Zytokine und das genetische Risiko für Morbus Alzheimer und Morbus Parkinson

Neuroinflammatory processes are known to be involved in the pathogenesis of Alzheimer's disease (AD) and Parkinson's disease. Next to other pro-inflammatory factors such as complements or oxidative stress, interleukine-1α as well as interleukine-6 are multifactorial cytokines playing a major role in neurodegenerative disorders. Accordingly, in the present study it was investigated to what extent the investigated polymorphisms IL-1α (-889) and IL-6 (-174) can be associated with a higher risk with either AD or PD on the basis of all existing allele-associated studies. In this context, it was also investigated whether any differences can be found in relation to age, sex, and the availability of the APOE-ε4-allele. In the current study, a relation was found between the polymorphism IL-1α (-889) and AD. Particularly, the allele 2 was strongly associated (odds ratio 7.2) with AD. Regarding the polymorphism IL-6 (-174), no significant relation to AD could be verified in the investigated sample. Moreover, results showed no indication of a positive association between the polymorphism IL-1α (-889) and the occurrence of PD. In an additional investigation of a sub-sample of patients with an early onset of Parkinson's disease, an increased risk of coming down with PD for homocygous bearers of the IL-1α (-889) allele 2 could not be verified. The well-known relation between the APOE-ε4-allele and the risk of AD could be confirmed by the results of the current study. Altogether, the results of this study are consistent with evidence of previous studies regarding neuroinflammatory processes possibly being of great importance in the pathogenesis of AD. The current research adds valuable evidence for better understanding of the multi-factorial pathogenesis of neurodegenerative disorders. By means of the present research, the importance of cytokines as a component in inflammatory cascades can additionally be illustrated. On the basis of this study, their actual relevance in the pathogenesis of neurodegenerative disorders such as AD and PD needs to be clarified in further research.