A nationwide survey of pediatric acquired demyelinating syndromes in Japan.

OBJECTIVE: To investigate the clinical and epidemiologic features of pediatric acquired demyelinating syndromes (ADS) of the CNS in Japan. METHODS: We conducted a nationwide survey and collected clinical data on children with ADS aged 15 years or younger, who visited hospitals between 2005 and 2007. RESULTS: Among 977 hospitals enrolled, 723 (74.0%) responded to our inquiries and reported a total of 439 patients as follows: 244 with acute disseminated encephalomyelitis (ADEM), 117 with multiple sclerosis (MS), 14 with neuromyelitis optica (NMO), and 64 with other ADS. We collected and analyzed detailed data from 204 cases, including those with ADEM (66), MS (58), and NMO (10). We observed the following: (1) the estimated annual incidence rate of pediatric ADEM in Japan was 0.40 per 100,000 children (95% confidence interval [CI], 0.34-0.46), with the lowest prevalence in the north; (2) the estimated prevalence rate of MS was 0.69 per 100,000 children (95% CI, 0.58-0.80), with the lowest prevalence in the south; (3) NMO in Japan was rare, with an estimated prevalence of 0.06 per 100,000 children (95% CI, 0.04-0.08); and (4) the sex ratio and mean age at onset varied by ADS type, and (5) male/female ratios correlated with ages at onset in each ADS group. CONCLUSIONS: Our results clarify the characteristic clinical features of pediatric ADS in the Japanese population.

Functional MxA promoter polymorphism associated with subacute sclerosing panencephalitis.

BACKGROUND: The antivirally active MxA protein is induced by interferon (IFN) alpha/beta and inhibits the replication of single-stranded RNA viruses including measles virus (MV). The authors investigated whether the MxA gene contributed to the development of subacute sclerosing panencephalitis (SSPE) in Japanese individuals. METHODS: Single-nucleotide polymorphisms (SNP) in the promoter region of the MxA gene were screened, association studies were performed between two SNP and SSPE, and then a functional difference in the promoter activities of the two SNP was investigated by a dual luciferase reporter assay. RESULTS: Four SNP were found (-88 G/T, -123 C/A, -200 T/C, and -213 G/T), and SSPE patients exhibited a higher frequency of both the -88T allele and the -88TT genotype than controls (p = 0.040 and 0.003). The IFN-induced up-regulation of the MxA promoter activity of the sequence with -88T was found to be significantly higher than that with G. CONCLUSIONS: MxA promoter -88 G/T SNP may confer host genetic susceptibility to SSPE in Japanese individuals. The finding that homozygotes of the MxA -88T allele with a high MxA-producing capability were more frequently seen in SSPE patients suggests that the MxA protein promotes the establishment of persistent MV infection of neural cells.

Immunological studies on Behçet's and Harada's diseases. I. Cell-mediated immunity in Behçet's and Harada's diseases. II. HL-A antigens associated with Behçet's disease.

Behçet's and Harada's diseases were studied for cell-mediated immunity, utilizing leukocyte migration inhibition test (agarose droplet method). Patients with Behçet's disease during an attack showed cellular hypersensitivity to their aqueous humor, vitreous humor, and synovial fluid, but not to the normal tissue extracts of humans, such as oral mucous membrane, skin, retina and uvea, nor to their peripheral blood leukocytes. The patients with Harada's disease, in whom uveitis was recurrent and depigmentation present in various parts of the body, showed cellular hypersensitivity to bovine uveal extract. It is probably that in Behçet's disease cellular hypersensitivity is the result of inflammatory processes rather than being an important pathogenic mechanism, whereas in Harada's disease it is implicated in the pathogenesis of the disease process.