Killer immunoglobulin-like receptor and their HLA ligands in Guillain–Barré Syndrome

Temporal trends and regional variations in mortality related to Guillain-Barré syndrome in the United States: a retrospective study from 1999 to 2020

AIM

Guillain-Barré syndrome (GBS) is an autoimmune neurological disorder, with an estimated 6.4% increase in cases worldwide from 1990 to 2019. We aim to identify the GBS-related mortality trends in the US stratified by age, sex, race, and region.

METHODS

We used data from the CDC-WONDER database to calculate crude (CMR) and age-adjusted mortality rates (AAMRs) per 1,000,000 people. We examined the temporal trends through annual percent change (APC) and the average annual percent change (AAPC) in rates using Joinpoint regression.

RESULTS

From 1999 to 2020, a total of 10,097 GBS-related deaths occurred in the US. The AAMR decreased till 2014 (APC: -1.91) but increased back to initial levels by 2020 (APC: 3.77). AAMR was higher in males (1.7) than females (1.1), decreasing till 2015 for females and 2014 for males, but increasing thereafter only for females. Non-Hispanic (NH) American Indians or Alaska Natives displayed the highest AAMR (1.8) while NH Asians or Pacific Islanders displayed the lowest (0.6). AAMRs also varied by region (West: 1.5; South: 1.5; Midwest: 1.4; Northeast: 1.1). Rural regions exhibited a higher AAMR (1.7) than urban regions (1.3). Most deaths occurred in medical facilities (60.99%). The adults aged ≥85 years exhibited an alarmingly high CMR (14.0).

CONCLUSIONS

While the mortality rates for GBS initially declined till 2014, they climbed back up afterwards. Highest mortality was exhibited by males and NH American Indians or Alaska Natives, residents of rural regions, and adults ≥85 years. Equitable efforts are needed to reduce the burden on high-risk populations.

Therapeutic potential of natural killer cells in neuroimmunological diseases

Natural killer (NK) cells, a major component of the innate immune system, have prominent immunoregulatory, antitumor proliferation, and antiviral activities. NK cells act as a double-edged sword with therapeutic potential in neurological autoimmunity. Emerging evidence has identified NK cells are involved in the development and progression of neuroimmunological diseases such as multiple sclerosis, neuromyelitis optica spectrum disorders, autoimmune encephalitis, Guillain-Barré Syndrome, chronic inflammatory demyelinating polyneuropathy, myasthenia gravis, and idiopathic inflammatory myopathy. However, the regulatory mechanisms and functional roles of NK cells are highly variable in different clinical states of neuroimmunological diseases and need to be further determined. In this review, we summarize the evidence for the heterogenic involvement of NK cells in the above conditions. Further, we describe cutting-edge NK-cell-based immunotherapy for neuroimmunological diseases in preclinical and clinical development and highlight challenges that must be overcome to fully realize the therapeutic potential of NK cells.

Integrated gene expression profiling and functional enrichment analyses to discover biomarkers and pathways associated with Guillain-Barré syndrome and autism spectrum disorder to identify new therapeutic targets

Guillain-Barré syndrome (GBS) is one of the most prominent and acute immune-mediated peripheral neuropathy, while autism spectrum disorders (ASD) are a group of heterogeneous neurodevelopmental disorders. The complete mechanism regarding the neuropathophysiology of these disorders is still ambiguous. Even after recent breakthroughs in molecular biology, the link between GBS and ASD remains a mystery. Therefore, we have implemented well-established bioinformatic techniques to identify potential biomarkers and drug candidates for GBS and ASD. 17 common differentially expressed genes (DEGs) were identified for these two disorders, which later guided the rest of the research. Common genes identified the protein-protein interaction (PPI) network and pathways associated with both disorders. Based on the PPI network, the constructed hub gene and module analysis network determined two common DEGs, namely CXCL9 and CXCL10, which are vital in predicting the top drug candidates. Furthermore, coregulatory networks of TF-gene and TF-miRNA were built to detect the regulatory biomolecules. Among drug candidates, imatinib had the highest docking and MM-GBSA score with the well-known chemokine receptor CXCR3 and remained stable during the 100 ns molecular dynamics simulation validated by the principal component analysis and the dynamic cross-correlation map. This study predicted the gene-based disease network for GBS and ASD and suggested prospective drug candidates. However, more in-depth research is required for clinical validation.Communicated by Ramaswamy H. Sarma.

