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Differences between clinical medicine, public health, and epidemiology.

Although clinical medicine, public health, and epidemiology are similar, the differences and boundaries between them are difficult to understand.  Let's consider the difference in this article.

clinical medicine, public health, epidemiology

There seems to be a general consensus (just me?) that clinical medicine is the study of the health of individual patients, and public health (or epidemiology) is the study of the health of a group.

If I were to use a more precise expression, it would be something like this:

• Clinical Medicine: Emphasis on individual patients (or “cases”). A study that focuses on the effects and impact of diagnosis, treatment, and treatment on individual patients, and their subsequent outcomes.
• Public Health: A discipline that focuses on the dissemination of healthcare-related information, the degree of acquisition of health-related knowledge, the determination and implementation of healthcare policies, and the evaluation and countermeasures of various health-related problems.
• Epidemiology: The study of the patterns and manifestations of disease and health-related events (including infection and onset) in populations, the measurement of prevalence and incidence, and the factors that contribute to disease and health-related events.

In this way, we can see that epidemiology is used both to generate information for input into public health activities and as background information in the clinical setting.

For example, when we have to decide on some kind of medical policy, we need information such as, "How many patients are currently suffering from disease A, and how many are expected to increase in the future?" ” or “Factors that predispose people to disease A”, it is possible to think of measures to eliminate the cause or factor.

On the other hand, in terms of clinical medicine, when treating the patient in front of us, information known from epidemiology (e.g., people with these characteristics are more likely to develop disease A. People with such lifestyles, are susceptible to disease A.) can be used as a basis for lifestyle guidance and treatment strategies.

Epidemiological purpose

Epidemiology has four main objectives:

1. Discover the factors that influence health. Not only major factors but also mediating factors and environmental factors are covered.
2. If multiple factors contribute to illness, deterioration, or death, rank the importance of those factors.
3. Identify high-risk populations (susceptible to disease, high risk of death).  This is the information you need for a "high-risk approach" in medicine.
4. Evaluate how effective (or ineffective) healthcare-related policies, services, etc. are.

Classical epidemiology and clinical epidemiology

Classical epidemiology is an image that focuses on a relatively wide area (for example, local government level such as prefectures). Collecting information such as infection factors for infectious diseases, nutritional information, environmental factors, behaviors and ways of thinking (customs, culture) peculiar to the region, economic aspects, etc., for people living in a certain municipality, It is a wide-ranging analysis of the impact of  For example, in certain regions of a country, the consumption of animal protein, including meat, is prohibited for religious reasons. There are cases such as the classic epidemiological analysis.

On the other hand, clinical epidemiology has an image of narrowing down the target compared to classical epidemiology, which studies patients at each medical facility. Epidemiological studies are closer to clinical medicine, such as how to improve prognosis, prevention, and early detection of specific diseases in people with or without risk factors for specific diseases. Clinical epidemiology can be said to incorporate methods and research designs.

summary

Epidemiology, medicine, and public health are often discussed in similar contexts, and the lines between them are sometimes blurred.

When I get confused when listening to the statements of people called "experts" on TV programs such as Wide Show, I can't help but wonder whether the statement is from the standpoint of "the health condition of the patient in front of me" or "the health condition of the group." right? Thinking about it might help you understand.

1. Introduction: What is a Bispecific Antibody?

Bispecific antibodies are antibodies that can bind to multiple targets simultaneously, unlike normal monoclonal antibodies. Antibodies of this type are attracting attention in the medical field because they can have multiple effects on specific cells or molecules, increasing drug selectivity and therapeutic efficacy.

A bispecific antibody has a Y-shaped structure similar to that of a normal monoclonal antibody, but the two arms are designed to bind to different antigens. This structure allows it to bind to two different molecules simultaneously, for example, in cancer therapy, it can specifically bind to cancer cells while also binding to immune cells to promote immune responses.

Bispecific antibodies are expected to have higher specificity and potency than monoclonal antibodies with a single target. Therefore, it is being applied in various fields such as cancer treatment and treatment of autoimmune diseases. It is hoped that more effective treatments will be developed in the future.

2. A review of the basic structure of antibodies

To understand the structure of a bispecific antibody, let's first review the basic structure of an antibody.

Antibodies are Y-shaped molecules, and the upper two parts are called "Fab regions" and specifically bind to antigens. On the other hand, one part at the bottom is called the "Fc region", which binds to immune cells and exerts its function.

A Fab region consists of a variable region and a constant region. The variable region has an amino acid sequence that differs between antibody types and creates the shape for antigen binding. The constant region has the same amino acid sequence regardless of the type of antibody and forms the shape of the Fc region that binds to immune cells.

