ANCA are detectable in nearly all patients with active severe Wegener's granulomatosis

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.

Recurrent Coronary Vasospasm in a 50-Year-Old Woman with Granulomatous Polyangiitis: A Case Report

Granulomatosis with polyangiitis (GPA) is a necrotizing granulomatous vasculitis classified as an autoimmune small-vessel vasculitis. Clinically, approximately 80% of affected organs in GPA involve the upper/lower respiratory tract and kidneys, with cardiovascular system involvement being rare. Here, we report a case of a 50-year-old female patient who presented with sudden-onset chest pain lasting for 1 hour. The patient had normal body temperature, and markers of infection such as C-reactive protein and erythrocyte sedimentation rate were within normal limits. Electrocardiography revealed ST-segment elevation in inferior, precordial, and posterior leads. Emergency coronary angiography showed no significant obstructive disease, prompting consideration of vasospastic angina given the patient's recurrent chest pain symptoms and findings on laboratory and imaging studies. The patient underwent treatment including coronary vasospasm antagonists and immunomodulation, resulting in clinical improvement and subsequent discharge. During a 7-month follow-up period, the patient did not experience any further adverse cardiovascular events.

A framework for exclusion of alternative diagnoses in sarcoidosis

Sarcoidosis is a multisystem granulomatous syndrome that arises from a persistent immune response to a triggering antigen(s). There is no "gold standard" test or algorithm for the diagnosis of sarcoidosis, making the diagnosis one of exclusion. The presentation of the disease varies substantially between individuals, in both the number of organs involved, and the manifestations seen in individual organs. These qualities dictate that health care providers diagnosing sarcoidosis must consider a wide range of possible alternative diagnoses, from across a range of presentations and medical specialties (infectious, inflammatory, cardiac, neurologic). Current guideline-based diagnosis of sarcoidosis recommends fulfillment of three criteria: 1) compatible clinical presentation and/or imaging 2) demonstration of granulomatous inflammation by biopsy (when possible) and, 3) exclusion of alternative causes, but do not provide guidance on standardized strategies for exclusion of alternative diagnoses. In this review, we provide a summary of the most common differential diagnoses for sarcoidosis involvement of lung, eye, skin, central nervous system, heart, liver, and kidney. We then propose a framework for testing to exclude alternative diagnoses based on pretest probability of sarcoidosis, defined as high (typical findings with sarcoidosis involvement confirmed in another organ), moderate (typical findings in a single organ), or low (atypical/findings suggesting of an alternative diagnosis). This work highlights the need for informed and careful exclusion of alternative diagnoses in sarcoidosis.

Proteinase 3-specific antineutrophil cytoplasmic antibody-associated vasculitis

Proteinase 3 (PR3)-specific antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis is one of two major ANCA-associated vasculitis variants and is pathogenically linked to granulomatosis with polyangiitis (GPA). GPA is characterised by necrotising granulomatous inflammation that preferentially affects the respiratory tract. The small vessel vasculitis features of GPA are shared with microscopic polyangiitis. Necrotising granulomatous inflammation of GPA can lead to PR3-ANCA and small vessel vasculitis via activation of neutrophils and monocytes. B cells are central to the pathogenesis of PR3-ANCA-associated vasculitis. They are targeted successfully by remission induction and maintenance therapy with rituximab. Relapses of PR3-ANCA-associated vasculitis and toxicities associated with current standard therapy contribute substantially to remaining mortality and damage-associated morbidity. More effective and less toxic treatments are sought to address this unmet need. Advances with cellular and novel antigen-specific immunotherapies hold promise for application in autoimmune disease, including PR3-ANCA-associated vasculitis. This Series paper describes the inter-related histopathological and clinical features, pathophysiology, as well as current and future targeted treatments for PR3-ANCA-associated vasculitis.

The Diagnosis of Granulomatosis With Polyangiitis When Serology and Biopsies are Negative

Objective

Granulomatosis with polyangiitis (GPA) is a potentially fatal condition which often manifests in the head and neck. Currently, diagnosis relies on antineutrophil cytoplasmic autoantibody (c-ANCA) serology and mucosal or renal biopsy. However, a significant proportion of patients with GPA limited to the head and neck are seronegative and biopsy negative. This study evaluates the role of clinical diagnosis of GPA in the absence of positive laboratory findings.

Study Design

Case series with chart review.

Setting

Academic Tertiary Medical Center.

Methods

This was a retrospective review of 143 patients treated in an outpatient otolaryngology clinic at a tertiary care hospital for known or suspected GPA from 1998 to 2021. Presenting symptoms, C-ANCA status at initial presentation, biopsy results, long-term serology results, and time to initiation of treatment were analyzed.

Results

Twenty-six of 143 (18.2%) patients were seronegative; only 3 of these patients (12%) had positive biopsies. Seventeen (73.9%) of these patients presented with nasal and sinus disease and 12 (52.2%) presented with airway involvement. Only 4 (17.4%) patients had renal involvement. Delay in treatment of patients with negative laboratory workup ranged from 0 months to 11 years. All patients who were seronegative and/or biopsy negative at presentation responded clinically to immunosuppressive therapy.

Conclusion

GPA cases are often limited to the upper respiratory tract, making diagnosis difficult, particularly in seronegative patients. These results suggest that, when GPA is suspected, despite negative serology, the diagnosis of GPA should be made on clinical grounds, and empiric therapy encouraged to prevent delay in treatment.

Combination treatment with telitacicept, cyclophosphamide and glucocorticoids for severe Granulomatous polyangiitis: a case report and literature review

Granulomatous polyangiitis (GPA) is a rare autoimmune disease that can involve multiple systems throughout the body, including the ear, nose, upper and lower respiratory tracts. It is classified as an antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. Telitacicept is a novel recombinant fusion protein targeting B-lymphocyte stimulator (BLyS). Telitacicept can inhibit the development and maturation of abnormal B cells by blocking BLyS, and inhibit the production of antibodies by abnormal plasma cells by blocking APRIL (A proliferation-inducing ligand), which is expected to become a new drug for the treatment of GPA. We report a 64-year-old man diagnosed at our hospital with GPA involving multiple systems including kidneys, lungs, nose and ears. Renal involvement was severe, with a clinical characteristic of rapidly progressive glomerulonephritis and a pathologic manifestation of crescentic nephritis with plasma cell infiltration. The patient was treated with hormones, immunoglobulins and cyclophosphamide (CYC) with the addition of telitacicept and a rapid reduction in hormone dosage. The patient's renal function improved significantly within a short period of time, and his hearing and lung lesions improved significantly. At the same time, he did not develop serious infections and other related complications. Our report suggests that short-term control of the patient's conditions is necessary in GPA patients with organ-threatening disease. Telitacicept combined with CYC and glucocorticoids may be an induction therapy with safety and feasibility. However, more clinical trials are needed to validate the efficacy and safety of the therapeutic regimen.

