Association Between Tumor Necrosis Factor And The Gene Polymorphism And Guillain-Barre Syndrome

Background: Guillain-Barre syndrome (GBS) includeseveral subsets, such as acute inflammatory demyelinatingpolyneuropathy (AIDP) and acute motor axonal neuropathy(AMAN). There are different features on the epidemiology,pathology and electrophysiology between the two subsets.Currently lots of available evidence suggests that this disease isimmunologically mediated. Tumor necrosis factor (TNF) whichcontains TNFαand TNFβ, is believed to play an important rolein GBS disease. TNFαis secreted from activated monocytes andTNF βis secreted from induced T-Lymphocytes, and they havesimilar biologic functions. TNF is known to induce myelindamage and degeneration of axons in patients with GBS.Recently found that TNF genes have polymorphism, which isassociated with high TNF production, suggesting theinvolvement of a genetic predisposition to high TNF alphasecretion in the development of GBS. TNF genes are closelylinked to HLA genes and have been mapped to humanchromosome 6.Objective: 1. To study the relations between thesusceptibility to AIDP and AMAN, two subsets of GBS, and thefrequencies of TNFα/βgene polymorphysim; 2. To study therelations between TNFα/βgene polymorphism and serumconcentrations of TNFα/βin GBS patients. 3. To define apossible pathogenic role of TNF in patients with GBS during theinitial phases of the disease.Methods: 1. A case-control research was down on 48 GBSpatients and 58 healthy individuals as control group. Thepatients underwent a thorough clinical examination andelectrophysiological examination. All patients fulfilled thecriteria of GBS made by Asbury. Motor conductive velocity(MCV), distal latency, F wave and motor evoked amplitude helpto define the two subtypes of GBS. 2. DNA was extracted fromperipheral blood leukocytes by improved fast saltingout. 3. PCRwas used to amplify the aim genemic sequence. 4. The genepolymorphism of TNFαand TNFβwere detected by means ofpolymerase chain reaction (PCR) with restriction fragmentlength polymorphisms (RFLP) techniques. The products wereseparated on agarose gel stained with ethidium bromide andvisualized under ultraviolet light. 5. Serum samples were frozenin aliquots at –70°C within 1h of collection and repeatedfreezing and thawing of samples was avioded. Levels of TNF intest and control subjects were determined by means of sandwichenzyme-linked immunosorbent assay (ELISA), using TNFimmunoassay kits. 6. Statistical evaluation was done usingSPSS 10.0 statistical analysis software. Genotype distributionunderwent the Hardy-Weinberg (HW) equilibrium calculation,the control groups is presentative of the overall population.Serum TNF levels were reported as median±SD. Descriptivedata of continuous variables were tested by Student t test. Thedifferences in allele distribution and allele frequency wereexamined for statistical significance with the x2 test or withFisher exact test when appropriate. Differences were consideredsignificant when P values were <0.05.Results: 1. the serum concentration of TNFαand TNFβwere47.24 ±0.55 pg/ml and 216.97 ±3.61pg/ml, respectedly, bothraised in GBS group, (P<0.05); serious GBS patients in clinicalstage (4~5) have more high TNFαconcentration (50.42 ±0.50pg/ml) and TNFβconcentation (239.54 ±4.54 pg/ml) than thepatients in clinical stage (1~3), (P<0.05). 2. On the research ofTNF gene polymorphism, it shows that TNFα2 allele frequencyincrease significantly in GBS patients, (P<0.05), related risk is4.82. TNFβ1 allele frequency increase significantly in GBSpatients, (P<0.05), related risk is 1.88. 3. TNFα2 frequencyincrease significantly in AIDP group and AMAN group,(P<0.05), related risks are 4.36 and 5.39 respectedly. 4. TNFαserum concentrations were higher in GBS patients with TNFα2allele and TNFβconcentrations were higher in GBS patientswith TNFβ1 allele, P<0.05.Conclution: 1. Serum TNF concentration elevates in GBSpatients during initial period and has relationship with diseaseseverity. 2. There are different distribution of TNFα2 andTNFβ1 alleles in GBS patients and normal individuals. GBSsusceptibility is associated with TNFα2 and TNFβ1 alleles.3.TNFα2 and TNFβ1 alleles are related to elevation of serum...