Antineutrophil cytoplasmic antibodies and the optic-spinal form of multiple sclerosis in Japan

HLA-DPB1*0501 is not uniquely associated with opticospinal multiple sclerosis in Japanese patients. Important role of DPB1*0301

Apart from its unique lesion distribution pattern, the opticospinal form of multiple sclerosis (OSMS) is distinct among Japanese patients who satisfy the diagnostic criteria of MS. OSMS has been suggested to be strongly associated with HLA-DPB1*0501 in Japanese. However, association of DPB1*0301 with non-OSMS and lack of DPB1*0301 in OSMS were also reported. To verify the role of DPB1*0501 and DPB1*0301 in Japanese MS patients we determined the frequencies of these alleles in 26 patients with OSMS, 167 with non-OSMS and 156 normal subjects, who were all residents of Hokkaido, the northernmost island of Japan. All (100%) OSMS were negative for DPB1*0301 while 32 (19%) of the non-OSMS were positive for the allele. In DPB1*0301-negatives, the frequencies of DPB1*0501 in OSMS (85%) and non-OSMS (82%) were similar, but both were higher than in the controls (66%). In DPB1*0301-positives, the frequency of DPB1*0501 was low but similar in non-OSMS (12/32; 38%) and controls (6/14; 43%). Periventricular white matter lesions (PVL) were noted in 31 of 32 (97%) DPB1*0301-positive non-OSMS patients but in only 22 out of 135 (16%) DPB1*0301-negative non-OSMS patients and two out of 26 (8%) OSMS patients. Our findings indicate that DPB1*0501 plays an important role in the development of MS in general, but not in OSMS. The strong association of DPB1*0501 with OSMS may be due to the over-representation of the DPB1*0301 allele among individuals in the non-OSMS group. In addition, DPB1*0301 might be relevant to the development of periventricular lesions in Japanese patients with MS.

Antineutrophil cytoplasmic antibodies in patients with idiopathic inflammatory-demyelinating diseases

OBJECTIVE

We assessed the clinical significance of antineutrophil cytoplasm antibodies (ANCA) in patients with idiopathic inflammatory-demyelinating disease (IIDD).

METHODS

A consecutive cohort of 269 subjects with IIDD and 595 controls was analyzed retrospectively.

RESULTS

Among all subjects, ANCA positivity rates were low [9.5% in a perinuclear pattern (pANCA) and 2.3% in a cytoplasmic pattern (cANCA)]. One of the 117 patients with multiple sclerosis (MS) had cANCA and 2 had pANCA. Ten patients with neuromyelitis optica (NMO; 13.9%) had pANCA and 3 (4.2%) had cANCA. Four patients with recurrent longitudinal extensive transverse myelitis (RLETM; 19.0%) had pANCA and 1 (4.8%) had cANCA. In monophasic TM, 22.9% were pANCA seropositive. Among patients with brainstem syndromes, 14.3% were pANCA seropositive. Patients with NMO, RLETM or monophasic TM had higher pANCA levels than patients with MS. There was a positive association between spinal cord (SC) lesions and ANCA, and especially between longitudinal extensive transverse myelitis and ANCA. Among anti-aquaporin 4 antibody-positive patients, ANCA-positive patients (n = 16) were older and had higher Expanded Disability Status Scale scores, more antinuclear antibodies, longer SC lesions and fewer brain abnormalities than the ANCA-negative patients (n = 68). In the NMO subgroup, ANCA-positive patients were older and had more antinuclear antibodies and longer SC lesions than ANCA-negative patients.

CONCLUSION

Among the IIDDs, we found a higher occurrence of ANCA in patients with NMO spectrum disorders than in patients with MS. Therefore, ANCA is another interesting marker of autoimmunity in IIDD patients, especially those with anti-aquaporin 4 antibody.

Is it necessary to perform connective tissue disorders laboratory tests when a patient experiences the first demyelinating attack?

BACKGROUND

It may be difficult to differentiate between the first demyelinating attack and the neurological manifestations of connective tissue diseases.

MATERIALS AND METHODS

A total of 79 patients with optic neuritis were compared with 79 healthy controls. Their blood samples were tested for erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), antiβ2-Glycoprotein I antibody (IgG, IgM), anticardiolipin antibody (IgM, IgG), lupus anticoagulant, anti-double strand DNA (anri-ds DNA), antinuclear antibody (ANA), anti-myeloperoxidae (p-ANCA), and anti-Proteinase 3 (C-ANCA).

