Comparison of Techniques for Diagnosis of Multiple Sclerosis

Comparison of Techniques for Diagnosis of Multiple SclerosisBackground There is change magnitude need to develop specific biomarkers for multiple sclerosis (MS) to aid in the diagnosis, improve the management of patients and the monitoring of the effectiveness of treatment. Oligoadenylate synthetase 1 (OAS1) is up regulated by type 1 interferon. A single nucleotide polymorphism (SNP) in exon 7 of OAS1 results in differential enzyme activity. Objective To correlate different OAS1 genotypes, in patients with relapsing remitting multiple scleroses (RRMS) under interferon-beta (IFN ) therapy, with disorder activity. Subjects and Methods OAS1 genotype was assessed in 20 patients with RRMS and 20 age and gender matched healthy controls. All patients were medicated with IFN . The patients were subdivided in terms of illness activity assessed by Expanded Disability Status Scale (EDSS), in two groups group I with minimal disease activity and group II with severely active disease. All patie nts were followed up every 6 months for a period of 2 years. Results Genotyping analysis of the OAS1 gene revealed a significant difference amongst RRMS patients and control group, with lower frequency of GG in patients (25%) comp ared to controls (65 %) (p = 0.0001). Furthermore, AA genotype was detected 35% of patients compared to 0% in controls (p = 0.01). Regarding disease activity, AA genotype had a significantly higher frequency (71.4%) in patients with severely active disease compared to 15.4% in patients with minimally active disease (p=0.0001). Conclusions The A-allele is considered risky and the G is protective, so those with the AA genotype in particular should be carefully monitored for evidence of disease activity. Conversely, GG genotype may protect against increased disease activity.IntroductionMultiple sclerosis (MS) is an inflammatory demyelinating disease of the central flyaway system, the etiology and pathogenesis of which remain largely elusive. The most common form of MS is the relapsingremitting form (RRMS), in which episodes of acute worsening of neurological function (relapses) are followed by partial or complete recovery periods (remissions) free of disease progression.1,2Type 1 interferons (IFNs) are innate immune cytokins that activate the JAK/Stat mansion pathway leading to induction of IFN-stimulated genes. The 2,5-OAS family is central to the IFN antiviral pathway for computer viruses whose replication includes production of double-stranded RNA. One member of this family of proteins, OAS1, induces RNAseL, resulting in degradation of viral RNA, inhibition of virus replication, and promotion of cellular apoptosis.1Several OAS1 polymorphisms generate been reported one located at the exon 7 splice-acceptor site results in alternative splicing of the OAS1 mRNA. Although clinical trials have proven the efficacy of interferon-beta (IFN ) in the treatment of RRMS2-4, over one-third of patients have continuing significant disease activ ity.5 On purely clinical grounds, patients have variously been considered to have responded poorly, based on relapse occurrence6-9 or on disablement progression while receiving IFN therapy.10 Therefore, cohorts of patients receiving IFN can be informative for evaluating general determinants of disease activity.Aim of work to examine the relationship between OAS1 genotype and indices of disease activity in RRMS under IFN therapy.Subjects and MethodsTwenty patients with RRMS according to revised McDonald criteria11 were enrolled from an outpatient and inpatient cosmos attending Neurology Department, Tanta University Hospital. Twenty unrelated age- and gender-matched volunteers, with no history of MS or other neurologic disease, were recruited as a control group. All patients certain IFN therapy and followed up every 6 months over a period of 2 years from January 2010 to January 2012. The Ethics Committee of Hospital approved the study, and a written advised consent was obtained from each participant.For all patients, baseline data collected included disease duration, age at onset, relapse history prior to therapy, and clinical disability measured using the Expanded Disability Status Scale (EDSS).12 Relapses were defined as an episode of neurologic disturbance lasting for at least 24 hours and not caused by a change in core body temperature or infection.13 Disability progression was defined as an increase in EDSS pee-pee by 1 point from baseline confirmed at 6 months.5Genomic DNA was isolated from peripheral blood samples. Primers were designed to specifically amplify a 347-bp product surrounding the rs10774671 SNP. A total of 5 grams of genomic DNA was amplified by PCR. Primer sequences used were rs 10774671 forward, TCCAGATGGCATGTCACAGT and reverse, AGAAGGCCAGGAGTCAGGA.Amplification conditions included initial denaturation at 94 centigrade for 2 minutes, followed by 28 cycles at 94 centigrade for 20 seconds, 62 centigrade for 40 seconds 72 centigrade f or 30 seconds, with a final extension for 7 minutes at 72 centigrade. The PCR products were digested with the ALU1 restriction enzyme. Digested products were analyzed by agrose gel electrophoresis and genotypes were assigned, the A-allele coding for a truncated form with low activity and the G conferring high enzymatic activity.Patients were assigned to 1 of 2 groups. Group I included minimal disease activity patients who experienced a maximum of 1 relapse aft(prenominal) 24 months of IFN therapy and had no sustained disability progression. Group II included a severely active disease patients who had 2 or more relapses on IFN therapy over 24 months with or without sustained disability progression.14Statistical AnalysisSPSS 10 was used for data analysis.15 P value