Review article: Drug-induced anti-neutrophil cytoplasmic antibody-associated vasculitis

Pathogenesis of Pulmonary Manifestations in ANCA-Associated Vasculitis and Goodpasture Syndrome

Pulmonary manifestations of vasculitis are associated with significant morbidity and mortality in affected individuals. They result from a complex interplay between immune dysregulation, which leads to vascular inflammation and tissue damage. This review explored the underlying pathogenesis of pulmonary involvement in vasculitis, encompassing various forms such as granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), eosinophilic granulomatosis with polyangiitis (EGPA), and anti-GBM disease. Mechanisms involving ANCA and anti-GBM autoantibodies, neutrophil activation, and neutrophil extracellular trap (NETs) formation are discussed, along with the role of the complement system in inducing pulmonary injury. Furthermore, the impact of genetic predisposition and environmental factors on disease susceptibility and severity was considered, and the current treatment options were presented. Understanding the mechanisms involved in the pathogenesis of pulmonary vasculitis is crucial for developing targeted therapies and improving clinical outcomes in affected individuals.

ANCA-associated vasculitis presenting with isolated neurological manifestations in a patient with cocaine abuse: a case report and literature review

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of rare conditions predominantly affecting small vessels of skin, musculoskeletal, pulmonary, renal, and rarely central and peripheral nervous systems. Isolated neurological manifestations of AAV are uncommon and challenging to diagnose. Cocaine has been reported as a potential trigger for the development of AAV. There are only a few case reports of isolated neurological involvement in cocaine-induced AAV with poorly characterized histopathological features. We present a unique case of AAV with isolated neurological manifestations presenting with multiple cranial neuropathies, leptomeningeal enhancement on imaging and histopathologic evidence of small-vessel vasculitis in the leptomeninges and brain and extensive dural fibrosis in a patient with cocaine abuse. The patient's progressive neurological deficits were controlled after starting immunosuppression with rituximab and prednisone. We also reviewed the literature to provide the diagnostic overview of AAV and evaluate intervention options. To our knowledge, this is the first case of AAV with isolated neurological manifestations and histopathologic evidence of small-vessel vasculitis in a patient with cocaine abuse. Patients with multiple cranial neuropathies and meningeal involvement should be screened for AAV, especially if they have a history of cocaine abuse.

An Unusual Presentation of Propylthiouracil-Induced Immunoglobulin A Vasculitis With Positive Anti-proteinase-3 and Anti-myeloperoxidase Antibodies

Propylthiouracil (PTU) has been identified as a known cause of anti-neutrophil cytoplasmic antibodies-associated vasculitis. However, the association between PTU and immunoglobulin A (IgA) vasculitis remains uncertain due to its rarity and diverse clinical presentation. Here, we report the case of a 57-year-old female with a past medical history of chronic leukopenia and Graves' disease treated with PTU that presented with pancytopenia and widespread non-blanching ecchymoses on the bilateral legs. A punch biopsy of the medial leg demonstrated IgA vasculitis and autoimmune antibody analysis revealed increased levels of anti-proteinase 3 antibodies compared to anti-myeloperoxidase antibodies. These findings led to the diagnosis of PTU-induced IgA vasculitis. Following the discontinuation of PTU, there was marked improvement in the appearance of the patient's cutaneous manifestations and hematological indices.

Propylthiouracil-Induced Antineutrophil Cytoplasmic Antibody-Associated Vasculitis with Overlap IgA Nephropathy: A Case Report

Background

The anti-thyroid medication propylthiouracil (PTU) is a recognised cause of drug-induced antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Pauci-immune crescentic glomerulonephritis is the characteristic feature of this condition on renal biopsy. We present a case of PTU-induced AAV with the unusual histological finding of overlap IgA nephropathy (IgAN) in a young female with treatment-resistant Graves' disease.

Case Report

A 26-year-old female presented with an acute kidney injury, macroscopic haematuria, and proteinuria 14 months after starting PTU for Graves' disease. She had a history of established thyroid eye disease and a previous severe adverse reaction to carbimazole. Her autoantibodies were strongly positive for myeloperoxidase-ANCA (199 U/mL). Renal biopsy demonstrated both necrotising crescentic glomerulonephritis and prominent (3+) mesangial deposition of IgA. She was treated with glucocorticoids and rituximab with sustained improvement in her renal function but persisting mild proteinuria and microscopic haematuria. PTU was ceased following a dose of radioactive iodine (RAI). Twelve months post-RAI, her Graves' orbitopathy remained stable, and her thyroid function was gradually normalising.

Conclusion

This was a case of drug-induced AAV with histological features of overlap IgAN. We suggest that this patient had pre-existing subclinical IgAN and then developed AAV secondary to PTU. The management of her thyroid disease was complex given the PTU-induced vasculitis, previous reaction to carbimazole, the risks of a thyroidectomy on immunosuppression, and the possible worsening of her eye disease with RAI. The glucocorticoids and Rituximab prescribed for vasculitis may have prevented the progression of her Graves' orbitopathy after RAI.

Diagnostic dilemma: drug-induced vasculitis versus systemic vasculitis

Drug-induced vasculitis can rarely cause inflammation and necrosis of blood vessel walls of both kidney and lung tissue. Diagnosis is challenging because of the lack of difference between systemic and drug-induced vasculitis in clinical presentation, immunological workup and pathological findings. Tissue biopsy guides diagnosis and treatment. Pathological findings must be correlated with clinical information to arrive at a presumed diagnosis of drug-induced vasculitis. We present a patient with hydralazine-induced antineutrophil cytoplasmic antibodies-positive vasculitis with a pulmonary-renal syndrome manifesting as pauci-immune glomerulonephritis and alveolar haemorrhage.

