Fatal West Nile Encephalomyelitis in a Young Woman with Hypoparathyroidism and Sjögren’s Syndrome - Molecular Insights into Viral Neuro-Invasivity

Sep 30, 2026

Uploaded by Ezra

West Nile virus (WNV) is an arthropod-borne flavivirus endemic in Italy, where most infections remain asymptomatic while a small fraction progresses to neuroinvasive disease with high mortality. This case describes a 45-year-old woman with post-surgical hypoparathyroidism and Sjögren’s syndrome who developed severe encephalomyelitis linked to WNV, complicated by ventilator-associated pneumonia and death. Neuropathology documented characteristic brain and lung lesions, with molecular and immunohistochemical evidence supporting trans-synaptic spread along motor-control pathways.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages13

Reading Time33 min

AccessFree to download

Abstract

1. Introduction

Case Report Fatal West Nile Encephalomyelitis in a Young Woman with Hypoparathyroidism and Sjögren’s Syndrome. Molecular Insights into Viral Neuro-Invasivity Pasquale Padalino , Laura Secco , Eva Grosso, Giorgia Franchetti, Stefano Palumbi , Renzo Giordano and Guido Viel * Academic Editor: João Pedro Silva Received: 19 September 2025 Revised: 17 December 2025 Accepted: 18 December 2025 Published: 22 December 2025 Copyright: © 2025 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license. Legal Medicine and Toxicology, Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, Via G. Falloppio 50, 35121 Padova, Italy; pasquale.padalino@studenti.unipd.it (P.P.); [laura.secco@studenti.unipd.it](laura.secco@studenti.unipd.it) (L.S.); [eva.grosso@studenti.unipd.it](eva.grosso@studenti.unipd.it) (E.G.); [giorgia.franchetti@unipd.it](giorgia.franchetti@unipd.it) (G.F.); [stefano.palumbi@studenti.unipd.it](stefano.palumbi@studenti.unipd.it) (S.P.); [renzo.giordano.padova@gmail.com](renzo.giordano.padova@gmail.com) (R.G.) * Correspondence: [guido.viel@unipd.it](guido.viel@unipd.it); Tel.: +39-0498218975 Abstract West Nile virus (WNV) is an arthropod-borne flavivirus first identified in 1937 . Overtime, WNV has spread globally and is now endemic in Italy. Although most human WNV infections are asymptomatic (80%), less than 1% progress to a neuroinvasive disease with high mortality rates. This case involves a 45-year-old woman with post-surgical hypoparathyroidism and Sjögren’s syndrome who developed severe encephalomyelitis linked to WNV, leading to ventilator-associated pneumonia and death. Neuropathological findings revealed a bilaterally cribriform thalamus and reddish punctate lesions near the dentate nucleus of the cerebellum. The trachea and bronchial hilum branches contained whitish foamy liquid. The left lung showed multiple brownish-violet areas, with whitish regions at dissection. The heart appeared unremarkable. A detailed neuropathological examination focused on areas involved in motor control pathways. Tissue samples were stained with hematoxylin and eosin and trichrome techniques, and immunohistochemistry was performed using CD68, CD3, and CD20 . A significant damage was observed in the lenticular nucleus and motor thalamus, with prominent concentric vascular calcifications. The cerebellar cortex showed near-total depletion of Purkinje cells. In the spinal cord, CD68 and CD3 positivity was noted in the lateral funiculi, anterior horns, and Clarke’s column. Lung findings showed pulmonary edema, chronic emphysema, and bronchopneumonia. The observed CD3 and CD68 positivity confirms that WNV spreads trans-synaptically along motor control pathways. We speculate on the potential molecular mechanisms by which hypoparathyroidism and Sjögren’s syndrome may have played a role in theneuroinvasive progression of the disease. Keywords: west Nile virus; WNV; viral encephalomyelitis 1. Introduction West Nile virus (WNV) is an arthropod-borne flavivirus that was first isolated from the blood of a febrile Ugandan woman in 1937 [1] . Like other flaviviruses, it is a small, enveloped virus containing a single positive-sense RNA genome [2] . Eight phylogenetic lineages are currently known: Lineage 1 (L1) to Lineage 8 (L8), with WNV L1 and L2 being the most widespread and pathogenic ones [3] . The virus exhibits a roughly spherical morphology, with an approximate diameter of 50 nm, composed of an icosahedral nucleocapsid enclosed within a lipid envelope [4,5] . Its genomic RNA, approximately 11 kilobases (kb) in length, encodes a single long open reading frame (ORF) flanked by two non-coding regions [2] . The ORF is translated into a polyprotein, which is subsequently cleaved by both cellular and viral proteases into three structural proteins—capsid,

FAQs

What patient conditions were associated with the fatal outcome in this case report?

The patient had post-surgical hypoparathyroidism and Sjögren’s syndrome, and developed fatal WNV-related severe encephalomyelitis.

What key neuropathological and tissue findings were reported?

Findings included bilaterally cribriform thalamus changes and reddish punctate cerebellar lesions, plus pulmonary edema, chronic emphysema, and bronchopneumonia; Purkinje cells were nearly depleted.

How does the report support WNV spread within the nervous system?

Immunohistochemistry showed CD3 and CD68 positivity consistent with trans-synaptic spread along motor control pathways, with additional discussion of possible molecular mechanisms involving the patient’s underlying diseases.

Sep 30, 2026

Uploaded by Ezra