Abstract
Purpose :
Keratoconus (KC) is a progressive ocular disorder with a complex pathophysiology that is known to involve impaired immune response. Tumor necrosis factor alpha (TNF-α) is a key part of the acute inflammatory response of the immune system. It mediates the release of other proinflammatory cytokines including IL-17 and IL-6 and plays an important part in inflammation and the healing process. In a previous study, we compared the expression of TNF-α in KC tissues and controls from the northern areas of Pakistan amongst a predominantly Pakhtun population and found elevated levels of TNF-α expression in these corneas compared to controls. In this replication study, we did an analysis of the expression levels of this gene in the KC tissues from areas other than north of the country and in a non-Pakhtun population and compared them with the healthy control samples to evaluate the generalizability of our results outside the Pakhtun population.
Methods :
Total RNA was extracted from KC cases (KC) and from control corneas. This was then converted into cDNA. Real time quantitative PCR (RT-qPCR) was used to observe the expression of TNF-α in the samples. The statistical analysis was done using Mann-Whitney U test.
Results :
We analyzed a total of 6 corneas from 6 patients in this study. 3 of these were healthy age and gender matched controls and 3 patient corneas with KC. The expression of TNF-α was not significantly different between KC and control samples with a fold change of 1.08268983 and a p-value > 0.05.
Conclusions :
There was no significant difference in the expression of TNF-α in the KC corneal tissues with reference to the normal corneal tissues. This may suggest that elevated TNF-α levels may only play a part in the development of KC in a subgroup of KC patients. However, one limitation of our study was the small sample size. Future studies looking at TNF-α expression in a larger genetically heterogenous group of subjects is warranted.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.