Neuromyelitis optica and multiple sclerosis in sisters

Familial neuromyelitis optica spectrum disorders: Case series and systematic review

BACKGROUND

Neuromyelitis optica spectrum disorders (NMOSD) is considered a complex multifactorial disorder. Most cases are sporadic, and familial NMOSD is assumed as a rare occurrence. However, few studies reported familial aggregation of the disorder.

OBJECTIVES

To report familial NMOSD cases in Thailand and conduct a systematic review of familial NMOSD.

METHODS

A retrospective chart review of familial NMOSD patients at the university hospital was performed. Articles related to "genetic" and "NMOSD" were systematically searched and reviewed. We included NMOSD patients whose one or more relatives were diagnosed with the same disease or multiple sclerosis (MS). Data regarding demographics, clinical features, disease outcomes, and genetic testing were collected and analyzed using descriptive statistics.

RESULTS

We identified 6 familial cases from 165 NMOSD cases (3.6%) at our hospital and gathered 77 cases from a systematic review, totaling 83 cases from 40 families. The mean (SD) age at onset was 37.2 (18.0) years. Familial NMOSD involved 1-2 generations with mainly 2 affected individuals. The most common kinship pattern was siblingship in 21 families (52.5%). Initial syndromes were mostly optic neuritis and transverse myelitis. Serum aquaporin-4 IgG was positive in 79.7% of cases. Median number of relapses was 3 (range 1-26). Median expanded disability status scale in the last visit was 2 (range 0-8). Reported human leukocyte antigens (HLA) alleles shared between familial cases were HLA-A*01 and HLA-DRB1*03.

CONCLUSION

Familial clustering of NMOSD is more common than would be expected in the general population. The demographic, clinical, and outcome profiles of familial cases were not different from sporadic cases. Certain specific HLA haplotypes were shared among familial cases. Our systematic review highlighted complex genetic predisposition to NMOSD.

Neuromyelitis optica is an HLA associated disease different from Multiple Sclerosis: a systematic review with meta-analysis

Neuromyelitis Optica and Multiple Sclerosis are idiopathic inflammatory demyelinating diseases of the central nervous system that currently are considered distinct autoimmune diseases, so differences in genetic susceptibility would be expected. This study aimed to investigate the HLA association with Neuromyelitis Optica by a systematic review with meta-analysis. The STROBE instrument guided research paper assessments. Thirteen papers published between 2009 and 2020 were eligible. 568 Neuromyelitis Optica patients, 41.4% Asians, 32.4% Latin Americans and 26.2% Europeans were analyzed. Only alleles of the DRB1 locus were genotyped in all studies. Neuromyelitis Optica patients have 2.46 more chances of having the DRB1*03 allelic group than controls. Ethnicity can influence genetic susceptibility. The main HLA association with Neuromyelitis Optica was the DRB1*03:01 allele in Western populations and with the DPB1*05:01 allele in Asia. Differences in the Multiple Sclerosis and Neuromyelitis Optica genetic susceptibility was confirmed in Afro descendants. The DRB1*03 allelic group associated with Neuromyelitis Optica has also been described in other systemic autoimmune diseases.

Familial clustering of neuromyelitis optica and multiple sclerosis: clues pointing towards shared risks?

We examine the prevalence of the familial association of concordant NMOSD/NMOSD and discordant NMOSD/MS cases among a large NMOSD cohort. Familial association was examined in a monocenter cohort of 119 NMOSD patients and 45 patients at high risk of NMOSD from French West Indies. Data mining gathered 31 multiplex families. Twin monozygotic sisters concordant for NMOSD/NMOSD, and four discordant NMOSD/MS families, accounted respectively for 0.8% and 3.4% of the NMOSD cohort. Familial clustering was more frequent than random association. In discordant NMOSD/MS families, the NMOSD patient was always from the parental generation. The non-random successive familial cases of NMOSD and MS suggest a change of risk factor over generations.

HLA-alleles class I and II associated with genetic susceptibility to neuromyelitis optica in Brazilian patients

OBJECTIVE

To study the genetic susceptibility to neuromyelitis optica (NMO) as well as the relationship between HLA genotypes and susceptibility to the disease in the southern Brazilian population.

METHODS

We analyzed patients with NMO, who met criteria for Wingerchuk's diagnosis of NMO, with detected serum anti-AQP4-IgG antibody. The HLA genotyping was performed by high-resolution techniques (Sanger sequencing) in patients and controls. The HLA genotypes were statistically compared with a paired control population.