RESULTS

In clinically isolated syndrome group β2-Glycoprotein (IgM) and lupus anti-coagulant were positive in 1.3% of patients whereas ANA was positive in 1.3% and anti-β2-Glycoprotein I (IgM) was positive in 2.5% of control group. No rheumatologic disease was found in objects with positive tests.

CONCLUSION

This study shows no specific difference between two groups.

Gender differences in circulating levels of neutrophil extracellular traps in serum of multiple sclerosis patients

Neutrophil extracellular traps (NETs) trap and kill pathogens very efficiently but also activate dendritic cells and prime T cells. Previously, we demonstrated that neutrophils are primed and circulating NETs are elevated in relapsing remitting multiple sclerosis (RRMS), a T cell-mediated autoimmune disease. Here, we demonstrate gender specific differences in circulating NETs but not in neutrophil priming in RRMS patients. Although the results from our systematic and in depth characterization of these patients argue against a major role of circulating NETs in this disease, they suggest that NETs may underlie gender-specific differences in MS pathogenesis.

A three-dimensional approach for understanding the spectrum of idiopathic inflammatory demyelinating disorders: importance of the 'attack-related severity' axis

Understanding the spectrum of idiopathic inflammatory demyelinating disorders (IIDD) of the central nervous system is an important issue for accurate diagnosis and advancing research on the pathogenesis as well as treatment strategies, but the nosology and the classification of the IIDD remains confusing. Until now, we have tried to apply each disorder within the spectrum to an adequate co-ordinate on a two-dimensional plane. One axis is clinical course and the other is lesion distribution. We reviewed some disorders of the IIDD spectrum, and our recent findings on the fulminant nature of each attack and the expansion of each lesion, which we called attack-related severity in Japanese multiple sclerosis (MS). From our findings and the literature, attack-related severity appears to be a third important factor, in addition to lesion distribution and clinical course. Introduction of the third axis produces a three-dimensional space for a better understanding of the heterogeneous characteristics of IIDD and 'MS' syndrome, and can advance treatment strategies for these disorders. As severe attacks seem to be relatively common in Asians but rare in the west, ethnic-related heterogeneity should be considered in understanding the spectrum of IIDD, and there is an urgent need to develop a common general concept of the spectrum, especially for MS.

Antibody association with a novel model for primary progressive multiple sclerosis: induction of relapsing-remitting and progressive forms of EAE in H2s mouse strains

Multiple sclerosis (MS) can be divided into 4 clinical forms: relapsing-remitting (RR), primary progressive (PP), secondary progressive (SP), and progressive relapsing (PR). Since PP-MS is notably different from the other forms of MS, both clinically and pathologically, the question arises whether PP-MS is immunologically similar to the other forms. The pathogenesis of the PP-MS remains unclear, partly due to a lack of highly relevant animal models. Using an encephalitogenic peptide from myelin oligodendrocyte glycoprotein (MOG)92-106, we have established animal models that mimic different forms of MS in 2 strains of H-2s mice, SJL/J and A.SW. We induced experimental allergic encephalomyelitis (EAE) using MOG92-106 in the presence or absence of supplemental Bordetella pertussis (BP). Although, SJL/J mice developed RR-EAE whether BP was given or not, A.SW mice developed PP-EAE without BP and SP-EAE with BP. Histologically, SJL/J mice developed mild demyelinating disease with T cell infiltration, while A.SW mice developed large areas of plaque-like demyelination with immunoglobulin deposition and neutrophil infiltration, but with minimal T cell infiltration. In A.SW mice without BP, high titer serum anti-MOG antibody was detected and the anti-MOG IgG2a/IgG1 ratio correlated with survival times of mice. We hypothesized that, in A.SW mice, a Th2 response favors production of myelinotoxic antibodies, leading to progressive forms with early death. Our new models indicate that a single encephalitogen could induce either RR-, PP-, or SP- forms of demyelinating disease in hosts with immunologically different humoral immune responses.

