Faculty Bibliography

Introduction: Cognitive impairment in pediatric onset multiple sclerosis (POMS) occurs in up to one third of cases.
Objective(s): To screen for cognitive impairment early in the disease course of POMS, measure predictive factors, and determine the effect of relapse on cognitive processing speed.
Aim(s): To identify cognitive processing speed impairment among POMS and pediatric clinically isolated (CIS) patients enrolled in the US Pediatric MS and Other Demyelinating Disease Registry. In March 2014, the Symbol Digit Modalities Test (SDMT) scores were analyzed from March 2014, when the SDMT was added to the clinical evaluation through July 2018, when the data set was locked.
Method(s): SDMT raw scores were converted to age-normative z-scores using validated age and sex adjusted means. Processing speed impairment was defined with z-score increments of-1.0. Clinically meaningful decline in longitudinal analyses was defined by a z-score decrease of 1.0 or more.
Result(s): For the POMS (n=500) and CIS (n=116) with at least one SDMT, the mean age at symptom onset was 13.5 years and the mean (+SD) disease duration at the initial SDMT assessment was 3.0 + 2.9 years. A total of 23.4% of MS and 16.4% of CIS patients had impaired processing speed at initial assessment. SDMT impairment was predicted by worse EDSS, longer disease duration, and lower level of mother's educational achievement. On longitudinal follow-up (n=383, mean follow-up: 1.8 years), 14.1% had clinically meaningful decline predicted by older age of MS onset, male gender, and longer test-retest interval. Disease relapse and steroid use were associated with transient SDMT worsening.
Conclusion(s): Early in the disease course, a subgroup of POMS patients are at risk for cognitive impairment and subsequent decline. Screening for cognitive slowing is critical for prompt identification of potential cognitive deficits and initiation of additional services

OBJECTIVE/UNASSIGNED:The aim of this study was to determine whether a vitamin D genetic risk score (vitDGRS) is associated with 25-hydroxyvitamin D (25(OH)D) level and multiple sclerosis (MS) relapses in children. METHODS/UNASSIGNED:DNA samples were typed for single nucleotide polymorphisms (SNPs) from four genes previously identified to be associated with 25(OH)D levels. SNPs with strong associations with 25(OH)D after multiple comparison correction were used to create a genetic risk score (vitDGRS). Cox regression models tested associations of vitDGRS with relapse hazard. RESULTS/UNASSIGNED:Two independent SNPs within or near GC and NADSYN1/DHCR7 genes were strongly associated with 25(OH)D levels in the discovery cohort ( n = 182) after Bonferroni correction. The vitDGRS of these SNPs explained 4.5% of the variance of 25(OH)D level after adjustment for genetic ancestry. Having the highest versus lowest vitDGRS was associated with 11 ng/mL lower 25(OH)D level (95% confidence interval (CI) = -17.5, -4.5, p = 0.001) in the discovery cohort. Adjusting for ancestry, sex, disease-modifying therapy (DMT), and HLA-DRB1*15 carrier status, the highest versus lowest vitDGRS was associated with 2.6-fold (95% CI = 1.37, 5.03, p = 0.004) and 2.0-fold (95% CI = 0.75, 5.20, p = 0.16) higher relapse hazard in the discovery and replication cohorts, respectively. CONCLUSION/UNASSIGNED:The vitDGRS identifies children at greater risk of relapse. These findings support a causal role for vitamin D in MS course.