RESULTS

The HLA genotyping revealed the diversity of the southern Brazilian population whose HLA profile resembled European and Asian populations. Some alleles had statistical correlations with a positive association (increased susceptibility) with NMO, particularly the HLA-DRB1*04:05 and *16:02.

CONCLUSIONS

In our study, the HLA genotype was different to that previously reported for other Brazilian populations. Although our study had a small cohort, HLA genotypes were associated with increased susceptibility to NMO for HLA-DRB1*04:05 and *16:02. The alleles of HLA class I HLA-A*02:08 and *30:09, HLA-B*08:04 and *35:04 showed an association before the Bonferroni correction.

Clinical and demographic features in Iranian multiple sclerosis patients: a systematic review and meta-analysis

Aim: This study was conducted to determine the clinical and demographic features in Iranian multiple sclerosis (MS) patients including clinical courses, positive MS family history, disability and age of disease onset. Materials & methods: All stages of the study were reported according to the PRISMA guidelines. A systematic review of published literature in Persian and English journals with a comprehensive search was conducted on English international databases including Scopus, PubMed/Medline, Cochrane Library, Science Direct, Web of Science, Embase, PsycINFO, as well as the Google Scholar search engine and national databases. Results: The prevalence of clinical courses of relapsing remitting, primary progressive, secondary progressive and relapsing progressive in Iranian patients with MS was 77.1% (95% CI: 72.2–81.3), 6.2% (95% CI: 4.1–9.2), 9.5% (95% CI: 6.8–13.1) and 0.4% (95% CI: 0.2–0.8), respectively. Positive family history of MS in Iranian MS patients was 8.9% (95% CI: 6.9–11.4). The mean age of disease onset was 28.9 years (95% CI: 27.8–30.1). Conclusion: The results of this meta-analysis in an Iranian population can provide useful information for neurologists and healthcare.

Epidemiology of neuromyelitis optica in Latin America

A major development over the past two decades was the recognition of recurrent neuromyelitis optica (NMO) as a particular central nervous system disorder different from multiple sclerosis (MS). Here we reviewed the epidemiology of NMO in Latin America (LATAM). A predominance of a mixed population is found in this region. Recurrent NMO in black women was described in the Caribbean Islands and in Rio de Janeiro. The prevalence of NMO in LATAM varied from 0.37/100,000 (Volta Redonda city) to 4.2/100,000 inhabitants (Caribbean Islands). NMO differs significantly from MS with respect to gender, ethnicity, morbidity and genetic susceptibility. An association of the HLA DRB1*03 alleles with NMO was described in the French Antilles, Ribeirão Preto, Rio de Janeiro and Mexico. It is not common to find familial forms of NMO. NMO represents 11.8% of all inflammatory idiopathic diseases in South America (SA). In SA, the highest frequency of NMO occurs in African Brazilian young women. The overall relative frequency of NMO among MS cases in this region was 14%, decreasing following a north-south gradient, which parallels the percentage of nonwhite people.

Comparing epidemiology and baseline characteristic of multiple sclerosis and neuromyelitis optica: A case-control study

BACKGROUND

Autoimmune syndromes such as Multiple Sclerosis (MS) and Neuromyelitis Optica (NMO) are chronic, demyelinating diseases of the central nervous system which usually affect young adults. Both environmental risk factors and genetic susceptibility have been proposed to explain the etiology of these diseases. The aim of this study was to compare epidemiology and possible risk factors in MS and NMO in Tehran, Iran.

METHOD

A population-based incident case-control study was performed in Tehran based on a study conducted on1513 MS patients from Iranian MS Society registry center of Tehran, from 2014 to 2015, and 83 NMO patients diagnosed with NMO in 2015 at Sina hospital, a tertiary care referral center in Tehran. The random digit dialing (RDD) methods were established to select 400 population-based controls. A checklist was designed to cover the epidemiological variables to estimate the possible risk factors for MS and NMO based on a questionnaire designed for multinational case-control studies of environmental risk factors in multiple sclerosis. Structured face to face interviews with cases, and telephone interviews with controls were conducted by trained interviewers to collect data. The multiple logistic regression analysis was done via SPSS package.

RESULTS

The adjusted odds ratio (OR) estimate of MS for females compared to males was (OR =1.47; 95% CI: 1.12, 1.95), and it was (OR=1.54; 95% CI: 1.17, 2.02) for people aged 18-27 years compared to younger ones aged 28-37 years. The adjusted OR estimate of NMO for people aged over 48 years compared to those aged 28-37 years was (OR=3.49; 95% CI: 1.59, 7.64). The point estimates were greater than eight-fold increased risk associated with MS among patients with a positive familial history 8.80 (95% CI: 4.10, 18.90).

