Demographic, Clinical, and Immunologic Correlates among a Cohort of 50 Cocaine Users Demonstrating Antineutrophil Cytoplasmic Antibodies

Rheumatic masqueraders: mimics of primary vasculitis - a case-based review

INTRODUCTION

Vasculitis conditions are often serious and sometimes fatal diseases, therefore it is paramount to diagnose correctly and treat appropriately. Mimics of primary vasculitis can include either non-inflammatory syndromes or secondary vasculitis where the underlying etiology of the vasculitis is being driven by infection, malignancy, drug-effect or other.

AREAS COVERED

This review comprises six individual cases of vasculitis mimics. Each case is presented and the clinical, radiographic, and histological features that distinguish the case from primary vasculitis are highlighted. Key mimics in large, medium and small vessel vasculitis are outlined.

EXPERT OPINION

The diagnosis of vasculitis requires a comprehensive assessment of clinical, radiographic, and histologic features. Clinicians should be familiar with mimics of primary vasculitis conditions. In the case of non-inflammatory mimics, it is important to differentiate from primary vasculitides in order to avoid unnecessary and potentially harmful immunosuppression. For cases of secondary vasculitis, identification of the correct etiologic cause is critical because treatment of the underlying stimulus is necessary for successful management and outcomes.

[Cocaine-induced vasculitis and mimics of vasculitis]

Cocaine is a psychotropic tropane alkaloid and stimulant drug. Nasal insufflation of cocaine powder is a common route of administration. In Germany, cocaine is frequently adulterated with levamisole, an anthelminthic drug with immunomodulatory effects. Both substances are linked to various autoimmune conditions. Cocaine-induced midline destructive lesions cause a progressive destruction of osteocartilaginous structures within the upper respiratory tract and can mimic localized granulomatosis with polyangiitis. In addition, systemic vasculitis due to cocaine and levamisole has been reported. Differentiation of these conditions from primary vasculitis can be challenging because antineutrophil cytoplasmic antibodies (ANCA) are commonly detected. Early diagnosis of these conditions is crucial as clinical improvement is closely related to drug cessation.

Levamisole and ANCA positivity in childhood nephrotic syndrome

BACKGROUND

This study aimed to determine the prevalence of ANCA positivity in children managed with levamisole as a steroid-sparing agent for nephrotic syndrome (NS).

METHODS

Medical records of children with steroid-sensitive NS managed with levamisole therapy at Sydney Children's Hospital between 1/1/2000 and 31/12/2018 were retrospectively reviewed. Main outcome measure was side effects of levamisole therapy including ANCA positivity.

RESULTS

Seventy-one children, median age 3 years and 1 month (IQR 29-68 months) at first presentation, were subsequently managed with levamisole. 60.6% were male and 65% Caucasian. 47.9% had frequently relapsing (FR)NS and 52.1% steroid-dependent (SD)NS. Overall, there was a median reduction in relapses from 3 (IQR 1-5) to 0.4 relapses (IQR 0-1) per year after levamisole was commenced. Levamisole was successful in preventing relapse in 19 (29%) patients and was used for median 24 (22 to 25) months. Levamisole was discontinued due to relapse in 25 patients (38%) after median 12 (5-28) months. Side effects occurred in 28 patients (42.4%); the most common side effect was ANCA positivity in 12 patients. In eleven of these patients, levamisole was discontinued; in one patient, low-level titres were documented and spontaneously resolved without cessation of levamisole. Two patients developed ANCA-associated vasculitis.

CONCLUSION

ANCA positivity is a common side effect of levamisole and was seen in 18.2% of our patients. Monitoring is required to determine side effects including ANCA positivity and treatment modified accordingly.

Peripheral Retinal Neovascularization in a Patient with Sarcoidosis and Cocaine-Associated Autoimmunity

A 63-year-old African-American female with history of sarcoidosis (lymph node biopsy proven) and cocaine abuse for 8 years was referred to us because of new floater. Her ocular history was unremarkable except for vague complaints of visual disturbance during a hospital admission in 2016. On presentation, her visual acuity was 20/400 in the right eye and 20/30 in the left eye. Dilated fundus exam and multimodal imaging showed thick epiretinal membrane (ERM) superior to optic nerve head causing a lamellar macular hole and intra retinal edema in the right eye, a full thickness macular hole, and peripheral neovascularization in the left eye. Peripheral vasculitis was appreciated in both eyes and peripheral neovascularization in the left eye on fluorescein angiography. The patient underwent laser therapy, and the new vessels regressed in the left eye without any changes in systemic medications. Multiple factors may contribute to retinal vasculitis and neovascularization including sarcoidosis, cocaine abuse, and other undiagnosed systemic vasculitis, which makes this case a mystery.

Role of Neutrophils in Systemic Vasculitides

Neutrophils and neutrophil extracellular traps (NETs) contribute to the pathogenesis of many autoimmune diseases, including vasculitis. Though neutrophils, and NETs, can break self-tolerance by being a source of autoantigens for autoantibodies in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, playing a key role in driving the autoimmune response, the role of neutrophils and NETs in large vessel vasculitis, including giant cell arteritis (GCA), is not well understood. In this review, we summarize the current insight into molecular mechanisms contributing to neutrophil-mediated pathology in small and medium vessel vasculitis, as well as provide potential translational perspectives on how neutrophils, and NETs, may partake in large vessel vasculitis, a rare disease entity of unclear pathogenesis.

Leaf: an open-source, model-agnostic, data-driven web application for cohort discovery and translational biomedical research

OBJECTIVE

Academic medical centers and health systems are increasingly challenged with supporting appropriate secondary use of clinical data. Enterprise data warehouses have emerged as central resources for these data, but often require an informatician to extract meaningful information, limiting direct access by end users. To overcome this challenge, we have developed Leaf, a lightweight self-service web application for querying clinical data from heterogeneous data models and sources.

MATERIALS AND METHODS

Leaf utilizes a flexible biomedical concept system to define hierarchical concepts and ontologies. Each Leaf concept contains both textual representations and SQL query building blocks, exposed by a simple drag-and-drop user interface. Leaf generates abstract syntax trees which are compiled into dynamic SQL queries.

RESULTS

Leaf is a successful production-supported tool at the University of Washington, which hosts a central Leaf instance querying an enterprise data warehouse with over 300 active users. Through the support of UW Medicine (https://uwmedicine.org), the Institute of Translational Health Sciences (https://www.iths.org), and the National Center for Data to Health (https://ctsa.ncats.nih.gov/cd2h/), Leaf source code has been released into the public domain at https://github.com/uwrit/leaf.

DISCUSSION

Leaf allows the querying of single or multiple clinical databases simultaneously, even those of different data models. This enables fast installation without costly extraction or duplication.

CONCLUSIONS

Leaf differs from existing cohort discovery tools because it does not specify a required data model and is designed to seamlessly leverage existing user authentication systems and clinical databases in situ. We believe Leaf to be useful for health system analytics, clinical research data warehouses, precision medicine biobanks, and clinical studies involving large patient cohorts.