Post-Infectious Autoimmunity in the Central (CNS) and Peripheral (PNS) Nervous Systems: An African Perspective

HIV-1 infection facilitates Alzheimer's disease pathology in humanized APP knock-in immunodeficient mice

Objectives

Amyloid-β (Aβ) plaque deposition in the brain is a principal pathological feature of both Alzheimer's disease (AD) and progressive human immunodeficiency virus type one (HIV-1) infection. Both enable Aβ assembly and Aβ protein aggregation. The potential link between HIV-1 and AD remains uncertain, supporting the need for a reliable animal model. HIV-1 is tropic and pathogenic for humans. It does not replicate in mice. The restricted species tropism has slowed progress in basic research activities. The current study seeks to correct animal model limitations.

Methods

We created an AD mouse to address the need to develop an small animal model that allows studies of viral infection by making a knock-in (KI) with the human amyloid precursor protein (APP)KM670,671NL Swedish mutation to the mouse genome. The resulting founder mice were crossed with immunodeficient NOG (NOD. Cg-Prkdc scid Il2rg tm1Sug Tg(CMV-IL-34)1/Jic) to generate NOG/APPKM670,671NL/IL-34 (NAIL) mice. The mice were reconstituted with human hematopoietic stem cells to generate NAIL mice with functional adaptive and innate human immune systems. Four-month-old, humanized NAIL mice were infected with HIV-1ADA, a macrophage-tropic viral strain then evaluated for viral infection and AD pathology.

Results

Productive HIV-1 infection was confirmed by plasma HIV-1 RNA levels in infected NAIL mice. The viral load increased by tenfold between day 10 and day 25 post-infection. By day 25, viral DNA confirmed the establishment of HIV-1 reservoirs in CD45+ cells from the immune tissues of infected NAIL mice. Additionally, p24 measurements in lymphoid and brain tissues of NAIL mice validated productive HIV-1 infection. Amyloid burden from infected NAIL mice was increased. Immunofluorescence staining revealed co-localization of Aβ fibrils and HLA-DR+ microglia in infected NAIL mice.

Conclusions

These results highlight the AD-HIV model's unique pathobiological and infectious features where the viral and immune responses can now be measured.

Epidemiological Characteristics of Neuro-Specific Antibodies Following Viral Infections

This study aims to explore the epidemiological characteristics of neuro-specific antibodies (ns-Ab) induced by different viral infections within the central nervous system (CNS). Additionally, it seeks to compare the autoimmune effects following several typical viral infections in CNS. We conduct a retrospective study to compare and analyze the prevalence trends of ns-Ab in patients with different viral infections. Additionally, evaluate the intensity of CNS inflammatory responses postviral infection by correlating clinical characteristics and laboratory findings, and briefly demonstrate the immune effects in CNS following various viral infections. This study retrospectively collected data from 1037 patients hospitalized with suspected CNS infections. A total of 654 patients (63.1%) were included in the final analysis. A higher proportion of patients with pathogens present in their cerebrospinal fluid (CSF) (114 out of 332, 34.3%) tested positive for ns-Ab compared to those without pathogens (70 out of 322, 21.7%) (p = 0.0004). Specifically, the screening rate for ns-Ab in patients with CNS viral infections (83 out of 165, 50.3%) and the prevalence of ns-Ab (27 out of 83, 32.5%) were significantly higher than in those with other pathogen infections (p < 0.0001 and p = 0.016, respectively). Among these, human herpesvirus 7 (HHV7) patients had the highest detection rate of ns-Ab during the disease course (11 out of 26, 42.3%), but exhibited infection characteristics distinctly different from those of herpes simplex virus 1 (HSV1). Viral infections significantly promote the development of autoimmune responses in CNS. The production of ns-Ab and the subsequent autoimmune response vary across different viral infections. There is a strong statistical correlation between HHV7 and the presence of ns-Ab, suggesting that HHV7 may serve as an early indicator of secondary autoimmune response following CNS infections.

Spatiotemporal Analysis of HIV/AIDS Incidence in China From 2009 to 2019 and Its Association With Socioeconomic Factors: Geospatial Study

BACKGROUND

The Joint United Nations Program on HIV/AIDS (UNAIDS) has set the "95-95-95" targets to ensure that 95% of all people living with HIV will know their HIV status, 95% of all people living with HIV will receive sustained antiretroviral therapy (ART), and 95% of all people receiving ART will achieve viral suppression (<1000 copies/mL). However, few countries have currently achieved these targets, posing challenges to the realization of the UNAIDS goal to eliminate the global HIV/AIDS epidemic by 2030. The Chinese government has implemented corresponding policies for HIV/AIDS prevention and control; however, it still faces the challenge of a large number of HIV/AIDS cases. Existing research predominantly focuses on the study of a particular region or population in China, and there is relatively limited research on the macro-level analysis of the spatiotemporal distribution of HIV/AIDS across China and its association with socioeconomic factors.