Late Onset of Rivaroxaban-Associated Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis

Although anti-thyroid drugs (ATDs) are the most common cause of drug-associated anti-neutrophil cytoplasmic antibody (ANCA) vasculitis (AAV), many other classes of drugs can lead to drug-associated AAV. We present a unique case of rivaroxaban-associated AAV. A 76-year-old female with a past medical history of atrial fibrillation on rivaroxaban presented with fatigue, bilateral lower extremity purpura, and hemoptysis to an outside hospital. Investigations revealed a positive cytoplasmic-ANCA (c-ANCA) titer of 1:320 and a positive anti-myeloperoxidase (anti-MPO), and negative perinuclear-ANCA (p-ANCA) and anti-proteinase 3 (anti-PR3). In addition, chest imaging demonstrated bilateral ground-glass opacities which raised suspicion for diffuse alveolar hemorrhage (DAH). A lung biopsy revealed acute and ongoing DAH with focally active capillaritis and characteristic pathological findings, which strongly suggested that was likely secondary to rivaroxaban. Rivaroxaban was discontinued, and the patient received pulses of intravenous glucocorticosteroids and rituximab. Her symptoms improved. She continued immunosuppressive therapy with rituximab for 2 years. She presented to our hospital for a second opinion regarding the discontinuation of rituximab, and we decided to discontinue rituximab. After discontinuation, the patient remained stable after 1.5 years of follow-up and did not have any relapses. This is a unique case of rivaroxaban-associated AAV. Clinicians should consider drug-associated AAV in all patients who present with an atypical clinical presentation and/or pathological findings of AAV. Given the broad and rapidly increasing use of novel anticoagulants, it is important to raise awareness of this potential complication. Prompt discontinuation of the drug and initiation of immunosuppressant treatment in severe cases may be lifesaving.

Nitrofurantoin and Minocycline-Associated Vasculitic Neuropathy: Case Reports and Literature Review

BACKGROUND

Vasculitic neuropathies usually present acutely to subacutely, with an asymmetric pattern, involving multiple peripheral nerve territories. Drug-induced vasculitis is an often overlooked etiology of vasculitic neuropathy.

METHODS

We present the first reported case of nitrofurantoin-associated and an illustrative case of minocycline-associated vasculitic neuropathy, with a review of the literature.

RESULTS

The first patient is a 60-year-old woman who developed axonal sensorimotor peripheral neuropathy after nitrofurantoin use, with a superficial radial nerve biopsy confirming vasculitis. The second patient is a 23-year-old woman, with a history of acne vulgaris treated with minocycline, who presented with a subacute right common peroneal mononeuropathy followed by a left deep peroneal mononeuropathy, with elevated antinuclear, perinuclear-antineutrophil cytoplasmic, and myleoperoxidase antibodies, and MPO titers, and a sural nerve biopsy showing large arteriole vasculitis. Finally, we provide a comprehensive review of previously published cases.

CONCLUSIONS

Medications should be considered as a trigger for medication-induced vasculitic neuropathy. Accurate diagnosis would ensure timely treatment.

A case of crescentic glomerulonephritis induced by afatinib for lung adenocarcinoma

Afatinib is a second-generation, oral, epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI). One of the most common adverse effects of affatinib is diarrhea, which may lead to acute kidney injury (AKI) due to severe plasma volume loss; however, no case of glomerular injury directly induced by afatinib has been reported to date. Here, we describe the case of a 53-year-old Japanese male patient with advanced lung adenocarcinoma who twice developed AKI requiring dialysis, once after starting and once after increasing the dose of afatinib. Although serum anti-neutrophil cytoplasmic antibodies were negative, crescentic glomerulonephritis with no immune deposits was confirmed on kidney biopsy. No vasculitis-like signs were observed in other organs, such as lung, skin, or peripheral nerves. Afatinib was considered the cause of glomerular damage and was immediately discontinued; corticosteroids were administered. Renal function gradually recovered thereafter, with serum creatinine levels at ~ 2.3 mg/dL after second-line therapy with bevacizumab and atezolizumab. Several cases of cutaneous leukocytoclastic vasculitis have been reported in patients treated with other EGFR-TKIs; therefore, afatinib-induced vasculitis may lead to crescentic glomerulonephritis. Although afatinib-induced glomerular injury is extremely rare and has an unclear mechanism, renal function and urinary findings need to be closely monitored.

A Spotlight on Drug-Induced Vasculitis

PURPOSE OF REVIEW

Drug-induced vasculitis (DIV) is a rare form of vasculitis related to the use of various drugs. DIV primarily affects small to medium size vessels, but it can potentially involve vessels of any size. Differentiating between primary systemic vasculitis and DIV can be challenging; however, it is crucial, so that the offending agent can be discontinued promptly.

RECENT FINDINGS

The clinical phenotype of DIV is protean and depends on the size of the affected vessels. It ranges from arthralgias, to an isolated cutaneous rash, to severe single or multi-organ involvement. While withdrawal of the offending drug is the most important step in management, a significant number of patients require immunosuppressive therapy for varying periods of time. DIV can affect any vascular bed size, leading to protean vasculitic syndromes. Increased awareness among general practitioners, specialty, and subspecialty physicians is crucial for early recognition, and withdrawal of drug for better outcomes.

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.

Acute tubulointerstitial nephritis associated with antineutrophil cytoplasmic antibody following cimetidine treatment: a case report

Background

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis usually induces rapidly progressive glomerulonephritis, including pauci-immune necrotizing crescentic glomerulonephritis. Acute tubulointerstitial nephritis (ATIN), which is often drug-induced, is a frequent cause of kidney injury. However, ATIN associated with ANCA without any glomerular lesions has been rarely reported, and drug-induced ATIN associated with ANCA is not well recognized. Here we present a case of an older woman with ATIN associated with myeloperoxidase-ANCA (MPO-ANCA) following cimetidine treatment.

Case presentation

A 70-year-old woman was admitted to our hospital due to acute kidney injury and mild proteinuria. She had a one-year history of chronic thyroiditis and dyslipidemia, for which she was taking levothyroxine sodium and atorvastatin, respectively. Two weeks before admission she had started cimetidine, methylmethionine sulfonium chloride, and itopride hydrochloride for gastric discomfort persistent since a month. She had experienced fatigue for two weeks and later appetite loss. The patient demonstrated a positive titer for MPO-ANCA (192 IU/mL) and a positive drug-induced lymphocyte stimulation test for cimetidine. She underwent two kidney biopsies that revealed ATIN without any glomerular lesions. Despite discontinuation of cimetidine on admission, renal injury continued with the presence of high MPO-ANCA titer. Oral steroid treatment was closely related with the recovery of her renal function and disappearance of MPO-ANCA.

Conclusions

In this case, ATIN presented as sustained renal insufficiency and high MPO-ANCA titer despite withdrawal of cimetidine. Therefore, we reason that the development of ANCA-associated ATIN was caused by cimetidine. Serologic follow-up with measurement of MPO-ANCA titers and renal biopsy are recommended when the clinical history is inconsistent with the relatively benign course of drug-induced ATIN.