CONCLUSION

The results of this study reveal that the risk of MS is significantly higher in female and younger people in comparison to NMO. Having positive family history of MS can increase the risk of MS substantially. The findings of the study indicated that factors that predict susceptibility to MS, including a positive history of MS in relatives, do not appear to have any association with NMO.

New insights into neuromyelitis optica

Neuromyelitis optica (NMO) is an idiopathic inflammatory disorder of the central nervous system (CNS) that preferentially affects the optic nerves and spinal cord. In Asia, NMO has long been considered a subtype of multiple sclerosis (MS). However, recent clinical, pathological, immunological, and imaging studies have suggested that NMO is distinct from MS. This reconsideration of NMO was initially prompted by the discovery of a specific antibody for NMO (NMO-IgG) in 2004. NMO-IgG is an autoantibody that targets aquaporin-4 (AQP4), the most abundant water channel in the CNS; hence, it was named anti-AQP4 antibody. Since it demonstrated reasonable sensitivity and high specificity, anti-AQP4 antibody was incorporated into new diagnostic criteria for NMO.The spectrum of NMO is now known to be wider than was previously recognized and includes a proportion of patients with recurrent, isolated, longitudinally extensive myelitis or optic neuritis, and longitudinally extensive myelitis or optic neuritis associated with systemic autoimmune disease or with brain lesions typical of NMO. In this context, a new concept of "NMO spectrum disorders" was recently introduced. Furthermore, seropositivity for NMO-IgG predicts future relapses and is recognized as a prognostic marker for NMO spectrum disorders. Humoral immune mechanisms, including the activation of B-cells and the complement pathway, are considered to play important roles in NMO pathogenesis. This notion is supported by recent studies showing the potential pathogenic role of NMO-IgG as an initiator of NMO lesions. However, a demonstration of the involvement of NMO-IgG by the development of active immunization and passive transfer in animal models is still needed. This review focuses on the new concepts of NMO based on its pathophysiology and clinical characteristics. Potential management strategies for NMO in light of its pathomechanism are also discussed.

Neuromyelitis optica in Japanese sisters

We report cases of Japanese sisters with neuromyelitis optica (NMO). The elder sister was 25, when she was diagnosed with right optic neuritis. After 3 months, she developed left optic neuritis and myelitis. At age 27, she had the second relapse, but she has been free from episodes thereafter. The younger sister was 26, when she was diagnosed with optic neuritis. Thus far, she has 9 relapses, comprising both myelitis and optic neuritis. Both sisters had normal brain MRI scans, longitudinally extensive transverse myelitis over 3 vertebral segments, and positive results for anti-aquaporin-4 antibody (AQAP4Ab). They fulfilled the Wingerchuk criteria for definite NMO. Both sisters shared some immunogenetic factors, but they were not exposed to the same environmental factors after their early twenties. The final disability status was almost the same in both cases, and both showed a very benign course. These data suggest that genetic factors affect the age at onset and environmental factors may affect the frequency of relapse.

Familial neuromyelitis optica

BACKGROUND

Detection of aquaporin-4-specific immunoglobulin G (IgG) has expanded the spectrum of neuromyelitis optica (NMO). Rare reports of familial aggregation have suggested a component of genetic susceptibility but these reports mostly antedated the discovery of the NMO-IgG biomarker and recently updated diagnostic criteria.

METHODS

We report a case series describing the demographic, clinical, neuroimaging, and NMO-IgG serologic status of 12 multiplex NMO pedigrees with a total of 25 affected individuals.

RESULTS

Twenty-one patients (84%) were women. Families were Asian (n = 5), Latino (n = 4), white (n = 1), or African (n = 2). Apparent transmission was either maternal (n = 5) or paternal (n = 2). In 1 family, 3 individuals had NMO; in the others, 2 individuals were affected. Sibling pairs (n = 6), parent-child (n = 4), and aunt-niece (n = 3) pairs were observed. Nineteen patients (76%) were NMO-IgG positive. Twelve (48%) had clinical or serologic evidence of another autoimmune disease. Familial occurrence of NMO occurs in approximately 3% of patients with well-established diagnosis of NMO.

CONCLUSIONS

A small proportion of patients with NMO have relatives with this condition, but familial occurrence is more common than would be expected from its frequency in the general population. Familial NMO is indistinguishable from sporadic NMO based on clinical symptoms, age at onset, sex distribution, and frequency of NMO-IgG detection. One or 2 generations were affected and affected individuals represented a small fraction of family members. Taken together, these data suggest complex genetic susceptibility in NMO.