Anti-ganglioside antibodies were not detected in human subjects infected with or vaccinated against 2009 pandemic influenza A (H1N1) virus

Neurological complications of pandemic A(H1N1)2009pdm, postpandemic A(H1N1)v, and seasonal influenza A

OBJECTIVES

Not much is known about influenza-associated neurological complications. We aimed to describe the case series of hospitalized patients who were confirmed with influenza A and presented with neurological symptoms in order to capture the broad spectrum of influenza clinical manifestation and suggest including influenza diagnostic in some neurological conditions.

MATERIALS AND METHODS

The inclusion criteria were age ≥ 18 and laboratory-confirmed influenza presenting with neurological symptoms. Influenza-associated neurological complication was described as a development of neurological symptom with no other origin. The outcomes were classified into 5 categories: 1. recovery with no significant disability; 2. minor disability (able to manage on their own); 3. moderate disability (requiring some help but able to walk without assistance); 4. severe disability (unable to walk without assistance and perform daily activities); 5. death.

RESULTS

In total, 12 patients (five women and seven men) were enrolled, with age range 18-71 years old. Neurological complications of pandemic A(H₁ N₁ )2009pdm influenza developed in seven out of 69 (10.1%) hospitalized patients. The most common neurological complication was encephalopathy. Neurological complications developed in two out of 24 (8.3%) hospitalized patients during postpandemic (H₁ N₁ )_V period. One patient presented with encephalopathy, another with meningoencephalitis. During the 2018 influenza season, there was one patient who has developed influenza A neurological complications. Overall, two out of 104 (1.9%) influenza A patients developed influenza-associated neurological complications in 2019.

CONCLUSIONS

Every patient with unexplained neurological symptoms and signs similar to aseptic and septic meningitis/encephalitis has to be tested for influenza virus during epidemics and pandemics.

The hidden burden of influenza: A review of the extra-pulmonary complications of influenza infection

Severe influenza infection represents a leading cause of global morbidity and mortality. Although influenza is primarily considered a viral infection that results in pathology limited to the respiratory system, clinical reports suggest that influenza infection is frequently associated with a number of clinical syndromes that involve organ systems outside the respiratory tract. A comprehensive MEDLINE literature review of articles pertaining to extra‐pulmonary complications of influenza infection, using organ‐specific search terms, yielded 218 articles including case reports, epidemiologic investigations, and autopsy studies that were reviewed to determine the clinical involvement of other organs. The most frequently described clinical entities were viral myocarditis and viral encephalitis. Recognition of these extra‐pulmonary complications is critical to determining the true burden of influenza infection and initiating organ‐specific supportive care.

Identification and characterization of epitopes from influenza A virus hemagglutinin that induce broadly cross-reactive antibodies

Influenza is the most common infectious disease and is caused by influenza A virus (IAV) infection. Hemagglutinin (HA) is an important viral protein of influenza A and is a major component of current IAV vaccines. The side effects associated with IAV vaccination are well studied; however, the HA‑induced immunopathological changes have remained largely elusive. The primary objective of the present study was to determine the tissue cross‑reactive epitopes of HA proteins. Monoclonal antibodies (McAbs) were generated according to traditional methods using purified HA proteins from influenza vaccine lysates. The specificity of these McAbs was analyzed using western blot analysis and ELISA. Human tissue microarrays were employed for immunohistochemical staining to screen these McAbs. Rat brain tissues were subjected to immunohistochemical staining and electron microscopy to demonstrate the subcellular localization of antibodies targeting specific antigens. A total of 67 hybridoma cell lines positive for McAb against HA antigen were obtained. Three cross‑reactive McAbs (H1‑13, H1‑15 and A1‑10) were discovered through tissue screening. Based on the 3 cross‑reactive McAbs and the amino acid sequence of HA, the presence of two broadly cross‑reactive HA epitopes, 194‑WGIHH‑198 and 365‑WYGYHH‑370, was assumed. McAbs against these synthetic epitope peptides were obtained. They reacted with porphyrin ring‑containing molecules, including hemoglobin (Hb) and protoporphyrin, and with numerous types of normal tissue. In conclusion, the present study identified two broadly cross‑reactive epitopes on HA (194‑WGIHH‑198 and 365‑WYGYHH‑370). Antibodies against these epitopes react with Hb and numerous types of important normal tissues/organs. These newly identified cross‑reactive epitopes from IAV HA may provide crucial information for influenza research.

