Background incidence rates of adverse events of special interest related to COVID-19 vaccines in Ontario, Canada, 2015 to 2020, to inform COVID-19 vaccine safety surveillance

Background: Background incidence rates are critical in pharmacovigilance to facilitate identification of vaccine safety signals. We estimated background incidence rates of nine adverse events of special interest related to COVID-19 vaccines in Ontario, Canada. Methods: We conducted a population-based retrospective observational study using linked health administrative databases for hospitalizations and emergency department visits among Ontario residents. We estimated incidence rates of Bells palsy, idiopathic thrombocytopenia, febrile convulsions, acute disseminated encephalomyelitis, myocarditis, pericarditis, Kawasaki disease, Guillain-Barre syndrome, and transverse myelitis during five pre-pandemic years (2015-2019) and 2020. Results: The average annual population was 14 million across all age groups with 51% female. The pre-pandemic mean annual rates per 100,000 population during 2015-2019 were 43.9 for idiopathic thrombocytopenia, 27.8 for Bells palsy, 25.0 for febrile convulsions, 22.8 for acute disseminated encephalomyelitis, 11.3 for myocarditis/pericarditis, 8.6 for pericarditis, 2.9 for myocarditis, 1.9 for Guillain-Barre syndrome, 1.7 for transverse myelitis, and 1.6 for Kawasaki disease. Females had higher rates of acute disseminated encephalomyelitis and transverse myelitis while males had higher rates of myocarditis, pericarditis, and Guillain-Barre syndrome. Bells palsy, acute disseminated encephalomyelitis, and Guillain-Barre syndrome increased with age. The mean rates of myocarditis and/or pericarditis increased with age up to 79 years; males had higher rates than females: from 12-59 years for myocarditis and 12 years and older for pericarditis. Febrile convulsions and Kawasaki disease were predominantly childhood diseases and generally decreased with age. Conclusions: Our estimated background rates will permit estimating numbers of expected events for these conditions and facilitate detection of potential safety signals following COVID-19 vaccination.

Comparison of Clinical, Immunological And Radiological Characteristics In Autoimmune GFAP Astrocytopathy, MOGAD And AQP4-Igg +NMOSD Mimicking Infectious Meningitis As The Initial Manifestation

Objective: Several autoimmune CNS inflammatory diseases, including autoimmune glial fibrillary acidic protein astrocytopathy (A-GFAP-A), myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) and aquaporin-4-immunoglobulin-G-positive neuromyelitis optica spectrum disorders (AQP4-IgG+ NMOSD) often presented initially with similar infectious meningitis-like symptoms. However, it was not easy to differentiate them at disease onset without antibody detection. The present study aimed to compare the clinical, immunological and radiological features among the three diseases. Methods: In our single-center cohorts, 9 A-GFAP-A, 17 MOGAD and 11 AQP4-IgG+ NMOSD patients mimicking infectious meningitis as initial symptoms were retrospectively included. The autoantibodies were detected with cell-based assays. The clinical, immunological and radiological characteristics of the three groups were summarized. Results: AQP4-IgG+ NMOSD patients were statistically more often in men (10, 90.9%, P=0.003). Tremor was predominated in A-GFAP-A (4, 44.4%) over MOGAD (1, 5.9%, P= 0.034) and never found in AQP4-IgG+NMOSD (0, P=0.026). The Modified Rankin Score (mRS) at the clinical nadir of diseases was lower in AQP4-IgG+NMOSD (2.2 [IQR, 1-3]) compared to A-GFAP-A (3.7 [IQR, 3-5], P=0.04). On CSF examination, white blood cell count (WBC) was higher in A-GFAP-A (median, 272×106/L [range, 0-1600]) compared to AQP4-IgG+NMOSD (median, 12×106/L [range, 0-48], P=0.049). Significant increase in CSF protein (1490.7±871.2 mg/L), lactic acid (3.43±0.81 mmol/L), IgG (130.9±60.4 mg/L), IgM (8.6±6.1mg/L) and IgA (23.0±11.4mg/L) levels in A-GFAP-A was found compared to MOGAD (CSF protein: 606.7±379.4 mg/L, P<0.001; lactic acid: 2.15 ± 0.62mmol/L, P<0.001; IgG: 77.9±71.3 mg/L, P=0.043; IgM, 2.7±2.9mg/L, P=0.002; IgA, 11.3±12.1mg/L, P=0.012) and AQP4-IgG+NMOSD (CSF protein: 441.8±178.0 mg/L, P<0.001; lactic acid: 2.40 ± 0.66 mmol/L, P=0.003; IgG, 53.2±30.3 mg/L, P=0.01; IgM, 2.1±3.9mg/L, P=0.003; IgA, 5.2±5.0mg/L, P=0.001). Over half of the A-GFAP-A patients (5/8, 62.5%) showed small (<2 cm), symmetrical lesions in ganglia and thalamus (5/8, 62.5%), but never in MOGAD (0%, P=0.001) and AQP4-IgG+NMOSD (0%, P=0.026). Diffuse meningeal enhancement was common in A-GFAP-A (8, 88.9%) compared to MOGAD (5, 29.4%, P=0.011) and AQP4-IgG+NMOSD (1/6, 16.7%, P=0.011). Acute disseminated encephalomyelitis (ADEM) -like lesions occurred frequently in MOGAD (6/16, 37.5%) but never in A-GFAP-A and AQP4-IgG+NMOSD (P=0.02). Conclusion: Our study demonstrated that several signs including the symptom of tremor, a more severe disease course, higher CSF immunological profiles and ganglia bilateral symmetrical lesions, diffuse meningeal enhancement were distinct features in A-GFAP-A, and ADEM-like lesions occurred only in MOGAD mimicking infectious meningitis as initial symptoms, providing possible clinical implications for patient differential diagnosis.

