¶ … risk of development and progression of Multiple Sclerosis with the different CD 24 polymorphisms: V/V, a/a and a/V.
To assess the expressivity of various gene polymorphism on T cells.
To check any tendency in the development of Multiple Sclerosis within family members and different ethnic groups.
Materials and Methods:
The study checked the single nucleotide polymorphism in a population of Multiple Sclerosis patients and controls. These patients were diagnosed with Multiple Sclerosis, using the Mc Donald criteria. The short nucleotide polypeptide was recognized by using PCR-RFLP, using primers, and tests were applied to check for differences in observations between the groups.
The studies established a link between CD 24 and the development of Multiple Sclerosis and its progression.
INTRODUCTION:
The etiology of multiple sclerosis involves interplay between genetic and environmental factors. It is a disease of northern Europeans and occurs less frequently in other racial groups. The lifetime risk of multiple sclerosis in northern Europe is 1:800, increasing to 1:50, 1:20 and 1:3 for the offspring, siblings and monozygotic twin partners of affected individuals, respectively. (D.A, 1996)
In Multiple Sclerosis, the myelin producing oligodendrocytes of the central nervous system are the target of recurrent cell mediated autoimmune attack, which starts with the entry of activated T-cells through the blood-brain barrier. These recognize myelin derived antigens on the surface of the nervous system's antigen presenting cells, the microglia, and undergo clonal proliferation. The resulting inflammatory cascade releases cytokines and initiates destruction of the oligodendrocyte myelin unit by macrophages. (D.A, 1996)
Other than the already established candidate genes (DRB, 1.1501, DRB 5.0101, DQA1.0102 AND DQV2.0602) preliminary evidence also associates CD 24 to multiple sclerosis, as a factor, modifying disease progression. These genes are not the causative factors but play a role in modifying the susceptibility of an individual towards multiple sclerosis. (D.A, 1996)
CD 24 is a cell surface glycoprotein present on many cells, including activated T cells, B cells, macrophages, dendritic cells and local antigen presenting cells in the CNS. Many of these CD24 expressing cells are involved in the pathogenesis of multiple sclerosis. (Zhou, Rammohan, Lin, Robinson, & Li, 2005)
This review has been extracted from two studies; 'CD 24 V/V is an allele associated with the risk of developing multiple Sclerosis in the Spanish population' . (D Otaegui1, A Sa'enz1, P Caman "o1, 2006) and 'CD24 is a genetic modifier for risk and progression of Multiple Sclerosis' (Zhou, Rammohan, Lin, Robinson, & Li, 2005)
MATERIAL AND METHOD:
In the above mentioned studies of CD24 and the role of genetic polymorphism in the risk and progression of Multiple Sclerosis, the following method was applied.
The samples were approved by the institutional review board and informed consent was taken from all the subjects. These patients were diagnosed with Multiple Sclerosis using the Mc Donald criteria. According to the Mc Donald Criteria, diagnosis is made on clinical attack and lesions observed on MRI as follows:
Patient presenting with two or more lesions on MRI along with two or more clinical attacks provides no additional need for further investigations. This clinical evidence, on its own, forms the basis of diagnosis.
For diagnosing Multiple Sclerosis in patients who present with two or more clinical attacks and one lesion, there needs to be dissemination in space or two or more lesions on MRI consistent with MS plus positive CSF.
In patients who present with one clinical attack and two or more objective lesions, there needs to be dissemination in time, for diagnosis.
If there has been one clinical attack and one lesion, there needs to be dissemination in space by two or more MRI lesions, consistent with MS plus positive CSF, and dissemination in time by MRI.
To make a diagnosis, the above mentioned criteria must be present. If there isn't sufficient evidence, one must wait for another clinical attack.
Patients with no clinical attacks but one or more lesions must be followed for a year, to evaluate disease progression, and at least two out of the following three must be checked:
Positive brain MRI ( 9 T2 lesions and 4 or more T2 lesions with positive VEP)
Positive spinal cord MRI (2 or more focal T2 lesions)
Positive CSF (Boon, 2006)
The degree of disability was assessed with the Expanded Disability Status Scale (EDDS), which is scored using the following basic rules.
The EDSS provides a total score on a scale that ranges from...
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