Vaccination and autoimmune diseases: is prevention of adverse health effects on the horizon?

Autoimmune diseases, including multiple sclerosis and type 1 diabetes mellitus, affect about 5% of the worldwide population. In the last decade, reports have accumulated on various autoimmune disorders, such as idiopathic thrombocytopenia purpura, myopericarditis, primary ovarian failure, and systemic lupus erythematosus (SLE), following vaccination. In this review, we discuss the possible underlying mechanisms of autoimmune reactions following vaccinations and review cases of autoimmune diseases that have been correlated with vaccination. Molecular mimicry and bystander activation are reported as possible mechanisms by which vaccines can cause autoimmune reactions. The individuals who might be susceptible to develop these reactions could be especially not only those with previous post-vaccination phenomena and those with allergies but also in individuals who are prone to develop autoimmune diseases, such as those with a family history of autoimmunity or with known autoantibodies, and the genetic predisposed individuals. Further research is encouraged into the direct associations between vaccines and autoimmune conditions, and the biological mechanisms behind them.

The safety of influenza vaccines in children: An Institute for Vaccine Safety white paper

Most influenza vaccines are generally safe, but influenza vaccines can cause rare serious adverse events. Some adverse events, such as fever and febrile seizures, are more common in children than adults. There can be differences in the safety of vaccines in different populations due to underlying differences in genetic predisposition to the adverse event. Live attenuated vaccines have not been studied adequately in children under 2 years of age to determine the risks of adverse events; more studies are needed to address this and several other priority safety issues with all influenza vaccines in children. All vaccines intended for use in children require safety testing in the target age group, especially in young children. Safety of one influenza vaccine in children should not be extrapolated to assumed safety of all influenza vaccines in children. The low rates of adverse events from influenza vaccines should not be a deterrent to the use of influenza vaccines because of the overwhelming evidence of the burden of disease due to influenza in children.

Autoantibodies against ganglioside GM3 are associated with narcolepsy-cataplexy developing after Pandemrix vaccination against 2009 pandemic H1N1 type influenza virus

Following the mass vaccinations against pandemic influenza A/H1N1 virus in 2009, a sudden increase in juvenile onset narcolepsy with cataplexy (NC) was detected in several European countries where AS03-adjuvanted Pandemrix vaccine had been used. NC is a chronic neurological disorder characterized by excessive daytime sleepiness and cataplexy. In human NC, the hypocretin-producing neurons in the hypothalamus or the hypocretin signaling pathway are destroyed by an autoimmune reaction. Both genetic (e.g. HLA-DQB1*0602) and environmental risk factors (e.g. Pandemrix) contribute to the disease development, but the underlying and the mediating immunological mechanisms are largely unknown. Influenza virus hemagglutinin is known to bind gangliosides, which serve as host cell virus receptors. Anti-ganglioside antibodies have previously been linked to various neurological disorders, like the Guillain-Barré syndrome which may develop after infection or vaccination. Because of these links we screened sera of NC patients and controls for IgG anti-ganglioside antibodies against 11 human brain gangliosides (GM1, GM2, GM3, GM4, GD1a, GD1b, GD2, GD3, GT1a, GT1b, GQ1b) and a sulfatide by using a line blot assay. Samples from 173 children and adolescents were analyzed: 48 with Pandemrix-associated NC, 20 with NC without Pandemrix association, 57 Pandemrix-vaccinated and 48 unvaccinated healthy children. We found that patients with Pandemrix-associated NC had more frequently (14.6%) anti-GM3 antibodies than vaccinated healthy controls (3.5%) (P = 0.047). Anti-GM3 antibodies were significantly associated with HLA-DQB1*0602 (P = 0.016) both in vaccinated NC patients and controls. In general, anti-ganglioside antibodies were more frequent in vaccinated (18.1%) than in unvaccinated (7.3%) individuals (P = 0.035). Our data suggest that autoimmunity against GM3 is a feature of Pandemrix-associated NC and that autoantibodies against gangliosides were induced by Pandemrix vaccination.

Evaluating the status of antiganglioside antibodies in children with Guillain-Barré syndrome

OBJECTIVE

Antiganglioside antibodies have been reported to play a role in the pathophysiology of Guillain-Barré syndrome (GBS).