Background: Adult MS research has identified an increased prevalence of various autoimmune conditions among family members of diagnosed patients. There has not been comparable studies of pediatric MS populations, while this cohort may represent a unique population from a risk factors perspective.
Objective(s): This study was undertaken to quantify the incidence of autoimmune conditions among first and second degree relatives of pediatric MS patients as compared to controls. The study sought to quantify both the rate, type and patterns of diagnoses seen throughout family members of pediatric MS patients.
Method(s): A multi center case-control study of risk factors for pediatric MS has been ongoing for since 2011. Pediatric patients with a diagnosis of MS and pediatric controls were recruited to provide data and biologic specimens for a number of research projects. Included in this effort was the acquisition of family history questionnaires. The medical data from these questionnaires were analyzed for the presence of certain medical diagnoses among first and second degree relatives. Logistic regression models were used to test for differences between cases and controls in reporting a family history of autoimmune diseases, when adjusting for sex, race, age, ethnicity, and mother's education level. Odds ratios and 95% confidence intervals were calculated based on the logistic regression models.
Result(s): Several conditions were found to have statistically significant differences in prevalence among first and second degree family members of MS patients as compared to controls. Diabetes, thyroid disorders and rheumatoid arthritis has the most notable differences between patients and controls while eczema and psoriasis were not different. The odds ratio of any family history of autoimmune disease was 2.27 among cases compared to controls. The odds ratio of an autoimmune disease among family members was significantly higher among paternal relatives as compared to maternal relatives (eg OR of 6.37 compared to 2.64).
Conclusion(s): This study has identified an increased prevalence of certain autoimmune disorders among first and second degree family members of pediatric MS patients. This aligns with prior findings among adult populations that found higher rates of autoimmune disorders among family members of adult onset MS patients. Novel to this study was the difference in relative risk of autoimmune conditions occurring in paternal versus maternal family members

Multiple sclerosis (MS) is an autoimmune disease with high prevalence among populations of northern European ancestry. Past studies have shown that exposure to ultraviolet radiation could explain the difference in MS prevalence across the globe. In this study, we investigate whether the difference in MS prevalence could be explained by European genetic risk factors. We characterized the ancestry of MS-associated alleles using RFMix, a conditional random field parameterized by random forests, to estimate their local ancestry in the largest assembled admixed population to date, with 3,692 African Americans, 4,915 Asian Americans, and 3,777 Hispanics. The majority of MS-associated human leukocyte antigen (HLA) alleles, including the prominent HLA-DRB1*15:01 risk allele, exhibited cosmopolitan ancestry. Ancestry-specific MS-associated HLA alleles were also identified. Analysis of the HLA-DRB1*15:01 risk allele in African Americans revealed that alleles on the European haplotype conferred three times the disease risk compared to those on the African haplotype. Furthermore, we found evidence that the European and African HLA-DRB1*15:01 alleles exhibit single nucleotide polymorphism (SNP) differences in regions encoding the HLA-DRB1 antigen-binding heterodimer. Additional evidence for increased risk of MS conferred by the European haplotype were found for HLA-B*07:02 and HLA-A*03:01 in African Americans. Most of the 200 non-HLA MS SNPs previously established in European populations were not significantly associated with MS in admixed populations, nor were they ancestrally more European in cases compared to controls. Lastly, a genome-wide search of association between European ancestry and MS revealed a region of interest close to the ZNF596 gene on chromosome 8 in Hispanics; cases had a significantly higher proportion of European ancestry compared to controls. In conclusion, our study established that the genetic ancestry of MS-associated alleles is complex and implicated that difference in MS prevalence could be explained by the ancestry of MS-associated alleles.

Children with pediatric-onset multiple sclerosis and pediatric controls were enrolled across 16 pediatric multiple sclerosis centers in the United States and completed questionnaires that addressed time of first unaided walking and acquisition of 2-word phrases. A total of 467 (308 female) cases and 428 (209 female) controls were enrolled. Pediatric multiple sclerosis (n = 467) were not delayed in walking or using 2-word phrases compared to healthy controls (n = 428) (2.2% vs 5.7%, respectively). Children with disease onset before age 11 versus onset at 11 years or after were more likely to need an individualized education plan ( P = .002), reading assistance ( P = .0003), and math assistance ( P = .001). Children with multiple sclerosis onset prior to age 18 are not delayed in meeting the 2 major early developmental milestones but do have a significantly increased use of special services or learning assistance at school. Further research will need to address whether other measures of development (eg, rate of language acquisition or fine motor skills) differ between pediatric multiple sclerosis and controls.

