Current status of Guillain-Barré syndrome (GBS) in China: a 10-year comprehensive overview

Guillain-Barré syndrome (GBS) is an acute inflammatory polyradiculoneuropathy; a disease involving the peripheral nervous system which is the most common cause of acute flaccid paralysis worldwide. So far, it is still lack of a comprehensive overview and understanding of the national epidemiological, clinical characteristics, and the risk factors of GBS in China, as well as differences between China and other countries and regions in these respects. With the global outbreak of the coronavirus disease 2019 (COVID-19), an epidemiological or phenotypic association between severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection and GBS has attracted great attention. In this review, we outlined the current clinical data of GBS in China by retrieving literature, extracting and synthesizing the data of GBS in China from 2010 to 2021. Besides, we compared the characteristics of epidemiology, preceding events and clinical profiles of GBS between China and other countries and regions. Furthermore, in addition to conventional intravenous immunoglobulin (IVIG) and plasma exchange (PE) therapy, the potential therapeutic effects with novel medications in GBS, such as complement inhibitors, etc., have become the research focus in treatments. We found that epidemiological and clinical findings of GBS in China are approximately consistent with those in the International GBS Outcome Study (IGOS) cohort. We provided an overall picture of the present clinical status of GBS in China and summarized the global research progress of GBS, aiming to further understand the characteristics of GBS and improve the future work of GBS worldwide, especially in countries with the middle and low incomes.

Characteristics of Patients Diagnosed With Guillain-Barré Syndrome at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, From 2000 to 2018

BACKGROUND

Guillain-Barré syndrome (GBS) is the leading cause of non-polio acute flaccid paralysis worldwide, emphasizing the importance of epidemiological studies on this condition. Therefore, well-designed epidemiological studies in different populations can provide a better understanding of the characteristics of patients with GBS and the nature of the disease. To our knowledge, no previous study has attempted to describe the characteristics of patients with GBS in Kingdom of Saudi Arabia (KSA) based on disease subtypes and clinical features in both adult and pediatric patients. This study aimed to assess the frequencies of GBS subtypes and their relationships with patient characteristics and clinical data in a tertiary hospital in Jeddah, KSA.

METHODS

This was a retrospective review of patients diagnosed with GBS between January 2000 and January 2018 at King Abdulaziz University Hospital (KAUH), a tertiary center in Jeddah, KSA.

RESULTS

In total, 47 patients with GBS (median age: seven years for pediatric and 36 years for adult patients) were included in the current study. There were six male and three female pediatric patients and 19 male and 19 female adult patients. Among patients with GBS who were classified into a specific electrophysiological subtype (n = 28), 13 (46.2%) had acute inflammatory demyelinating polyneuropathy (AIDP), 11 (39%) had an axonal subtype, and four (14%) had Miller Fisher syndrome (MFS). Patients required prolonged hospitalization of approximately 20 ± 22 days (2.83 ± 3.11 weeks). Patients with MFS were more likely to have higher cytoalbuminologic dissociation than those with other subtypes.

CONCLUSION

AIDP was the most frequent type of GBS, followed by the axonal type. Patients required prolonged hospitalization of approximately 20 ± 22 days (2.83 ± 3.11 weeks). Patients with MFS were more likely to have higher cytoalbuminologic dissociation than those with other subtypes. GBS type did not show a relationship with ICU admission or mechanical ventilation use. There was no association between specific therapies and different GBS subtypes and no significant difference in outcomes between different patterns of clinical presentation. Intravenous immunoglobulin (IVIg) and plasma exchange (PE) treatments both had the same efficacy in relation to outcomes for patients with GBS.

Factors Influencing Background Incidence Rate Calculation: Systematic Empirical Evaluation Across an International Network of Observational Databases

Objective: Background incidence rates are routinely used in safety studies to evaluate an association of an exposure and outcome. Systematic research on sensitivity of rates to the choice of the study parameters is lacking. Materials and Methods: We used 12 data sources to systematically examine the influence of age, race, sex, database, time-at-risk, season and year, prior observation and clean window on incidence rates using 15 adverse events of special interest for COVID-19 vaccines as an example. For binary comparisons we calculated incidence rate ratios and performed random-effect meta-analysis. Results: We observed a wide variation of background rates that goes well beyond age and database effects previously observed. While rates vary up to a factor of 1,000 across age groups, even after adjusting for age and sex, the study showed residual bias due to the other parameters. Rates were highly influenced by the choice of anchoring (e.g., health visit, vaccination, or arbitrary date) for the time-at-risk start. Anchoring on a healthcare encounter yielded higher incidence comparing to a random date, especially for short time-at-risk. Incidence rates were highly influenced by the choice of the database (varying by up to a factor of 100), clean window choice and time-at-risk duration, and less so by secular or seasonal trends. Conclusion: Comparing background to observed rates requires appropriate adjustment and careful time-at-risk start and duration choice. Results should be interpreted in the context of study parameter choices.

