RT Journal Article
SR Electronic
T1 Absence of GluD2 Antibodies in Patients With Opsoclonus-Myoclonus Syndrome
JF Neurology
JO Neurology
FD Lippincott Williams & Wilkins
SP e1082
OP e1087
DO 10.1212/WNL.0000000000011410
VO 96
IS 7
A1 Petit-Pedrol, Mar
A1 Guasp, Mar
A1 Armangue, Thais
A1 Lavarino, Cinzia
A1 Morales La Madrid, Andres
A1 Saiz, Albert
A1 Graus, Francesc
A1 Dalmau, Josep
YR 2021
UL http://n.neurology.org/content/96/7/e1082.abstract
AB Objective A recent study showed glutamate receptor delta 2 antibodies (GluD2-ab) in sera of patients with opsoclonus-myoclonus syndrome (OMS). Inconsistencies between cerebellar immunoreactivity and expression of GluD2 led us to hypothesize that these antibodies are not biomarkers of OMS.Methods Serum of 45 children with OMS (10 [22%] with neuroblastoma), 158 adults with OMS (53 [34%] with tumors), and 172 controls including 134 patients with several types of neurologic disorders, 18 with neuroblastoma without OMS, and 20 healthy participants were investigated. Antibodies were determined with 3 different techniques: (1) rat brain immunohistochemistry, (2) a live cell-based assay using a standard secondary antibody (2-step CBA), and (3) a similar CBA with a secondary and tertiary antibodies (3-step CBA). Two plasmids were used in the CBA studies. Three commercial GluD2-ab and 2 human sera with GluD2-ab served as controls for expression of GluD2.Results The 3 commercial GluD2-ab showed predominant reactivity with the molecular and Purkinje cell layers (where GluD2 is highly enriched), and were also positive with the indicated CBAs. Substantially milder reactivity with brain tissue and CBA was obtained with the 2 control human sera containing GluD2-ab. None of the 203 patients with OMS and 172 controls showed immunoreactivities consistent with GluD2-abs. Compared with a standard 2-step CBA, the 3-step assay did not improve antibody detection and showed more frequent nonspecific reactivity that was not immunoabsorbed with GluD2.Conclusion We did not find GluD2-ab in a large cohort of patients with OMS. GluD2-ab should not be considered diagnostic biomarkers of OMS.CBA=cell-based assay; GluD2=glutamate receptor delta 2; GluD2-ab=glutamate receptor delta 2 antibody; IgG=immunoglobulin G; OMS=opsoclonus-myoclonus syndrome; RT=room temperature