HLA-A, HSPA5, IGFBP5 and PSMA2 Are Restriction Factors for Zika Virus Growth in Astrocytic Cells

(1) Background: Zika virus (ZIKV), an arbo-flavivirus, is transmitted via Aeges aegyptii mosquitoes Following its major outbreaks in 2013, 2014 and 2016, WHO declared it a Public Health Emergency of International Concern. Symptoms of ZIKV infection include acute fever, conjunctivitis, headache, muscle & joint pain and malaise. Cases of its transmission also have been reported via perinatal, sexual and transfusion transmission. ZIKV pathologies include meningo-encephalitis and myelitis in the central nervous system (CNS) and Guillain-Barré syndrome and acute transient polyneuritis in the peripheral nervous system (PNS). Drugs like azithromycin have been tested as inhibitors of ZIKV infection but no vaccines or treatments are currently available. Astrocytes are the most abundant cells in the CNS and among the first cells in CNS infected by ZIKV; (2) Methods: We previously used SOMAScan proteomics to study ZIKV-infected astrocytic cells. Here, we use mass spectrometric analyses to further explain dysregulations in the cellular expression profile of glioblastoma astrocytoma U251 cells. We also knocked down (KD) some of the U251 cellular proteins using siRNAs and observed the impact on ZIKV replication and infectivity; (3) Results & Conclusions: The top ZIKV dysregulated cellular networks were antimicrobial response, cell death, and energy production while top dysregulated functions were antigen presentation, viral replication and cytopathic impact. Th1 and interferon signaling pathways were among the top dysregulated canonical pathways. siRNA-mediated KD of HLA-A, IGFBP5, PSMA2 and HSPA5 increased ZIKV titers and protein synthesis, indicating they are ZIKV restriction factors. ZIKV infection also restored HLA-A expression in HLA-A KD cells by 48 h post-infection, suggesting interactions between this gene product and ZIKV.

Sex differences in Guillain Barré syndrome, chronic inflammatory demyelinating polyradiculoneuropathy and experimental autoimmune neuritis

Guillain Barré syndrome (GBS) and its variants, and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP and its variants, are regarded as immune mediated neuropathies. Unlike in many autoimmune disorders, GBS and CIDP are more common in males than females. Sex is not a clear predictor of outcome. Experimental autoimmune neuritis (EAN) is an animal model of these diseases, but there are no studies of the effects of sex in EAN. The pathogenesis of GBS and CIDP involves immune response to non-protein antigens, antigen presentation through non-conventional T cells and, in CIDP with nodopathy, IgG4 antibody responses to antigens. There are some reported sex differences in some of these elements of the immune system and we speculate that these sex differences could contribute to the male predominance of these diseases, and suggest that sex differences in peripheral nerves is a topic worthy of further study.

Genetic basis of Guillain-Barre syndrome

Guillain-Barré syndrome (GBS) is an autoimmune disease in which the peripheral nerves are affected. GBS has different subtypes, such as acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN). Infections, e.g. Campylobacter jejuni, influenza, etc., can lead to GBS. Both environmental and genetic factors play a major role in the occurrence of GBS. Several studies have investigated the genetic basis of GBS. Human leukocyte antigens (HLA) genes, Cluster of Differentiation (CD) 1A, FAS, Fc gamma receptors (FcGR), Intercellular adhesion molecule-1 (ICAM1), different interleukins, Nucleotide oligomerization domain (NOD), Toll-like receptor 4 (TLR4), Tumor necrosis factor-α (TNF-α) are among the genes reported to be involved in susceptibility to the disease. Dysregulation and dysfunction of the mentioned gene products, even though their role in the pathogenesis of GBS is controversial, play a role in inflammatory pathways, regulation of immune cells and system, antigen presentation, axonal degeneration, apoptosis, and cross-reaction. This review aims to summarize associated genes with GBS to contribute to better understanding of GBS pathogenesis and discover the gene pathways that play role in GBS occurrence.