Atypical Pattern of Leukocytoclastic Vasculitis in Granulomatosis With Polyangiitis

Granulomatosis with polyangiitis (GPA), formerly Wegener's granulomatosis, is a small- and medium-vessel vasculitis with characteristic cutaneous morphologic presentation and systemic involvement. Most patients have palpable purpura at some point in their disease course, but this is not always the presenting manifestation. This autoimmune disorder can affect a range of organs, with the upper and lower respiratory tract, kidneys, and nervous system being commonly implicated, while gastrointestinal and cardiac involvement is less frequent. This is a 44-year-old female presenting to the emergency department (ED) with polyarthralgia and palpable purpura. Palpable purpura was distributed on the oral palate, elbow, and lower back, and a punch biopsy revealed leukocytoclastic vasculitis (LCV). While this was an atypical distribution for leukocytoclastic vasculitis, the skin biopsy provided the necessary evidence to diagnose GPA. This case characterizes non-specific and atypical signs and symptoms of GPA that all providers should be aware of in order to diagnose the condition early in its disease course.

Peripheral T-cell lymphoma mimicking granulomatosis with polyangiitis

Upper respiratory tract involvement is common in patients with granulomatosis with polyangiitis (GPA), but malignancies should be kept in mind in the differential diagnosis. A 68-year-old man was referred to rheumatology to investigate for GPA after nasal excisional biopsy. After careful radiologic and pathologic assessment, he was diagnosed with peripheral T‑cell lymphoma, nasal type. This is a rare case of T‑cell lymphoma in a patient who was referred as GPA.

Native Tricuspid Valve Infective Endocarditis After Breast Skin Abscess

Tricuspid valve infective endocarditis is a rare disease in non-intravenous drug users. It can occur with congenital heart disease, foreign bodies such as central venous catheters and intracardiac devices, and in immunocompromised patients. In the present case, there was a left-sided breast abscess associated with tricuspid valve endocarditis in a patient without any apparent underlying causative factors. We present a case of a young female in her early 20s who arrived at the emergency department with complaints of fever, epistaxis, and vomiting. On clinical examination, she was found to have a fading 2 cm pinkish left breast skin lesion, which had formed on her breast 10 days ago. Blood cultures identified methicillin-resistant Staphylococcus aureus in the blood. A CT scan of the chest, abdomen, and pelvis revealed splenomegaly and an infective focus in the spleen. Subsequent echocardiography confirmed the diagnosis of infective endocarditis of the native tricuspid valve, which was treated with intravenous vancomycin. There was no history of intravenous drug abuse, congenital heart disease, placement of an intracardiac device, central venous catheter, or an immunocompromised state in this patient. Therefore, the diagnosis of infective endocarditis, characterized by a native tricuspid valve vegetation identified as a consequence of a left breast skin abscess, was made. A high index of suspicion is required for a non-specific presentation of tricuspid valve infective endocarditis and in the absence of any prior history of risk factors for right-sided infective endocarditis. Timely initiation of antibiotics depends on a preliminary clinical diagnosis.

Ocular Involvement of Granulomatosis with Polyangiitis

Granulomatosis with polyangiitis (GPA), formerly referred to as Wegener's disease, is a form of ANCA-associated vasculitis. It manifests mainly in the kidneys and the upper respiratory tract, but ocular involvement is not uncommon. In this article, four cases with ocular manifestations are presented with comprehensive photographic documentation. We describe the way to proper diagnosis, which may be long, the possible treatment, and the final outcomes. Our patients had the following ocular manifestations of GPA: retinal vasculitis, anterior necrotizing scleritis, medial orbital wall and orbital floor erosion with middle face deformation, compressive optic neuropathy due to retrobulbar inflammatory mass, and the abscess of the eyelids, inflammatory intraorbital mass causing exophthalmos and diplopia. This manuscript includes the description of severe forms of GPA, the initial signs and symptoms, relapses, and difficulties in achieving remission. The extraocular involvement is described with diagnostic modalities and laboratory findings. One of the reported cases was diagnosed by an ophthalmologist on the basis of ocular symptoms in the early stages of the disease. Our outcomes are compared with those discussed in the literature.

Clair EW, Ytterberg SR, Stone JH, Robinson WH, Specks U. Activation of a Latent Epitope Causing Differential Binding of Antineutrophil Cytoplasmic Antibodies to Proteinase 3

OBJECTIVE

Proteinase 3 (PR3) is the major antigen for antineutrophil cytoplasmic antibodies (ANCAs) in the systemic autoimmune vasculitis, granulomatosis with polyangiitis (GPA). PR3-targeting ANCAs (PR3-ANCAs) recognize different epitopes on PR3. This study was undertaken to study the effect of mutations on PR3 antigenicity.

METHODS

The recombinant PR3 variants, iPR3 (clinically used to detect PR3-ANCAs) and iHm5 (containing 3 point mutations in epitopes 1 and 5 generated for epitope mapping studies) immunoassays and serum samples from patients enrolled in ANCA-associated vasculitis (AAV) trials were used to screen for differential PR3-ANCA binding. A patient-derived monoclonal ANCA 518 (moANCA518) that selectively binds to iHm5 within the mutation-free epitope 3 and is distant from the point mutations of iHm5 was used as a gauge for remote epitope activation. Selective binding was determined using inhibition experiments.

RESULTS

Rather than reduced binding of PR3-ANCAs to iHm5, we found substantially increased binding of the majority of PR3-ANCAs to iHm5 compared to iPR3. This differential binding of PR3-ANCA to iHm5 is similar to the selective moANCA518 binding to iHm5. Binding of iPR3 to monoclonal antibody MCPR3-2 also induced recognition by moANCA518.

CONCLUSION

The preferential binding of PR3-ANCAs from patients, such as the selective binding of moANCA518 to iHm5, is conferred by increased antigenicity of epitope 3 on iHm5. This can also be induced on iPR3 when captured by monoclonal antibody MCPR2. This previously unrecognized characteristic of PR3-ANCA interactions with its target antigen has implications for studying antibody-mediated autoimmune diseases, understanding variable performance characteristics of immunoassays, and design of potential novel treatment approaches.

Muscle Biopsy-proven Drug-induced Microscopic Polyangiitis in a Patient with Tuberculosis

We herein report a case of muscle biopsy-proven microscopic polyangiitis (MPA) in a patient with tuberculosis. The patient had developed a persistent fever after the initiation of treatment for tuberculosis and was positive for myeloperoxidase-antineutrophil cytoplasmic antibody (ANCA). However, because conventional symptoms were lacking, determination of the biopsy site was difficult. Based on the findings of a biopsy of the biceps femoris, which confirmed small vessel vasculitis, the patient was diagnosed with MPA. The fever was alleviated by glucocorticoids. Tuberculosis and antituberculosis drugs can cause ANCA-associated vasculitis (AAV). A muscle biopsy is useful for the diagnosis of AAV.