Diagnosis and management of acute myelopathies

BACKGROUND

Acute myelopathies represent a heterogeneous group of disorders with distinct etiologies, clinical and radiologic features, and prognoses. Transverse myelitis (TM) is a prototype member of this group in which an immune-mediated process causes neural injury to the spinal cord, resulting in varying degrees of weakness, sensory alterations, and autonomic dysfunction. TM may exist as part of a multifocal CNS disease (eg, MS), multisystemic disease (eg, systemic lupus erythematosus), or as an isolated, idiopathic entity.

REVIEW SUMMARY

In this article, we summarize recent classification and diagnostic schemes, which provide a framework for the diagnosis and management of patients with acute myelopathy. Additionally, we review the state of current knowledge about the epidemiology, natural history, immunopathogenesis, and treatment strategies for patients with TM.

CONCLUSIONS

Our understanding of the classification, diagnosis, pathogenesis, and treatment of TM has recently begun to expand dramatically. With more rigorous criteria applied to distinguish acute myelopathies and with an emerging understanding of immunopathogenic events that underlie TM, it may now be possible to effectively initiate treatments in many of these disorders. Through the investigation of TM, we are also gaining a broader appreciation of the mechanisms that lead to autoimmune neurologic diseases in general.

CSF pleocytosis and expansion of spinal lesions in Japanese Multiple sclerosis with special reference to the new diagnostic criteria

New diagnostic criteria for multiple sclerosis (MS) were recently proposed from the international panel on the diagnosis of MS, and they include exclusion criteria, such as lesions extending over more than two vertebral segments on spinal MRI and CSF pleocytosis of more than 50/mm3. We reviewed the clinical features of 158 patients who satisfied the diagnostic criteria for MS except for having the above atypical paraclinical findings. All patients exhibited two or more clinical attacks and objective clinical evidence of multiple lesions without any evidence of other disorders. Thirty-three (20.9%) patients had one or both atypical paraclinical findings. Twenty-one out of the 33 patients were classified as having optico-spinal MS (OSMS), and the other 12 as non-OSMS patients with atypical large expanding or destructive cerebral, cerebellar or brainstem lesions on MRI as well as one or both atypical paraclinical findings. Based on this heterogeneity in clinical findings in MS, there is an urgent need to develop a common general concept of the "MS" syndromes, and the ethnic-related heterogeneity should be considered in the revised criteria for the diagnosis of MS.

Attack-related severity: a key factor in understanding the spectrum of idiopathic inflammatory demyelinating disorders

Understanding the spectrum of idiopathic inflammatory demyelinating disorders (IIDD) is a fundamental issue for the diagnosis and treatment of these disorders as well as for the approach to their pathogenesis. The spectrum of IIDD is usually classified according to clinical course and lesion distribution. We compared the demographic features, clinical characteristics, laboratory findings, and genetic backgrounds between 193 Japanese patients with and without clinically or radiographically fulminant attacks who all satisfied the diagnostic criteria for multiple sclerosis (MS). "Fulminant attacks" in the current study represent attack-related clinically or radiologically severe relapses but do not necessarily mean severe disability. Patients with fulminant attacks were clinically and immunogenetically distinct from those free of such attacks, and the previously described characteristics of the opticospinal form of MS (OSMS) or neuromyelitis optica (NMO) were mostly shared by patients with fulminant attacks. HLA profiles were similar among patients with fulminant attacks irrespective of the lesion distributions. The GG homozygous and G alleles of the CTLA4 gene A/G coding SNP at position 49 in exon 1 were significantly more common in patients with fulminant attacks than in those without. Attack-related severity may be an important factor if validated by prospective studies defining criteria and establishing relationships to disease course and treatment regimens.

Multiple sclerosis in the Japanese population

Multiple sclerosis (MS) in Asian populations is characterised by the selective and severe involvement of the optic nerve and spinal cord as well as low prevalence rates. 15-40% of cases of MS in Japan are of this "opticospinal" type. This form of MS generally has a higher age at onset and a higher female to male ratio than conventional MS. Opticospinal MS is also characterised by frequent relapses, severe disability, few brain lesions visible on MRI, long lesions extending over many vertebral segments visible on spinal-cord MRI, pleocytosis and an absence of oligoclonal bands in the CSF, and a pronounced shift in the responses of T-helper-1 and T-cytotoxic-1 cells throughout relapse and remission phases. Conventional MS in Japanese people is, like MS in white people, associated with HLA-DRB1*1501, whereas opticospinal MS is associated with HLA-DPB1*0501. In Japanese people born after modernisation in the 1960s, the ratio of conventional to opticospinal MS has increased rapidly. Opticospinal MS is likely to have a distinct immune-mediated mechanism, which is not operative in conventional MS.

