West Nile virus-associated vasculitis and intracranial hemorrhage

Pathology of Primary Angiitis of the Central Nervous System

Primary angiitis of the central nervous system (PACNS) is a rare and potentially severe form of vasculitis that is limited to the brain, spinal cord, and meninges. Despite extensive research, the etiology and underlying immunologic mechanisms of PACNS remain largely unknown. PACNS presents with a variety of clinical, radiological, and pathologic features, but it is generally characterized by inflammation and destruction of the walls of blood vessels in the CNS, which can lead to tissue ischemia and/or hemorrhage. Three main histopathologic patterns have been identified, namely granulomatous, lymphocytic, and necrotizing vasculitis.

Alström Syndrome: A Systematic Review

Alström syndrome (AS) is a rare multisystem disorder characterized by cone-rod retinal dystrophy leading to vision loss, hearing deficiency, obesity, type 2 diabetes mellitus, and insulin resistance with hyperinsulinemia. The conditions include dilated cardiomyopathy, recurrent fibrotic pulmonary infections, and progressive renal, hepatic, and endocrinological dysfunction. Other clinical findings consist of thyroid problems, short height, and growth hormone insufficiency. In addition, patients present with normal IQ, but in some cases delay in psychomotor and cognitive development is described. There is no treatment for AS, and life expectancy is around 40 years. However, an early identification of the disease can help in reducing the progression to severe conditions and in ameliorating the patient's quality of life. Our intent was to analyze the clinical data in literature on AS and provide an up-to-date review.

Spectrum of Large- and Medium-Vessel Vasculitis in Adults: Neoplastic, Infectious, Drug-Induced, Autoinflammatory, and Primary Immunodeficiency Diseases

PURPOSE OF REVIEW

To provide a comprehensive review of drugs and neoplastic, infectious, autoinflammatory, and immunodeficiency diseases causing medium- to large-vessel vasculitis in adults with emphasis on information essential for the initial diagnostic process.

RECENT FINDINGS

Entities with medium- to large-vessel vasculitis as clinical manifestations have been described recently (e.g., adenosine deaminase-2 deficiency, VEXAS-Syndrome), and vasculitis in established autoinflammatory or immunodeficiency diseases is increasingly being identified. In the diagnostic process of medium- to large-vessel vasculitis in adults, a large variety of rare diseases should be included in the differential diagnosis, especially if diagnosis is made without histologic confirmation and in younger patients. Although these disorders should be considered, they will undoubtedly remain rare in daily practice.

Pathology and Pathogenesis of Eurasian Blackbirds (Turdus merula) Naturally Infected with Usutu Virus

The Usutu virus (USUV) is a mosquito-borne zoonotic flavivirus. Despite its continuous circulation in Europe, knowledge on the pathology, cellular and tissue tropism and pathogenetic potential of different circulating viral lineages is still fragmentary. Here, macroscopic and microscopic evaluations are performed in association with the study of cell and tissue tropism and comparison of lesion severity of two circulating virus lineages (Europe 3; Africa 3) in 160 Eurasian blackbirds (Turdus merula) in the Netherlands. Results confirm hepatosplenomegaly, coagulative necrosis and lymphoplasmacytic inflammation as major patterns of lesions and, for the first time, vasculitis as a novel virus-associated lesion. A USUV and Plasmodium spp. co-infection was commonly identified. The virus was associated with lesions by immunohistochemistry and was reported most commonly in endothelial cells and blood circulating and tissue mononucleated cells, suggesting them as a major route of entry and spread. A tropism for mononuclear phagocytes cells was further supported by viral labeling in multinucleated giant cells. The involvement of ganglionic neurons and epithelial cells of the gastrointestinal tract suggests a possible role of oral transmission, while the involvement of feather follicle shafts and bulbs suggests their use as a diagnostic sample for live bird testing. Finally, results suggest similar pathogenicity for the two circulating lineages.

Neuroinvasive West Nile Infection with an Unusual Clinical Presentation: A Single-Center Case Series

The 2018 West Nile Virus (WNV) season in Europe was characterized by an extremely high infection rate and an exceptionally higher burden when compared to previous seasons. Overall, there was a 10.9-fold increase in incidence in Italy, with 577 human cases, 230 WNV neuroinvasive diseases (WNNV) and 42 WNV-attributed deaths. Methods: in this paper we retrospectively reported the neurological presentation of 7 patients admitted to University Hospital of Udine with a diagnosis of WNNV, especially focusing on two patients who presented with atypical severe brain stem involvement. Conclusions: the atypical features of some of these forms highlight the necessity to stay vigilant and suspect the diagnosis when confronted with neurological symptoms. We strongly encourage clinicians to consider WNNV in patients presenting with unexplained neurological symptoms in mild climate-areas at risk.

Acute Cryptogenic Stroke During West Nile Virus Infection: Case Report

West Nile virus is an emerging infection in North America but has not traditionally been associated with acute vascular events. We report a 57-year-old healthy male who developed pharyngitis and a corporeal rash, followed 1 week later by an acute cryptogenic stroke. Following successful endovascular thrombectomy, cerebrospinal fluid analysis revealed acute West Nile virus infection. While severe cases of vasculopathy have been described with flavivirus infection, stroke associated with relatively mild symptoms has not been. Given increasing evidence that viral and bacterial infections of many varieties may be stroke triggers, West Nile virus and other flaviviruses may represent an uncommon but underappreciated trigger of cryptogenic stroke. We review indirect evidence that viral endothelial tropism or a nonspecific peri-infectious inflammatory state may be causative mechanisms.