Propylthiouracil-Induced Antineutrophil Cytoplasmic Antibody-Associated Vasculitis after COVID-19 Vaccination

We report the case of a patient who developed antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) after receiving the coronavirus disease 2019 (COVID-19) vaccine BNT162b (Pfizer–BioNTech). A 37-year-old Japanese woman had been taking propylthiouracil for Graves’ disease. She had erythema on her forearm on the 12th day after receiving the first dose of the vaccine, fever on the 13th day, and redness and swelling of her left auricle on the 25th day. Her serum myeloperoxidase-ANCA and proteinase 3-ANCA levels, which were negative before the Graves’ disease treatment, were elevated. She had unilateral auricular symptoms but no other typical relapsing polychondritis findings. She was diagnosed with propylthiouracil-induced AAV. She was treated with oral glucocorticoids, and her symptoms improved. Propylthiouracil is considered to be the main cause of the onset of AAV in this case, but it cannot be ruled out that BNT162b may have had some effect on the onset of the disease. Although the development of propylthiouracil-induced AAV in this case may have been incidental and unrelated to the vaccination, this report provides important data for evaluating the safety of the vaccine.

Renal-limited ANCA-associated vasculitis during erlotinib treatment for lung carcinoma

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) had clinical success in the treatment of non-small cell lung carcinoma (NSCLC). An effect of this drug on kidney has not been clarified and the occurrence of glomerulonephritis related to EGFR-TKI has rarely been reported. We present the case of a 71-year-old man with NSCLC who developed proteinuria and microscopic hematuria with the rise in a titer of MPO-ANCA, when 2 years and 3 months passed since the initiation of erlotinib, one of oral EGFR-TKI. Two serial biopsies support that ANCA-associated vasculitis may have been modified by the persistent use of erlotinib. We initiated intravenous pulse therapy with methylprednisolone followed by oral prednisone. The proteinuria has decreased and serum CRP was normalized. However, the serum creatinine level and hematuria did not change during the treatment period. While EGFR inhibition is implicated in protective control for glomerulonephritis, it may exacerbate vasculitis. Close monitoring of the kidney function and urinary findings is required during the use of EGFR inhibitors, such as erlotinib, because it may cause renal adverse events.

A worldwide pharmacoepidemiological update of drug-associated ANCA-associated vasculitis at the time of targeted therapies

OBJECTIVE

The literature data supporting the role of a drug in the onset of drug-associated anti-neutrophil cytoplasmic antibody-associated vasculitis (DA-AAV) mainly rely on case reports or short series and implicate old treatments. The advent of new treatments may have modified the epidemiology of these adverse drug reactions (ADRs). We therefore aimed to update this list by using a pharmacovigilance-based data mining approach.

METHODS

We collected data on ADRs reported with the MedDRA preferred term "Anti-neutrophil cytoplasmic antibody positive vasculitis" up to November 2020 from the World Health Organization pharmacovigilance database (VigiBase^® ). For each retrieved drug, a case/noncase analysis was performed, and disproportionate reporting was calculated by using the information component (IC). A positive IC₀₂₅ value, which is the lower end of the 95% credibility interval, was considered significant.

RESULTS

A total of 483 deduplicated individual case safety reports of DA-AAV involving 15 drugs with an IC₀₂₅ >0 were retrieved. DA-AAV occurred in 264 (71.2%, n=371) women, the median age at onset was 62 years [45-72], and the median time to onset between the introduction of the suspected drug and DA-AAV was 9 months [1-36]. DA-AAV occurrence was considered serious in 472 (97.7%, n=481) cases and fatal in 43 (8.9%) cases. The drugs associated with the highest disproportionate reporting were hydralazine, propylthiouracil, thiamazole, sofosbuvir, minocycline, carbimazole, mirabegron, and nintedanib.

CONCLUSION

This study strengthens the previously suspected association but also identifies 3 new drugs that may cause DA-AAV. Particular attention should be given to these drugs by prescribers and in experimental studies.

[Purpura in a young woman with hyperthyroidism]

INTRODUCTION

Propylthiouracil (PTU) is a synthetic antithyroid drug that can induce ANCA-associated vasculitis.

OBSERVATION

A 27-year-old woman diagnosed with Graves' disease was on PTU for the past 10 years. She developed purpuric lesions of the legs and on the tip of the nose diagnosed as vasculitis. ANCAs were positive, with anti-MPO and anti-PR3 on blood ELISA. After discontinuation of PTU, she was able to fully recover.

CONCLUSION

All synthetic antithyroid drugs can induce ANCA-associated vasculitis, more often PTU. In most cases, antibodies are directed against MPO. Dual anti-MPO and anti-PR3 positivity is possible, but rare. The mechanism could be through an accumulation of PTU in neutrophils, altering the structure of MPO and making it immunogenic. PTU can also induce ANCA-free or lupus vasculitis, maculopapular rashes or urticaria. Many other drugs can induce ANCA-associated vasculitis.

The biology, pathogenetic role, clinical implications, and open issues of serum anti-neutrophil cytoplasmic antibodies

Anti-neutrophil cytoplasmic antibodies (ANCA) are a group of autoantibodies, predominantly IgG, involved in the pathogenesis of several autoimmune disorders, detected either through indirect immunofluorescence or enzyme-linked immunosorbent assay. By means of indirect immunofluorescence, the main patterns are C-ANCA (cytoplasmic) and P-ANCA (perinuclear), while proteinase 3 (PR3) and myeloperoxidase (MPO) represent the main autoantigens in granulomatosis with polyangiitis and microscopic polyangiitis, both belonging to the family of ANCA-associated vasculitis (AAV). While several experiments established the pathogenicity of MPO-ANCA, evidence remains elusive for PR3-ANCA and an additional target antigen, i.e. LAMP2, has been postulated with specific clinical relevance. The presence of a subset of AAV without ANCA may be explained by the presence of further target antigens or the presence of molecules in blood which make ANCA undetectable. A rise in ANCA titers is not necessarily predictive of a flare of disease in AAV if not accompanied by clinical manifestations. ANCA may develop through variable mechanisms, such as autoantigen complementarity, apoptosis impairment, neutrophil extracellular traps dysfunction and molecular mimicry. We will provide herein a comprehensive review of the available evidence on the biological mechanisms, pathogenetic role, and clinical implications of ANCA testing and disease management. Further, we will address the remaining open challenges in the field, including the role of ANCA in inflammatory bowel disease and in cocaine-induced vasculitis.

