This is a case report in which platinum-palladium improved the pathology of interstitial pneumonia. In addition to this case, there have been many reports of improvement in other clinics, and many cases of improvement in interstitial pneumonia with platinum-palladium have been confirmed. Therefore, it was suggested that platinum-palladium is an effective treatment method for interstitial pneumonia. Currently, treatment for interstitial pneumonia is mainly conservative, with the aim of preventing the condition from worsening, but improvement is difficult. However, in this case, improvement in daily living activities was observed, so it is possible that lung function may have improved. Although there are still many unknown aspects of the mechanism, we have considered the possibility. Although the cause of interstitial pneumonia is often unknown, it causes inflammation in the interstitium, so the production of reactive oxygen species is thought to be the cause [
33]. Reactive oxygen releases inflammatory cytokines and has a positive aspect as a system to defend the body, but excessive reactive oxygen is known to have a negative effect on normal cells, causing lifestyle-related diseases, aging, and chronic inflammation [
34,
35]. In this case, platinum-palladium was used, but as mentioned above, platinum-palladium causes moderate antioxidant activity, so it is possible that it did not remove necessary reactive oxygen, but only unnecessary reactive oxygen, which may have led to the improvement of interstitial pneumonia. In addition, when the activity of AMPK by platinum-palladium was confirmed at the in vitro level, AMPK activity was confirmed at a significance level of 1% in all groups. AMPK (AMP-activated protein kinase) is an energy sensor in the body and is a serine/threonine kinase that works to maintain homeostasis of glucose and lipid metabolism [
36]. It is said that activation of AMPK regulates energy metabolism and maintains energy homeostasis, and it has attracted attention as a potential therapeutic agent for metabolic diseases including type 2 diabetes and cancer [
36]. Energy is essential for human life, and the source of energy is ATP (adenosine triphosphate), which is generated when ATP is hydrolyzed and converted into ADP (adenosine diphosphate) [
37]. AMPK regulates ATP levels to maintain homeostasis and is expected to be effective against metabolic diseases such as cancer, type 2 diabetes, and obesity [
38,
39,
40]. It is thought that AMPK regulates metabolism by inhibiting ATP consumption pathways [
41,
42]. Therefore, AMPK contributes to maintaining health in the body by suppressing chronic inflammation [
43,
44]. It promotes autophagy [
45]. It may increase mitochondrial function [
46] and increase intracellular ATP levels by activating mitochondrial biosynthesis [
47,
48].
In addition, blood tests were performed on patients at the in vivo level to meas- ure the aforementioned KL-6 and blood hydrogen peroxide levels. KL-6 is a high molecular weight sialylated glycoprotein contained mainly in type II alveolar epithelial cells that is strongly involved in the production and secretion of pulmonary surfactant [
50], and is widely used clinically to assess the severity of chronic respiratory diseases because it correlates with the activity (severity) of chronic respiratory diseases [
51], and is released into the blood due to inflammatory damage to the alveoli [
52,
53]. It is strongly correlated with the severity of interstitial pneumonia, but it has also been reported to correlate with the severity of lung cancer and mixed disorders (combined with emphysema) [
54], and is used clinically [
55].In this experiment, the KL-6 value was significantly reduced, suggesting that the severity had improved. In the future, we plan to investigate what action in the body's dynamics is suppressing the release of KL-6, but one hypothesis is that this is due to improved alveolar function in patients with interstitial pneumonia. At the same time, hydrogen peroxide (H
2O
2) was examined. Hydrogen peroxide (H
2O
2) is one of the representative reactive oxygen species (ROS) [
56], and in normal physiological actions, it plays an important role in cell signaling, etc. [
57], but on the other hand, it induces oxidative stress in the body and is a factor in cell and tissue damage [
58,
59]. When glucose is ingested in the body, it enters the TCA cycle through the glycolysis process and then passes through the electron transport system to produce ATP [
60], but when glucose cannot be ingested, fat and protein are burned to produce ATP. In other words, ATP is essential for human life support [
61]. A large amount of oxygen is required to produce this ATP, and naturally this oxygen is taken in through breathing. Most of it is involved in energy production, but a few percent of it is converted into reactive oxygen species (ROS) [
62]. ROS have advantages and disadvantages for the body. One advantage is that ROS play a role in the body's defense mechanism, destroying bacteria and cancer cells in granules contained in neutrophils [
63]. It is known that ROS are related to various lifestyle-related diseases, including malignant neoplasms, and aging [
64]. Currently, the following four types of ROS are known to exist: 1) Superoxide (O2-), 2) Hydrogen peroxide (H
2O
2), 3) Hydroxyl radical (·OH), and 4) Singlet oxygen (
1O
2) [
65]. In recent years, methods for removing ROS have been studied both in Japan and overseas for the purpose of preventing diseases and combating aging [
66]. Since aging has been treated as a disease name since ICD-11, [
67]it is expected that further research on antioxidants will be conducted in the future. In this context, it has been confirmed that platinum-palladium is the only substance in the world that can remove all four types of reactive oxygen mentioned above [
68]. In this study, from the perspective that there may be a possibility that hydrogen peroxide is generated in large amounts in patients with interstitial pneumonia before and after taking platinum-palladium, [
69] the plasma hydrogen peroxide level was qualitatively measured, and a significant difference was observed in this experiment, confirming a tendency for hydrogen peroxide to decrease in the body when platinum-palladium was used. Hydrogen peroxide is a type of reactive oxygen species [
70], and it is possible that hydrogen peroxide may affect the alveoli in patients with interstitial pneumonia and COPD [
71] Therefore, the fact that a decreasing trend was observed in this study indicates that platinum-palladium significantly reduced KL-6 and hydrogen peroxide in patients with interstitial pneumonia. This suggests that platinum-palladium may be effective at the pharmaceutical level not only for interstitial pneumonia but also for COPD by protecting the alveoli in the reduction of KL-6, suppressing the effects of ROS caused by hydrogen peroxide, and increasing mitochondrial activity.