Abstract
Lung diseases are a growing threat to the whole world. In 2014 the mortality rate of lung diseases was found to be 7.7% of the EU-28. Estimates show that COPD will become the third leading cause of death worldwide in 2030 and with lung cancer causing 1.69 million deaths worldwide in 2015, it is a growing problem. Luckily now a days, an enormous amount of medical data is available. PubMed is a database of citations and abstracts for more than 28 million research articles. With new technological developments, all this data could benefit medical research progressively. This research investigated the current status of lung diseases and the status of research between mutations and lung diseases. The research has found an enormous growth in articles which had some sort of relation between mutations and lung diseases.
Introduction
Respiratory diseases, any disease and disorders of the airways and the lungs that affect human respiration. The respiratory tract is the site of a large range of disorders for three main reasons: The tract is exposed to the environment, possesses a large network of capillaries through which the entire output of the heart has to pass and may be the site of allergic phenomena that may profoundly affect function [1]. Most respiratory diseases are considered to be lung diseases. For a lot of these diseases it is proven that certain environmental factors are a cause for lung diseases. But genetics can also play a significant role in causing lung diseases. Multiple diseases like Cystic fibrosis [2] or Chronic Obstructive Pulmonary Disease (COPD) [3] have a lot of research linking genetic mutations to the disease. But this becomes more difficult when looking for lesser known diseases. Even in diseases like COPD there are still new genes being found that links them to the disease [4]. This article has looked at the current status of how much is known about mutations in lung diseases or respiratory diseases.
Materials and Methods
First a pre-study has been done. This study contained learning about the anatomy and physiology of the lungs and respiratory system. It also focused on understanding what kind of diseases there are, what they do, where they might happen, what causes them and which might be related to a mutation. Followed by this pre-study data has been collected. This data has been manually collected. First statistics about the amount of people with a lung or respiratory disease has been collected using sources like WHO [5] and Eurostat [6]. Because there are a lot of lung and respiratory diseases this research has taken a deeper look into how much is known about gene mutations responsible for causing COPD. Results about article publications per year has been made using advanced search terms [3][7] in PubMed [8] and using the results per year function available on PubMed itself. There has been searched for lung and respiratory diseases related to the words mutation or hereditary and Chronic Obstructive Pulmonary Disease or COPD related to the words mutation or hereditary. A search against lung diseases or respiratory diseases and COPD or Chronic Obstructive Pulmonary Disease has also been done. The total amount of articles has been used as a result. One of the articles of the COPD search has been manually inspected [9]. The term found in that article has also been searched using an advanced search term [10] in PubMed. Lastly the findings have been reviewed, considered how trustworthy they were and what it means for future progression in relating mutations to lung diseases.
Estimates show that COPD will become the third leading cause of death worldwide in 2030 and with lung cancer causing 1.69 million deaths worldwide in 2015, it is a growing problem.
Results
Respiratory diseases cause an immense worldwide health burden. According to the WHO it is estimated that 235 million suffer from asthma [11]. 65 million people have moderate to severe chronic obstructive pulmonary disease (COPD) [12]. 8.7 Million people develop tuberculosis (TB) annually [13]. Lung cancer is the most common cancer globally it was responsible for 1.69 million deaths worldwide in 2015[14]. In 2014, there were almost 382 thousand deaths in the EU-28 resulting from diseases of the respiratory system, equivalent to 7.7 % of all deaths (table1) [15]. More than 3 million people died worldwide of COPD in 2005, which corresponds to 5% of all deaths globally. Estimates show that COPD becomes in 2030 the third leading cause of death worldwide [16].
Table 1 shows that 7.7% of all deaths in the EU-28 was caused by respiratory diseases. The United Kingdom had the most deaths in numbers and percentage wise. Noticeable is that men had a mortality percentage of 8.3 while women had a rate of 7.2. The standardized death rate was in total 78.3 per 100 000 inhabitants. The death rate of men was 1.9 times higher as the women in the EU-28.
