Immunopathogenesis of vasculitis

Diascopy and histopathological evaluation of nonblanching erythematous dermatoses in dogs

BACKGROUND

Diascopy is a point-of-care diagnostic test used to differentiate skin erythema due to vascular dilation from haemorrhage. In the veterinary literature, only a handful of diseases have been described to be associated with a negative (nonblanching) diascopy result, and histological investigation of haemorrhage has been inconsistent.

OBJECTIVES

Retrospective study to undertake a histopathological investigation of canine, nonblanching erythematous dermatoses for the presence or absence of haemorrhage and vascular changes.

MATERIALS AND METHODS

Skin biopsies from dogs presented with moderate-to-severe nonblanching erythema were evaluated histologically. Additionally, clinical data about each patient were analysed.

RESULTS

Twenty cases were identified with nonblanching erythema. Diagnoses included vasculopathy (n = 6), canine eosinophilic dermatitis (n = 3), cutaneous epitheliotropic T-cell lymphoma (n = 2), and one case each of sterile granuloma and pyogranuloma syndrome, German shepherd dog pyoderma, multiple mast cell tumours, haemangiosarcoma, exfoliative cutaneous lupus erythematosus, canine leishmaniosis with sebaceous adenitis, sebaceous adenitis with concurrent dermatophytosis, calcinosis cutis and canine atopic dermatitis with insect-bite reaction. One or more vascular changes were present in all 20 cases and included perivascular oedema, endothelial swelling and neutrophilic infiltration of vessel walls. Haemorrhage was identified in 17 of 20 cases (85%). Three cases without dermal haemorrhage were calcinosis cutis, sebaceous adenitis with dermatophytosis and canine atopic dermatitis with insect-bite reaction.

CONCLUSIONS AND CLINICAL RELEVANCE

Negative diascopy was associated with haemorrhage and vascular pathological findings in the majority of cases, yet not all. Haemorrhage was identified histologically in all diseases previously reported as nonblanching as well as in a few additional diseases.

Current perspectives on the diagnosis, assessment, and management of vasculitic neuropathy

INTRODUCTION

Vasculitic neuropathy can present associated with both primary and secondary systemic vasculitis as a result from underlying diseases such as rheumatic diseases and infections, Moreover, confined vasculitis in the peripheral nervous system may be present. Thus, the diagnosis and management of vasculitic neuropathy require multidisciplinary approaches.

AREAS COVERED

Current views as well as relevant clinical research on the diagnosis, assessment, and management of vasculitic neuropathy are reviewed to suggest appropriate treatment strategies. We searched PubMed and Google Scholar for reports published between July 2017 and July 2022.

EXPERT OPINION

For the treatment of vasculitic neuropathy, determining the causative primary disease is important and often requires diagnosis by tissue biopsy. Due to the scarce research on the treatment of vasculitic neuropathy, treatment is empirically based on findings from studies of systemic vasculitides involving other organs, particularly antineutrophil cytoplasmic antibody-associated vasculitis. In addition to conventional glucocorticoids and immunosuppressive agents, complement-targeted therapy, anti-B-cell therapy, and disease-specific molecular targeted therapies have recently gained relevance. Future research is needed to develop new patient-specific therapeutic options.

Granulocyte colony-stimulating factor-associated aortitis in a woman with breast cancer: a case report

Background

Granulocyte colony-stimulating factor (G-CSF) is increasingly used to prevent chemotherapy-associated febrile neutropenia. Generally, aortitis is not considered a side effect of G-CSF and is thought to be extremely rare. Aortitis is an inflammation of the aorta and occurs mainly in connective tissue diseases (Takayasu arteritis, giant cell arteritis, etc.) and infectious diseases (bacterial endocarditis, syphilis, etc.). We report herein a rare case of G-CSF associated with aortitis in a woman with breast cancer.

Case presentation

Here, we present a case involving a 63-year-old woman with luminal type stage IIa breast cancer. The patient’s treatment was initiated with docetaxel and cyclophosphamide, with pegfilgrastim (PEG-G) as support. After PEG-G administration on day 3, the patient developed an intermittent fever of up to 39.4 °C on day 10 and visited our outpatient clinic on day 13 with persistent high fever. Laboratory tests revealed a high neutrophil count (14,000/μL) and a high C-reactive protein (CRP) level (42.8 mg/dL) without any other abnormalities. Contrast-enhanced computed tomography scanning revealed soft tissue thickening with weak enhancement around the wall of the thoraco-abdominal aorta, aortic arch and left subclavian artery. The patient did not respond to antimicrobial agents. On the basis of these observations, the patient was diagnosed with PEG-G-induced aortitis, and her condition rapidly improved without corticosteroids.

Conclusions

Clinicians should be aware of aortitis as a potential complication in patients undergoing G-CSF chemotherapy. In cases with persistent high fever after PEG-G administration, and in the absence of infection, aortitis should be suspected.

The incidence and clinical features of PEGylated filgrastim-induced acute aortitis in patients with breast cancer

Although PEGylated filgrastim-induced aortitis is very rare and unknown clinically, some cases were reported and increasing, especially in breast cancer patients. The present study investigated the prevalence, clinical features and treatment of aortitis induced by PEGylated filgrastim in patients with breast cancer. A total of 2068 consecutive patients who underwent neoadjuvant/adjuvant chemotherapy with PEGylated filgrastim for breast cancer were enrolled. From the medical record, clinical, laboratory, medication, and imaging evaluation findings were collected. PEGylated filgrastim-induced aortitis was established in 0.3% of the study population. Common clinical presentations included extremely high fever and chest/back pain with high levels of inflammatory markers without any signs of infection. Contrast-enhanced computed tomography scans revealed typical enhancing wall thickening and periaortic soft tissue infiltration at various levels of aorta. All patients improved rapidly after treatment with modest doses of prednisolone (0.5 mg/kg/day) without any complications. Clinicians should be aware of aortitis as a possible complication of granulocyte-colony stimulating factor therapy, especially PEGylated filgrastim, given the frequent misdiagnoses in neutropenic patients undergoing chemotherapy.