Second dose of measles-mumps-rubella-varicella vaccine (MMRV) and the risk of febrile convulsions

INTRODUCTION

Studies have shown an increased risk of febrile convulsions (FC) after first immunization with the quadrivalent measles-mumps-rubella-varicella vaccine (MMRV) compared to a first dose of measles-mumps-rubella vaccine (MMR) only or in combination with separately administered varicella vaccine (MMR + V). Therefore, it is recommended to give MMR + V at first dose and MMRV or MMR + V at second dose. Little is known on the risk of FC after MMRV at second dose, especially whether the risk depends on age, sex, history of FC or type of first dose vaccine.

METHODS

A retrospective cohort study using claims data from the German Pharmacoepidemiological Research database (GePaRD) was performed in children born between January 1st, 2004 and October 31st, 2015 who received two doses of MMRV, MMR + V or MMR. Cases were defined as hospitalization with a diagnosis of FC without neurological conditions coded as main discharge diagnosis. Unadjusted and adjusted odds ratios (OR) with 95% confidence intevals (CIs) were calculated to compare the risk of FC. Stratified analyses were performed to examine potential effect modification by age, sex, history of FC or type of first dose vaccine.

RESULTS

In the first 30 days after second dose vaccination, 464 FCs were observed in a cohort of 528,639 children with a median age of 17 months. After adjustment for potential confounders, the adjusted OR for FC in the 30 days after vaccination was 1.25 (95% CI 0.67-2.30) for MMRV compared to MMR + V and 1.04 (0.82-1.32) for MMRV compared to MMR. History of FC was the most important risk factor with an OR of 36.26 (29.30-44.89). We found no effect modification by age, sex, history of FC, or type of first dose vaccine.

CONCLUSION

Use of MMRV at second dose is not associated with an increased risk of FC compared to MMR + V or MMR, irrespective of age, sex, history of FC, or type of first dose vaccine.

Neurological autoimmune diseases following vaccinations against SARS-CoV-2: a case series

BACKGROUND AND PURPOSE

Population-based studies suggest that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines may trigger immune-mediated thrombotic thrombocytopenia (VITT) raising concerns for other autoimmune responses. The aim was to characterize neurological autoimmunity after SARS-CoV-2 vaccinations.

METHODS

In this single-centre prospective case study patients with neurological autoimmunity in temporal association (≤6 weeks) with SARS-CoV-2 vaccinations and without other triggers are reported. Clinical, laboratory and imaging data were collected with a median follow-up of 49 days.

RESULTS

In the study period 232,603 inhabitants from the main catchment area of our hospital (Rhein-Neckar-Kreis, county) received SARS-CoV-2 vaccinations. Twenty-one cases (new onset n = 17, flares n = 4) diagnosed a median of 11 days (range 3-23) following SARS-CoV-2 vaccinations (BNT162b2 n = 12, ChAdOx1 n = 8, mRNA-1273 n = 1) were identified. Cases included VITT with cerebral venous sinus thrombosis (n = 3), central nervous system demyelinating diseases (n = 8), inflammatory peripheral neuropathies (n = 4), myositis (n = 3), myasthenia (n = 1), limbic encephalitis (n = 1) and giant cell arteritis (n = 1). Patients were predominantly female (ratio 3.2:1) and the median age at diagnosis was 50 years (range 22-86). Therapy included administration of steroids (n = 15), intravenous immunoglobulins in patients with Guillain-Barré syndrome or VITT (n = 4), plasma exchange in cases unresponsive to steroids (n = 3) and anticoagulation in VITT. Outcomes were favourable with partial and complete remissions achieved in 71% and 24%, respectively. Two patients received their second vaccination without further aggravation of autoimmune symptoms under low-dose immunosuppressants.

CONCLUSIONS

In this study various neurological autoimmune disorders encountered following SARS-CoV-2 vaccinations are characterized. Given the assumed low incidence and mostly favourable outcome of autoimmune responses, the benefits of vaccinations outweigh the comparatively small risks.

Characterising the background incidence rates of adverse events of special interest for covid-19 vaccines in eight countries: multinational network cohort study

OBJECTIVE

To quantify the background incidence rates of 15 prespecified adverse events of special interest (AESIs) associated with covid-19 vaccines.

DESIGN

Multinational network cohort study.

SETTING

Electronic health records and health claims data from eight countries: Australia, France, Germany, Japan, the Netherlands, Spain, the United Kingdom, and the United States, mapped to a common data model.

PARTICIPANTS

126 661 070 people observed for at least 365 days before 1 January 2017, 2018, or 2019 from 13 databases.