Successful treatment of G-CSF-related aortitis with prednisolone during preoperative chemotherapy for breast cancer: a case report

Background

With the introduction of dose-dense therapy, the use of primary pegfilgrastim (PEG-G) has been increasing in breast cancer treatment. A rare side effect of PEG-G is aortitis. We describe a case of PEG-G-induced aortitis.

Case presentation

The patient was a 43-year-old woman with stage IIA breast cancer. Due to the subtype of triple-negative breast cancer, preoperative dose-dense epirubicin–cyclophosphamide chemotherapy was started. PEG-G was administered on day 3 after the first cycle of epirubicin–cyclophosphamide chemotherapy. On day 11, she had a fever (39.4 °C) and an elevated C-reactive protein level (27.1 mg/dL). Emergency computed tomography revealed diffused wall thickening of the aortic arch without any other signs of infection. Despite administering antibiotics, her general condition and laboratory findings deteriorated until day 18. Based on these observations, she was diagnosed with PEG-G-induced aortitis. Antibiotics were discontinued, and she was treated with prednisolone thereafter. Subsequently, her clinical symptoms and laboratory findings improved around day 39. A second computed tomography scan revealed a decrease in the aortic arch wall thickening, and she was discharged on day 43.

Conclusions

We successfully treated PEG-G-induced aortitis using prednisolone. Although this side effect is rare, cancer patients receiving PEG-G for chemotherapy should be monitored for aortic inflammation.

The Clinical and Pathological Features of Children With Microscopic Polyangiitis

Objective: The aim of this study was to explore the clinical features, pathological characteristics, and the prognosis of children with microscopic polyangiitis (MPA). Methods: Ten children with MPA that were hospitalized in our hospital were included in this study. The children's pre-diagnosis status, clinical manifestations, renal pathology, treatment, and prognosis data were analyzed retrospectively. Results: All 10 cases included female patients with a median age of 8.9 years old at the time of diagnosis. MPO-ANCA antibody was positive in all cases, combined with a positive anti-GBM antibody in two cases. Nine cases had primary AAV and one had antithyroid drug (ATD)-associated MPA (secondary to methimazole). Renal involvement was found in all 10 patients, lung impairment was present in eight cases, and anemia was present in nine patients. Renal biopsies were performed in all 10 patients. Segmental focal or global glomerular necrosis was observed in 70% of the patients (7/10). The treatment mainly included steroid use combined with Cyclophosphamide and Mycophenolate. The follow-up s of the patients revealed normal renal function in eight patients and progression to end-stage renal disease (ESRD) in two patients. Conclusions: Female predisposition and positive MPO-ANCA antibody were prominent in children with MPA. The patients' kidneys and lungs were the most frequently involved organs. Corticosteroid combined with immunosuppressive therapy was recommended for the treatment of MPA. Early diagnosis, prompt aggressive treatment, and regular follow-ups are also very important factors associated with a good prognosis.

Contribution of HLA-DRB1 * 09: 01 allele to development of minocycline induced antineutrophil cytoplasmic antibody (ANCA)-associated cutaneous vasculitis: report of two cases

We report two cases of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) that developed after long-term oral administration of minocycline and consider the contribution of human leukocyte antigen (HLA)-DRB 1 * 09: 01 allele to its development. Case 1; A 47-year-old man receiving minocycline for palmoplantar pustulosis for 24 months developed fever, arthralgia, and irregular livedo on the bilateral lower legs. Skin biopsy demonstrated vasculitis, while a blood test showed positivity of myeloperoxidase (MPO)-ANCA. Discontinuation of minocycline and oral administration of prednisolone relieved the symptoms promptly. Case 2; A 53-year-old woman developed reddish-brown livedo reticularis with tenderness on the bilateral lower legs after administration of minocycline to treat palmoplantar pustulosis for 24 months. Although skin biopsy did not demonstrate vasculitis, a blood test showed MPO-ANCA positivity. Cessation of minocycline resulted in rapid improvement of the cutaneous lesions and constitutional symptoms. We diagnosed both cases as having Drug-associated ANCA-associated Vasculitis (DAV) caused by minocycline according to the diagnostic criteria proposed by Cluver et al. Further examination revealed the presence of HLA-DRB1 * 09:01 allele in both cases. This allele has been implicated in the genetic background of idiopathic microscopic polyangiitis (MPA) in the Japanese population. Our finding suggests a relationship between the development of MPO-ANCA or DAV caused by minocycline and HLA-DRB1 * 09:01 allele, but will have to confirmed by further studies with larger numbers of patients.

An unusual presentation of propylthiouracil-induced anti-MPO and PR3 positive ANCA vasculitis with associated anti-GBM antibodies, IgA nephropathy and an IgG4 interstitial infiltrate: a case report

Background

A number of disease processes can culminate in rapidly progressive glomerulonephritis, including pauci-immune focal segmental necrotising glomerulonephritis, usually seen with positive serum antineutrophil cytoplasmic antibodies (ANCA). Propylthiouracil (PTU) has been associated with drug-induced ANCA-associated vasculitis (AAV), with antibodies against myeloperoxidase (MPO) and proteinase 3 (PR3) present individually and together having been recognised. ‘Double-positive’ vasculitis with ANCA and anti-glomerular basement membrane (GBM) antibodies has also been reported in association with PTU treatment. We present a case of PTU-induced anti-MPO and PR3 positive ANCA vasculitis with associated anti-GBM antibodies, IgA nephropathy and an IgG4 interstitial infiltrate.

Case presentation

A 51-year-old man presented 2 weeks after re-commencing propylthiouracil (PTU) treatment for Graves’ disease, with a severe acute kidney injury and haemato-proteinuria. He demonstrated positive titres for autoantibodies to PR3 (76.9 IU/mL), MPO (28.8 IU/mL) and GBM (94 IU/mL). Renal biopsy demonstrated numerous glomerular crescents, widespread IgG4-positive lymphoplasmacytic infiltrate and mesangial positivity for IgA. PTU was stopped and he was treated with steroids, plasma exchange and cyclophosphamide with sustained improvement in his renal function.