Gulf War Illness: Mechanisms Underlying Brain Dysfunction and Promising Therapeutic Strategies

Gulf War Illness (GWI), a chronic multisymptom health problem, afflicts ~30% of veterans served in the first GW. Impaired brain function is among the most significant symptoms of GWI, which is typified by persistent cognitive and mood impairments, concentration problems, headaches, chronic fatigue, and musculoskeletal pain. This review aims to discuss findings from animal prototypes and veterans with GWI on mechanisms underlying its pathophysiology and emerging therapeutic strategies for alleviating brain dysfunction in GWI. Animal model studies have linked brain impairments to incessantly elevated oxidative stress, chronic inflammation, inhibitory interneuron loss, altered lipid metabolism and peroxisomes, mitochondrial dysfunction, modified expression of genes relevant to cognitive function, and waned hippocampal neurogenesis. Furthermore, the involvement of systemic alterations such as the increased intensity of reactive oxygen species and proinflammatory cytokines in the blood, transformed gut microbiome, and activation of the adaptive immune response have received consideration. Investigations in veterans have suggested that brain dysfunction in GWI is linked to chronic activation of the executive control network, impaired functional connectivity, altered blood flow, persistent inflammation, and changes in miRNA levels. Lack of protective alleles from Class II HLA genes, the altered concentration of phospholipid species and proinflammatory factors in the circulating blood have also been suggested as other aiding factors. While some drugs or combination therapies have shown promise for alleviating symptoms in clinical trials, larger double-blind, placebo-controlled trials are needed to validate such findings. Based on improvements seen in animal models of GWI, several antioxidants and anti-inflammatory compounds are currently being tested in clinical trials. However, reliable blood biomarkers that facilitate an appropriate screening of veterans for brain pathology need to be discovered. A liquid biopsy approach involving analysis of brain-derived extracellular vesicles in the blood appears efficient for discerning the extent of neuropathology both before and during clinical trials.

Genetic polymorphisms in Guillain-Barré Syndrome: A field synopsis and systematic meta-analysis

OBJECTIVE

Guillain-Barré Syndrome (GBS) is considered to be a complex immune-mediated neuropathy. In the past few years, numerous studies were performed to detect the association between genetic polymorphisms and GBS risk. However, the findings of these studies were controversial. Thus, we conducted this field synopsis and systematic meta-analysis for further evaluating the possible associations between all available genetic polymorphisms and GBS susceptibility.

METHODS

Relevant studies focusing on the association between all genetic polymorphisms and GBS risk were obtained by a comprehensive literature search. The pooled odds ratios (ORs) as well as 95% confidence intervals (CIs) were used for assessing the strength of association. Subgroup analyses stratified by ethnicity and GBS subtype were further performed. Moreover, sensitive analysis and publication bias were conducted for evaluating the reliability of the results.

RESULTS

Among the initial identified 333 articles, 41 articles reporting on 220 genetic polymorphisms were extracted for conducting this systematic review. Then, we performed 95 primary and 94 subgroup meta-analyses for 59 variants with at least three independent studies available. The results showed significant association between four variants (FcγR IIA rs1801274, TNF-α rs1800629, HLA DRB1*0401 and HLA DRB1*1301) and GBS susceptibility. In the subgroup analysis, three (TNF-α rs1800629, TNF-α rs1800630 and TLR4 rs4986790) and two (FcγR IIA rs1801274, HLA DRB1*14) variants showed association with increased GBS risk in Asian and Caucasian population, respectively. Also, TNF-α rs1800629 was significant associated with AMAN subtypes of GBS. Furthermore, sensitivity analysis, funnel plots and Egger's test displayed robust results, except for FcγR IIA rs1801274. Additionally, for 161 variants with less than three studies, 17 genetic variants have been found to be significantly related with GBS risk in our systematic review.

INTERPRETATION

In our study, we assessed the association between all available genetic polymorphisms and GBS susceptibility. We hope our findings would be helpful for identifying novel genetic biomarkers and potential therapeutic targets for GBS.

Young woman with Guillain-Barré syndrome and cervical transverse myelitis-A new GBS variant, not coincidence

A case of antibody proven Guillain Barré Syndrome in a previously healthy young female with extra clinical features, scans, and physical exam findings consistent with cervical spine and cervical medullary junction myelitis, together a new variant to consider.

Significance of KIR like natural killer cell receptors in autoimmune disorders

Killer cell immunoglobulin-like receptors (KIRs), act as the regulators for the cytolytic activity of natural killer and certain T cells by interacting with the HLA class I ligands. KIRs have been shown to contribute to the pathogenesis of several autoimmune diseases. However, their specific roles are still not very clear. Autoimmune diseases are multifactorial in nature, highlighting the influence of both genetic and environmental factors. The innate immune response plays an important role in autoimmunity as it alters the self-glycans that mimic molecular patterns found on different intracellular pathogens. Natural killer (NK) cells have an important position in the innate immune response. NK cell receptors are encoded by the leukocyte receptor complex located on the chromosome 19q13.4 and lectin-like receptors on chromosome 12p13. This review focuses on the role of KIRs and their relationship with different autoimmune diseases.

