The Tnf- α Single nucleotide polymorphism and the role of inflammatory cytokines in diabetic neuropathy

Immunological and inflammatory reactions play a pivotal role in the initiation and perpetuation of Diabetic Neuropathy (DN). The present study is an attempt to estimate the levels of adenosine deaminase (ADA) and C-reactive protein (CRP) activity and for genotyping TNF alpha (-308) polymorphism in patients with Diabetic neuropathy. Methods: 50 cases presenting Diabetic neuropathy and 50 cases of age and sex matched healthy controls were included in the study. Serum ADA activity was measured spectrophotometrically at 630 nm and serum C-reactive protein was detected using Avitex CRP kit, which is a rapid latex agglutination test and ARMS PCR was done for genotyping of TNF alpha (-308) polymorphism using allele specific primers. Results: The mean ADA levels were 37.2 ± 5.0 in patients and 18.2 ± 5.6 in controls, significant at p< 0.01. CRP test was found to be positive in 20/20 cases of Diabetic Neuropathy and none of the controls. SNP at position −308 promoter gene of TNF-α was not significantly associated with development of Diabetic Neuropathy. Interpretation & conclusions: The present study observed the importance of ADA as a serum marker in addition to CRP for better therapeutic management of DN. SNP at position −308 promoter gene of TNF-α was not significantly associated with development of Diabetic neuropathy. The odds ratio and relative risk estimates of AA phenotype showed an increased risk to have the disease when compared with the other phenotypes.