was given immunosuppressant therapy and improvement in lab work and clinical symptoms were seen throughout the course of treatment. This case report is unique as GPA usually rarely presents with rheumatoid arthritis (RA), but in this case, the patient had a history of rheumatoid arthritis with a new biopsy-proven GPA. This case report will help future physicians to better diagnose similar cases and help to facilitate clinical recognition and treatment for the same.