Background/UNASSIGNED:There is limited information about the potential associations of multiple sclerosis (MS) and commonly used household chemicals. Methods/UNASSIGNED:We performed a case-control study of exposures to common household chemicals during childhood in children with MS and healthy pediatric controls. Exposures to household products were collected from a comprehensive questionnaire (http://www.usnpmsc.org/Documents/EnvironmentalAssessment.pdf) completed by parents at the time of enrollment in the study. Cases included children diagnosed with MS or clinically isolated syndrome with at least two silent T2 bright lesions on MRI, recruited within 4 years of disease onset from 16 pediatric MS clinics in the USA. Multivariate analyses using logistic regression were adjusted for possible confounders including age, sex, race, ethnicity, mother's highest level of education, and urban versus rural living. Results/UNASSIGNED: ≤ 0.001) anytime during childhood were associated with an increased risk for pediatric-onset MS in adjusted and multiple comparisons analyses. Conclusions/UNASSIGNED:Our findings suggest that exposure to specific household chemicals during early childhood is associated with the risk of developing pediatric-onset MS. Future studies are needed to elucidate a causal relationship and the exact agents involved.

Background/UNASSIGNED:We previously identified air quality as a risk factor of interest for pediatric multiple sclerosis. The purpose of this study is to more closely examine the association between the six criteria air pollutants and pediatric MS as well as identify specific areas of toxic release using data from the Toxic Release Inventory. Methods/UNASSIGNED:= 442) were included as part of an ongoing case-control study. We used the National Emissions Inventory system to estimate particulate exposure by county of residence for each participant. Proximity to Toxic Release Inventory (TRI) sites was also assessed using ArcGIS mapping tools. Risk-Screening Environmental Indicators (RSEI) classified counties at risk to exposure of environmental toxic releases. Results/UNASSIGNED:= 0.002). Average RSEI scores did not differ significantly between cases and controls. Conclusion/UNASSIGNED:, CO, and lead) were statistically associated with higher odds for pediatric MS.

BACKGROUND:While common variant non-HLA (human leukocyte antigen) alleles have been associated with MS risk, their role in disease course is less clear. We sought to determine whether established multiple sclerosis (MS) genetic susceptibility factors are associated with relapse rate in children and an independent cohort of adults with MS. METHODS:Genotyping was performed for 182 children with MS or clinically isolated syndrome with high risk for MS from two Pediatric MS Centers. They were prospectively followed for relapses. Fifty-two non-HLA MS susceptibility single nucleotide polymorphisms (SNPs) were evaluated for association with relapse rate. Cox regression models were adjusted for sex, genetic ancestry, disease-modifying therapy (DMT), 25-OH vitamin D level and HLA-DRB1*15:01/03 status. Investigation of pediatric subject SNP results was performed using a second cohort of 141 adult MS subjects of Northern European ancestry from the Southern Tasmanian Multiple Sclerosis Longitudinal Study. RESULTS:For pediatric subjects, 408 relapses were captured over 622 patient-years of follow-up. Four non-HLA risk SNPs (rs11154801, rs650258, rs12212193, rs2303759) were associated with relapses (p < 0.01) in the pediatric subjects. After adjustment for genetic ancestry, sex, age, vitamin D level, DMT use and HLA-DRB1*15 status, having two copies of the MS risk allele within AHI1 (rs11154801) was associated with increased relapses among children (HR = 1.75,95%CI = 1.18-2.48, p = 0.006) and this result was also observed among adults (HR = 1.81,95%CI = 1.05-3.03, p = 0.026). CONCLUSIONS:Our results suggest that the MS genetic risk variant within the gene AHI1 may contribute to disease course in addition to disease susceptibility.