Jun-ichi Kira

Differential diagnosis of suspected multiple sclerosis: a consensus approach

Background and objectives Diagnosis of multiple sclerosis (MS) requires exclusion of diseases that could better explain the clinical and paraclinical findings. A systematic process for exclusion of alternative diagnoses has not been defined. An International Panel of MS experts developed consensus perspectives on MS differential diagnosis. Methods Using available literature and consensus, we developed guidelines for MS differential diagnosis, focusing on exclusion of potential MS mimics, diagnosis of common initial isolated clinical syndromes, and differentiating between MS and non-MS idiopathic inflammatory demyelinating diseases. Results We present recommendations for 1) clinical and paraclinical red flags suggesting alternative diagnoses to MS; 2) more precise definition of “clinically isolated syndromes” (CIS), often the first presentations of MS or its alternatives; 3) algorithms for diagnosis of three common CISs related to MS in the optic nerves, brainstem, and spinal cord; and 4) a classification scheme and diagnosis criteria for idiopathic inflammatory demyelinating disorders of the central nervous system. Conclusions Differential diagnosis leading to MS or alternatives is complex and a strong evidence base is lacking. Consensus-determined guidelines provide a practical path for diagnosis and will be useful for the non-MS specialist neurologist. Recommendations are made for future research to validate and support these guidelines. Guidance on the differential diagnosis process when MS is under consideration will enhance diagnostic accuracy and precision.

Intracellular Aβ42 activates p53 promoter: a pathway to neurodegeneration in Alzheimer's disease

The amyloid β‐protein (Aβ) ending at 42 plays a pivotal role in Alzheimers disease (AD). We have reported previously that intracellular Aβ42 is associated with neuronal apoptosis in vitro and in vivo. Here, we show that intracellular Aβ42 directly activated the p53 promoter, resulting in p53‐dependent apoptosis, and that intracellular Aβ40 had a similar but lesser effect. Moreover, oxidative DNA damage induced nuclear localization of Aβ42 with p53 mRNA elevation in guinea‐pig primary neurons. Also, p53 expression was elevated in brain of sporadic AD and transgenic mice carrying mutant familial AD genes. Remarkably, accumulation of both Aβ42 and p53 was found in some degenerating‐shape neurons in both transgenic mice and human AD cases. Thus, the intracellular Aβ42/p53 pathway may be directly relevant to neuronal loss in AD. Although neurotoxicity of extracellular Aβ is well known and synaptic/mitochondrial dysfunction by intracellular Aβ42 has recently been suggested, intracellular Aβ42 may cause p53‐dependent neuronal apoptosis through activation of the p53 promoter; thus demonstrating an alternative pathogenesis in AD.

Spontaneous proliferation of peripheral blood lymphocytes increased in patients with HTLV‐I‐associated myelopathy

We found unstimulated (spontaneous) peripheral blood lymphocyte (PBL) proliferation significantly increased in 14 patients with human T-lymphotropic virus (HTLV)-I-associated myelopathy (HAM) compared with findings in HTLV-I seropositive non-HAM carriers (N = 8) or HTLV-I seronegative controls (N = 16). The proliferative response to phytohemagglutinin, concanavalin A, or pokeweed mitogen was decreased in the HAM patients. Cell clusters were frequent in cultures of unstimulated PBL from the HAM patients, but much less common in the controls or carriers. This spontaneous PBL proliferation was depressed when adherent-cell populations were depleted from the cultures. IL-2 activity increased in the supernatant of 3-day cultured cells from HAM patients, but not in cultured cells from the controls. Since IL-2 receptor positive cells increased in HAM, this spontaneous PBL proliferation is probably a response to IL-2 through the expression of IL-2 receptors.

Temporal changes and geographical differences in multiple sclerosis phenotypes in Japanese: nationwide survey results over 30 years.

Background There are two distinct phenotypes of multiple sclerosis (MS) in Asians, manifesting as optic-spinal (OSMS) and conventional (CMS) forms. In Japan, four nationwide surveys of MS have been conducted. The first three were in 1972, 1982, and 1989, and we performed the fourth in 2004. Results The recent survey showed six main findings as follows: (1) a four-fold increase in the estimated number of clinically definite patients with MS in 2003 (9900; crude MS prevalence, 7.7/100,000) compared with 1972; (2) a shift in the peak age at onset from early 30s in 1989 to early 20s in 2003; (3) a successive proportional decrease in optic-spinal involvement in clinically definite patients with MS; (4) a significant north–south gradient for the CMS/OSMS ratio; (5) after subdivision of the mainland (30–45° North) into northern and southern parts at 37°N, northern-born northern residents (northern patients) showed a significantly higher CMS/OSMS ratio and higher frequency of brain lesions fulfilling the Barkhof criteria (Barkhof brain lesions) than southern-born southern residents (southern patients); (6) among northern patients, the absolute numbers of patients with CMS and those with Barkhof brain lesions rapidly increased with advancing birth year. Conclusions These findings suggest that MS phenotypes are drastically altered by environmental factors, such as latitude and “Westernization.”