Estrogen receptor gene polymorphism and multiple sclerosis in Japanese patients: interaction with HLA-DRB1*1501 and disease modulation

We investigated PvuII and XbaI polymorphism in the estrogen receptor gene (ERG) and HLA-DRB1*1501 positivity in 116 conventional multiple sclerosis (MS) patients and 101 healthy controls in a Japanese population. Logistic analysis revealed independent associations of [P] allele in the profiles for PvuII (p=0.0005, adjusted odds ratio (aOR)=3.17) and DRB1*1501 (p=0.0089, aOR=2.61) with conventional MS. Synergistic elevated risk of MS due to interaction between the [P] allele and HLA-DRB1*1501 allele was found among female patients (odds ratio=16.0; 95% CI=3.99-63.8, p<0.0001). The [P] allele-positive patients with disease duration of more than 5 years had a significantly higher progression index (PI) of disability (p=0.0230) and a worse ranked MS severity score (p=0.0152) than their non-[P] counterparts.

Immunopathogenesis of acute transverse myelitis

Acute transverse myelitis is a group of disorders characterized by focal inflammation of the spinal cord and resultant neural injury. Acute transverse myelitis may be an isolated entity or may occur in the context of multifocal or even multisystemic disease. It is clear that the pathological substrate--injury and dysfunction of neural cells within the spinal cord--may be caused by a variety of immunological mechanisms. For example, in acute transverse myelitis associated with systemic disease (i.e. systemic lupus erythematosus or sarcoidosis), a vasculitic or granulomatous process can often be identified. In idiopathic acute transverse myelitis, there is an intraparenchymal or perivascular cellular influx into the spinal cord, resulting in the breakdown of the blood-brain barrier and variable demyelination and neuronal injury. There are several critical questions that must be answered before we truly understand acute transverse myelitis: (1) What are the various triggers for the inflammatory process that induces neural injury in the spinal cord? (2) What are the cellular and humoral factors that induce this neural injury? and (3) Is there a way to modulate the inflammatory response in order to improve patient outcome? Although much remains to be elucidated about the causes of acute transverse myelitis, tantalizing clues as to the potential immunopathogenic mechanisms in acute transverse myelitis and related inflammatory disorders of the spinal cord have recently emerged. It is the purpose of this review to illustrate recent discoveries that shed light on this topic, relying when necessary on data from related diseases such as acute disseminated encephalomyelitis, Guillain-Barré syndrome and neuromyelitis optica. Developing a further understanding of how the immune system induces neural injury will depend upon confirmation and extension of these findings and will require multicenter collaborative efforts.

Detection of brain-specific autoantibodies to myelin oligodendrocyte glycoprotein, S100beta and myelin basic protein in patients with Devic's neuromyelitis optica

Neuromyelitis optica (NMO) is a rare syndrome characterized by the combination of acute optic neuritis and transverse myelitis, usually not seen in Multiple Sclerosis (MS) and other demyelinating syndromes of the central nervous system (CNS). A high prevalence of various autoantibodies has been described in patients with NMO suggesting a polyclonal activation of the humoral immune system. We examined autoantibody responses to myelin (MBP, MOG with isotypes and epitopes) and astroglial (S100beta) antigens in four patients with NMO by ELISA and Immunoblot. All patients showed a positive anti-MOG response, with one showing reaction to the MOG epitope corresponding to amino acid sequence 63-87. MBP-autoantibodies were only detected in two and S100beta-autoantibodies in one patient. Despite the limited number of samples, these findings suggest a predominant anti-MOG rather than anti-MBP or anti-S100beta autoantibody response in NMO, though no NMO-specific antibody pattern was found, which is in keeping with a widespread acute immune activation, including a strong B-cell response.