The Fc region has the function of regulating immune responses by being recognized by cells. The structure of the Fc region differs depending on the type, such as IgG, IgA, and IgM.

Bispecific antibodies are designed to bind to two different targets based on this basic antibody structure. The next section details the structure of bispecific antibodies.

3. Explanation of the structure of bispecific antibodies

Bispecific antibodies have a Y-shaped structure similar to normal antibodies. However, the difference is that each arm of the antibody has a structure that specifically binds to a different antigen. Since this bispecific antibody can adhere to different types of cells, it is expected to have applications that are different from ordinary antibodies.

A bispecific antibody has two single-chain variable regions (scFv) that have specificities for different antigens. One variable domain binds to CD3 expressed on the surface of T cells and the other to B cell antigens such as CD19 expressed on the surface of cancer cells. Thus, the two variable regions can bind different antigens and promote the adhesion of different cells.

Bispecific antibodies are also synthesized by joining two single-chain variable regions with a linker. This linker must be of appropriate length and structure and has a significant impact on the stability and specificity of the bispecific antibody.

Bispecific antibodies are expected to be applied in many medical fields such as cancer treatment and autoimmune disease treatment. By adhering to two different cell types, these antibodies can reduce the time it takes for the antibody to reach its target and exert a more potent therapeutic effect.

4. Explain the mechanism of action of bispecific antibodies

Bispecific antibodies can form new target cells by binding to two different targets. One target can adhere to the target cell of the other, thus promoting cell-cell interactions.

For example, Blincyto can bind to CD3 and CD19. This antibody connects CD19-expressing cancer cells with T cells, allowing the T cells to attack the cancer cells, proliferate themselves, and recruit allies. Hemlibra, on the other hand, can bind to anticoagulant factors IXa and X. This can promote normal clotting even in hemophiliacs who are deficient in factor VIII.

By linking two different targets in this way, bispecific antibodies can promote cell-to-cell interaction and be useful in disease treatment.

5. Introduction of representative drugs

Since bispecific antibodies are still new drugs, their actual clinical use is limited. Among them, Belinsite and Hemlibra are well known.

Blincyto is used for relapsed or retargetfractory B-cell acute lymphoblastic leukemia. The drug simultaneously binds to the CD19 and CD3 antigens, tethering T and B cells to trigger antibody-dependent cellular cytotoxicity (ADCC) targeting B cells. Blincyte was approved by the FDA in 2014 and has become one of the most effective drugs for the treatment of B-cell acute lymphoblastic leukemia.

Hemlibra is used to treat congenital/acquired hemophilia A. This drug compensates for the lack of factor VIII by simultaneously targeting eating both anticoagulant factors IXa and X. Hemlibra was approved by the FDA in 2017 and has shown superior results to conventional therapies in the treatment of hemophilia A.

These drugs are one of the breakthrough treatments that take advantage of the excellent properties of bispecific antibodies, and further development is expected in the future.

6. Future expectations: development of trispecific antibodies

While the application of bispecific antibodies is progressing, the development of tri-specific antibodies using more advanced technology is also expected in the future. For example, Sanofi is currently developing a tri-spirit-specific civic antibody that simultaneously recognizes the CD38 antigen, the CD3 protein complex, and the CD28 antigen.

Trispecific antibodies can specific Civico recognize two target molecules of bispecific antibodies, plus the ability to recognize one additional target molecule. This is expected to enable more accurate cancer treatment. In addition, tri-specific antibodies are expected to be applied not only to cancer therapy but also to the treated specifictment of autoimmune diseases.

However, at present, tri-specific antitri-specificbodies have not yet reached clinical application and are still in the stage of research and development. In the future, it is expected that more advanced technology will be developed and lead to clinical application.

7. Summary

Bispecific antibodies are antibodies that can bind to two different antigens simultaneously, unlike conventional monospecific antibodies. Taking advantage of this specificity, it is applied in many fields such as cancer treatment and hemophilia treatment. In addition, the development of trispecific antibodies is currently underway, and new therapeutic methods are expected to be developed in the future.

Representative drugs include Blincyto, which targets relapsed or refractory B-cell acute lymphoblastic leukemia, and Hemlibra, which is used to treat congenital/acquired hemophilia A. These agents take full advantage of the properties of bispecific antibodies and suggest new therapeutic possibilities.

Further development of bispecific antibodies is expected in the future, which is expected to lead to the realization of new treatment methods in fields such as cancer treatment, immunotherapy, and blood diseases.