Conclusions

This case of drug-induced AAV presented a unique and intriguing collection of serological and histological features. We propose that the PTU-induced AAV resulted in epiphenomena of anti-GBM antibody production and an IgG4-cell-rich tubulointerstitial infiltrate. It is uncertain whether the mesangial IgA deposition preceded or resulted from the AAV.

2020 international consensus on ANCA testing beyond systemic vasculitis

This document follows up on a 2017 revised international consensus on anti-neutrophil cytoplasm antibodies (ANCA) testing in granulomatosis with polyangiitis and microscopic polyangiitis and focuses on the clinical and diagnostic value of ANCA detection in patients with connective tissue diseases, idiopathic interstitial pneumonia, autoimmune liver diseases, inflammatory bowel diseases, anti-glomerular basement membrane (GBM) disease, infections, malignancy, and during drug treatment. Current evidence suggests that in certain settings beyond systemic vasculitis, ANCA may have clinical, pathogenic and/or diagnostic relevance. Antigen-specific ANCA targeting proteinase-3 and myeloperoxidase should be tested by solid phase immunoassays in any patient with clinical features suggesting ANCA-associated vasculitis and in all patients with anti-GBM disease, idiopathic interstitial pneumonia, and infective endocarditis associated with nephritis, whereas in patients with other aforementioned disorders routine ANCA testing is not recommended. Among patients with autoimmune liver diseases or inflammatory bowel diseases, ANCA testing may be justified in patients with suspected autoimmune hepatitis type 1 who do not have conventional autoantibodies or in case of diagnostic uncertainty to discriminate ulcerative colitis from Crohn's disease. In these cases, ANCA should be tested by indirect immunofluorescence as the target antigens are not yet well characterized. Many questions concerning the optimal use of ANCA testing in patients without ANCA-associated vasculitis remain to be answered.

Main tract stenosis complicated by granulomatous with polyangiitis: A case report

Granulomatosis with polyangiitis (GPA) is a rheumatic auto-immune disease involved in vasculitis. It is rarely reported that anti-neutrophil cytoplasmic antibodies (ANCAs) associated with GPA would cause main tract stenosis. The current report documents a 54-year-old woman, with a history of severe cough, presented with wheezing and shortness of breath. Although she was treated with cephalosporin antibiotics for half a month, the symptoms were not alleviated. Accordingly, laboratory testing, radiology and pathology was performed at the Department of Respiratory and Critical Care Medicine, Huashan Hospital. Blood samples were tested negative for ANCAs. Chest CT revealed stenosis of the main trachea and uneven thickening of the tracheal wall. Nasal sinuses CT scanning indicated thickening of the nasal mucosa. Pathological analysis demonstrated chronic granulomatous inflammation with focal lesions. According to the classification criteria of ACR/EULAR provisional 2017, the patient was diagnosed with the ANCAs-negative GPA. Following treatment with oral prednisone only for 6 months, obstruction of main tract was significantly improved. This case study is of interest for the promotion a potentially novel therapeutic intervention for GPA associated with the absence ANCA of in clinic.

Animal Models of ANCA Associated Vasculitis

Anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV) is a rare and severe autoimmune multisystemic disease. Its pathogenesis involves multiple arms of the immune system, as well as complex interactions between immune cells and target organs. Experimental animal models of disease can provide the crucial link from human disease to translational research into new therapies. This is particularly true in AAV, due to low disease incidence and substantial disease heterogeneity. Animal models allow for controlled environments in which disease mechanisms can be defined, without the clinical confounders of environmental and lifestyle factors. To date, multiple animal models have been developed, each of which shed light on different disease pathways. Results from animal studies of AAV have played a crucial role in enhancing our understanding of disease mechanisms, and have provided direction toward newer targeted therapies. This review will summarize our understanding of AAV pathogenesis as has been gleaned from currently available animal models, as well as address their strengths and limitations. We will also discuss the potential for current and new animal models to further our understanding of this important condition.

Pegfilgrastim-associated large-vessel vasculitis developed during adjuvant chemotherapy for breast cancer: A case report and review of the literature

Introduction

Granulocyte colony-stimulating factor (G-CSF) is widely used as a neutrophil supportive therapy in breast cancer chemotherapy. Common adverse events of G-CSF include bone pain, headache, and fatigue; however, reports of G-CSF-associated vasculitis are few.

Case report

A 66-year-old woman who had undergone surgery for breast cancer received adjuvant chemotherapy with prophylactic use of pegfilgrastim (peg-G). She developed peg-G-associated vasculitis 11 days after initially receiving peg-G. Management and outcome: Although various blood and culture tests were required to rule out other vasculitis syndromes and infections, her symptoms spontaneously disappeared without any treatment other than discontinuation of the causal drug.

Discussion

G-CSF-associated vasculitis is occasionally accompanied by severe complications such as aortic dissection and aneurysm formation. This case report is important to draw attention towards this rare and difficult-to-diagnosis adverse event of peg-G.

Propylthiouracil-induced antineutrophil cytoplasmic antibody-associated vasculitis and agranulocytosis in a patient with Graves' disease

SUMMARY

This case is the first to describe a patient who experienced concomitant agranulocytosis and anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis as an adverse effect of propylthiouracil treatment for Graves' disease. A 42-year-old female with Graves' disease presented to the emergency department (ED) with a 2-week history of fevers, night sweats, transient lower limb rash, arthralgia, myalgia and fatigue. She had been taking propylthiouracil for 18 months prior to presentation. On admission, agranulocytosis was evident with a neutrophil count of 0.36 × 109/L and immediately propylthiouracil was stopped. There was no evidence of active infection and the patient was treated with broad-spectrum antibodies and one dose of granulocyte colony-stimulation factor, resulting in a satisfactory response. On further investigation, ANCAs were positive with dual positivity for proteinase 3 and myeloperoxidase. There was no evidence of end-organ damage secondary to vasculitis, and the patient's constitutional symptoms resolved completely on discontinuation of the drug precluding the need for immunosuppressive therapy.

LEARNING POINTS

Continued vigilance and patient education regarding the risk of antithyroid drug-induced agranulocytosis is vital throughout the course of treatment. ANCA-associated vasculitis is a rare adverse effect of antithyroid drug use. Timely discontinuation of the offending drug is vital in reducing end-organ damage and the need for immunosuppressive therapy in drug-induced ANCA-associated vasculitis. Similarities in the pathogenesis of agranulocytosis and drug-induced ANCA-associated vasculitis may offer insight into an improved understanding of vasculitis and agranulocytosis.

