Researchers from the University Institute for Applied Ophthalmobiology (IOBA) of the University of Valladolid (UVa), the University Hospital of Valladolid, the University Hospital of Salamanca and the University of Salamanca (Spain) have analyzed the data in six independent studies to verify if those who present the polymorphism rs243865 MMP-2 have a greater risk of developing macular degeneration associated with age (DMAE). The results, published in & # 39; PLOS One & # 39 ;, indicate that there is no relationship, unlike what was collected in some previous individual studies with small populations.
In recent years, personalized medicine has been transforming healthcare. The information that the scientific community has about certain biomarkers – genes, proteins, etc. – makes it possible to adapt the treatments to the characteristics of each patient and even to predict how a disease will evolve.
But reaching these biomarkers is not an easy task. Many studies and clinical trials are left en route and some that appear representative may not achieve good results when transferred to clinical practice.
One of the many candidate biomarkers described in the scientific literature is the polymorphism rs243865 MMP-2, which appears to be associated with an increased risk of developing Age-Associated Macular Degeneration (AMD). This disease is considered to be the leading cause of blindness in people over 65 years of age and it is a problem that can increase due to the increasing aging of the Spanish population, because one of the major risk factors is age. That is why it is essential to find biomarkers that can give clues about people with a greater tendency to develop it.
Image of a retina affected by macular degeneration associated with age. (Photo: DICYT)
But the data on the polymorphism rs243865 MMP-2 is contradictory, because some studies point to its potential and others reject it. "These works have been performed with very small populations, so the representativeness of the study is reduced. Validation studies with larger populations are needed to get definitive results," DiCYT Salvador Pastor-Idoate, one of the lead authors of the article & # 39 ; PLOS One & # 39 ;, details.
To mitigate the limitations of these earlier works, the researchers made a meta-analysis, that is, they summarized these isolated works and obtained new global results through statistical techniques.
"We have established criteria for inclusion in the meta-analysis and in the end only six studies were added that met these criteria. In this way it was possible to increase the population to 1,682 patients with AMD and 2,295 healthy subjects, a number of patients and controls that would take a long time to recruit in a normal study, "Pastor-Idoate emphasizes.
Moreover, they have been able to study people from different backgrounds in this way. "In genetic studies, the mutations of a gene are separated according to the population studied. That is, it is not the same to study European, American or Asian. What we also achieve with this work is to mix people of different origins, what We have been able to increase the number of patients analyzed and on the other we have a more representative sample of all populations, "explains Ricardo Usategui-Martín, one of the other lead authors.
The results of the meta-analysis, which include the data from six previous studies, suggest that the rs243865 MMP-2 polymorphism is not related to the development of AMD. "The most important conclusion we get is that this variable does not affect the risk of getting the disease, either in terms of the type of population or age, which is a little bit contrary to what has been described so far," emphasizes Usategui- Martin.
Although working with negative results is not that common, they are very important because they serve as a guide for future research. (Source: Cristina G. Pedraz / DICYT)