Cytotoxic Immunity in Peripheral Nerve Injury and Pain

Cytotoxicity and consequent cell death pathways are a critical component of the immune response to infection, disease or injury. While numerous examples of inflammation causing neuronal sensitization and pain have been described, there is a growing appreciation of the role of cytotoxic immunity in response to painful nerve injury. In this review we highlight the functions of cytotoxic immune effector cells, focusing in particular on natural killer (NK) cells, and describe the consequent action of these cells in the injured nerve as well as other chronic pain conditions and peripheral neuropathies. We describe how targeted delivery of cytotoxic factors via the immune synapse operates alongside Wallerian degeneration to allow local axon degeneration in the absence of cell death and is well-placed to support the restoration of homeostasis within the nerve. We also summarize the evidence for the expression of endogenous ligands and receptors on injured nerve targets and infiltrating immune cells that facilitate direct neuro-immune interactions, as well as modulation of the surrounding immune milieu. A number of chronic pain and peripheral neuropathies appear comorbid with a loss of function of cellular cytotoxicity suggesting such mechanisms may actually help to resolve neuropathic pain. Thus while the immune response to peripheral nerve injury is a major driver of maladaptive pain, it is simultaneously capable of directing resolution of injury in part through the pathways of cellular cytotoxicity. Our growing knowledge in tuning immune function away from inflammation toward recovery from nerve injury therefore holds promise for interventions aimed at preventing the transition from acute to chronic pain.

Guillain-Barré syndrome, transverse myelitis and infectious diseases

Guillain-Barré syndrome (GBS) and transverse myelitis (TM) both represent immunologically mediated polyneuropathies of major clinical importance. Both are thought to have a genetic predisposition, but as of yet no specific genetic risk loci have been clearly defined. Both are considered autoimmune, but again the etiologies remain enigmatic. Both may be induced via molecular mimicry, particularly from infectious agents and vaccines, but clearly host factor and co-founding host responses will modulate disease susceptibility and natural history. GBS is an acute inflammatory immune-mediated polyradiculoneuropathy characterized by tingling, progressive weakness, autonomic dysfunction, and pain. Immune injury specifically takes place at the myelin sheath and related Schwann-cell components in acute inflammatory demyelinating polyneuropathy, whereas in acute motor axonal neuropathy membranes on the nerve axon (the axolemma) are the primary target for immune-related injury. Outbreaks of GBS have been reported, most frequently related to Campylobacter jejuni infection, however, other agents such as Zika Virus have been strongly associated. Patients with GBS related to infections frequently produce antibodies against human peripheral nerve gangliosides. In contrast, TM is an inflammatory disorder characterized by acute or subacute motor, sensory, and autonomic spinal cord dysfunction. There is interruption of ascending and descending neuroanatomical pathways on the transverse plane of the spinal cord similar to GBS. It has been suggested to be triggered by infectious agents and molecular mimicry. In this review, we will focus on the putative role of infectious agents as triggering factors of GBS and TM.

Inflammatory neuropathies: pathology, molecular markers and targets for specific therapeutic intervention

Inflammatory neuropathies encompass groups of heterogeneous disorders characterized by pathogenic immune-mediated hematogenous leukocyte infiltration of peripheral nerves, nerve roots or both, with resultant demyelination or axonal degeneration or both. Inflammatory neuropathies may be divided into three major disease categories: Guillain-Barré syndrome (particularly the acute inflammatory demyelinating polyradiculoneuropathy variant), chronic inflammatory demyelinating polyradiculoneuropathy and nonsystemic vasculitic neuropathy (or peripheral nerve vasculitis). Despite major advances in molecular biology, pathology and genetics, the pathogenesis of these disorders remains elusive. There is insufficient knowledge on the mechanisms of hematogenous leukocyte trafficking into the peripheral nervous system to guide the development of specific molecular therapies for immune-mediated inflammatory neuropathies compared to disorders such as psoriasis, inflammatory bowel disease, rheumatoid arthritis or multiple sclerosis. The recent isolation and characterization of human endoneurial endothelial cells that form the blood-nerve barrier provides an opportunity to elucidate leukocyte-endothelial cell interactions critical to the pathogenesis of inflammatory neuropathies at the interface between the systemic circulation and peripheral nerve endoneurium. This review discusses our current knowledge of the classic pathological features of inflammatory neuropathies, attempts at molecular classification and genetic determinants, the utilization of in vitro and in vivo animal models to determine pathogenic mechanisms at the interface between the systemic circulation and the peripheral nervous system relevant to these disorders and prospects for future potential molecular pathology biomarkers and targets for specific therapeutic intervention.

