Neuromyelitis optica IgG status in acute partial transverse myelitis.
BACKGROUND
Neuromyelitis optica (NMO) IgG is a specific marker for NMO. Furthermore, a high proportion of patients with longitudinally extensive transverse myelitis (characterized by spinal cord lesions extending 3 vertebral segments or more on magnetic resonance imaging) are seropositive for NMO-IgG and are considered to have a limited form of NMO. The NMO-IgG status in mild cases of acute partial transverse myelitis asociated with minimal magnetic resonance imaging abnormalities (spinal cord lesions <2 vertebral segments on magnetic resonance imaging) is unknown.


OBJECTIVE
To investigate the NMO-IgG status of patients with acute partial transverse myelitis and a normal cerebral magnetic resonance image.


METHODS
Observational, retrospective consecutive case series with longitudinal follow-up.


METHODS
Allegheny Multiple Sclerosis Treatment Center.


METHODS
Three groups of patients were tested for NMO-IgG. Group 1 consisted of 22 patients with acute partial transverse myelitis, group 2 consisted of 4 patients with definite NMO (by 1999 criteria of Wingerchuk et al), and group 3 consisted of 6 patients with definite multiple sclerosis.


METHODS
NMO-IgG status. A commercially available assay for NMO antibodies was performed at the Mayo Clinic. Testing was performed during the convalescent stage of the illness.


RESULTS
Of the 22 patients with acute partial transverse myelitis, only 1 was seropositive for NMO-IgG at presentation. This patient subsequently developed recurrent episodes of longitudinally extensive transverse myelitis that are typicaly seen in association with NMO-IgG. Three of the 4 patients meeting criteria for NMO were seropositive. None of the patients with multiple sclerosis had NMO-IgG detected.


CONCLUSIONS
NMO-IgG is rarely encountered in patients with acute partial transverse myelitis, which is in sharp contrast to the high frequency of this antibody in patients with NMO and longitudinally extensive transverse myelitis.
Scott
Thomas F
TF
Department of Neurology, Drexel University College of Medicine and Allegheny General Hospital, Pittsburgh, PA, USA. tscott@wpahs.org
Kassab
Salima L
SL
Pittock
Sean J
SJ
D005500:Follow-Up Studies; D006801:Humans; D007118:Immunoassay; D007074:Immunoglobulin G / Q000097:blood*; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D009188:Myelitis, Transverse / Q000097:blood* / Q000175:diagnosis* / Q000276:immunology; D009471:Neuromyelitis Optica / Q000097:blood* / Q000175:diagnosis* / Q000276:immunology; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012698:Serologic Tests; D013116:Spinal Cord / Q000276:immunology / Q000473:pathology* / Q000503:physiopathology
D007074:Immunoglobulin G