Processionary Caterpillar Setae and Equine Fetal Loss

Pregnant mares were experimentally exposed to whole caterpillar or exoskeleton of the Processionary caterpillar ( Ochrogaster lunifer) via gavage. Tissues were collected from resulting abortions and near or full-term pregnancies consisting of 13 aborted fetuses, 3 fetuses from treated euthanized mares, membranes of 5 foals, and organs from 3 foals. Three control membranes and 1 control fetus and membranes were examined. Caterpillar setal fragments were present in the allantochorion of the 3 fetuses from the euthanized mares and 11 of 12 aborted fetuses (92%) embedded in the chorion (villi or stroma) or allantois (vasculature or stroma). Placental locations of fragments ranged from the cervical pole region to the body encompassing the umbilical insertion and pregnant horn. Numbers in each fetus ranged from 1 to 7 fragments. Setae were present in the allantochorion from 2 to 22 days after the initial treatment. Acute to chronic active inflammation was present in all aborted fetuses, all euthanized fetuses, and within at least 1 tissue level (chorion, allantois, umbilical cord, or amnion) of the membranes from full-term foals. Amnionitis, funisitis, and allantoitis were present in 95% of the examined membranes. Pneumonia was present in 95% of the specimens, and bacteria were present histologically in 90.5% of the specimens with or without accompanying inflammation. The rapid migration of setae within 2 days after mare exposure suggests that direct setal migration into the fetal membranes is a likely initiating factor for equine amnionitis and fetal loss (EAFL).

Cutaneous vasculitis in small animals

Cutaneous vasculitis is an inflammatory process targeting blood vessels. Underlying factors include drugs, infectious diseases, adverse reactions to food, malignancies, and immune-mediated diseases. Vasculitis is a reaction pattern warranting a workup to identify triggers. Presenting symptoms include purpura, pitting edema, and skin ulcerations. Constitutional signs include fever, depression, and anorexia and seem to be present in the majority of patients. Once a diagnosis is confirmed, treatment and follow-up must be tailored to the individual. High-dose immunosuppressive medications are only recommended once infectious diseases capable of producing a similar constellation of clinical signs have been ruled out.

Vascular lesions in pigs experimentally infected with porcine circovirus type 2 serogroup B

Vasculitis is a hallmark lesion of the severe form of systemic porcine circovirus-associated disease (PCVAD). In 2 experimental studies with porcine circovirus type 2 serogroup b (PCV2b), 2 pigs developed fatal PCVAD with acute vasculitis, and 5 related pigs developed chronic lymphohistiocytic and plasmacytic peri- and endarteritis. Five of these pigs (1 with acute vasculitis and 4 with chronic vasculitis) had also been inoculated with bovine viral diarrhea virus type 1 (BVDV1) or BVDV1-like virus. Vascular lesions were similar, independent of whether pigs had been inoculated singly with PCV2b or dually with PCV2b and BVDV1 or BVDV1-like virus. The acute vasculitis was accompanied by marked pulmonary and mesenteric edema and pleural effusion. In situ hybridization demonstrated abundant intracytoplasmic porcine circovirus type 2 (PCV2) nucleic acid in endothelial, smooth muscle-like, and inflammatory cells within and around affected arteries. The pigs with lymphohistiocytic and plasmacytic vasculitis had lesions of systemic PCVAD, including multisystemic lymphoplasmacytic and histiocytic or granulomatous inflammation. PCV2 nucleic acid was detected in renal tubule epithelial cells, mononuclear inflammatory cells, and rare endothelial cells in noninflamed vessels in multiple tissues of these animals. The 2 pigs with acute vasculitis had no PCV2-specific antibodies (or a low titer of), whereas the pigs with lymphohistiocytic and plasmacytic vasculitis developed high antibody titers against this virus. These observations suggest that (1) acute vasculitis observed in the current studies is directly caused by PCV2b, (2) chronic vasculitis may in part be mediated by the subsequent immune response, and (3) host factors and viral strain may both contribute to vasculitis in animals infected with PCV2b.

Cutaneous vasculitis

Vasculitis is defined as inflammation of blood vessels and can affect multiple organs. Several classification systems exist to categorize vasculitis such as vessel size, presence of anti-neutrophil cytoplasmic antibody, pathogenesis of the inflammation, and type of inflammatory cell infiltrate. Cutaneous vasculitis occurs as a manifestation of many diseases including rheumatologic diseases, hypersensitivity syndromes, infections, and malignancies. The diagnosis of the cutaneous vasculitis and the underlying cause requires a complete history and physical exam and usually a biopsy or angiogram. The treatment depends on the etiology of the inflammation and includes immunosuppression, withdrawal of the offending agent, antibacterial/antiviral agents, and chemotherapies. A clear understanding and approach to this condition will improve the physician's ability to provide optimal patient care.

Granulomatous vasculitis

Granulomatous vasculitis is a subset of systemic necrotizing vasculitis and has granulomatous inflammation as the main histopathologic feature. Etiopathogenesis remains poorly understood, although recent advances suggest an important role for certain pro-inflammatory cytokines, such as tumor necrosis factor-alpha. They are a heterogeneous group of clinical disorders with protean manifestations. Serologic abnormalities are present, and the presence of granular cytoplasmic staining-antineutrophil cytoplasmic antibodies is most important and is particularly useful for the diagnosis of active Wegener's granulomatosis. Corticosteroids and cyclophosphamide remain very useful in the treatment of most of these disorders.