Macrophage migration inhibitory factor in the cerebrospinal fluid of patients with conventional and optic-spinal forms of multiple sclerosis and neuro-Behçet's disease

Macrophage migration inhibitory factor (MIF) is becoming increasingly recognized as an important regulator of immune and inflammatory responses. It is released by activated T lymphocytes and macrophages and up-regulates the proinflammatory activity of these cells. MIF is required for antigen- and mitogen-driven T cell activation, and stimulates macrophages to release cytokines and nitric oxide. On the basis of the recent suggestion that pharmacological modulation of MIF production and neutralization of its activity may have important implications for treatment of a variety of autoimmune or inflammatory conditions, we determined the level of MIF in the cerebrospinal fluid (CSF) of patients with conventional-form multiple sclerosis (C-MS) and optic-spinal form multiple sclerosis (OpS-MS), and neuro-Behçet's disease (NBD). As control, the CSF of patients with non-inflammatory neurological diseases (NIND) was used. The concentration of MIF in CSF samples was significantly elevated in relapsed cases of C-MS (4.13+/-1.07 ng/ml) (mean+/-S.D.) compared with control samples (2.38+/-0.60 ng/ml) (P<0.0001), whereas MIF in the CSF of C-MS patients in remission was not elevated (2.65+/-0.67 ng/ml). The concentration of MIF in the CSF of OpS-MS patients in relapse (5.53+/-1.74 ng/ml) was higher than that of patients with C-MS in relapse (P<0.05). In NBD patients, the concentration of MIF in CSF was significantly elevated (7.47+/-5.61 ng/ml) compared with control samples (P<0.01) and correlated well with cell count in these samples (r=0.910, P<0.005). These results suggest that MIF may play a pivotal role in immune-mediated diseases of the central nervous system, and that MIF may be useful in the study of differences between C-MS and OpS-MS.

Both the HLA-CPB1 and -DRB1 alleles correlate with risk for multiple sclerosis in Japanese: clinical phenotypes and gender as important factors

The purpose of this study was to clarify the association of HLA-DRB1 and -DPB1 alleles with multiple sclerosis (MS) in Japanese, to determine whether optico-spinal MS (OS-MS) and conventional MS are immunogenetically distinct, and to verify the role of gender difference in HLA associations of MS. We studied HLA-DRB1 and -DPB1 polymorphisms in 166 Japanese patients with MS. Forty-seven patients were classified as having the optico-spinal MS (OS-MS) and 119 as having conventional MS. A lack of DPB1*0301 and a higher frequency of DPB1*0501 compared with controls (corrected P<0.0074; odds ratio=9.48) were found in OS-MS. By contrast, we found for the first time an association of DPB1*0301 with conventional MS in Japanese (corrected P=0.0444; odds ratio=3.28). Logistic analysis, adjusted for sex and age, revealed independent associations of DPB1*0301 (P=0.0004, adjusted odds ratio (aOR)=4.70), DPB1*0501 (P=0.0081, aOR= 2.50) and DRB1*1501 (P=0.0252, aOR=2.21) with conventional MS. However, the frequencies of DRB1*1501 and DPB1*0501 in male patients with conventional MS were equal to those in male controls while the DPB1*0301 frequency was increased in both male and female patients. We did not find any association of these HLA alleles with disease course and severity. In conclusion, OS-MS is a DPB1*0501-associated distinct subtype of MS, and DPB1*0301 is the most strongly associated allele with conventional MS in Japanese. In addition, gender plays an important role in HLA association with MS.

CTLA-4 gene polymorphism may modulate disease in Japanese multiple sclerosis patients

Multiple sclerosis (MS) is widely believed to have a T-cell-mediated autoimmune etiology. The CTLA-4 gene is a strong candidate for involvement in autoimmune diseases because it plays an important role in the termination of T-cell activation. To examine the genetic association of the CTLA-4 gene locus with MS, we analyzed the CTLA-4 gene exon 1 A/G polymorphism in 74 Japanese MS patients and 93 controls. We also investigated the possible interactions of the CTLA-4 gene polymorphism with clinical course and severity, with MRI findings, with another genetic marker-HLA antigens, and with oligoclonal bands (OCB) in the cerebrospinal fluid (CSF). The CTLA-4 exon 1 polymorphism was similar between MS patients and controls. Conversely, clinical disability was significantly more severe in AA homozygous patients than in the other patients, and the allele frequency and the phenotype frequency of the A allele were significantly higher in patients with severe-grade MRI findings of cerebral white matter than in patients with mild-grade MRI findings. The allele frequency and the phenotype frequency of the A allele were significantly higher in patients with OCB than in patients without. This CTLA-4 polymorphism may modulate the prognosis of patients with MS and may be relevant to generation of OCB in the CSF.