Every year more data is being generated. With better and faster sequencing methods comes a lot of new research and progression towards new discoveries in genetics. With smart search terms a graph has been created, showing how many articles on PubMed are posted each year. Figure 2 shows the number of articles each year about lung and respiratory diseases with relation to mutations or hereditary attributes. In total these were 35966 articles. While searching normally for lung or respiratory diseases returned 846403 articles. Figure 3 also uses this method for COPD. In total this search returned 565 articles and searching for only COPD resulted in 77343. Observed in these figures is an enormous growth in articles. In both around 1990, the amount of data growth increases immensely. Noticeable is that COPD related to mutation research started after 1960 while lung and respiratory diseases linked to mutations started after 1920. The amount articles in figure 3 is less than 1/60th of the number of articles of figure 2.
Figure 2[3]: the number of articles each year about COPD with relation to mutations or hereditary attributes are displayed in graph form in this figure. On the x-axis are the years displayed and on the y-axis the number of articles published.
Inspecting one of the top articles using the COPD term used for Figure 3 leads to an article [6] describing α-1-antitrypsin deficiency(A1ATD) [16]. This mutation has first been found in by Carl-Bertil Laurell in 1963 [16]. It is caused by a mutation in the SERPINA1 gene. According to this article from 2013 A1ATD is an under-recognized hereditary disorder associated with the premature onset of chronic obstructive pulmonary disease. Upon searching for this mutation using an advanced term 1126 articles are found.
Discussion
The introduction was left with a question about how much is known about mutations in lung diseases or respiratory diseases. A disease was considered to be a lung disease if it influences either the function or structure of the lungs negatively. This includes almost if not all respiratory diseases.
The method used for this research collects data about the amount of people affected by lung diseases and investigates the growth of data about lung diseases and COPD related to mutations on PubMed. It also compares the advanced search to a search without linking it to mutations. One random article on COPD linked to mutations is chosen to look further into. The mutation from this article has also been searched on PubMed. Due to there being lots of different sources for statistical data and inconsistency among them, the Who and Eurostat were chosen as main source for researching the amount of people affected by lung diseases. These are considered to be trustworthy sources. Not all people affected by lung diseases are recorded into the statistics, that’s why to give insight over how many people suffer from lung diseases the multiple statistics and the Eurostat morality rate has been used instead. PubMed is one of the biggest sources for bio-medical articles. That is why it has been used to discover how much research about lung diseases had been done. The search term used for this might not have captured all articles or might even have captured unrelated articles. The term looks for both chronic obstructive pulmonary disease and COPD. To validate the data a random article of COPD has been selected. The mutation found in the article was looked up on PubMed to see if it has anything to do with the disease or not.
The results found by this research showed that lung diseases were becoming more of a problem in the future. Figure 1 gave an overview of the mortality rate which showed a total mortality rate and standardized rates which was a good indication for a lot of countries and how many people were affected by lung diseases. For countries like Iceland which only had a population of about 300 000 people this was not a good indication. Figure 1 showed a higher mortality rate in men compared to women. The rate could be due to different habits, enviroments or genetics. The findings of the PubMed searches showed that only a small portion of all articles investigated mutations. Figure 2 and figure 3 showed an immense growth in data. According to the validation, the articles did indeed talk about a relationship between a lung disease and a mutation. It also showed that not a lot is known yet about this gene and more research will have to be done. With the amount of data available researches will not be able to always manually find which mutations are all involved with lung diseases. With new methods to find useful data researches might be able discover hereditary or later on mutated genes in the human genome linked to lung diseases.
Conclusion
With the rise of lethality in lung diseases it is important to know which data is available. The research showed a rise of research in relating genetic mutations to lung diseases. With the help of new methods researchers might be able to find hereditary or mutated genes linked to lung diseases in the human genome.
