Immunoglobulin M seroneutralization for improved confirmation of Japanese encephalitis virus infection in a flavivirus-endemic area

Abstract

Background The mainstay of diagnostic confirmation of acute Japanese encephalitis (JE) involves detection of anti-JE virus (JEV) immunoglobulin M (IgM) by enzyme-linked immunosorbent assay (ELISA). Limitations in the specificity of this test are increasingly apparent with the introduction of JEV vaccinations and the endemicity of other cross-reactive flaviviruses. Virus neutralization testing (VNT) is considered the gold standard, but it is challenging to implement and interpret. We performed a pilot study to assess IgG depletion prior to VNT for detection of anti-JEV IgM neutralizing antibodies (IgM-VNT) as compared with standard VNT. Methods We evaluated IgM-VNT in paired sera from anti-JEV IgM ELISA-positive patients (JE n=35) and negative controls of healthy flavivirus-naïve (n=10) as well as confirmed dengue (n=12) and Zika virus (n=4) patient sera. IgM-VNT was subsequently performed on single sera from additional JE patients (n=76). Results Anti-JEV IgG was detectable in admission serum of 58% of JE patients. The positive, negative and overall percentage agreement of IgM-VNT as compared with standard VNT was 100%. A total of 12/14 (86%) patient samples were unclassified by VNT and, with sufficient sample available for IgG depletion and IgG ELISA confirming depletion, were classified by IgM-VNT. IgM-VNT enabled JE case classification in 72/76 (95%) patients for whom only a single sample was available. Conclusions The novel approach has been readily adapted for high-throughput testing of single patient samples and it holds promise for incorporation into algorithms for use in reference centres.

Deep Proteomics Network and Machine Learning Analysis of Human Cerebrospinal Fluid in Japanese Encephalitis Virus Infection

“…JEV has a predilection for the thalamus and substantia nigra of the basal ganglia . One of the proteins were “group enriched” in the thalamus, MMP9, from the HPA database.…”

“…JEV has a predilection for the thalamus and substantia nigra of the basal ganglia. 26 One of the proteins were “group enriched” in the thalamus, MMP9, from the HPA database. Four proteins were associated with the GO term “substantia nigra development”, associated with BASP1, Glucose-6-phosphate dehydrogenase (G6PD), YWHAH, and 14-3-3 protein epsilon (14-3-3epsilon).…”

“…JEV infection was confirmed, as recommended by the World Health Organization, by detection of anti-JEV IgM by ELISA in CSF or seroconversion in paired serum samples. All anti-JEV IgM positive samples were subsequently confirmed by the gold-standard virus neutralization assay see cited reference ( 26 ). Power analysis was performed to estimate the sample size that would be required using different values.…”

Shotgun Characterization of the Circulating IgM Antigenome of an Infectious Pathogen by Immunocapture-LC–MS/MS from Dried Serum Spots

“…IgM is part of the first line of immune defense in mammals as shown by its protective role against infectious diseases. − Furthermore, its diagnostic value as an infection dynamics marker is well acknowledged. − However, there are some intrinsic challenges in dealing with this class of antibodies, which may explain the general lack of studies using IgM as a marker or target. At the structural level, serological IgM is predominantly secreted by B cells as a pentamer with five identical subunits linked by a J-chain and, occasionally, as a hexamer. , This structure has a high molecular weight of approximately 900 kDa, which hinders its immunoprecipitation (IP), probably due to their unstable binding to the protein A or G, commonly used as IgG immunoprecipitants.…”