Clinical characteristics, prognosis, and seropositivity to the anti-aquaporin-4 antibody in Korean patients with longitudinally extensive transverse myelitis

Abstract

Longitudinally extensive transverse myelitis (LETM) is a syndrome with extensive spinal cord lesions spanning three or more vertebral segments on spinal cord MRI. Although many reports have indicated that LETM is a characteristic feature of neuoromyelitis optica (NMO) in Western countries, the clinical characteristics and risk for development of NMO in Korean patients with LETM is not clear. We retrospectively investigated the clinical, laboratory, radiological features, and prognosis of Korean patients with a first-ever episode of idiopathic LETM. Patients were classified into four subgroups, depending on their clinical course: monophasic LETM, recurrent LETM, NMO, and classic multiple sclerosis (MS). We compared various clinical, laboratory, and radiological features between groups. Of 20 patients with first-ever LETM, 15 (75%) were men, and 13 (65%) experienced clinical relapse over a mean follow-up period of 58 months. Three of 20 patients (two with NMO, one with recurrent myelitis) were seropositive for anti-AQP4 antibodies. The predominance of men in the monophasic and recurrent LETM groups compared to the NMO group was remarkable. In conclusion, Korean patients with LETM are predominantly male and have low seropositivity for anti-AQP4 antibody, which distinguishes them from LETM patients in Western countries. Patients with LETM and seropositivity for anti-AQP4 antibody have a high risk of relapse. The male predominance and the relatively low seropositive rate for anti-AQP4 suggests that rather than being a limited form of NMO, recurrent LETM is a new clinical entity in Koreans.

Acute transverse myelitis in demyelinating diseases among the Chinese

“…Idiopathic ATM on MRI is characterized by a centrally located high T2 signal lesion occupying more than two-thirds of the cross-sectional area of the cord, greater than three vertebral segments in length, with a predilection for the thoracolumbar cord [23,24]. The present study showed some deviations from these reports in the clinical profiles of Chinese patients with idiopathic ATM: (1) M-ATM was found in only 31.0% (9/29) of idiopathic ATM patients, while R-ATM was common (69.0%, 20/29); (2) there was no peak age of onset between 10 and 19 years; (3) female predominance in R-ATM was different from other reports [25][26][27]; (4) spinal lesions occupying more than two-thirds of the cross-sectional area of the cord were rare, and only 11.1% (1/9) M-ATM patients and 15.0% (3/20) R-ATM had holocord lesions.…”

“…Three western studies reported that idiopathic R-ATM was different from classical MS [25,27,32], and recurrent longitudinal extensive myelitis (RLEM), with high serum positive rate for NMO-IgG antibodies was included in the NMO spectrum [29]. In contrast, in Asia, idiopathic R-ATM without extra-spinal lesions may be considered as spinal MS [33], and RLEM was different from spinal-restricted NMO [26,34]. Therefore, the nosology of idiopathic R-ATM remains controversial.…”

Etiologic Spectrum and Prognosis of Longitudinally Extensive Transverse Myelopathies

“…None of the seronegative LETM patients experienced a second relapse. Other authors have also reported a low percentage of positive NMO-IgG antibodies in patients presenting with LETM [21,22,23]. Nonetheless, a recent study evaluating LETM patients in an international reference center reported that almost 60% of cases presented antibodies against aquaporin-4 [9].…”

Serological markers associated with neuromyelitis optica spectrum disorders in South India

“…Male predominance in seronegative LETM has been highlighted in earlier studies too. [19] These patients may represent a heterogeneous group, and some patients may have other unidentified antigenic targets in the central nervous system.…”