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Biomedical subjects

Bruce A C Cree

Publications and source records attributed to Bruce A C Cree.

7 recordsLinked to original sources

A whole-genome admixture scan finds a candidate locus for multiple sclerosis susceptibility.

Multiple sclerosis is a common disease with proven heritability, but, despite large-scale attempts, no underlying risk genes have been identified. Traditional linkage scans have so far identified only one risk haplotype for multiple sclerosis (at HLA on chromosome 6), which explains only a fraction of the increased risk to siblings. Association scans such as admixture mapping have much more power, in principle, to find the weak factors that must explain most of the disease risk. We describe here the first high-powered admixture scan, focusing on 605 African American cases and 1,043 African American controls, and report a locus on chromosome 1 that is significantly associated with multiple sclerosis.

Black or African American↗

Therapeutic considerations for disease progression in multiple sclerosis: evidence, experience, and future expectations.

In the management of patients with multiple sclerosis (MS), providers are all faced with the highly formidable challenge of ascertaining whether, and to what degree, disease-modifying therapy is effective in the individual patient. While much has been learned in randomized, controlled clinical trials, we cannot simply extrapolate the outcomes of these initiatives and apply them to the care of a single patient. In the future, the application of pharmacogenetic techniques, proteomics, and microarray analysis will yield novel profiling information on individual patients that will substantially refine the specific therapeutic questions of relevance: (1) What is the best treatment for an individual patient? (2) Which patients require intensive therapeutic combination regimens to optimize control of the disease process? (3) What are the appropriate drug dosing targets for an individual patient? and (4) Which patients will be predisposed to the development of drug-related adverse events? Such data may provide a novel variable of drug responsiveness that will mandate its inclusion into the process of covariate analyses for clinical trials.

Disease Progression↗

Response to interferon beta-1a treatment in African American multiple sclerosis patients.

BACKGROUND: African Americans (AAs) with multiple sclerosis (MS) seem to have a more severe disease course than white Americans (WAs). To our knowledge, it is not known to what extent treatment with interferon beta-1a will effect the MS disease course within the AA population. OBJECTIVE: To compare the response to treatment with interferon beta-1a between AA and WA MS patients. DESIGN: This is an exploratory post hoc analysis of the Evidence of Interferon Dose-Response: European North American Comparative Efficacy (EVIDENCE) study. SETTING: The EVIDENCE study is a randomized controlled trial that compared the efficacy of once weekly, intramuscular, 30-microg interferon beta-1a treatment with thrice weekly, subcutaneous, 44-microg interferon beta-1a therapy in treatment-naïve MS subjects. PARTICIPANTS: Thirty-six AA subjects were compared with 616 WA subjects. MAIN OUTCOME MEASURES: The number of MS exacerbations, the proportion of exacerbation-free subjects, and the number of new MS lesions present on brain magnetic resonance imaging were compared between AA and WA subjects at 24 and 48 weeks after initiating treatment with interferon beta-1a. RESULTS: The AA subjects experienced more exacerbations and were less likely to remain exacerbation free (statistical trends). The AA subjects developed more new MS lesions on T2-weighted brain magnetic resonance imaging at 48 weeks (P = .04). CONCLUSIONS: Despite the small sample size, AA subjects appeared less responsive to treatment than WA subjects on outcome measures, reaching significance only for T2-weighted lesion count at 48 weeks. However, it is difficult to base these differences solely on response to treatment given the potential differing in MS disease course in AA patients.

Adjuvants, Immunologic↗

Linkage and association with the NOS2A locus on chromosome 17q11 in multiple sclerosis.

A large body of research supports a multifactorial cause in multiple sclerosis (MS), with an underlying genetic susceptibility likely acting in concert with undefined environmental exposures. Here, we used a highly efficient multilocus genotyping assay to study single nucleotide polymorphisms representing variation in 34 genes from inflammatory pathways in a well-characterized MS familial data set. Evidence of transmission distortion was present for several polymorphisms. Results for the NOS2A locus (exon 10 C/T, D346D) on chromosome 17q11 remained significant after correction for multiple testing and were reproduced in a second independent African American MS data set. In addition, linkage to a NOS2A promoter region polymorphism, (CCTTT)(n), was present in a third data set of multicase MS families. Our results provide strong evidence for linkage and association to a new candidate disease gene on chromosome 17q11 in MS and suggest that variation within NOS2A or a nearby locus contributes to disease susceptibility.

Adult↗

Mapping multiple sclerosis susceptibility to the HLA-DR locus in African Americans.

An underlying complex genetic susceptibility exists in multiple sclerosis (MS), and an association with the HLA-DRB1*1501-DQB1*0602 haplotype has been repeatedly demonstrated in high-risk (northern European) populations. It is unknown whether the effect is explained by the HLA-DRB1 or the HLA-DQB1 gene within the susceptibility haplotype, which are in strong linkage disequilibrium (LD). African populations are characterized by greater haplotypic diversity and distinct patterns of LD compared with northern Europeans. To better localize the HLA gene responsible for MS susceptibility, case-control and family-based association studies were performed for DRB1 and DQB1 loci in a large and well-characterized African American data set. A selective association with HLA-DRB1*15 was revealed, indicating a primary role for the DRB1 locus in MS independent of DQB1*0602. This finding is unlikely to be solely explained by admixture, since a substantial proportion of the susceptibility chromosomes from African American patients with MS displayed haplotypes consistent with an African origin.

Alleles↗

Neuromyelitis optica.

Whether neuromyelitis optica (NMO), the co-occurrence of myelitis and optic neuritis, is a variant of multiple sclerosis (MS) or a unique disease is controversial. Distinct neuropathological features and a fulminant clinical course argue in favor of NMO as a distinct disease. However, the combination of neurological impairments of myelitis and optic neuritis occurs in patients with several inflammatory disorders, including multiple sclerosis and collagen vascular diseases. NMO is also associated with certain infectious diseases. The fact that the NMO phenotype occurs in a variety of disease states suggests that NMO does not represent a specific clinical entity. To better understand NMO and its associations with recognized diseases, a systematic review of the literature using MEDLINE was conducted. The history of NMO, its nosology, associations with other diseases, and current concepts of its pathogenesis and treatment is reviewed in this article.

Adult↗