Drug-induced anti-neutrophil cytoplasmic antibody-associated vasculitis

OBJECTIVE

In recent years, an increasing number of drugs have been proved to be associated with the induction of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). This article reviews the latest research progress on drug-induced AAV.

DATA SOURCES

We conducted a comprehensive and detailed search of the PubMed database. The search terms mainly included drug-induced, ANCA, and vasculitis.

STUDY SELECTION

We summarized the original articles and reviews on drug-induced AAV in recent years. The extracted information included the definition, epidemiology, associated drugs, pathogenesis, clinical features, diagnosis, treatment, and prognosis of drug-induced AAV. We also focused on the differences between drug-induced AAV and primary vasculitis.

RESULTS

The offending drugs leading to drug-induced AAV are almost from pharmacologic categories and we need to be vigilant when using these drugs. The pathogenesis of drug-induced AAV might be multifactorial. The formation of neutrophil extracellular traps is an important mechanism for the development of drug-induced AAV. The clinical features of drug-induced AAV are similar to those of primary AAV. Understanding the difference between drug-induced AAV and primary AAV is helpful to identify drug-induced AAV. Stopping the offending drug at once after diagnosis may be sufficient for those patients with mild symptoms. Immunosuppressive therapy should only be used in patients with vital organs involvement.

CONCLUSIONS

Patients with drug-induced AAV usually have a good prognosis if they stop using the offending drug immediately. Recent advances in research on AAV are expected to help us better understand the pathogenesis of drug-induced AAV.

Clozapine-induced antineutrophil cytoplasmic antibody-associated vasculitis: a case report

Clozapine is the most effective antipsychotic medication for refractory schizophrenia, but it has many possible serious side effects, including antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). However, the rare case reports available have not presented sufficient characteristic features of drug-induced AAV. Herein, we report a case of a 48-year-old Japanese woman with schizophrenia who presented with fever, arthralgia, myalgia and skin rash after 2 years of clozapine treatment. Her C-reactive protein (CRP) level increased, myeloperoxidase ANCA was positive and skin biopsy revealed leukocytoclastic vasculitis. Initially, steroid administration achieved remission, but her symptoms and high CRP levels relapsed every time the steroid dosage was tapered down. Upon discontinuation of clozapine, her symptoms and elevated CRP level immediately improved and the steroid was successfully tapered and discontinued. This outcome suggested that clozapine was the main cause of AAV.

Incidentally Diagnosed Alport Syndrome in a Patient with Drug-Induced Vasculitis

A 53-year-old woman is admitted with a serum creatinine of 16 mg/dl. Seven months earlier, she was diagnosed with heart failure and started on several medications, including Hydralazine. Laboratory studies revealed the presence of dual Anti-Neutrophil Cytoplasmic Antibodies (anti-MPO and anti-PR3), anti-nuclear and anti-histone antibodies. The clinical diagnosis was Drug-Induced ANCA Vasculitis (DIAV). Kidney histology, however, did not reveal crescents, but showed characteristic features of Alport's syndrome.

Laboratory Assessment of Patients with Suspected Rheumatic Musculoskeletal Diseases: Challenges and Pitfalls

Current patient care in rheumatology relies primarily on a combination of traditional clinical assessment and standard laboratory tests. Investigators seek to discover new biomarkers and novel technologies to boost the research in this field. Mechanistic biomarkers such as cytokines, cell types, antibodies, signaling molecules, are rooted in the mechanism underlying the disease and can guide the clinical management of the disease. Conversely, descriptive biomarkers are byproducts of the disease process, depict the state of a disease but are not involved in its pathogenesis. In this article, we reviewed the field of common laboratory biomarkers in rheumatology, highlighting both their descriptive or mechanistic value as well as their role in clinical practice.

Case report: de novo ANCA-associated vasculitis after kidney transplantation treated with rituximab and plasma exchange

Background

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis causes end-stage renal failure in up to a third of cases even with treatment. The disease recurs occasionally after kidney transplantation, but new onset of ANCA-associated vasculitis after transplantation is highly unusual. The use of rituximab or plasmapheresis for de novo disease after transplantation has not previously been reported.

Case presentation

Routine post-transplant follow-up for a 66-year old asymptomatic woman revealed a rise in creatinine from 1.8 to 2.6 mg/dl and increased proteinuria. She had received a cadaveric kidney transplant 20 months previously for end-stage autosomal dominant polycystic kidney disease. Renal allograft biopsy unexpectedly demonstrated pauci-immune glomerulonephritis with extracapillary proliferation and interstitial inflammation. Concurrent serum tested strongly positive for ANCA specific to proteinase 3 (PR3), but stored pre- and post-transplantation serum samples tested negative. These findings established a diagnosis of de novo ANCA-associated vasculitis in the renal allograft.

We started treatment with high-dose corticosteroid and rituximab. Despite this, serum creatinine continued to rise and glomerulonephritis remained active in a repeat biopsy. Escalation of the treatment with seven sessions of plasmapheresis led to a temporary improvement in creatinine. No further features of vasculitis emerged and PR3-ANCA titres declined. However, multiple infections complicated the recovery period and were associated with progressive loss of renal transplant function. Four months after the index presentation, transplant function became insufficient and dialysis was restarted.

Conclusions

De novo ANCA-associated vasculitis after renal transplantation is exceptionally rare. It poses a significant risk to graft survival even in the context of intensified immunosuppression. Management relies on clinical evidence from populations with native renal function, yet post-transplant patients may be at increased risk of treatment-related adverse events. Precautions against these risks are crucial in the delivery of care.

Methimazole-Induced Pauci-Immune Glomerulonephritis and Anti-Phospholipid Syndrome: An Important Association to Be Aware of

While methimazole (MMI) is the first line treatment for hyperthyroidism, this medication is not devoid of adverse effects. In this article, we present a 70-year-old male who admitted the hospital with right lower extremity pain and rash. The patient was recently treated with MMI for hyperthyroidism. Imaging studies revealed bilateral renal and splenic infarcts along with thrombosis of popliteal artery. Laboratory data revealed hematuria and proteinuria with positive (MPO), anti-proteinase-3 (PR3) and anti-cardiolipin IgG antibodies. Renal biopsy revealed pauci-immune glomerulonephritis and features with anti-phospholipid antibody syndrome (APS). MMI was discontinued and the patient was treated successfully with steroid therapy and anti-coagulation with resolution of proteinuria, hematuria and normalization of laboratory parameters. While MMI-induced pauci-immune glomerulonephritis has been previously reported, its association with APS has never been described before. Our case demonstrates that this rare diagnosis can be treated by early withdrawal of MMI and initiation of steroids along with anticoagulation.

