Combating Cancer and Viruses with Immune Power
NK cell therapy is a treatment method that utilizes the power of natural killer (NK) cells, which are naturally present in the human body.
NK cell is an abbreviation for "Natural Killer Cell," a type of leukocyte that constitutes a crucial component of the innate immune system (natural immunity) present from birth. These cells continuously patrol the bloodstream and various organs, monitoring and eliminating abnormal cells that are detrimental to the body.
Specifically, NK cells possess receptors on their cell surface to recognize abnormal cells. When an NK cell encounters a virus-infected cell or a cancer cell, it will immediately attack.
True to their name, Natural Killer cells are highly capable of eliminating abnormal cells. In NK cell therapy, these cells are extracted from the body, expanded and activated ex vivo, then reinfused to bolster the body's disease-fighting capabilities.
This treatment bolsters the body's endogenous immune strength, without recourse to complex pharmaceuticals, and is garnering attention as a form of cancer immunotherapy.
The Role of Immunity and the Importance of NK Cells
The human body possesses an immune system to protect itself from threats such as bacteria, viruses, and cancer cells. Immunity can be categorized into two types: innate immunity (natural immunity), which is present from birth, and adaptive immunity (acquired immunity), which is acquired later.
NK cells are key cells that regulate innate immunity, and with their inherent capabilities, they can quickly recognize and eliminate abnormalities. For instance, cells infected with influenza viruses or small cancerous cells that emerge daily are, in many cases, eliminated early by NK cells, thereby maintaining health.
Impaired NK cell function renders individuals susceptible to viral infections or facilitates the proliferation of cancer cells. Consequently, NK cells play a critical role in health maintenance.
Basic Mechanism of NK Cell Therapy
NK cell therapy is a treatment method that actively harnesses the power of NK cells.
Specifically, NK cells from the patient themselves or from a donor are taken from the body, then in a special environment, these cells are multiplied and activated (their vitality is enhanced), and then returned to the patient's body.
Through a method known as "culture," NK cell numbers are expanded manifold. Subsequently, by stimulating these cells with agents such as Interleukin 2 (IL-2) and Interferon Gamma (IFN-γ), they are transformed into a highly active effector state, surpassing their usual activity.
Then, by reintroducing NK cells through transfusion, the NK cells work hard in the patient's body to fight cancer cells and virus-infected cells.
In other words, NK cell therapy can be described as a treatment that enhances disease defense by increasing the number and strength of the body's immune patrols.
NK Cell Mechanism
How NK Cells Work in the Body
NK cells continuously function as sentinels within the body. To differentiate normal from abnormal cells, they examine information on the cell surface.
Healthy cells send "I am a normal cell" signals, but virus-infected cells or cancer cells show disrupted or lost signals.
NK cell detects this disturbance through its "antennae" (receptors) and when it assesses "this cell might be dangerous," it immediately takes action.
NK cell activity is very fast, and because they have been programmed since birth, they can immediately find and overcome enemies without needing to learn first.
It truly functions as a rapid response team within the body, dealing with infections at an early stage or very small cancer growths.
Mechanism of Attack against Cancer Cells and Abnormal Cells
When NK cells detect abnormal cells, they directly attack them. This mechanism broadly comprises two main types.
The first step involves NK cells making contact with abnormal cells and releasing a substance called perforin. Perforin functions by creating pores in the membrane of target cells, thereby enabling NK cells to inflict damage upon the abnormal cells.
The second is, after creating a pore, to deliver an enzyme called granzyme. Granzyme enters the enemy cell and "pushes the self-destruct button" to cause that cell to die.
Through these mechanisms, NK cells eliminate intrinsically virally infected or cancerous cells and safely process them. Furthermore, because NK cell responses are initiated without awaiting specific commands, NK cells can mitigate threats more rapidly than the adaptive immune response (T cells or B cells), which is activated following pathogen infection.
Benefits of NK Cell Therapy (Natural Immune Enhancement, Cancer Suppression, etc.)
NK cell therapy offers several advantages. Firstly, it enhances natural immune strength. By boosting the patient's intrinsic immune power, the body's overall defense mechanisms are strengthened, which can contribute to the prevention of disease recurrence and other infections.