Relevance of Combined Clinicopathologic Phenotype and Antineutrophil Cytoplasmic Autoantibody Serotype in the Diagnosis of Antineutrophil Cytoplasmic Autoantibody Vasculitis

Introduction

Granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA), 2 major clinicopathologic variants of antineutrophil cytoplasmic autoantibody (ANCA) vasculitides, are mostly associated with proteinase 3 (PR3)-ANCA and myeloperoxidase (MPO)-ANCA, respectively. Less is known regarding the uncommon forms of ANCA vasculitis, PR3-ANCA MPA and MPO-ANCA GPA.

Methods

In this cohort study we detailed the clinical presentation and outcome of patients with PR3-ANCA MPA and MPO-ANCA GPA from the Glomerular Disease Collaborative Network (GDCN) inception cohort. Baseline clinical manifestations, relapses, end-stage kidney disease (ESKD), and survival were compared within MPA cases by PR3-ANCA (n = 116) versus MPO-ANCA (n = 173) and within GPA cases by PR3-ANCA (n = 108) versus MPO-ANCA (n = 43). Fisher's exact test and Wilcoxon two sample test were used for comparisons. Proportional hazards models were used to evaluate the development of relapses, ESKD, and death.

Results

Patients with PR3-ANCA MPA were younger (53 years vs. 62 years, P = 0.0007) and had increased prevalence of joint involvement (56% vs. 40%, P = 0.0115) and ear, nose, and throat (ENT) involvement (44% vs. 26%, P = 0.002) than MPO-ANCA MPA. Relapses, ESKD, and survival were similar between both MPA subsets. Within the GPA group, patients with MPO-ANCA GPA were older (61 years vs. 46 years, P = 0.0007) and more likely female (56% vs. 35%, P = 0.027) than PR3-ANCA GPA patients. MPO-ANCA GPA was also characterized by less prevalent ENT manifestations (58% vs. 77%, P = 0.028) and neurologic manifestations (5% vs. 25%, P = 0.0029), and increased ESKD and mortality.

Conclusions

PR3-ANCA MPA and MPO-ANCA GPA are clinicopathologically distinct subsets of ANCA vasculitis that differ from MPO-ANCA MPA and PR3-ANCA GPA. Although the impact of these differences on the clinical management and outcome warrants further evaluation, these results support the recommendation of including both the phenotypic diagnosis and ANCA serotype in the diagnosis of ANCA vasculitis.

Serum ANCA as Disease Biomarkers: Clinical Implications Beyond Vasculitis

Usually associated with autoimmune diseases, anti-neutrophil cytoplasmic antibodies are also detected in other conditions, such as infections, malignancies, and after intake of certain drugs. Even if the mechanisms of production and their pathogenic role have not been fully elucidated yet, ANCA are widely recognized as a clinically alarming finding due to their association with various disorders. While ANCA target several autoantigens, proteinase-3, and myeloperoxidase are the ones proved to be most frequently related to chronic inflammation and tissue damage in murine models. Albeit these autoantibodies could be present as an isolated observation without any implications, ANCA are frequently used in clinical practice to guide the diagnosis in a suspect of small vessel vasculitis. Conditions that should prompt the clinician to test ANCA status range from various forms of lung disease to renal or peripheral nervous system impairment. ANCA positivity in the presence of an autoimmune disease, especially rheumatoid arthritis, or connective tissue diseases, is frequently correlated with more clinical complications and treatment inefficacy, even in the absence of signs of vasculitis. For this reason, it has been postulated that ANCA could represent the final expression of an immune dysregulation rather than a pathogenic event responsible for organs damage. Recently, it has also been proposed that ANCA specificity (PR3 or MPO) could possibly define ANCA-associated vasculitides better than clinical phenotype. This review aims at summarizing the latest advancements in the field of ANCA study and clinical interpretation.

Granulomatosis With Polyangiitis in Untreated Graves' Disease: A Rare Event

Antithyroid medications can cause antineutrophil cytoplasmic antibody (ANCA) vasculitis. However, no literature in English describes the coexistence of granulomatosis with polyangiitis (GPA) and untreated Graves' disease. We present a 19-year-old female with thyroid storm and additional complaints of cough, hemoptysis, nasal discharges, polyarthralgia, and skin lesions. Imaging showed peri-hilar cavities and acute-on-chronic sinusitis. Elevated cytoplasmic pattern antineutrophil cytoplasmic antibody (C-ANCA) and anti-proteinase-3 antibody levels plus histopathology of the nasal and skin biopsies suggested GPA. Propranolol, methimazole, and potassium-iodide resolved the thyroid storm. Induction therapy (steroids, rituximab) for GPA provided relief of chronic symptoms stressing the importance of early recognition and swift initiation of treatment.

Rituximab pediatric drug development: Pharmacokinetic and pharmacodynamic modeling to inform regulatory approval for rituximab treatment in patients with granulomatosis with polyangiitis or microscopic polyangiitis

Anti-neutrophil cytoplasmic antibody-associated vasculitides granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) are rare, potentially organ- and life-threatening autoimmune conditions affecting adult and pediatric patients. An open-label phase II study was conducted to determine safe and effective dosing regimens of rituximab in pediatric patients with GPA/MPA. To determine the selection of an appropriate dose regimen in children for induction and maintenance, a population pharmacokinetic approach was used (nonlinear mixed-effect modeling), combining pediatric data with data from adults with GPA/MPA. The time course of B-cell depletion was assessed in both populations. The exposure-effect relationship was assessed by logistic regression. Twenty-five pediatric patients (80% female patients; age range, 6-17 years) were enrolled in the trial and received the induction regimen of intravenous rituximab 375 mg/m² weekly for 4 weeks, which resulted in a similar exposure to that of adults. Based on pharmacokinetic modeling, a maintenance dosing regimen of 250 mg/m² administered twice over 14 days followed by 250 mg/m² every 6 months is expected to result in similar rituximab exposure as that of adults receiving the approved maintenance dose of 500 mg administered twice over 14 days followed by 500 mg every 6 months. The time course of B-cell depletion was similar between the pediatric and adult populations, supporting the similarities in response in both populations and allowing extrapolation to patients less than 6 years old. Using a partial extrapolation approach helped identify safe and effective dosing regimens of rituximab in pediatric patients with GPA/MPA and lead to regulatory approval.

