%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Bharucha, T.
%A Ayhan, N.
%A Pastorino, B.
%A Rattanavong, S.
%A Vongsouvath, M.
%A Mayxay, M.
%A Changthongthip, A.
%A Sengvilaipaseuth, O.
%A Phonemixay, O.
%A Pommier, J. D.
%A Gorman, C.
%A Zitzmann, N.
%A Newton, P. N.
%A Lamballerie de, X.
%A Dubot Pérès, Audrey
%T Immunoglobulin M seroneutralization for improved confirmation of Japanese encephalitis virus infection in a flavivirus-endemic area
%D 2022
%L fdi:010085151
%G ENG
%J Transactions of the Royal Society of Tropical Medicine and Hygiene
%@ 0035-9203
%K diagnostics ; flavivirus ; Laos ; neglected tropical disease ; neurological ; infection ; seroneutralization
%K LAOS ; ZONE TROPICALE
%M ISI:000797986400001
%P [11 ]
%R 10.1093/trstmh/trac036
%U https://www.documentation.ird.fr/hor/fdi:010085151
%> https://www.documentation.ird.fr/intranet/publi/2022-07/010085151.pdf
%V [Early access]
%W Horizon (IRD)
%X 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-naive (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.
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