Clinical manifestations of granulomatosis with polyangiitis: key considerations and major features

BACKGROUND

Granulomatosis with polyangiitis (GPA) presents a wide spectrum of manifestations from the common respiratory symptoms to infrequent neurological and cardiac complications. The challenge in diagnosis and management makes the rapidly progressive disorder one of the most challenging dilemmas in clinical medicine.

METHOD

An extensive electronic literature search was done using multiple databases (e.g. PubMed) from January 2007 to August 2017 to gather information on the etiopathogenesis, clinical presentation, and current treatment management plan of GPA. The language used was English. Search items included 'Granulomatosis with Polyangiitis symptoms,' 'Wegener's Granulomatosis,' and 'Treatment of Granulomatosis with Polyangiitis' for the databases. Inclusion criteria consisted of published articles in the English language which reported on the clinical manifestations of GPA, as well as on the treatment of the disease. Exclusion criteria included articles that: (1) did not specifically report on GPA vasculitis but also focused on discussion of other vasculitis such as MPA or Churg-Strauss; (2) reported on treatment/symptoms of GPA prior to 2007.

RESULT

This review provides an overview of work undertaken in key areas of GPA research, including its complex multifactorial etiology, clinical manifestations, treatment strategies, and treatment-related adverse effects.

CONCLUSION

Major advances in the understanding and treatment of GPA over recent decades have contributed to the notable decline in morbidity and mortality of patients. The ultimate goal is an improved prognosis through outcome measures which assesses the disease control with minimal adverse effects of intensive immunosuppressive regimens, an integral part of the clinical approach to improve the quality of life of GPA patients.

Cutaneous Drug Reactions in the Elderly

Cutaneous adverse drug reactions comprise a significant proportion of all adverse drug reactions. They may mimic other dermatologic or systemic illnesses and may cause significant morbidity or mortality. Seven morphologic groups encompass the most commonly encountered cutaneous drug reaction syndromes: exanthematous (maculopapular), dermatitic/eczematous, urticarial, pustular, blistering, purpuric, and erythrodermic. Drug reactions may have significant downstream consequences for the older individual.

Clinical Characteristics and Outcomes of Propylthiouracil-Induced Antineutrophil Cytoplasmic Antibody-Associated Vasculitis in Patients with Graves' Disease: A Median 38-Month Retrospective Cohort Study from a Single Institution in China

BACKGROUND

This study sought to investigate the clinical characteristics and outcomes of propylthiouracil (PTU)-induced antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis in patients with Graves' disease.

METHODS

Sixteen patients diagnosed with PTU-induced ANCA-associated vasculitis at the authors' hospital from January 2010 to June 2017 were analyzed retrospectively.

RESULTS

All 16 patients with PTU-induced ANCA-associated vasculitis were female. The mean age ± standard deviation of the patients was 39.4 ± 15.3 years (range 19-69 years), and the median time of onset was 36 months (range 1-193 months) post-PTU initiation. The median dose at the onset of PTU-induced ANCA-associated vasculitis was 150 mg/day (range 50-300 mg/day). All patients had a positive serum perinuclear staining pattern (p-ANCA) and antibodies directed against myeloperoxidase (anti-MPO). Six patients tested positive for both anti-MPO antibodies and antibodies directed against proteinase-3. Seven (43.8%) patients presented with involvement of a single organ. The kidney was the organ most commonly affected, as 12 (75%) patients were found to have disease involving this organ. PTU was stopped in all patients, corticosteroids were administered to two patients, and immunosuppressive agents and corticosteroids were administered to five patients. Three patients were lost to follow-up. However, the remaining patients achieved remission after a median follow-up period of 38 months (range 6-76 months). Patients who were positive for pANCA and displayed cytoplasmic staining showed negative findings at rates of approximately 53.8% (7/13) and 100% (6/6), respectively, following treatment.

CONCLUSIONS

PTU-induced ANCA-positive vasculitis occurs at varying times and after exposure to various doses of PTU. The condition has a milder course and has a better prognosis after PTU cessation.

Treatment and clinicopathological characteristics of lupus nephritis with anti-neutrophil cytoplasmic antibody positivity: a case-control study

OBJECTIVE

To assess the clinical features, pathological presentations, treatments and outcomes of lupus nephritis (LN) with anti-neutrophil cytoplasmic antibody (ANCA) positivity.

DESIGN

A case-control study.

METHODS

Patients (n=49) were retrospectively included from Jinling Hospital in China if presenting with biopsy-proven ANCA-positive LN between 1985 and 2008. Clinicopathological characteristics and outcomes were analysed and compared with those of a control group (n=1279). We further compared treatment responses and outcomes of ANCA-positive LN patients based on the treatment issued.

RESULTS

The study included 40 women and 9 men (median age 33 years at biopsy): 38 with myeloperoxidase (MPO)-ANCA, 7 with proteinase 3 (PR3)-ANCA and 4 with double positivity. ANCA-positive LN patients exhibited higher haematuria, serum creatinine levels and systemic lupus erythematosus disease activity index scores. On pathological evaluation, class IV LN was predominant, accounting for 61.22% of cases. Light microscopy revealed significantly higher activity index and chronicity index scores, including cellular crescents, interstitial inflammation, tubular atrophy and interstitial fibrosis. ANCA-positive LN patients receiving mycophenolate mofetil as induction therapy had a higher remission rate and better renal outcomes than those receiving cyclophosphamide. During follow-up, end-stage renal disease developed in seven (14.29%) ANCA-positive LN patients, all of them were MPO-ANCA positive.

CONCLUSIONS

The characteristics of ANCA-positive LN were massive haematuria and advanced renal insufficiency. We observed a higher remission rate and better prognoses when using mycophenolate mofetil than when using cyclophosphamide as induction therapy.