Proteomic analysis of human brain identifies α-enolase as a novel autoantigen in Hashimoto’s encephalopathy

Hashimotos encephalopathy (HE) is a rare autoimmune disease associated with Hashimotos thyroiditis (HT). To identify the HE‐related autoantigens, we developed a human brain proteome map using two‐dimensional electrophoresis and applied it to the immuno‐screening of brain proteins that react with autoantibodies in HE patients. After sequential MALDI‐TOF‐MASS analysis, immuno‐positive spots of 48 kDa (pI 7.3–7.8) detected from HE patient sera were identified as a novel autoimmuno‐antigen, α‐enolase, harboring several modifications. Specific high reactivities against human α‐enolase were significant in HE patients with excellent corticosteroid sensitivity, whereas the patients with fair or poor sensitivity to the corticosteroid treatment showed less reactivities than cut‐off level. Although a few HT patients showed faint reactions to α‐enolase, 95% of HT patients, patients with other neurological disorders, and healthy subjects tested were all negative. These results suggest that the detection of anti‐α‐enolase antibody is useful for defining HE‐related pathology, and this proteomic strategy is a powerful method for identifying autoantigens of various central nervous system diseases with unknown autoimmune etiologies.

Heterozygous deletion of ITPR1, but not SUMF1 in spinocerebellar ataxia type 16

We have previously mapped autosomal dominant spinocerebellar ataxia (SCA) 16 to 3p26, overlapping with the locus of SCA15. Recently, partial deletions of ITPR1 and the neighbouring SUMF1 in the SCA15 and two additional families were reported. In the present study we determined the copy number of these genes by real time quantitative polymerase chain reaction (PCR) and found a heterozygous deletion of exons 1-48 of ITPR1, but not SUMF1 in SCA16. Breakpoint analysis revealed that the size of the deletion is 313,318 bp and the telomeric breakpoint is located in the middle of their intergenic region. Our data provide evidence that haploinsufficiency of ITPR1 alone causes SCA16 and SCA15.

A novel autosomal dominant spinocerebellar ataxia (SCA16) linked to chromosome 8q22.1-24.1.

Objective: To characterize a distinct form of autosomal dominant cerebellar ataxia (ADCA) clinically and genetically. Background: ADCAs are a clinically, pathologically, and genetically heterogeneous group of neurodegenerative disorders. Nine responsible genes have been identified for SCA-1, -2, -3, -6, -7, -8, -10, and -12 and dentatorubral-pallidoluysian atrophy (DRPLA). Loci for SCA-4, -5, -11, -13, and -14 have been mapped. Methods: The authors studied a four-generation Japanese family with ADCA. The 19 members were enrolled in this study. The authors performed the mutation analysis by PCR and a genome-wide linkage analysis. Results: Nine members (five men and four women) were affected. The ages at onset ranged from 20 to 66 years. All affected members showed pure cerebellar ataxia, and three patients also had head tremor. Head MRI demonstrated cerebellar atrophy without brain stem involvement. The mutation analysis by PCR excluded diagnoses of SCA-1, -2, -3, -6, -7, -8, and -12 and DRPLA. The linkage analysis suggested linkage to a locus on chromosome 8q22.1-24.1, with the highest two-point lod score at D8S1804 (Z = 3.06 at θ = 0.0). The flanking markers D8S270 and D8S1720 defined a candidate region of an approximately 37.6-cM interval. This candidate region was different from the loci for SCA-4, -5, -10, -11, -13, and -14. Conclusion: The family studied had a genetically novel type of SCA (SCA-16).

