Incidence and outcome of acquired demyelinating syndromes in Dutch children: update of a nationwide and prospective study.

INTRODUCTION: Acquired demyelinating syndromes (ADS) are immune-mediated demyelinating disorders of the central nervous system in children. A nationwide, multicentre and prospective cohort study was initiated in the Netherlands in 2006, with a reported ADS incidence of 0.66/100,000 per year and MS incidence of 0.15/100,000 per year in the period between 2007 and 2010. In this study, we provide an update on the incidence and the long-term follow-up of ADS in the Netherlands. METHODS: Children < 18 years with a first attack of demyelination were included consecutively from January 2006 to December 2016. Diagnoses were based on the International Paediatric MS study group consensus criteria. Outcome data were collected by neurological and neuropsychological assessments, and telephone call assessments. RESULTS: Between 2011 and 2016, 55/165 of the ADS patients were diagnosed with MS (33%). This resulted in an increased ADS and MS incidence of 0.80/100,000 per year and 0.26/100,000 per year, respectively. Since 2006 a total of 243 ADS patients have been included. During follow-up (median 55 months, IQR 28-84), 137 patients were diagnosed with monophasic disease (56%), 89 with MS (37%) and 17 with multiphasic disease other than MS (7%). At least one form of residual deficit including cognitive impairment was observed in 69% of all ADS patients, even in monophasic ADS. An Expanded Disability Status Scale score of ≥ 5.5 was reached in 3/89 MS patients (3%). CONCLUSION: The reported incidence of ADS in Dutch children has increased since 2010. Residual deficits are common in this group, even in monophasic patients. Therefore, long-term follow-up in ADS patients is warranted.

Mannose-binding lectin polymorphisms are not associated with rheumatoid arthritis--confirmation in two large cohorts.

OBJECTIVES: In RA, conflicting results have been described on the association between genotypes of the complement factor mannose-binding lectin (MBL) and disease susceptibility and severity. This might be due to underpowerment of previous research work and the fact that no confirmation cohorts were used. Therefore a different approach is warranted. METHODS: MBL2 gene polymorphisms were determined in two RA cohorts (378 and 261 cases) and 648 controls. Considering MBL polymorphisms, cases and controls were categorized in groups of high, intermediate and low MBL production. The total sample size allows detection of a potential association between RA susceptibility and MBL groups with an odds ratio of 1.37 (alpha < 0.05; 1-beta > 0.8). Disease severity as defined by the need for anti-TNF therapy was also analysed for possible associations with MBL groups. RESULTS: There was no difference in the frequencies between MBL genotypes of RA cases and controls that are associated with high (cases 54.4%, controls 57.0%), intermediate (cases 28.9%, controls 27.5%) or low (cases 16.7%, controls 15.5%) MBL production. Furthermore, there was no association between MBL groups and disease severity. CONCLUSIONS: MBL genotype groups are not associated with RA disease susceptibility or severity in this large study including a confirmation cohort. Compared with previous smaller studies these results add to more definite conclusions.

HLA class II alleles are not a general susceptibility factor in Guillain-Barré syndrome.

OBJECTIVE: To assess whether human leukocyte antigen (HLA)-DRB1 and HLA-DQB1 alleles confer susceptibility to Guillain-Barre syndrome (GBS) or are related to specific clinical or serologic subgroups of GBS. METHODS: The HLA-DRB1 and HLA-DQB1 loci were genotyped by PCR amplification with sequence-specific primers in 164 well-documented Dutch patients with GBS and 207 healthy Dutch control subjects. Patients with GBS were divided into subgroups based on clinical features, severity of disease, antecedent infection, and anti-ganglioside antibodies. Data were compared with those of all case-control HLA studies in GBS performed previously. RESULTS: In this case-control study, HLA-DRB1 and HLA-DQB1 alleles did not differ between GBS patients and control subjects. The frequency of HLA-DRB1*01 was increased in patients who needed mechanical ventilation (odds ratio 4.2; 95% CI 1.9 to 9.6; p(c) = 0.02). Multivariate logistic regression analysis showed that this association was independent of the severity of paresis and the presence of cranial nerve involvement (all p < 0.05). There was a tendency toward an association between certain HLA alleles and several anti-ganglioside antibodies. CONCLUSIONS: Human leukocyte antigen (HLA) class II antigens are not a general susceptibility factor in Guillain-Barre syndrome (GBS). However, HLA class II alleles may be a determinant in distinct subgroups of GBS, indicating the need for further exploration in large-scale studies.

Associations with autoimmune disorders and HLA class I and II antigens in inclusion body myositis.

Whether autoimmune mechanisms play a role in the pathogenesis of inclusion body myositis (IBM) is unknown. Human leukocyte antigen (HLA) analysis in 52 patients, including 17 with autoimmune disorders (AIDs), showed that patients were more likely to have antigens from the autoimmune-prone HLA-B8-DR3 ancestral haplotype than healthy control subjects, irrespective of the presence of AIDs. Patients lacked the apparently protective HLA-DR53 antigen. The results provide further support for an autoimmune basis in IBM.

The occurrence of Guillain-Barre syndrome within families.

This report describes 12 Dutch families of which at least two members have had Guillain-Barre syndrome (GBS). The authors observed an earlier onset of GBS in successive generations. The occurrence of GBS within families suggests a role for genetic factors in the pathogenesis of GBS.