Diffuse Cerebral Vasoconstriction in a Intravascular Lymphoma Patient with a High Serum MPO-ANCA Level

An 87-year-old woman presented with a 3-month history of fever, edema of the lower legs, and gait disturbance. A laboratory examination revealed high serum levels of myeloperoxidase-specific antineutrophil cytoplasmic antibody (MPO-ANCA). Although microscopic polyangiitis was initially suspected and treated, the patient subsequently developed transient hemiparesis and disturbed consciousness. Brain magnetic resonance imaging/angiography revealed infarct-like lesions, pachymeningeal involvement, and diffuse cerebral vasoconstriction. A random skin biopsy confirmed the histological diagnosis of intravascular lymphoma. Diffuse cerebral vasoconstriction and a high serum MPO-ANCA level have rarely been reported in patients with intravascular lymphoma. Endothelial damage due to immune-mediated mechanisms, tumor derived factors, or the direct interaction of lymphoma cells with endothelial cells may commonly predispose patients to both cerebral vasoconstriction and the development of ANCAs.

Diagnosing ANCA-associated vasculitis in ANCA positive patients: A retrospective analysis on the role of clinical symptoms and the ANCA titre

Currently no validated diagnostic system for antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is available. Therefore, diagnosing AAV is often challenging. We aimed to identify factors that lead to a clinical diagnosis AAV in ANCA positive patients in a teaching hospital in The Netherlands.In this study, all patients that tested positive for ANCA proteinase 3 (PR3) and/or myeloperoxidase (MPO) between 2005 and 2015 were analysed. Patients with a clinical diagnosis of AAV were compared with patients without a clinical diagnosis of AAV. Clinical symptoms and laboratory variables at presentation, including the ANCA titre, were collected for both patients with and without AAV. Clinical and laboratory variables related with AAV were investigated, using multivariable logistic regression.Two hundred thirty seven consecutive patients with a positive ANCA were included, of whom 119 were clinically diagnosed with AAV. Of the 118 ANCA positive patients without AAV, 87 patients had an alternative diagnosis, including inflammatory bowel disease (n = 24), other rheumatic diseases (n = 23), infection (n = 11), malignancy (n = 4), and other diagnoses (n = 25). In a multivariable regression model, a high ANCA titre (odds ratio [OR] 14.16, 95% confidence interval [CI] 6.93-28.94) and a high number of affected organ systems (OR 7.67, 95% CI 3.69-15.94) were associated with AAV.MPO and PR3 ANCA can be positive in a variety of diseases that mimic AAV. A higher ANCA titre and multiple affected organ systems may help to discriminate between AAV and other systemic illnesses in anti-PR3 and anti-MPO positive patients. A diagnostic scoring system incorporating these factors should be considered.

Possibly propylthiouracil-induced antineutrophilic cytoplasmic antibody-associated vasculitis manifested as blood coagulation disorders: A case report

BACKGROUND

Propylthiouracil is the most common drug used to treat hyperthyroidism. However, this drug could cause a severe disease, antineutrophilic cytoplasmic antibody-associated vasculitis (AAV), which was usually misdiagnosed.

METHODS

We reported a 60-year-old woman of propylthiouracil-induced AAV manifested as blood coagulation disorders. The patient was admitted because of hyperthyroidism and leukopenia. At the time of hospitalization, she suffered from dry cough, erythema and knee joints ache, and gradually became febrile. And then BP decreased and PLT was reduced with coagulation disorders. ANCA: c-ANCA positive (1:100), p-ANCA positive (1:320), MPO-IgG positive, PR3-IgG positive, GBM-IgG negative. Erythrocyte sedimentation rate and C-reactive protein increased markedly. Chest high-resolution computed tomography (HRCT) showed that scattered spots, patch and ground-glass opacity.

RESULTS

Finally, we made a terminal diagnosis of PTU-induced AAV possibly. After drug withdrawal and use of steroid, the patient recovered well and then accepted RAI therapy. As the patient was given imipenem-cilastatin before the reduction of PLT and coagulation disorders, we considered that the hematologic disorders might be caused by antibiotics or a clinical presentation of the vasculitis itself.

CONCLUSION

Drug-induced vasculitis is relatively good prognosis, but early diagnosis and timely withdrawal of associated drugs are the key to the treatment.

Bilateral dacryoadenitis as initial presentation of a locally aggressive and unresponsive limited form of orbital granulomatosis with polyangiitis

Limited orbital granulomatosis with polyangiitis (GPA) is uncommon and its diagnosis may be delayed, especially when isolated lacrimal involvement is the initial presentation, because clinical manifestations are non-specific and systemic diagnostic criteria are not applicable. Making an early diagnosis despite the absence of systemic progression is extremely important because in some cases the disease is locally destructive, with irreversible visual and functional loss, and it can be refractory to corticosteroids and conventional immunosuppressive drugs to induce remission. The authors report an unusual limited form of orbital GPA in a 35-year-old woman presenting with bilateral dacryoadenitis, evolving later to locally aggressive bilateral orbital pseudotumour leading to proptosis, extraocular myositis, diplopia and medial deviation of the nasal septum. She had never had systemic manifestations but her disease was persistently active and unresponsive to corticosteroids and immunosuppressors. The aim of this paper is to provide further evidence of aggressive and refractory limited forms of GPA.

Hydralazine-induced pauci-immune glomerulonephritis: intriguing case series with misleading diagnoses

Hydralazine has been used since the 1950s for the management of hypertension. Evidence for hydralazine-associated vasculitis dates to pre-ANCA (antineutrophil cytoplasmic antibodies) era. This abstract describes two cases of ANCA-positive pauci-immune glomerulonephritis (GN) in challenging scenarios where diagnosis was misconstrued. A comprehensive literature review was done to understand the pathogenesis of drug-induced pauci-immune GN. We have described key diagnostic features that are helpful in distinguishing idiopathic ANCA vasculitis from drug-induced vasculitis. Additionally, we have also described different treatments meant to provide therapy options with the least side effects.

Carbimazole-induced exudative pleural effusions

Carbimazole, an antithyroid drug, is associated with a significant number of side effects, but pleuropulmonary complications are rare. We report the case of a 42-year-old Caucasian man who developed dyspnoea secondary to bilateral exudative pleural effusions while on carbimazole therapy. Extensive investigations, including a vasculitic screen, ruled out other potential causes for this patient's clinical presentation. This patient's pleural effusions gradually resolved within a few months of stopping carbimazole therapy, suggesting a role for the latter in the aetiopathogenesis of his presentation. Clinicians should consider discontinuing treatment with carbimazole and introducing alternative antithyroid therapy in this setting, once other potential causes of a pleural effusion have been systematically ruled out.