Levamisole-Induced Leukoencephalopathy in Russia: Analysis of 30 Cases

Aims: To raise medical specialists’ awareness regarding the severity of possible complications of levamisole administration and demonstrate the role of accurate medical history collection in differential diagnosis. Background: Levamisole, an anthelmintic drug with immunomodulatory effects, has long been used worldwide till early 2000s, when its association with demyelinating leukoencephalopathy was established. However, in the developing countries it is still widely used for prevention and treatment of helminthic invasion in humans. Actual prevalence of levamisole-induced multiple inflammatory leukoencephalopathy (LEV-induced MIL) in Russia remains unknown, and therefore, the study of its frequency and characteristics is indisputably important. Objectives: To determine the clinical features and MRI findings of levamisole-induced MIL in the Russian population and to analyse the frequency of diagnostic errors at the initial assessment. Methods: A single-center retrospective analysis of total 30 patients who were diagnosed with LEV-induced MIL and attended Research Center of Neurology was conducted. Inclusion criteria were 1) clinically: acute or subacute polysymptomatic onset of neurological disturbances, 2) MRI: multifocal demyelinating lesion with no evidence of dissemination in time, 3) anamnestic data: levamisole exposure from 2 to 8 weeks before symptoms onset as well as monophasic disease course (absence of relapses according to follow up assessments up to 3 years). Results: Clinically, presentation with constitutional symptoms, including headache, fever, fatigue and myalgia, focal motor disturbances and dysarthria prevailed in our cohort. On the brain MRI, multiple foci of demyelination with simultaneous gadolinium enhancement were observed. The link between neurological symptoms and levamisole intake has often been detected only during follow-up assessments. Patients were most often misdiagnosed with acute disseminated encephalomyelitis, stroke and multiple sclerosis. In most cases LEV-induced MIL was successfully treated with intravenous corticosteroids and/or plasma exchange (PLEX), however, residual neurologic symptoms preserved in some patients. Additionally, two detailed clinical cases of patients being initially misdiagnosed are presented in the article. Conclusion: The differential diagnosis remains difficult for suspected cases of LEV-induced MIL that could lead to delayed therapy initiation, and consequently incomplete recovery. Growing evidence suggests that a single administration of levamisole even in low doses might potentially lead to severe neurological deficit or death. Therefore, changes in medication management policies are required in order to prevent uncontrolled use of levamisole.