MAIN OUTCOME MEASURES

Events of interests were 15 prespecified AESIs (non-haemorrhagic and haemorrhagic stroke, acute myocardial infarction, deep vein thrombosis, pulmonary embolism, anaphylaxis, Bell's palsy, myocarditis or pericarditis, narcolepsy, appendicitis, immune thrombocytopenia, disseminated intravascular coagulation, encephalomyelitis (including acute disseminated encephalomyelitis), Guillain-Barré syndrome, and transverse myelitis). Incidence rates of AESIs were stratified by age, sex, and database. Rates were pooled across databases using random effects meta-analyses and classified according to the frequency categories of the Council for International Organizations of Medical Sciences.

RESULTS

Background rates varied greatly between databases. Deep vein thrombosis ranged from 387 (95% confidence interval 370 to 404) per 100 000 person years in UK CPRD GOLD data to 1443 (1416 to 1470) per 100 000 person years in US IBM MarketScan Multi-State Medicaid data among women aged 65 to 74 years. Some AESIs increased with age. For example, myocardial infarction rates in men increased from 28 (27 to 29) per 100 000 person years among those aged 18-34 years to 1400 (1374 to 1427) per 100 000 person years in those older than 85 years in US Optum electronic health record data. Other AESIs were more common in young people. For example, rates of anaphylaxis among boys and men were 78 (75 to 80) per 100 000 person years in those aged 6-17 years and 8 (6 to 10) per 100 000 person years in those older than 85 years in Optum electronic health record data. Meta-analytic estimates of AESI rates were classified according to age and sex.

CONCLUSION

This study found large variations in the observed rates of AESIs by age group and sex, showing the need for stratification or standardisation before using background rates for safety surveillance. Considerable population level heterogeneity in AESI rates was found between databases.

Incidence of Guillain-Barré syndrome in an Uruguayan population. A prospective cohort study

Guillain-Barre syndrome (GBS) is an acute autoimmune peripheral inflammatory neuropathy and the most frequent cause of non-poliovirus acute flaccid paralysis worldwide. Background annual GBS incidence rates (IRs) in Latin America (LA) varies from 0.40 to 2.12/100000 persons per year. We performed a prospective population-based epidemiological study to determine the incidence and clinical profile of GBS in the most densely populated regions in Uruguay. The incidence of GBS in the population living in Montevideo and Canelones was studied in the period between June 01, 2018 and May 31, 2020. Patients older than 16 years of age diagnosed with GBS were prospectively enrolled. The mean global annual IR in the Uruguayan population was 1.7/100000 persons (95% CI 1.25-2.25). The highest rate was observed in the 65 to 74 age group among men (5.25/100000 per year) and in the 55 to 64 age group among women (2/100.000 per year). The mean age was 53.9 ± 19.5, years, without difference by sex (53.5 women, 54.5 men). The in-hospital mortality rate was 5.8%. A total of 51 patients were diagnosed with GBS: 42 (82%) had typical GBS, 5 (10%) Miller-Fisher syndrome (MFS), 3 (7%) a bilateral facial nerve palsy, 1 patient had a GBS-MFS overlap (2.3%). This is the first population-based GBS incidence study in LA using a prospective design. Our IR can be a useful tool in establishing the background rate to examine future disease trends caused by the introduction of new viruses or vaccines in Uruguay.

Characterizing the incidence of adverse events of special interest for COVID-19 vaccines across eight countries: a multinational network cohort study

BACKGROUND

As large-scale immunization programs against COVID-19 proceed around the world, safety signals will emerge that need rapid evaluation. We report population-based, age- and sex-specific background incidence rates of potential adverse events of special interest (AESI) in eight countries using thirteen databases.

METHODS

This multi-national network cohort study included eight electronic medical record and five administrative claims databases from Australia, France, Germany, Japan, Netherlands, Spain, the United Kingdom, and the United States, mapped to a common data model. People observed for at least 365 days before 1 January 2017, 2018, or 2019 were included. We based study outcomes on lists published by regulators: acute myocardial infarction, anaphylaxis, appendicitis, Bell's palsy, deep vein thrombosis, disseminated intravascular coagulation, encephalomyelitis, Guillain-Barre syndrome, hemorrhagic and non-hemorrhagic stroke, immune thrombocytopenia, myocarditis/pericarditis, narcolepsy, pulmonary embolism, and transverse myelitis. We calculated incidence rates stratified by age, sex, and database. We pooled rates across databases using random effects meta-analyses. We classified meta-analytic estimates into Council of International Organizations of Medical Sciences categories: very common, common, uncommon, rare, or very rare.