A 49-year-old man with ischemic cardiomyopathy and persistent hemoptysis for eighteen months

Idiopathic pulmonary hemosiderosis (IPH) is a rare cause of recurrent episodes of diffuse alveolar hemorrhage (DAH). IPH commonly manifests with hemoptysis, radiologic chest infiltrates and anemia. The etiology of IPH is unknown, but an immunologic mechanism is widely speculated. The definitive diagnosis of IPH requires a thorough exclusion of other causes of DAH, such as infections, inflammation, malignancy, cardiac diseases, drug and toxin exposure, and medications. Due to the rarity of the disease, a diagnosis is often delayed by years. We present the case of a 49-year-old man with ischemic cardiomyopathy who presented with hemoptysis for eighteen months. Serologic workup was negative for vasculitides and autoimmune diseases. Bronchoscopy revealed DAH. A surgical lung biopsy showed 'bland pulmonary hemorrhage.' A right heart catheterization ruled out cardiac causes of DAH. The patient was diagnosed with IPH and started on systemic corticosteroids with rapid improvement of hemoptysis.

Autoimmune markers in screening for orbital inflammatory disease

PURPOSE

Immunogenic causes of inflammation may be difficult to differentiate in the work-up of orbital inflammatory disease. The study aims to investigate the utility of autoimmune markers in the screening for orbital inflammation. Markers studied included angiotensin-converting enzyme (ACE), antinuclear antibody (ANA), anti-neutrophilic cytoplasmic autoantibodies (ANCA), extractable nuclear antigen (ENA), anti-cyclic citrullinated peptide (Anti-CCP) and anti-double stranded DNA antibody (Anti-dsDNA antibody).

METHODS

A retrospective single-centre study of consecutive patients with non-infective orbital inflammation screened for autoimmune markers at presentation. Serology was interpreted alongside clinical course and other investigations (e.g. radiographic features and histopathology). Tabulated data and Pearson's Chi-square allowed analysis of trends between serology, diagnosis and the decision to biopsy.

RESULTS

79 patients, between 1999 and 2021, were included (50 females, mean age was 50.4 ± 17.4 years). 28 (34.6%) patients had specific orbital inflammation and 53 (65.4%) patients had non-specific orbital inflammation (NSOI). Of the 12 patients with positive serology and a specific diagnosis, only 5 (41.7%) patients had concordant serological results. There was no association between serology results and the patient undergoing biopsy (P = 0.651). Serology was unable to exclude nor differentiate NSOI from other specific conditions and ANA had limited discriminatory value between specific conditions and NSOI.

CONCLUSION

Serological testing alone may not provide a clear direction for further investigation of orbital inflammation and a biopsy may occur independently of the serological results. The value of autoimmune markers may lie in subsequent follow-up as patients may develop suggestive symptoms after an indeterminate positive result or initially seronegative disease.

Differentiation of idiopathic pulmonary hemosiderosis from rheumatologic and autoimmune diseases causing diffuse alveolar hemorrhage: establishing a diagnostic approach

This narrative review provides an overview of diffuse alveolar hemorrhage (DAH) associated with rheumatologic and autoimmune diseases and their differentiation from idiopathic pulmonary hemosiderosis (IPH). Relevant immunologic diseases associated with DAH are discussed, and a diagnostic flowchart is proposed to establish a "definitive" diagnosis of IPH within the spectrum of DAH. IPH is a rare cause of recurrent DAH both in children and adults. In adults, a definitive diagnosis of IPH requires a lung biopsy and histopathologic examination demonstrating intraalveolar hemorrhage, hemosiderin-laden macrophages, and a variable degree of fibrosis in the absence of both capillaritis and cellular inflammation. The presence of small vessel vasculitis points towards immunologic, well-differentiated, or sometimes undifferentiated rheumatologic diseases. However, it is essential to recognize that many rheumatologic diseases may in the initial phase present with DAH without any evidence of capillaritis, thus mimicking IPH. Although not definitely established, it is likely that immunologic processes are involved in IPH, and we, therefore, suggest the consideration of a more suitable term for the disease, e.g., "Immune-mediated Pulmonary Hemosiderosis" to acknowledge the aberrancy in the immune parameters and a positive response to immunosuppressive therapy.

Different Types of ANCA Determine Different Clinical Phenotypes and Outcome in ANCA-Associated Vasculitis (AAV)

Aim

Accumulating evidence supports the use of antineutrophil cytoplasmic antibody (ANCA) type to classify different clinical entities. We aimed to evaluate whether the presence and type of ANCA determine different diseases, based on clinical phenotypes, renal involvement, and response to treatment.

Patients and Methods

Differences in terms of clinical manifestations, disease activity, laboratory parameters, and histology were recorded between patients with focal necrotizing glomerulonephritis (FNGN) due to myeloperoxidase (MPO-), proteinase 3-ANCA(+) [PR3-ANCA(+)], and ANCA(-) disease at time of diagnosis. Patients were treated with the same protocol and followed-up for 24 months, in a scheduled basis of every month for the first year and every 3 months for the second year. Primary end points were: (i) Combined end-stage renal disease (ESRD) and/or death and (ii) The presence of major or minor relapse during follow-up and secondary endpoint was the combination of ESRD and reduction of estimated glomerular filtration rate (eGFR) ≥ 50%.

Results

A total of 92 patients (M/F 39/53, mean age 59.1 ± 15 years) diagnosed with FNGN due to ANCA-associated vasculitis (AAV), 36 (39.1%) patients diagnosed with PR3-ANCA, 39 (42.4%) patients diagnosed with MPO-ANCA, and 17 (18.5%) patients diagnosed with ANCA(-) were included. Number of involved systems differed significantly between PR3-, MPO-ANCA, and ANCA(-), with only renal involvement in 3, 25.5, and 29% of patients, two systems involved in 33, 31, and 59% of patients, and > 3 systems involved in 64, 43.5, and 12% of patients, respectively (p = 0.002). Histology classification revealed focal, crescentic, mixed, and sclerotic type in 14, 64, 19, and 3% of PR3-ANCA(+), 8, 28, 18, and 46% of MPO-ANCA, and 41, 29, 6, and 24% of ANCA(-), respectively (p < 0.0001). Primary end point of ESRD ± Death was reached in 11 (30.6%), 16 (41%), and 6 (35.5%) patients with PR3-ANCA(+), MPO-ANCA(+), and ANCA(-), respectively (p = NS); similarly, ESRD± > 50% eGFR reduction in 8 (22.2%), 15 (38.5%), and 5 (29.4%) patients, respectively (p = NS), meaning that patients with MPO-ANCA(+) showed a propensity to decline renal function. Rate of relapse was increased in the presence of patients with PR3-ANCA(+), 14 (38.9%), 4 (11.8%), and 2 (10.3%) of patients with PR3-ANCA(+), MPO-ANCA(+), and ANCA(-), had at least one relapse during the two-year follow-up (p = 0.006).

Conclusion

Clinical phenotype and renal histology differ significantly between PR3-ANCA(+), MPO-ANCA(+), and ANCA(-) disease and FNGN; however, renal function outcome is similar, despite the increased rate of relapses in patients with PR3-ANCA(+).