OBJECTIVE

This study seeks to identify the impact of these factors on the spatiotemporal distribution of HIV/AIDS incidence in China, aiming to provide scientific recommendations for future policy development.

METHODS

This study employed ArcGIS 10.2 (Esri) for spatial analysis, encompassing measures such as the imbalance index, geographical concentration index, spatial autocorrelation analysis (Moran I), and hot spot analysis (Getis-Ord Gi*). These methods were used to unveil the spatiotemporal distribution characteristics of HIV/AIDS incidence in 31 provinces of China from 2009 to 2019. Geographical Detector was used for ecological detection, risk area detection, factor detection, and interaction detection. The analysis focused on 9 selected socioeconomic indicators to further investigate the influence of socioeconomic factors on HIV/AIDS incidence in China.

RESULTS

The spatiotemporal distribution analysis of HIV/AIDS incidence in China from 2009 to 2019 revealed distinct patterns. The spatial distribution type of HIV/AIDS incidence in China was random in 2009-2010. However, from 2011 to 2019, the distribution pattern evolved toward a clustered arrangement, with the degree of clustering increasing each year. Notably, from 2012 onwards, there was a significant and rapid growth in the aggregation of cold and hot spot clusters of HIV/AIDS incidence in China, stabilizing only by the year 2016. An analysis of the impact of socioeconomic factors on HIV/AIDS incidence in China highlighted the "urbanization rate" and "urban basic medical insurance fund expenditure" as the primary factors influencing the spatial distribution of HIV/AIDS incidence. Additionally, among social factors, indicators related to medical resources exerted a crucial influence on HIV/AIDS incidence.

CONCLUSIONS

From 2009 to 2019, HIV/AIDS incidence in China was influenced by various socioeconomic factors. In the future, it is imperative to optimize the combination of different socioeconomic indicators based on regional incidence patterns. This optimization will facilitate the formulation of corresponding policies to address the challenges posed by the HIV/AIDS epidemic.

Cerebral Necrotizing Encephalopathy in a 7-year-old Child after being Infected with COVID-19, A Case Report

New daily data on the COVID-19 pandemic are circulating globally. This disease usually appears with respiratory symptoms such as cough, shortness of breath, and fever. The neurological complications of the disease are somewhat known in adults but rarely reported in children. Acute necrotizing encephalopathy of childhood (ANEC) is one of the brain complications associated‌ with Coronavirus disease that usually has a poor prognosis in children. In this case, we report a rare case of a 7-year-old boy who was referred to the hospital with symptoms of convulsions after contracting COVID-19 and developed cerebral necrotizing encephalopathy caused by COVID-19 infection. Although ANEC is a rare disease, clinical examination and MRI and CT scan findings play an essentialrole in diagnosing and treating the disease.‌.

Clinical characteristics and prognostic analysis of acute necrotizing encephalopathy of childhood: a retrospective study at a single center in China over 3 years

Objective

Acute Necrotizing Encephalopathy of Childhood (ANEC) is a rare, fulminant neurological disease in children with unknown mechanisms and etiology. This study summarized the clinical characteristics, treatment, and prognosis of ANEC through a retrospective analysis, providing insights into the ANEC early diagnosis and prognosis assessment.

Methods

Clinical data of children diagnosed with ANEC at the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University from July 1, 2020, to June 30, 2023, were retrospectively analyzed.

Results

There were 25 cases, 14 males and 11 females, with a median age of 3 years. Hospital admissions were mainly in the winter (14/25, 56%) and spring (9/25, 36%). All patients presented with varying degrees of fever and altered consciousness, with 92% (23/25) experiencing high body temperatures (>39.1°C) and 88% (22/25) having a Glasgow coma scale (GCS) score of ≤8. Seizures were observed in 88% (22/25) of patients. Laboratory findings indicated 100% B lymphocyte activation (14/14), and 78% (14/18) of patients showed cytokine storm (interleukin (IL)-6, IL-8, IL-10, interferon (IFN)-α). Neuroimaging showed symmetrical thalamus involvement, commonly involving basal ganglia and brainstem regions. Viral infection (23/24, 96%) was the predominant etiological finding, with 42% (10/24) of cases due to SARS-CoV-2 infection and 42% (10/24) to influenza A virus infection. Multi-organ dysfunction occurred in 68% (17/25) of patients, and 52% (13/25) died. Correlation analysis revealed the death group exhibited higher proportion of male, lower GCS scores, higher IL-6 level and a greater likelihood of associated brainstem impairment (p < 0.05).

Conclusion

ANEC is more prevalent in the winter and spring, and its etiology may be associated with B lymphocyte activation and cytokine storm following viral infections. Clinical manifestations lack specific features, with fever, consciousness disturbances, and seizures being the main presentations, particularly in cases of high fever and hyperpyrexia. ANEC progresses rapidly and has a high mortality rate. The child's gender, GCS score, IL-6 levels, and the presence of brainstem involvement can serve as important risk factors for assessing the risk of mortality.