Characteristic Cerebrospinal Fluid Cytokine/Chemokine Profiles in Neuromyelitis Optica, Relapsing Remitting or Primary Progressive Multiple Sclerosis

Background Differences in cytokine/chemokine profiles among patients with neuromyelitis optica (NMO), relapsing remitting multiple sclerosis (RRMS), and primary progressive MS (PPMS), and the relationships of these profiles with clinical and neuroimaging features are unclear. A greater understanding of these profiles may help in differential diagnosis. Methods/Principal Findings We measured 27 cytokines/chemokines and growth factors in CSF collected from 20 patients with NMO, 26 with RRMS, nine with PPMS, and 18 with other non-inflammatory neurological diseases (OND) by multiplexed fluorescent bead-based immunoassay. Interleukin (IL)-17A, IL-6, CXCL8 and CXCL10 levels were significantly higher in NMO patients than in OND and RRMS patients at relapse, while granulocyte-colony stimulating factor (G-CSF) and CCL4 levels were significantly higher in NMO patients than in OND patients. In NMO patients, IL-6 and CXCL8 levels were positively correlated with disability and CSF protein concentration while IL-6, CXCL8, G-CSF, granulocyte-macrophage colony-stimulating factor (GM-CSF) and IFN-γ were positively correlated with CSF neutrophil counts at the time of sample collection. In RRMS patients, IL-6 levels were significantly higher than in OND patients at the relapse phase while CSF cell counts were negatively correlated with the levels of CCL2. Correlation coefficients of cytokines/chemokines in the relapse phase were significantly different in three combinations, IL-6 and GM-CSF, G-CSF and GM-CSF, and GM-CSF and IFN-γ, between RRMS and NMO/NMOSD patients. In PPMS patients, CCL4 and CXCL10 levels were significantly higher than in OND patients. Conclusions Our findings suggest distinct cytokine/chemokine alterations in CSF exist among NMO, RRMS and PPMS. In NMO, over-expression of a cluster of Th17- and Th1-related proinflammatory cytokines/chemokines is characteristic, while in PPMS, increased CCL4 and CXCL10 levels may reflect on-going low grade T cell and macrophage/microglia inflammation in the central nervous system. In RRMS, only a mild elevation of proinflammatory cytokines/chemokines was detectable at relapse.

Targeted lipidomics reveals mPGES-1-PGE2 as a therapeutic target for multiple sclerosis

The arachidonic acid (AA) cascade produces eicosanoids, such as prostaglandins (PGs), that regulate physiological and pathological functions. Although various nonsteroidal anti-inflammatory drugs have been developed, blocking upstream components (cyclooxygenase-1 and -2) of the AA cascade leads to severe side effects, including gastrointestinal ulcers and cardiovascular events, respectively, due to the complexity of the AA cascade. Here, using an AA cascade-targeted lipidomics approach, we report that microsomal PGE synthase 1 (mPGES-1) plays a key role in experimental autoimmune encephalomyelitis (EAE). Eicosanoids (mainly PGD2) are produced constitutively in the spinal cord of naive mice. However, in EAE lesions, the PGE2 pathway is favored and the PGD2, PGI2, and 5-lipoxygenase pathways are attenuated. Furthermore, mPGES-1−/− mice showed less severe symptoms of EAE and lower production of IL-17 and IFN-γ than mPGES-1+/+ mice. Expression of PGE2 receptors (EP1, EP2, and EP4) was elevated in EAE lesions and correlated with clinical symptoms. Immunohistochemistry on central nervous systems of EAE mice and multiple sclerosis (MS) patients revealed overt expression of mPGES-1 protein in microglia/macrophages. Thus, the mPGES-1-PGE2-EPs axis of the AA cascade may exacerbate EAE pathology. Our findings have important implications for the design of therapies for MS.

Nationwide survey of juvenile muscular atrophy of distal upper extremity (Hirayama disease) in Japan

Juvenile muscular atrophy of the distal upper extremity (JMADUE, Hirayama disease) was first reported in 1959 as ‘juvenile muscular atrophy of unilateral upper extremity’. Since then, similar patients in their teens or 20s have been described, under a variety of names, not only in Japan, but also in other Asian countries, as well as Europe and North America. Biomechanical abnormalities associated with JMADUE have recently been reported through various imaging examinations, proposing its disease mechanism. Since JMADUE differs from motor neuron disease, or spinal muscular atrophy, this disease entity should be more widely recognized, and early detection and effective treatments should be considered. We report an epidemiological study in Japan. Two nationwide questionnaire‐based surveys, conducted in Japan from 1996 to 1998, identified 333 cases. The numbers of patients per year, distribution of ages at onset, mode of onset, time lapse between onset and quiescence, neurological signs and symptoms, imaging findings, and the effects of conservative treatments were analyzed. The peak age was 15 to 17 years, with a marked male preponderance, usually a slow onset and progression, and quiescence six or fewer years after onset. There was a predominantly unilateral hand and forearm involvement with ‘cold paresis’. The imaging findings are described.