Secondly, tumor suppressive effects are anticipated. Activated NK cells not only directly attack and eliminate cancer cells, but also, by damaging and sensitizing these cells, synergistic effects can be achieved when combined with other therapeutic modalities (e.g., chemotherapy or radiotherapy).
Furthermore, NK cell therapy is considered relatively safe (a key advantage being the rare occurrence of serious adverse events, as will be discussed subsequently). Moreover, given NK cells' ability to combat a wide range of cancers and viruses, there is potential for the elimination of a broad spectrum of abnormal cells, not merely specific targets.
Thus, NK cell therapy can be regarded as a novel treatment option that bolsters the body's intrinsic defenses and combats disease.
NK Cell Therapy System
Expected Diseases and Symptoms Associated with NK Cell Therapy (e.g., Cancer Treatment, Immunosuppression, Viral Infections)
NK cell therapy is anticipated to find widespread application across diverse fields.
Cancer treatment is a prime example. Research is ongoing into the potential efficacy of NK cell therapy against solid tumors (e.g., lung cancer, liver cancer, breast cancer, etc.) and hematological cancers (leukemia and lymphoma). In clinical trials of NK cell therapy in cancer patients, reports are beginning to emerge indicating tumor shrinkage or slowed growth.
Additionally, in situations where immunocompromise is observed, NK cell therapy is anticipated. For instance, in elderly individuals or patients with severe diseases experiencing compromised immunity, or patients with reduced immune cell counts following bone marrow transplantation or chemotherapy, supplementing NK cells may potentially aid in infection prevention and the restoration of energy and overall recovery.
Furthermore, their application in viral infections is also being explored. Given NK cells' capacity to target virus-infected cells, research is currently underway concerning chronic viral infections (e.g., hepatitis B and C viruses) and as a prophylactic strategy against severe outcomes for newly emergent viruses.
Finally, attention is also given to the somewhat unique field of anti-aging and lifestyle disease prevention. It is known that NK cell function declines with age. Studies are investigating whether NK cell therapy, by maintaining active immune surveillance, can prevent the onset of age-related diseases or extend healthspan.
Thus, NK cell therapy offers the potential to meet diverse needs, ranging from cancer treatment to immune support and preventive medicine.
Expected Effects (Cancer Immunotherapy, Viral Infection Prevention, Anti-Aging)
Below is a summary of the specific effects that can be anticipated from NK cell therapy, categorized by area.
- Effects as Cancer Immunotherapy
Activated NK cells patrol the body and directly attack cancer cells, with the expectation of shrinking tumors or suppressing their growth. Additionally, by damaging and weakening cancer cells, there is a possibility of increasing the effectiveness of other treatments (chemotherapy or radiotherapy). This can also lead to a reduction in the risk of recurrence after treatment.
- Pencegahan Infeksi Virus:
Because NK cells can eliminate virus-infected cells earlier, it is hoped that this will have the effect of reducing the viral load in chronic viral infections, for example, or preventing severity upon exposure to viral infection. By supplementing NK cells in people with weakened immune systems, there is a possibility of benefit for the prevention of secondary infections such as influenza or pneumonia.
- Anti-Aging dan Pemeliharaan Kesehatan:
When natural immunity is activated through NK cell therapy, the ability to suppress daily cellular abnormalities (such as nascent cancer cells and the accumulation of senescent cells resulting from regeneration) is expected to increase. Consequently, it may be possible to prevent age-related diseases or to improve and maintain one's health status. For instance, there are case reports of patients experiencing daily health benefits such as "increased resistance to the flu" or "reduced fatigue."
As mentioned above, NK cell therapy is expected to have various effects not only from the therapeutic effect itself, but also from the perspective of prevention and improving quality of life.
However, it is important to note that effects can vary among individuals, and not all patients will exhibit similar effects.
Upon the accumulation of ongoing clinical research findings, a clearer understanding of efficacy and optimal indications will be achieved.