Antineutrophil cytoplasmic antibody-negative granulomatosis with polyangiitis localized to the lungs

Patients with granulomatosis with polyangiitis (GPA), formerly known as Wegener's granulomatosis, sometimes exhibit no clinical features. Here, we describe a case of antineutrophil cytoplasmic antibody (ANCA)-negative GPA presenting with only lung granuloma. A 55-year-old woman with a right upper lung mass underwent lobectomy for suspected lung cancer; however, only granuloma was detected, and the etiology was not identified. Serum ANCA results were negative. Four years postoperatively, another pulmonary nodule appeared in the left lung's apex. The kidneys and sinuses were not impaired, but re-examination of the resected specimen revealed necrotizing vasculitis and granulomas around the vessels. Thus, the patient was diagnosed with GPA localized to the lungs. Although this was a non-life-threatening disease, the patient was administered oral prednisolone (PSL) and intravenous cyclophosphamide (IVCY) to prevent fatal complications of GPA as she was non-elderly and had no comorbidities, leading to a decrease in the mass size. Detailed re-examination by expert pulmonary pathologists could aid in GPA diagnosis when clinical features are absent, as in our case. In patients with granulomas of unknown etiology, a careful multidisciplinary approach is pivotal in the diagnosis. If patients tolerate adverse effects, a PSL and IVCY combination may prevent fatal outcomes, even in patients with non-life-threatening disease.

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.

De-Novo Antineutrophil Cytoplasmic Antibody-Associated Vasculitis Following the mRNA-1273 (Moderna) Vaccine for COVID-19

Antineutrophil cytoplasmic antibody (ANCA) is a systemic autoimmune disorder characterized by antibodies directed against small- and moderate-sized vessels. While there are few reported cases of autoimmune illnesses associated with influenza vaccination, two cases of de-novo anti-proteinase (PR3) ANCA-associated pauci immune glomerulonephritis are reported after the mRNA-1273 coronavirus disease 2019 (COVID-19) vaccine. Here, we report the third case of ANCA-associated glomerulonephritis after the mRNA-1273 COVID-19 vaccine. Our patient presented with acute kidney injury and sub-nephrotic proteinuria four days after receiving the second dose of the COVID vaccine. He was found to have elevated c-ANCA and anti-PR3 antibodies. Renal biopsy confirmed focal necrotizing and diffuse crescentic glomerulonephritis. He was diagnosed with pauci immune glomerulonephritis. The patient achieved remission 10 weeks after the diagnosis with successful treatment.

Successful Rituximab Treatment in a Patient With ANCA-Negative Granulomatosis With Polyangitis: A Case Report

A 68-year-old woman was referred to our hospital for further evaluation of fever, nasal congestion, deafness, and multiple pulmonary nodules refractory to antibiotic use. Despite negative findings of antineutrophil cytoplasmic antibodies, she was diagnosed with granulomatosis with polyangiitis based on the analysis of biopsy specimens of pulmonary nodules. The administrations of oral prednisolone and six intravenous cyclophosphamide (IVCY) resulted in the prompt relief of symptoms and disappearance of pulmonary nodules. However, 3 months after the completion of IVCY therapy, nasal congestion and deafness flared up with an increase in the C-reactive protein level; a repeat computed tomography revealed a left lung nodule. Consequently, she underwent remission induction and maintenance therapy with rituximab (RTX), which resulted in the symptomatic improvement and disappearance of pulmonary nodule after 6 months. The patient remained in remission thereafter. Therefore, RTX may be an effective therapeutic option even in the absence of detectable autoantibodies.

Construction of an MRI-based decision tree to differentiate autoimmune and autoinflammatory inner ear disease from chronic otitis media with sensorineural hearing loss

Autoimmune and autoinflammatory inner ear diseases (AIED/AID) are characterized by the symptom of sensorineural hearing loss (SNHL). To date, standardized diagnostic tools for AIED/AID are lacking, and clinically differentiating AIED/AID from chronic otitis media (COM) with SNHL is challenging. This retrospective study aimed to construct a magnetic resonance imaging (MRI)-based decision tree using classification and regression tree (CART) analysis to distinguish AIED/AID from COM. In total, 67 patients were enrolled between January 2004 and October 2019, comprising AIED/AID (n = 18), COM (n = 24), and control groups (n = 25). All patients underwent 3 T temporal bone MRI, including post-contrast T1-weighted images (postT1WI) and post-contrast FLAIR images (postFLAIR). Two radiologists evaluated the presence of otomastoid effusion and inner ear contrast-enhancement on MRI. A CART decision tree model was constructed using MRI features to differentiate AIED/AID from COM and control groups, and diagnostic performance was analyzed. High-intensity bilateral effusion (61.1%) and inner ear enhancement (postFLAIR, 93.8%; postT1WI, 61.1%) were the most common findings in the AIED/AID group. We constructed two CART decision tree models; the first used effusion amount as the first partitioning node and postT1WI-inner ear enhancement as the second node, whereas the second comprised two partitioning nodes with the degree of postFLAIR-enhancement of the inner ear. The first and second models enabled distinction of AIED/AID from COM with high specificity (100% and 94.3%, respectively). The amount of effusion and the degree of inner ear enhancement on MRI may facilitate the distinction between AIED/AID and COM with SNHL using decision tree models, thereby contributing to early diagnosis and intervention.

A rare case of coexistence of Wegener's granulomatosis and pulmonary tuberculosis with subsequent development of thrombosis of the cerebral veins

BACKGROUND

Granulomatosis with polyangiitis (GPA), also known as Wegener's granulomatosis, is an idiopathic systemic disease typically affecting the lungs, although other organs may also be involved.

CASE PRESENTATION

A 28-year-old male was admitted to Baqiyatallah university hospital in Teheran (Iran) after a 3-week history of fever and productive cough. The patient gradually developed fatigue, arthralgia, hematuria, nausea, vomiting, dyspnea, hemoptysis, weight loss, oliguria and then anuria. Chest-X-ray (CXR) and computerized tomography scan revealed cavitating nodular opacities in the right lung lobe. Furthermore, plasma creatinine increased from 2.2 to 4 mg/dl in a few days. Histopathological examination of kidney biopsy revealed peri-glomerular and peri-vascular inflammation, degeneration and necrosis of the tubular epithelial lining, red blood cell casts, distorted glomerular structure, fibrin thrombi, segmental breaks of the glomerular basal membrane, disruption of Bowman's capsular membrane and crescent formation of the affected glomeruli. An abnormal CXR, an abnormal urinary sediment and a typical kidney histology were used as criteria to diagnose glomerulonefritis with poliangiitis (GPA). Bronchoalveolar lavage smear and PCR turned out positive for mycobacterium tuberculosis. After 3 months of treatment for (GPA) and tuberculosis the patient developed headache and seizure. Cerebral Magnetic Resonance Venography revealed cerebral venous thrombosis of the sinus transverse and sigmoid.