Association of vitamin D receptor gene polymorphism with multiple sclerosis in Japanese

1,25-Dihydroxyvitamin D3 (1,25(OH)2D3), the biologically active form of vitamin D, exerts an immunosuppressive effect and can completely prevent experimental autoimmune encephalomyelitis (EAE). 1,25(OH)2D3 exerts most of its actions only after it has bound to its specific nuclear receptors. To investigate the possible role of vitamin D receptor gene (VDRG) polymorphism in susceptibility to or disease-modulation of MS, we evaluated 77 Japanese patients with 'conventional' MS and 95 controls. A VDRG allelic polymorphism was assessed by Bsm1 endonuclease restriction after specific PCR amplification. Genotypic polymorphism was clearly defined as BB (absence of restriction site on both alleles), bb (presence of restriction site on both alleles), or Bb (heterozygous). We found overexpression of the b allele (92.9 vs. 84.2%: P=0.0138) and homozygote bb (85.7 vs. 71.6%; P=0.0263) in MS patients compared with controls. The results indicate for the first time an association of MS with VDRG polymorphism, which may be involved in pathogenesis of MS, or in the linkage disequilibrium of VDRG to another pathogenic gene loci. The role of VDR gene polymorphism should be further studied in other populations, and the distribution of other polymorphism, such as Apa I, Taq I, should be also analyzed to confirm another susceptibility gene for MS and to obtain more adequate strategies for treatment of MS.

The significance of oligoclonal bands in multiple sclerosis in Japan: relevance of immunogenetic backgrounds

We compared clinical and demographic features, MRI findings, and HLA profiles of 57 Japanese patients with multiple sclerosis (MS) between groups with and without oligoclonal IgG bands (OCB) in the cerebrospinal fluid (CSF). Patients with the optic-spinal form of MS (OpS-MS) or acute transverse myelopathy (ATM), which are distinctive and relatively common in Japanese MS, were excluded in this study. The OCB-positive rate was only 56.1% (32/57) among these 57 'conventional' MS patients, of whom clinical features were similar to those of Western MS patients. The demographic features, clinical course, disability, and cerebral abnormalities seen on MRI were similar in the OCB-negative and OCB-positive patient groups. HLA-DR2 antigen, which has been confirmed to be associated with MS in many populations, was more common in the OCB-positive than in the OCB-negative and control groups. Furthermore, DR4 antigen was statistically more common in the OCB-negative patient group. These results raise the possibility that the presence of OCB is related to the immunogenetic background of the patient, and that there may be at least two subpopulations in Japanese patients with 'conventional' MS from the viewpoint of immunogenetics. In one subpopulations, MS is associated with the DR2 antigen, and shows a stronger humoral immune response in the CSF, while in the other MS is associated with DR4, which has a milder humoral response. Further investigations involving more patients are warranted.

Clinical and laboratory features of myelitis patients with anti-neutrophil cytoplasmic antibodies

Although perinuclear anti-neutrophil cytoplasmic antibodies (pANCA) are associated with vasculitic neuropathy, their association with central nervous system (CNS) disorders has not been studied except for one report on optic-spinal type of multiple sclerosis associated with serum pANCA. We examined pANCA in sera from 98 patients with various CNS disorders, such as 58 MS, 17 myelitis, 12 HTLV-1 associated myelopathy, and 11 other CNS diseases using indirect immunofluorescence methods. The results showed serum pANCA to be positive in five patients with a peculiar type of myelitis, including two with MS and three with etiology unknown myelitis. All of these ANCA-positive patients were women and had acute or subacute myelopathy with various severities. MRI revealed segmental swelling of the spinal cord with T2 hyperintensity in the acute stage of the disease. Marked pleocytosis (227.8+/-101/mm3) and elevated protein level (128.8+/-52 mg/dl) in CSF were noted. Four of the patients had anti-nuclear antibodies and two had previous histories of symptoms suggesting autoimmune disorders. In a search for target antigens of pANCA, myeloperoxidase reactivity was found in the sera from two myelitis patients. Clinical and laboratory features of myelitis patients with pANCA in the present study are different from those of typical MS patients. Further study will be needed to delineate the role of pANCA in the pathogenesis of a specific type of myelitis.