NMO-IgG and Devic's neuromyelitis optica: a French experience.
BACKGROUND
A serum autoantibody biomarker, NMO-IgG has been recently described in patients with Devic's neuromyelitis optica (DNMO) and so called ;high-risk' patients for this disease. Our objectives were to replicate the test and to assess its usefulness.


METHODS
Indirect immunofluorescence with a substrate of adult rat cerebellum and midbrain was used to identify the distinctive NMO-IgG staining pattern. We tested masked sera from 26 patients with DNMO (group 1), 21 patients with idiopathic acute transverse myelitis (ATM) (group 2), 21 patients with bilateral and/or recurrent idiopathic optic neuritis (group 3), 52 patients with classical multiple sclerosis (MS) (group 4), 36 patients with HTLV-1 infection (group 5) and 7 patients with miscellaneous disorders (group 6).


RESULTS
We identified a vascular staining pattern typical of NMO-IgG. This particular staining was observed in 14/26 samples in group 1, 7/21 in group 2 (positive only in longitudinally extensive acute transverse myelitis: 7/13), 4/21 in group 3 (with bilateral loss of vision in all seropositive cases), 5/52 in group 4 (none of them suggestive of DNMO), 0/36 in group 5 and 0/7 in group 6. Sensitivity of the test was 54% considering detection of DNMO (group 1), and specificity was respectively 94% and 90% when considering groups 4, 5 and 6 altogether or group 4 of MS patients only.


CONCLUSIONS
Detection of NMO-IgG is contributory to the distinction of DNMO and 'DNMO high-risk' syndromes from MS. This test may allow earlier diagnosis and help therapeutic decisions.
Marignier
Romain
R
Service de Neurologie A and EDMUS Co-ordinating Center, Hôpital Neurologique Pierre Wertheimer, Hospices Civils de Lyon, 59 boulevard Pinel Lyon Bron cedex, F-69677, France. romain.marignier@chu-lyon.fr
De Sèze
Jérôme
J
Vukusic
Sandra
S
Durand-Dubief
Françoise
F
Zéphir
Hélène
H
Vermersch
Patrick
P
Cabre
Philippe
P
Cavillon
Gaëlle
G
Honnorat
Jérôme
J
Confavreux
Christian
C
D000293:Adolescent; D000328:Adult; D000818:Animals; D000918:Antibody Specificity; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood*; D002648:Child; D015331:Cohort Studies; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D005602:France / Q000453:epidemiology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000453:epidemiology / Q000276:immunology; D009188:Myelitis, Transverse / Q000453:epidemiology / Q000276:immunology; D009471:Neuromyelitis Optica / Q000453:epidemiology* / Q000276:immunology*; D051381:Rats; D012307:Risk Factors; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies
D001323:Autoantibodies; D015415:Biomarkers; D007074:Immunoglobulin G