CONCLUSIONS

Tuberculosis may coexist with GPA, as it occurred in our patient. Since a crescentic glomerulonephritis can progress to renal failure, clinicians should always be aware of potential multiple conditions when considering differential diagnoses.

Challenging Mimickers in the Diagnosis of Sarcoidosis: A Case Study

Sarcoidosis is a systemic granulomatous disease of unknown cause characterized by a wide variety of presentations. Its diagnosis is based on three major criteria: a clinical presentation compatible with sarcoidosis, the presence of non-necrotizing granulomatous inflammation in one or more tissue samples, and the exclusion of alternative causes of granulomatous disease. Many conditions may mimic a sarcoid-like granulomatous reaction. These conditions include infections, neoplasms, immunodeficiencies, and drug-induced diseases. Moreover, patients with sarcoidosis are at risk of developing opportunistic infections or lymphoma. Reliably confirming the diagnosis of sarcoidosis and better identifying new events are major clinical problems in daily practice. To address such issues, we present seven emblematic cases, seen in our department, over a ten-year period along with a literature review about case reports of conditions misdiagnosed as sarcoidosis.

Phase IIa Global Study Evaluating Rituximab for the Treatment of Pediatric Patients With Granulomatosis With Polyangiitis or Microscopic Polyangiitis

Objective

To assess the safety, tolerability, pharmacokinetics, and efficacy of rituximab (RTX) in pediatric patients with granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA).

Methods

The Pediatric Polyangiitis Rituximab Study was a phase IIa, international, open‐label, single‐arm study. During the initial 6‐month remission‐induction phase, patients received intravenous infusions of RTX (375 mg/m² body surface area) and glucocorticoids once per week for 4 weeks. During the follow‐up period, patients could receive further treatment, including RTX, for GPA or MPA. The safety, pharmacokinetics, pharmacodynamics, and exploratory efficacy outcomes with RTX were evaluated.

Results

Twenty‐five pediatric patients with new‐onset or relapsing disease were enrolled at 11 centers (19 with GPA [76%] and 6 with MPA [24%]). The median age was 14 years (range 6–17 years). All patients completed the remission‐induction phase. During the overall study period (≤4.5 years), patients received between 4 and 28 infusions of RTX. All patients experienced ≥1 adverse event (AE), mostly grade 1 or grade 2 primarily infusion‐related reactions. Seven patients experienced 10 serious AEs, and 17 patients experienced 31 infection‐related AEs. No deaths were reported. RTX clearance correlated with body surface area. The body surface area–adjusted RTX dosing regimen resulted in similar exposure in both pediatric and adult patients with GPA or MPA. Remission, according to the Pediatric Vasculitis Activity Score, was achieved in 56%, 92%, and 100% of patients by months 6, 12, and 18, respectively.

Conclusion

In pediatric patients with GPA or MPA, RTX is well tolerated and effective, with an overall safety profile comparable to that observed in adult patients with GPA or MPA who receive treatment with RTX. RTX is associated with a positive risk/benefit profile in pediatric patients with active GPA or MPA.

Nodular Pachymeningitis Associated With Relapsing Polychondritis and Crohn Disease Responsive to Adalimumab and Prednisone

Objectives

To review the previous literature on the associations of pachymeningitis with Crohn disease (CD) and relapsing polychondritis (RP) and to describe a new case occurring in association with both in addition to highlighting its positive response to steroid and adalimumab treatment.

Methods

We review the patient's clinical presentation, diagnostic workup (serum and CSF testing), and MRI findings in detail and chronicle the response of the pachymeningitis to intensive immunotherapy. We contrast this case against previous reports of pachymeningitis occurring in association with RP and inflammatory bowel disease that were found on PubMed.

Results

Only 2 cases of ulcerative colitis and 5 cases of RP were found in association with pachymeningitis; there were no cases in association with CD. Our patient presented with symptoms isolated to a steroid-responsive headache in the setting of normal neurologic and rheumatologic examinations. Her preceding history was notable for long-standing CD and increasingly active symptoms referable to RP. Focal nodular pachymeningitis was seen overlying the left hemisphere on brain MRI. An extensive serum and CSF workup and body fluorodeoxyglucose-PET scan failed to identify an alternative etiology beyond her underlying autoimmune inflammatory disorders. After adding prednisone and adalimumab to her preexisting treatment of methotrexate, she responded dramatically both clinically and radiographically.

Conclusions

Although exceptionally rare, pachymeningitis may occur as a neuroinflammatory complication of CD and RP.

ANCA Status or Clinical Phenotype - What Counts More?

PURPOSE OF REVIEW

There is ongoing debate concerning the classification of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. That is, whether classification should be based on the serotype (proteinase 3 (PR3)- or myeloperoxidase (MPO)-ANCA) or on the clinical phenotype (granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA)). To add clarity, this review focused on integration of the most recent literature.

RECENT FINDINGS

Large clinical trials have provided evidence that a serology-based risk assessment for relapses is more predictive than distinction based on the phenotype. Research conducted in the past decade indicated that a serology-based approach more closely resembles the genetic associations, the clinical presentation (i.e., lung involvement), biomarker biology, treatment response, and is also predicting comorbidities (such as cardiovascular death). Our review highlights that a serology-based approach could replace a phenotype-based approach to classify ANCA-associated vasculitides. In future, clinical trials and observational studies will presumably focus on this distinction and, as such, translate into a "personalized medicine."

ANCA-Associated Vasculitis: An Update

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) represents a group of small vessel vasculitides characterized by granulomatous and neutrophilic tissue inflammation, often associated with the production of antibodies that target neutrophil antigens. The two major antigens targeted by ANCAs are leukocyte proteinase 3 (PR3) and myeloperoxidase (MPO). AAV can be classified into 3 categories based on patterns of clinical involvement: namely, granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA) and eosinophilic GPA (EGPA). Clinically, AAV involves many organ systems including the lungs, kidneys, skin, and nervous system. The prognosis of AAV has improved dramatically due to advances in the understanding of its pathogenesis and treatment modalities. This review will highlight some of the recent updates in our understanding of the pathogenesis, clinical manifestations, and treatment options in patients with AAV focusing on kidney involvement.

All-cause and cause-specific mortality in ANCA-associated vasculitis: overall and according to ANCA type

OBJECTIVE

The objective of this study was to evaluate causes of death in a contemporary inception cohort of ANCA-associated vasculitis patients, stratifying the analysis according to ANCA type.

