No association of apolipoprotein E epsilon4 genotype with faster progression or less recovery of relapses in a Spanish cohort of multiple sclerosis

Peroxidation of lipoproteins in multiple sclerosis

Human plasma low density lipoproteins (LDL) and high density lipoproteins (HDL) are involved in the transport of lipids, modulate membrane lipid composition and regulate signal transduction. HDL-like lipoproteins have been shown also in human cerebrospinal fluid and it has been hypothesized that they could have a role in lipid transport in central nervous system. After synthesis, lipoproteins are susceptible to lipid peroxidation triggered by reactive oxygen species (ROS and RNS) produced by peripheral and brain cells. Aim of the paper has been to review the scientific literature on the role of lipid peroxidation of LDL and HDL in the molecular mechanisms of multiple sclerosis (MS). Several studies have demonstrated a significant increase in lipid peroxidation products in brain, plasma and cerebrospinal fluid of MS patients. The increase of antibodies against ox-LDL in plasma and the presence of ox-LDL in demyelinating plaques in MS brain suggests that the disease is associated with oxidative damage of lipoproteins. The impairment of antioxidant systems or an increase in the production of ROS and RNS could contribute to lipoprotein peroxidation in MS. Oxidized lipoproteins show several alterations of their functions, they are neurotoxic and have pro-inflammatory properties. Therefore lipoprotein lipid peroxidation products could be involved in demyelination and axonal injury in MS.

Natural history of multiple sclerosis: early prognostic factors

Multiple sclerosis is a heterogeneous disease, and predicting its course is difficult at the individual level. In this article, clinical, demographic, and additional features that are associated with the risk of relapses and of intermediate-term disability are reviewed.

The immune-modulatory role of apolipoprotein E with emphasis on multiple sclerosis and experimental autoimmune encephalomyelitis

Apolipoprotein E (apoE) is a 34.2 kDa glycoprotein characterized by its wide tissue distribution and multiple functions. The nonlipid-related properties of apoE include modulating inflammation and oxidation, suppressing T cell proliferation, regulating macrophage functions, and facilitating lipid antigen presentation by CD1 molecules to natural killer T (NKT) cells, and so forth. Increasing studies have revealed that APOE ε allele might be associated with multiple sclerosis (MS), although evidence is still not sufficient enough. In this review, we summarized the current progress of the immunomodulatory functions of apoE, with special focus on the association of APOE ε allele with the clinical features of MS and of its animal model experimental autoimmune encephalomyelitis (EAE).

The genetics of clinical outcome in multiple sclerosis

Multiple sclerosis (MS) is a common inflammatory disease of the central nervous system (CNS), the clinical course of which varies considerably between patients. Genetic complexity and interactions with as yet unknown environmental factors have hindered researchers from fully elucidating the aetiology of the disease. In addition to influencing disease susceptibility, epidemiological evidence suggests that genetic factors may affect phenotypic expression of the disease. Genes that affect clinical outcome may be more effective therapeutic targets than those which determine susceptibility. We present in this review a comprehensive survey of the genes (both MHC- and non-MHC-related) that have been investigated for their role in disease outcome in MS. Recent studies implicating the role of the genotype and epistatic interactions in the MHC in determining outcome are highlighted.

Apolipoprotein E genotype does not associate with disease severity measured by Multiple Sclerosis Severity Score

OBJECTIVES

During the last years, the association between apolipoprotein E (APOE) polymorphism and disease severity in multiple sclerosis (MS) has been studied with conflicting results. As a result of a considerable individual variation in the clinical course of MS, there is no consensus method for measuring progression using single assessments of disability. Recently, Multiple Sclerosis Severity Score (MSSS) method has been proposed for comparing disease progression using single data. We evaluate in our population if there is any correlation between APOE genotype and severity according to MSSS.

METHODS

We studied 82 patients followed up in our Neurology Unit throughout the year 2005, diagnosed with MS, and with disease duration of at least 2 years. We collected data concerning demographic and clinical variables including age of onset, disease duration, Expanded Disability Status Scale (EDSS) score and the total number of relapses. When reached, we determined the latency to EDSS scores of 4.0 and 6.0. We calculated progression index (PI) and relapse rate (RR). We ascertained MSSS for our patients in the global MSSS table.

RESULTS

We found four patients heterozygous for the E2 allele and 16 for the E4 allele. No patient was homozygous for E2 or E4. RR (P = 0.017 with 95% CI: 0.005-0.57) and PI (P = 0.016 with 95% CI: 0.004-0.38) were significantly lower in E4 carriers. MSSS scores were not associated with carriership of E2 or E4.

CONCLUSION

Our results show no effect of the APOE genotype on the severity of MS measured by MSSS, as a recently published meta-analysis has noticed. So, our data do not support a role for APOE in MS severity, in spite of the seeming influence shown using other measures such as PI. MSSS is probably the best method to measure severity with a single measure of disability and should be used more frequently when performing genetic research.

Recent advances in genetic analysis of multiple sclerosis: genetic associations and therapeutic implications

Epidemiological studies have confirmed that genetic factors are a key component in the pathogenesis of multiple sclerosis (MS) and that those determining MS susceptibility have been extensively studied. Many papers have been published regarding the heritable differences useful in genetic studies; these include variations in DNA, such as single-nucleotide polymorphisms, microsatellites and insertion/deletion polymorphisms. However, to date, among other regions, HLA is the only region confirmed to possess genes that determine MS susceptibility. In this article, we review the progress during the last 5 years in the studies on the susceptibility genes and the pharmacogenetics of MS. Newer techniques and methods of analysis will hopefully result in better screening of individuals who are at highest risk and novel treatments.