Guinea Pig IgG (Fab) [HRP]

This study aimed to assess the diagnostic test accuracy (DTA) of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) serological test methods and the kinetics of antibody positivity. Systematic review and meta-analysis were conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. We included articles evaluating the diagnostic accuracy of serological tests and the kinetics of antibody positivity. MEDLINE through PubMed, Scopus, medRxiv and bioRxiv were sources of articles. Methodological qualities of included articles were appraised using QUADAS-2 while Metandi performs bivariate meta-analysis of DTA using a generalized linear mixed-model approach. Stata 14 and Review Manager 5.3 were used for data analysis. The summary sensitivity/specificity of chemiluminescence immunoassay (CLIA), enzyme-linked immunosorbent assay (ELISA) and lateral flow immunoassay (LFIA) were 92% (95% CI: 86%-95%)/99% (CI: 97%-99%), 86% (CI: 82%-89%)/99% (CI: 98%-100%) and 78% (CI: 71%-83%)/98% (95% CI: 96%-99%), respectively. Moreover, CLIA-based assays produced nearly 100% sensitivity within 11-15 days post-symptom onset (DPSO). Based on antibody type, the sensitivity of ELISA-total antibody, CLIA-IgM/G and CLIA-IgG gauged at 94%, 92% and 92%, respectively. The sensitivity of CLIA-RBD assay reached 96%, while LFIA-S demonstrated the lowest sensitivity, 71% (95% CI: 58%-80%). CLIA assays targeting antibodies against RBD considered the best DTA. The antibody positivity rate increased corresponding with DPSO, but there was some decrement when moving from acute phase to convalescent phase of infection. As immunoglobulin isotope-related DTA was heterogeneous, our data have insufficient evidence to recommend CLIA/ELISA for clinical decision-making, but likely to have comparative advantage over RT-qPCR in certain circumstances and geographic regions.

Objective:We report the case of a young woman with postinfectious onset of myasthenia gravis after COVID-19 with mild respiratory symptoms and anosmia/ageusia 1 month before admission to our neurological department. Methods:Patient data were derived from medical records of Hannover Medical School, Germany. Written informed consent was obtained from the patient. Results:The 21-year-old female patient presented with subacute, vertically shifted double vision evoked by right sided partial oculomotor paresis and ptosis. About 4 weeks earlier she had suffered from mild respiratory symptoms, aching limbs and head without fever, accompanied by anosmia/ageusia. During the persistence of the latter symptoms for around 10 days the patient had already noticed "tired eyes" and fluctuating double vision. Clinical assessment including a positive test with edrophonium chloride and increased acetylcholine receptor antibodies related the ocular manifestation etiologically to myasthenia gravis. Antibodies (IgA/IgG) against SARS-CoV-2 using three different serological tests (Abbott, DiaSorin, Euroimmun) were detected in serum suggesting this specific coronavirus as previously infectious agent in our patient. The myasthenic syndrome was treated successfully with intravenous immunoglobulins and oral pyridostigmine. Conclusion:This is the first case presentation of postinfectious myasthenia gravis as neurological complication in a COVID-19 patient.