METHODS

We identified a consecutive inception cohort of patients newly diagnosed with ANCA-associated vasculitis from 2002 to 2017 in the Partners HealthCare System and determined vital status through the National Death Index. We determined cumulative mortality incidence and standardized mortality ratios (SMRs) compared with the general population. We compared MPO- and PR3-ANCA+ cases using Cox regression models.

RESULTS

The cohort included 484 patients with a mean diagnosis age of 58 years; 40% were male, 65% were MPO-ANCA+, and 65% had renal involvement. During 3385 person-years (PY) of follow-up, 130 patients died, yielding a mortality rate of 38.4/1000 PY and a SMR of 2.3 (95% CI: 1.9, 2.8). The most common causes of death were cardiovascular disease (CVD; cumulative incidence 7.1%), malignancy (5.9%) and infection (4.1%). The SMR for infection was greatest for both MPO- and PR3-ANCA+ patients (16.4 and 6.5). MPO-ANCA+ patients had an elevated SMR for CVD (3.0), respiratory disease (2.4) and renal disease (4.5). PR3- and MPO-ANCA+ patients had an elevated SMR for malignancy (3.7 and 2.7). Compared with PR3-ANCA+ patients, MPO-ANCA+ patients had a higher risk of CVD death [hazard ratio 5.0 (95% CI: 1.2, 21.2]; P = 0.03].

CONCLUSION

Premature ANCA-associated vasculitis mortality is explained by CVD, infection, malignancy, and renal death. CVD is the most common cause of death, but the largest excess mortality risk in PR3- and MPO-ANCA+ patients is associated with infection. MPO-ANCA+ patients are at higher risk of CVD death than PR3-ANCA+ patients.

Granulomatous interstitial nephritis in granulomatosis with polyangiitis mimicking leprosy: A case report

Granulomatous polyangiitis (GPA) is a small vessel vasculitis commonly affecting the upper and lower respiratory tracts and kidneys. About 90% of the cases are associated with ANCA, namely, PR3-ANCA and MPO-ANCA. Herein, we describe a patient of GPA who presented with anasarca, sensory neuropathy, recurrent upper airway congestion, epistaxis, and rapidly progressive glomerulonephritis. Granulomatous interstitial nephritis and necrotizing granulomatous inflammation of the nasal septum were found on biopsy of the kidney and nasal septum, respectively both of which are rare findings. PR3-ANCA and MPO-ANCA were negative. Fulfilling the ACR criteria, this case of GPA proves that biopsy is still the gold standard of diagnosis.

Relapse rate and renal prognosis in ANCA-associated vasculitis according to long-term ANCA patterns

Long-term observation of patients with ANCA-associated vasculitis (AAV) allows the identification of different longitudinal patterns of ANCA levels during follow-up. This study aimed to characterize these patterns and to determine their prognostic significance. All ANCA determinations performed in two university hospitals during a 2-year period were retrospectively reviewed. Patients were included in the analysis if they had high titers of anti-myeloperoxidase (anti-MPO) or anti-proteinase 3 (anti-PR3) antibodies at least once, ≥ 5 serial ANCA determinations and AAV diagnosed by biopsy or American College of Rheumatology (ACR) classification criteria. Patients' time-course ANCA patterns were classified as monophasic, remitting, recurrent or persistent. Associations between ANCA patterns and prognostic variables (relapse rate and renal outcome) were analysed by univariate and multivariate statistics. A total of 99 patients [55 with microscopic polyangiitis (MPA), 36 with granulomatosis with polyangiitis (GPA) and eight with eosinophilic granulomatosis with polyangiitis (EGPA)] were included. Median follow-up was 9 years. Among patients diagnosed with MPA or GPA, recurrent or persistent ANCA patterns were associated with a higher risk of clinical relapse [hazard ratio (HR) = 3·7, 95% confidence interval (CI) = 1·5-9·1 and HR = 2·9, 95% CI = 1·1-8·0, respectively], independently of clinical diagnosis or ANCA specificity. In patients with anti-MPO antibodies, the recurrent ANCA pattern was associated with worsening renal function [odds ratio (OR) = 5·7, 95% CI = 1·2-26·0]. Recurrent or persistent ANCA patterns are associated with a higher risk of clinical relapse. A recurrent ANCA pattern was associated with worsening renal function in anti-MPO-associated vasculitis.

Hypophysitis in granulomatosis with polyangiitis: rare presentation of a multisystem disease

Granulomatosis with polyangiitis (GPA) is a type of granulomatous vasculitis that can involve any organ in the body. The pituitary gland is one of the uncommon sites to be involved in this condition, with only a few cases reported in the literature. Our patient initially presented with central diabetes insipidus, epistaxis and haematuria. Diagnosis was established by antineutrophil cytoplasmic antibodies (cANCA) positivity against a background of typical clinical features and a bulky pituitary on magnetic resonance imaging (MRI) scan. Patient was started on steroids and methotrexate which were later changed to mycophenolate mofetil due to intolerance. Due to the refractory nature of the disease the patient was treated with one course of rituximab. Since then she has not had epistaxis, joint pains or haematuria. She continues to have diabetes insipidus although the requirement of desmopressin has come down. We thus report a case of GPA with hypophysitis which is one of the rare manifestations of the disease.

Localized Granulomatous with Polyangiitis (GPA): Varied Clinical Presentations and Update on Treatment

PURPOSE OF REVIEW

Granulomatosis with polyangiitis is a primary systemic vasculitis commonly described with the typical triad of upper airway, lung, and kidney involvement. Upper and lower airway involvement is characteristic in patients with granulomatosis with polyangiitis and can sometimes represent the initial or in some instances the sole manifestation. The objective of this review is to summarize the various clinical manifestations of localized disease in GPA and their treatment.

RECENT FINDINGS

Sinonasal disease is seen in up to 90% of patients. Otologic and ocular involvement is also commonly seen. Laryngeal and tracheal disease although less common is associated with significant morbidity and can be therapeutically challenging. Clinicians need to be aware of these localized GPA manifestations as they may be presenting disease features in the absence of other systemic findings. Treatment of localized GPA involves both immunosuppressive and surgical interventions for specific manifestations. Collaboration between specialists including rheumatologists, otolaryngologists, and ophthalmologists is often crucial to ensure optimal outcomes for patients. This is a narrative review that provides a comprehensive overview of localized granulomatosis with polyangiitis and current treatment options.

When Anti-Neutrophil Cytoplasmic Antibody Fails: A Case of Anti-Neutrophil Cytoplasmic Antibody Negative Granulomatosis With Polyangiitis

Granulomatosis with polyangiitis (GPA) is a vasculitis of small and medium-sized vessels and presents with varying signs and symptoms. It includes upper and lower airway manifestations and glomerulonephritis with a positive antineutrophil cytoplasmic antibody (ANCA) in serology in 90% of cases. However, about 10% of cases with GPA can have negative serology, often resulting in a diagnostic delay. Obtaining a tissue pathology is needed to confirm GPA. Here we present a 77-year-old male who presented with generalized weakness and loss of appetite and was found to have glomerulonephritis and bilateral opacities in the lungs with a negative ANCA. He was diagnosed with ANCA negative granulomatosis with polyangiitis after a renal biopsy revealed necrotizing inflammation with crescent formation. He was successfully treated with systemic glucocorticoids and rituximab. In conclusion, prompt diagnosis and treatment of ANCA negative vasculitis are required to decrease mortality.