The specifics of encephalitis after COVID-19

Encephalitis is a group of acute infectious diseases affecting the substance of the brain. They often lead to disability or death, and, therefore, require urgent medical attention. The article discusses the etiology, pathogenesis, and clinical picture of encephalitis, with special attention to the course of this disease after the COVID-19 pandemic. We note the growing number of encephalitis cases, especially of autoimmune variety and those caused by herpes. The possible reason behind this trend is the disruption of operation of the immune system brought by COVID-19, which manifests as a cytokine storm, neuroinflammation, and autoimmune reactions. There are cases of COVID-19-dependent encephalitis described. The pathways taken by SARS-CoV-2 to penetrate into the cells of the central nervous system have not yet been fully studied, although there are hypotheses that this happens both trans-synaptically through mechanoreceptors and chemoreceptors of the respiratory system into the medulla oblongata, and through receptors of the angiotensin converting enzyme 2.

Acute necrotizing encephalopathy in children with COVID-19: a retrospective study of 12 cases

Background

Acute necrotizing encephalopathy (ANE) is a devastating neurologic condition that can arise following a variety of systemic infections, including influenza and SARS-Cov-2. The clinical features of COVID-19-associated ANE in pediatric patients based on multi-case data have not yet been described and remain obscure. We reviewed 12 pediatric patients to better describe the clinical features of ANE with COVID-19.

Methods

We retrospectively collected and summarized the clinical features of ANE in children with COVID-19. Clinical data were collected from 12 children, including their general status, clinical symptoms, laboratory tests, and neuroimaging features.

Results

Among the subjects, 10 were over 5 years old and they accounted for 83.33%. A large percentage of those affected (66.67%) were females. The major manifestations included fever (100%), impaired consciousness (100%), and convulsions (75%). We determined that increased interleukin (IL)-6 and IL-10, and tumor necrosis factor-α and interferon gamma were not predictive of severe ANE and mortality in children with COVID-19 in this study. All children presented with abnormal neuroimaging with multiple and symmetrically distributed lesions, involving the thalamus, basal ganglia, cerebellum, and brain hemispheres. Eight of the 12 children died, resulting in a mortality rate of 66.67%, and 75% of these children were females. Importantly, we found the timely administration of mannitol after an acute onset of convulsions or disturbance of consciousness may be decreased the high mortality induced by ANE children with COVID-19.

Conclusion

COVID-19 associated with ANE in children is characterized by sudden symptom onset, rapid disease progression, and high mortality.

Pathogenesis and Management of Acute Necrotizing Encephalopathy

INTRODUCTION

During the COVID-19 pandemic, many cases of acute necrotizing encephalopathy (ANE) secondary to COVID-19 have been reported. ANE is characterized by a rapid onset, a fulminant course, and low morbidity and fatality rates. Therefore, clinicians need to be vigilant for such disorders, especially during the influenza virus and COVID-19 epidemics.

AREAS COVERED

The authors summarize the most recent studies on the clinical spectrum and treatment essentials of ANE to provide references for prompt diagnosis and improved treatment of this rare but fatal disease.

EXPERT OPINION

ANE is a type of necrotizing lesion of the brain parenchyma. There are two major types of reported cases. One is isolated and sporadic ANE, which is primarily caused by viral infections, particularly influenza and HHV-6 virus. The other type is familial recurrent ANE, which is caused by RANBP2 gene mutations. ANE patients have rapid progression and a very poor prognosis, with acute brain dysfunction occurring within days of viral infection and requiring admission to the intensive care unit. Clinicians still need to investigate and find solutions for the problems of early detection and treatment of ANE.

The Peculiarity of Infection and Immunity Correlated with Guillain-Barré Syndrome in the HIV-Infected Population

Guillain-Barré syndrome (GBS) can occur at all stages of human immunodeficiency virus (HIV) infection. HIV, cytomegalovirus (CMV), and varicella zoster virus (VZV) are the main infectious agents in HIV-positive GBS cases. These cases include acute and chronic HIV infection, immune reconstitution inflammatory syndrome (IRIS) shortly after anti-retroviral therapy (ART), those with ART interruption, or those with cerebrospinal fluids (CSF) HIV escape. The mechanisms are involved in both humoral and cellular immunities. Demyelinating and axonal neuropathies are the main pathological mechanisms in GBS. Presentation and prognosis are identical to those in patients without HIV infection. Typical or atypical clinical manifestations, CSF analysis, electrophysiological and pathological examination, and antiganglioside antibody detection can help diagnose GBS and classify its various subtypes. Intravenous immunoglobulin and plasma exchange have been used to treat GBS in HIV-positive patients with a necessary ART, while ganciclovir or foscarnet sodium should be used to treat ongoing CMV- or VZV-associated GBS. Steroids may be beneficial for patients with IRIS-related GBS. We reviewed HIV-positive cases with GBS published since 2000 and summarized their features to highlight the necessity of HIV testing among patients with GBS. Moreover, the establishment of a multidisciplinary team will guarantee diagnostic and therapeutic advantages.