METHODS

This case-control study was designed to evaluate the status of antiganglioside antibodies in children with GBS. The study included 50 patients suffering from GBS as the case group and 30 children as the control group. Clinical information such as demographic data and recent digestive or respiratory infection (within the last month) was collected for all patients, and paraclinical studies including cerebrospinal fluid examination and electrophysiology were conducted by a subspecialized physician. Anti-GM1, anti-GQ1 and anti-GD1a antibodies were measured with ELISA and the EUROLINE method.

RESULTS

The mean age of patients in the case and control groups was 5.3 ± 3.8 and 5.4 ± 3.4 years, respectively. With the EUROLINE method, the results obtained for anti-GM1 were significant (p = 0.007); however, the p values for anti-GQ1a and anti-GQ1b were not significant (0.051 vs. 0.94), while with ELISA, comparing all three antibodies in both the case and control groups showed statistically significant results, with a p < 0.05.

CONCLUSION

EUROLINE is a new method used to evaluate antibodies in immune system diseases, but it is not useful for all antibodies specific to GBS, as the analysis was significant with a p value of 0.007 for anti-GM2.

Autoimmune/inflammatory syndrome induced by adjuvants (Shoenfeld's syndrome): clinical and immunological spectrum

An adjuvant is a substance that enhances the antigen-specific immune response, induces the release of inflammatory cytokines, and interacts with Toll-like receptors and the NALP3 inflammasome. The immunological consequence of these actions is to stimulate the innate and adaptive immune response. The activation of the immune system by adjuvants, a desirable effect, could trigger manifestations of autoimmunity or autoimmune disease. Recently, a new syndrome was introduced, autoimmune/inflammatory syndrome induced by adjuvants (ASIA), that includes postvaccination phenomena, macrophagic myofasciitis, Gulf War syndrome and siliconosis. This syndrome is characterized by nonspecific and specific manifestations of autoimmune disease. The main substances associated with ASIA are squalene (Gulf War syndrome), aluminum hydroxide (postvaccination phenomena, macrophagic myofasciitis) and silicone with siliconosis. Mineral oil, guaiacol and iodine gadital are also associated with ASIA. The following review describes the wide clinical spectrum and pathogenesis of ASIA including defined autoimmune diseases and nonspecific autoimmune manifestations, as well as the outlook of future research in this field.

Autoantibodies in immune-mediated neuropathies

PURPOSE OF REVIEW

Over the past 25 years, many autoantibodies directed against peripheral nerve glycan and protein antigens have been described. Principally through this area of research, significant advances have been achieved in the understanding of the pathophysiology of inflammatory neuropathies. More evidence constantly continues to emerge supporting the role of antibodies in pathogenesis. This review reports the recent studies highlighting the complex association between autoantibodies directed against various peripheral nerve antigens and immune polyneuropathies.

RECENT FINDINGS

The discovery of serum antibodies directed against ganglioside and glycolipid complexes has generated huge interest in this area of research. The expectation that nodal proteins are important targets continues to be pursued in line with the improvements in detection methodology. Basic studies continue to support a direct role for autoantibodies in neuropathy pathogenesis.

SUMMARY

Discovery of new target epitopes has not only raised hopes for further improvement in our understanding of pathophysiology and availability of new diagnostic markers, but also for future targeted therapies. Further studies are required to elucidate the precise pathological and clinical significance of these new antibodies.

The epidemiological and public health research response to 2009 pandemic influenza A(H1N1): experiences from Hong Kong

In recent years, Hong Kong has invested in research infrastructure to appropriately respond to novel infectious disease epidemics. Research from Hong Kong made a strong contribution to the international response to the 2009 influenza A (H1N1) pandemic (pH1N1). Summarizing, describing, and reviewing Hong Kong’s response to the 2009 pandemic, this article aimed to identify key elements of a real‐time research response. A systematic search in PubMed and EMBASE for research into the infection dynamics and natural history, impact, or control of pH1N1 in Hong Kong. Eligible articles were analyzed according to their scope. Fifty‐five articles were included in the review. Transmissibility of pH1N1 was similar in Hong Kong to elsewhere, and only a small fraction of infections were associated with severe disease. School closures were effective in reducing pH1N1 transmission, oseltamivir was effective for treatment of severe cases while convalescent plasma therapy has the potential to mitigate future pandemics. There was a rapid and comprehensive research response to pH1N1 in Hong Kong, providing important information on the epidemiology of the novel virus with relevance internationally as well as locally. The scientific knowledge gained through these detailed studies of pH1N1 is now being used to revise and update pandemic plans. The experiences of the research response in Hong Kong could provide a template for the research response to future emerging and reemerging disease epidemics.