Management of ANCA associated vasculitis

Anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV) is a small to medium vessel vasculitis associated with excess morbidity and mortality. This review explores how management of AAV has evolved over the past two decades with pivotal randomized controlled trials shaping the management of induction and maintenance of remission. Contemporary AAV care is characterized by approaches that minimize the cumulative exposure to cyclophosphamide and glucocorticoids, increasingly use rituximab for remission induction and maintenance, and consider therapies with less toxicity (for example, methotrexate, mycophenolate mofetil) for manifestations of AAV that do not threaten organ function or survival. Simultaneously, improvements in outcomes, such as renal and overall survival, have been observed. Additional trials and observational studies evaluating the comparative effectiveness of agents for AAV in various patient subgroups are needed. Prospective studies are necessary to assess the effect of psychosocial interventions on patient reported outcomes in AAV. Despite the expanding array of treatments for AAV, little guidance on how to personalize AAV care is available to physicians.

Rapidly progressive course of pauci-immune pulmonary capillaritis in a 70-year-old Asian male refractory to immunosuppression and plasma exchange

A 70-year-old man presented with acute respiratory failure, alveolar infiltrates and haemoptysis requiring supplemental oxygen. Flexible bronchoscopy with bronchoalveolar lavage identifies diffuse alveolar haemorrhage. Clinical and serological evaluations do not identify a precise aetiology and histopathology establishes the diagnosis of isolated pauci-immune pulmonary capillaritis. The patient received induction therapy with high dose methylprednisolone at 1000 mg/day for 5 days and weekly rituximab at 375 mg/m² scheduled over 4 weeks. Although the patient demonstrated clinical improvement after the first week, he experienced a rapid relapse requiring mechanical ventilation. His induction rituximab regimen was continued and plasma exchange was initiated. Despite these therapies, the patient's condition deteriorated and passed away. Our case adds insight to the management of this rare entity and describes the use of plasma exchange as salvage therapy.

Personalized Medicine in ANCA-Associated Vasculitis ANCA Specificity as the Guide?

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a small- to medium-vessel necrotizing vasculitis responsible for excess morbidity and mortality (1). The AAVs, which include granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA), are among the most difficult types of vasculitis to treat. Although clinicopathologic disease definitions have been used traditionally to categorize patients into one of these three diagnoses, more recently ANCA specificity for either proteinase 3 (PR3) or myeloperoxidase (MPO) has been advocated for the purpose of disease classification (2). This is because differences in genetics, pathogenesis, risk factors, treatment responses, and outcomes align more closely with PR3- or MPO-ANCA type than with the clinocopathologic diagnosis. Moreover, classifying patients as GPA or MPA can be challenging because biopsies are not obtained routinely in most cases and existing classification systems can provide discrepant classification for the same patient (3). In this review, we address the recent literature supporting the use of ANCA specificity to study and personalize the care of AAV patients (Table 1). We focus particularly on patients with GPA or MPA.

A Case of Granulomatosis with Polyangiitis: Consequences of Delayed Diagnosis in a Life-threatening Malady

Granulomatosis with polyangiitis (GPA) is one of three described anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV). Early diagnosis and treatment of GPA is paramount, as it may help prevent irreversible end-organ damage, especially renal and pulmonary failure. A 72-year-old male with a past medical history of lung adenocarcinoma in remission, chronic sinusitis status-post multiple sinus surgeries, and coronary artery disease presented with shortness of breath, dark urine, and asymmetric polyarthralgias. He had an acute kidney injury, leukocytosis, with urinalysis demonstrating pyuria and hematuria, without casts. Chest imaging showed cavitary nodular opacities in addition to interval increase of existing nodules compared to the most recent scan one month prior. His acute kidney injury progressed to renal failure requiring hemodialysis, and he developed an inflammatory polyarthritis. GPA was suspected clinically so he was started on high-dose intravenous corticosteroids, and subsequently plasmapheresis and rituximab. Serology returned with highly positive proteinase-3 antibodies, and cytoplasmic ANCA positivity on immunofluorescence. Renal biopsy demonstrated severely active pauci-immune glomerulonephritis. Several months after discharge, the patient passed away from gram positive bacteremia. This patient's recurrent sinusitis, pulmonary nodules, and subsequent renal failure were highly suggestive of GPA. A biopsy is recommended to confirm the diagnosis of GPA, but treatment should not be delayed if there is a high index of suspicion for the disease. Induction therapy with corticosteroids combined with rituximab or cyclophosphamide has significantly decreased the mortality of patients with GPA. Patients with GPA often have preceding history of nasopharyngeal and upper airway disease, and can present with fluctuating pulmonary infiltrates. Early recognition and treatment of patients with GPA can prevent life-threatening complications and reduce mortality.

A severe pleural complication associated with granulomatosis with polyangiitis

We describe the case of a previously healthy male patient who presented to a respiratory clinic with sinusitis, pulmonary cavities, and hemoptysis. Three weeks following a diagnosis of Granulomatosis with Polyangiitis (GPA) and initiation of immunosuppressive treatment, the patient suddenly developed a large pneumothorax that was complicated by empyema. In this report we discuss and highlight the rare pleural complications associated with GPA, and alert clinicians to monitor for these important complications even after disease-modifying treatment is initiated.

Remote Activation of a Latent Epitope in an Autoantigen Decoded With Simulated B-Factors

Mutants of a catalytically inactive variant of Proteinase 3 (PR3)—iPR3-Val¹⁰³ possessing a Ser195Ala mutation relative to wild-type PR3-Val¹⁰³—offer insights into how autoantigen PR3 interacts with antineutrophil cytoplasmic antibodies (ANCAs) in granulomatosis with polyangiitis (GPA) and whether such interactions can be interrupted. Here we report that iHm5-Val¹⁰³, a triple mutant of iPR3-Val¹⁰³, bound a monoclonal antibody (moANCA518) from a GPA patient on an epitope remote from the mutation sites, whereas the corresponding epitope of iPR3-Val¹⁰³ was latent to moANCA518. Simulated B-factor analysis revealed that the binding of moANCA518 to iHm5-Val¹⁰³ was due to increased main-chain flexibility of the latent epitope caused by remote mutations, suggesting rigidification of epitopes with therapeutics to alter pathogenic PR3·ANCA interactions as new GPA treatments.