The use of AQP4-antibody testing in diagnosis Thai patients with neuromyelitis optica

Background: There are several methods to detect AQP4-antibody which is essential for diagnosis neuromyelitis optica (NMO). Objective: To evaluate an accuracy of the commercially available kit compared with other available tests. Methods: One hundred and twelve patients who visited the multiple sclerosis (MS) clinic at Siriraj Hospital were tested for AQP4-antibody by cell-based assay with Sendai method (Postfix-CBA), a commercial kit (Prefix-CBA) and an indirect immunofluorescence tissue-based assay (IIF-TBA). The patients were classified to NMO, seropositive NMOSD (AQP4-pos NMOSD), seronegative NMOSD (AQP4-neg NMOSD), classic MS (CMS), atypical MS and clinical isolated syndrome (CIS). Results: Based on postfix-CBA, there were 26 NMO, 25 AQP4-pos NMOSD, 19 AQP4-neg NMOSD, 34 CMS, 4 atypical MS and 14 CIS. There were 5 (1 NMO, 2 AQP4-neg NMOSD, 2 CMS), 7 (1 NMO, 6 AQP4-pos NMOSD) and 2 patients (1 AQP4-neg NMOSD, 1 CIS) were seropositive only by CBA-kit, CBA-Sendai and IIF-TBA respectively. Sixteen patients were seropositive by both CBA but negative by IIF-TBA. Both CBA showed strong correlation. Conclusions: CBA-kit is a relatively sensitive, comparable assay to detect anti-AQP4 antibody in Thai NMO patients. Since the kit may have a few false-negative and false-positive results, a more sensitive assay is necessary for a much more proper diagnosis in the future.

MRI features and anti-AQP4 antibody status in Idiopathic infl ammatory demyelinating CNS disease (IIDCD) in Thai patients

Objective: To evaluate the MRI fi ndings in different status of anti-aquaporin 4 (AQP4) antibody in Thai patients with idiopathic infl ammatory demyelinating CNS diseases (IIDCDs). Methods: A retrospective study of 135 IIDCDs patients was performed. The available brain and spinal MRI were reviewed. All were tested for anti-AQP4 antibody. The MRI fi ndings were analyzed for any difference between patients with seronegative and seropositive anti-AQP4 antibody. Results: Eighty cases included 47 seronegative and 33 seropositive anti-AQP4 antibody were reviewed. Forty seven brain and 20 spinal MRIs from the seronegative group and 32 brain MRIs and 27 spinal MRIs (one with only spinal MRI) from the seropositive group were analyzed. There was no signifi cant difference between the two groups upon the number of patients who fulfi lled Barkhof’s MRI Criteria. When the patients were classifi ed according to the location and pattern of abnormal MRI fi ndings, more cases in the seropositive group had lesions at corticospinal tract or subependymal third/fourth ventricles (p<0.05). Long-extensive spinal cord lesion and central gray matter location were found more in the seropositive group whereas the short segment, peripheral location were found more in the seronegative group (p<0.05). Most of the seropositive cases had lesions at the cervicothoracic level in contrast to the seronegative cases which had more lesions at the thoracic cord level. Conclusion: MRI features were different between IIDCDs patients with seronegative and seropositive anti-AQP4 antibody. The characteristics and locations of the MRI lesions were mo

Brain and spinal cord magnetic resonance imaging in Thai multiple sclerosis patients

Objective: To evaluate magnetic resonance imaging (MRI) of multiple sclerosis (MS) patients in Thailand. Method: A retrospective review on the initial brain and spinal cord MRI in MS patients was done but primary progressive MS and the AQP4 antibody positive patients were excluded. The characteristics of brain and spinal cord MRI were analyzed. Results: For the initial brain MRI studies, fi fty percents satisfi ed McDonald MRI criteria for dissemination in space. For the initial spinal cord MRI, most lesions involved thoracic level and the mean length of spinal cord lesion is 1.29 vertebral body segments (range 0-3). Conclusion: For Brain MRIs in Thai MS patients, there was 50% in sensitivity by the 2005 McDonald’s Criteria for dissemination in space, which is similar to the previous Asian reports. For spinal MRI, the median length of lesions was less than previous Asian reports. This could be due to the fact that AQP4 antibody positive patients, in whom the clinical and imaging features are hard to differentiate from MS patients, were excluded. In other word, the neuromyelitis optica (NMO) spectrum disorders had been more effectively excluded in this study than those in the past. This supports the importance of NMO IgG/AQP4 antibody testing in differentiating MS from NMO spectrum disorders, especially in Asian patients.

A retrospective study of multiple sclerosis in Thailand

Objectives: To determine the prevalence of Thai demyelinating diseases regarding demographic data, symptoms and signs, associated diseases, disease progression, cerebrospinal fluid analysis and imaging findings. Methods: A multicenter retrospective study of 107 MS patients attending the Neurological Centers in Thailand during June and December 2004 was performed. Each had an initial diagnosis of demyelinating diseases. Results: From 107 patients, there were 78.5% female and 21.5% male with the female: male ratio of 3.7:1. The age at onset was 32.7±11.5 years. The mean disease duration was 3.8±5.1 years and the mean number of relapses was 4.6±4.4 with annual relapse rate of 1.5±1.3 times. None reported a family history of MS. Recurrent optico-spinal form was 27.1% followed by 17.8% of spinal form and 15% of western form of MS. The most common presenting symptom was visual impairment (51.4%). Only 24.1% demonstrated oligoclonal bands in CSF. The median score of EDSS at their latest visits was 3.0 with mean score of 3.8±3.0. Conclusions: MS in Thailand is different from Western countries. There were no occurrence of MS in families, higher incidence of visual impairment at onset, more common recurrent optico-spinal form and lower incidence of oligoclonal bands in the CSF.

Pediatric multiple sclerosis is similar to adult-onset form in Asia

Pediatric-onset multiple sclerosis is underreported because of difficulty in diagnosis and assessment. In Western series, pediatric-onset disease showed significant differences from adult-onset disease with higher female preponderance, polysymptomatic in onset, frequent systemic manifestation in relapses, higher relapse rate, but less disability, and fewer lesions in brain magnetic resonance imaging. Multiple sclerosis manifests differently in Asians, yet there was no large series of pediatric-onset multiple sclerosis reported. We found that pediatric-onset disease in Asians showed greater similarity with adult-onset disease without the reported differences in female preponderance, relapse rate, and magnetic resonance imaging findings. There were also similar proportion and clinical features in optico-spinal form, and long spinal cord lesions were common in both groups. The significant difference was less disability among the pediatric-onset group. Thus, although multiple sclerosis in Asia is different from Western countries, there is greater similarity between the pediatric-onset and adult-onset group in Asia.