FINDINGS

We analysed 126,661,070 people. Rates varied greatly between databases and by age and sex. Some AESI (e.g., myocardial infarction, Guillain-Barre syndrome) increased with age, while others (e.g., anaphylaxis, appendicitis) were more common in young people. As a result, AESI were classified differently according to age. For example, myocardial infarction was very rare in children, rare in women aged 35-54 years, uncommon in men and women aged 55-84 years, and common in those aged ≥85 years.

INTERPRETATION

We report robust baseline rates of prioritised AESI across 13 databases. Age, sex, and variation between databases should be considered if background AESI rates are compared to event rates observed with COVID-19 vaccines.

Epidemiological Features and Economic Burden of Guillain-Barré Syndrome in South Korea: A Nationwide Population-Based Study

BACKGROUND AND PURPOSE

Guillain-Barré syndrome (GBS) is rare, but its symptoms are severe and they occasionally lead to long-term disability. Country-specific epidemiological evidence is useful for detecting potential problems at the population level. This study investigated the epidemiological and economic characteristics of GBS in South Korea.

METHODS

The Korean National Health Insurance Service claims data from 2010 to 2016 were used to identify incident cases as newly hospitalized patients with a primary diagnosis of GBS (the 10th revision of the International Classification Disease code of G61.0). New cases were defined as patients not having claim records for GBS within one year prior to the hospital admission for GBS.

RESULTS

The incidence rate increased by 45.6% between 2010 and 2016, from 1.28 to 1.82 per 100,000 population. All age groups other than <20 years showed increasing trends. The incidence rate was highest in those aged 65 years to 74 years. Approximately 72% of the incident GBS cases had antecedent infection within 42 days before GBS was diagnosed. Children younger than 10 years constituted the highest proportion of antecedent infections (93.7%). The average length of stay per GBS hospitalization was 33.5 days. Patients had an average of 7.48 outpatient visits for GBS treatment per year. The economic burden from a societal perspective of treating GBS during the first year was USD 16,428.

CONCLUSIONS

The increasing incidence trend and substantial economic burden of GBS strongly advocate the development of effective strategies for preventing and managing GBS.

Post-Marketing Safety Surveillance for the Adjuvanted Recombinant Zoster Vaccine: Methodology

A diligent, systematic, regular review of aggregate safety data is essential, particularly early after vaccine introduction, as this is when safety signals not identified during clinical development may emerge. In October 2017, the US Centers for Disease Control and Prevention Advisory Committee on Immunization Practices recommended the adjuvanted recombinant zoster vaccine (RZV; Shingrix, GSK) as the preferred vaccine for preventing herpes zoster (HZ) and related complications in immunocompetent adults aged ≥ 50 years. Subsequently, GSK experienced an unprecedented high demand for RZV. In this methodology paper, we summarize the enhanced measures undertaken to assess RZV safety during its early post-marketing experience in the USA, Canada and Germany. In addition to the routine signal-detection methods already in place for all vaccines, GSK established tailored and enhanced safety monitoring for RZV based on aggregate data of spontaneous reports and manufacturing data. Proactive, near real-time detection and evaluation of signals was a key objective. A dedicated in-house signal-detection tool customized for RZV was employed on a weekly (rather than the routine monthly) basis, allowing for a centralized, more frequent review of data on a single web-based platform. We also identified the background incidence rates of preselected medical events of interest in the first countries to introduce RZV (USA, Canada and Germany) to perform observed-to-expected analyses. This approach may offer a solution to the challenges associated with the assessment and monitoring of vaccine safety in an efficient and timely manner in the context of high vaccine uptake.

Epidemiology of Guillain-Barré syndrome in Finland 2004-2014

At total mean incidence of 0.84–1.1/100,000 the occurrence of Guillain‐Barré syndrome (GBS) is reported to be low in Finland compared to other Caucasian populations. However, a recent study from Southwestern Finland reported an incidence of 1.82/100,000 which is comparable to other Caucasian populations. We analyzed discharge data covering the years 2004 through 2014 on all neurological admissions in all Finnish university and central hospitals with a primary diagnosis of GBS. A total of 989 admissions due to GBS (917 individuals) were identified. The standardized (European population) annual incidence rate was 1.70/100,000 person‐years (95% confidence interval 1.60–1.81). GBS incidence had an increasing trend with age. The likelihood of GBS was higher among girls and adolescent women than boys and men of same age (male:female incidence rate ratio [IRR] 0.56), while in the older age groups (>19 years) the occurrence of GBS was higher among males than females (male:female IRR 1.59). The incidence of GBS remained stable during the study period. There was no seasonal variation in GBS admission frequencies (p = 0.28). No significant effect of the 2009–2010 H1N1 influenza or vaccination against it for GBS occurrence was observed. We suggest that GBS is as common, and has similar age‐distribution in Finland as in other European countries. Sex‐associated susceptibility for GBS appears to be different in children‐adolescents and adults.