NK Cell Therapy Method
Workflow from NK Cell Collection to Administration (Blood Sample Collection → Cell Culture → Infusion)
NK cell therapy broadly involves three main steps: "NK cell collection" → "expansion and activation" → "reinfusion into the body". The general process is as follows:
- Pengumpulan NK Cell (Tes Darah):
Blood is drawn from the patient's arm. The required volume varies depending on the treatment, but usually only a few tens of milliliters of blood are sufficient (approximately 1-several large syringes, an amount less than a blood donation). The NK cells contained in this blood will then be isolated. In autologous therapy, blood from the patient themselves is used, whereas in allogeneic therapy, NK cells are collected from donor blood or umbilical cord blood.
- Kultur dan Aktivasi NK Cell:
The collected blood is sent to a specialized cell culture facility. There, NK cells are separated from other cells and cultured (the process of multiplying cells). Over a period of 1-2 weeks, the number of NK cells is increased to billions of cells. Simultaneously, by adding IL-2 (Interleukin 2) and other stimulating substances, NK cells are activated to transform them into a condition that more readily attacks cancer cells. During culture, a strict sterile environment is maintained, and extreme care is taken to prevent infection or mutation.
- Pemberian NK Cell (Transfusi):
Activated NK cells that have reached a sufficient number through culture are placed into a transfusion bag and returned to the patient. They are then administered into the body via transfusion or injection. In the case of a transfusion, just like a regular blood or drug transfusion, NK cells are slowly introduced through a vein in the arm. The administration itself is completed in tens of minutes to about an hour, without significant pain. In some cases, a local injection can also be performed to a specific area (e.g., tumor site). After administration, the patient rests briefly and their condition is monitored to ensure there are no issues.
This outlines the basic workflow for a single session of NK cell therapy. As a culture period of approximately 1-2 weeks is required from blood collection to administration, advance scheduling is performed.
Specific dates are established for patients' blood tests and transfusions. During the interval between these appointments, patients are able to maintain their normal routines. Upon completion of the culture, patients return to the medical facility to receive the transfusion. Inpatient admission is not required, and in many cases, both blood tests and transfusions can be performed on an outpatient basis.
Administration Method Options (Transfusion, Local Injection, Single Administration vs. Continuous Treatment)
The administration method and frequency of NK cell therapy are individualized according to the patient's clinical condition and therapeutic objectives. The principal approaches are as follows:
Rute Pemberian:Generally, systemic intravenous administration via transfusion is chosen. With transfusion, activated NK cells spread throughout the body, which has the advantage of being able to act on cancer cells or virus-infected cells wherever they are located in the body.
Alternatively, when it is desired to target therapeutic effects to specific areas, direct local administration may be considered. For instance, in cases of hepatocellular carcinoma, it can be administered via catheter into the hepatic vasculature. For cutaneous tumors, direct peritumoral injection is an option.
However, local injections are restricted to facilities equipped to administer them, and their effects are not exclusively confined to the local pathology, with potential systemic implications. Consequently, decisions are made on a case-by-case basis.
Frekuensi dan Jadwal Pengobatan:There is a single administration (one-time treatment) and continuous treatment (done multiple times). In many cases, NK cell therapy is performed with a multi-session schedule.
This is because infused NK cells function temporarily within the body and their numbers diminish over time. Therefore, to maintain and enhance their efficacy, periodic administration of NK cells is recommended.
For example, transfusions are administered bi-weekly, with this pattern repeated over several months for a total of 5-6 sessions (constituting one course of treatment). Depending on the patient's condition, the treatment duration may be extended, or the intervals adjusted.
Conversely, if the objective is cancer recurrence prevention or the maintenance of immune strength, it can be administered at longer intervals, with additional doses provided only as needed, subject to ongoing situational assessment.
The method of administration and frequency are determined by considering the balance between treatment effects and patient burden. Physicians consult with patients to establish an optimal plan, so if anything is unclear or if you have any concerns, please do not hesitate to ask. The number of administrations and the intervals between them vary among individuals but will be explained in detail during the treatment planning stage.
Treatment Duration and Procedure Schedule (Frequency and Number Individualized for the Patient)
The duration of NK cell therapy is variable for each patient, as outlined above; however, a common example is provided here.
For example, in some patients, a regimen is established where a total of 6 transfusions are administered over approximately 3 months as a single course, with subsequent monitoring of progress.