Biomarkers of Guillain-Barré Syndrome: Some Recent Progress, More Still to Be Explored

Guillain-Barré syndrome (GBS), the axonal subtype of which is mainly triggered by C. jejuni with ganglioside-mimicking lipooligosaccharides (LOS), is an immune-mediated disorder in the peripheral nervous system (PNS) accompanied by the disruption of the blood-nerve barrier (BNB) and the blood-cerebrospinal fluid barrier (B-CSF-B). Biomarkers of GBS have been extensively explored and some of them are proved to assist in the clinical diagnosis and in monitoring disease progression as well as in assessing the efficacy of immunotherapy. Herein, we systemically review the literature on biomarkers of GBS, including infection-/immune-/BNB, B-CSF-B, and PNS damage-associated biomarkers, aiming at providing an overview of GBS biomarkers and guiding further investigations. Furthermore, we point out further directions for studies on GBS biomarkers.

Contribution of KIR genes, HLA class I ligands, and KIR/HLA class I ligand combinations on the genetic predisposition to celiac disease and coexisting celiac disease and type 1 diabetes mellitus

BACKGOUND AND AIM

There are some common genetic features between celiac disease (CD) and diabetes mellitus type 1 (DM). However, the genetic risk factors have not been fully clarified for CD and the co-occurrence of CD and DM. KIR (killer immunoglobulin-like receptor) genes regulate the cytolitic activity of NK-cells and T lymphocytes. The aim of this study is to evaluate the contribution of KIR genes, KIR ligands, and combinations of KIR/ KIR ligands on the genetic predisposition to CD and co-occurrence of CD and DM.

MATERIAL AND METHODS

Forty six patients with CD (n = 46), 20 patients with CD+DM (n = 20), and 60 healthy controls (n = 60) were included in this study. KIR genes and KIR ligands were investigated with PCR-SSOP and PCR-SSP in all subjects, respectively.

RESULTS

This study showed that while the telomeric KIR genes (2DS5 and 3DS1), and combinations of 3DS1+HLA-BBw4-Thrand 3DS1+HLA-BBw4-Iso- (p < 0.001, p < 0.001, p < 0.001, and p < 0.001, respectively) were observed more frequently in patients with CD than in controls, the 2DS5, 3DS1 KIR genes, C1 ligand, and combinations of 3DS1+HLA-BBw4-Thr- and 3DS1+HLA-BBw4-Iso- (p = 0.002, p = 0.004, p = 0.036, p < 0.001, and p = 0.007, respectively) were observed more frequently in patients with CD+DM than in controls.

CONCLUSIONS

The results of this study indicated that some KIR genes, KIR ligands, and KIR/KIR ligand interactions may be responsible for a predisposition to CD and the coexistence of CD and DM. For development of coexisting CD and DM, the 2DS5 and 3DS1 genes, C1 ligand, and combinations of 3DS1+HLA-BBw4-Thr- and 3DS1+HLA-BBw4-Iso- were found to be risk factors.

The frequencies of Killer immunoglobulin-like receptors and their HLA ligands in chronic inflammatory demyelinating polyradiculoneuropathy are similar to those in Guillian Barre syndrome but differ from those of controls, suggesting a role for NK cells in pathogenesis

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an acquired inflammatory neuropathy, which has similar clinical and pathological features to Guillain-Barré Syndrome (GBS), but differs in time course. We investigated the frequency of genes encoding Killer immunoglobulin-like receptors and their HLA ligands in subjects with CIDP, in subjects with GBS and in healthy controls. There were no differences in KIR gene frequency among the 3 groups. The gene frequencies for HLA-B Bw4-I were significantly greater in CIDP than HC, but did not differ from GBS. The frequency of the combination of 3DL1/HLA-B Bw4I was greater in CIDP than HC, but did not differ from that of GBS. These data raise the possibility of NK cell function being an important factor in the pathogenesis of CIDP.