In this case, following an initial blood test and an approximate 2-week culture period, the first transfusion was performed. Subsequently, the sequence of blood test, culture, and transfusion was repeated every two weeks, for a total of 6 cycles (approximately 12 weeks). Upon completion of the sixth transfusion, an efficacy assessment was conducted. Based on the results, a decision was made regarding whether to terminate treatment, establish a drug-free period, or initiate a subsequent course.
Alternatively, there are regimens for short-term observation, or conversely, for long-term periodic maintenance. In oncology, treatment is frequently administered intensively over multiple sessions. However, for immune system support or anti-aging objectives, case reports describe ongoing administration at a frequency of approximately once every few months to half a year.
The treatment plan must be flexibly adjusted based on the patient's physiological condition and their observed response to therapy. If adequate effects are not achieved during treatment, a transition to alternative therapeutic approaches may be necessary. Conversely, if the patient's condition is stable and favorable, treatment intervals can be extended, leading to a shift towards ongoing monitoring.
The treatment schedule should be thoroughly discussed in advance, taking into consideration its impact on lifestyle. Should you have any concerns regarding the frequency or duration of visits, including the possibility of schedule modification, please consult your attending physician.
NK cell therapy is a treatment with a relatively low patient burden; however, it still necessitates routine visits. Therefore, establishing a sustainable plan that can be progressed at one's own pace is key to success.
Comparison with Other Immunotherapies (CAR-T, PD-1 Inhibitors, etc.)
When discussing the safety of NK cell therapy, it is often compared to other immunotherapies such as CAR-T cell therapy and immune checkpoint inhibitors (PD-1 inhibitors, etc.). All of these are treatment modalities that have recently garnered attention, but there are differences in their adverse event profiles.
Comparison with CAR-T Therapy:CAR-T therapy is a very powerful cancer treatment method using genetically modified T-cells. However, due to its potency, side effects such as cytokine release syndrome (an uncontrolled immune system response, high fever, and a drop in blood pressure) or neurotoxicity (neurological symptoms like impaired consciousness or seizures) can occur. There have been case reports requiring management in an intensive care unit.
Conversely, in NK cell therapy, the incidence of such severe adverse events is currently very low. NK cells tend not to proliferate extensively within the body or persist for extended periods, thereby making them less prone to uncontrolled expansion beyond therapeutic requirements.
Therefore, it is considered to have a wide safety margin. However, unlike CAR-T therapy, which can achieve a profound therapeutic effect with a single administration, NK cell therapy often requires repeated treatments.
Comparison with Immune Checkpoint Inhibitors: Inhibitor PD-1 (di Jepang, nivolumab
While highly effective, disinhibition of the immune system can result in autoimmune-related adverse events. Specifically, these may involve the immune system attacking self-organs or tissues, causing pneumonitis (lung inflammation), colitis, hepatitis, skin rash, endocrine abnormalities, and various other potential adverse events.
Given its potential to be life-threatening in severe cases, during checkpoint inhibitor therapy, close monitoring is crucial, and should adverse events occur, management with immunosuppressive agents is necessary.
Conversely, NK cell therapy is a treatment that involves introducing external cells into the body. However, because these cells are innate immune cells, instances of them attacking the body's own normal tissues, similar to an autoimmune reaction, are rare. In other words, NK cells specifically target and act upon abnormal cells without fundamentally harming normal cells, thereby limiting the scope of potential side effects.
However, when using allogeneic NK cells, caution regarding allergic reactions and other adverse events is required, as previously mentioned.
In conclusion, NK cell therapy presents a lower risk of side effects compared to other advanced immunotherapies. Naturally, every treatment has its advantages and disadvantages, and there are cases where other therapies may be more suitable. However, from a safety perspective, NK cell therapy can be considered a relatively less burdensome option for patients.
NK cell therapy is an advanced therapeutic approach that leverages the body's inherent immune capabilities. By activating and strengthening NK cells, which directly target cancer cells and virus-infected cells, we enhance the body's ability to combat disease.
Notably, a significant advantage is the minimal side effects and low physiological burden. When combined with immunotherapy or conventional cancer therapies, additional synergistic effects are anticipated. Furthermore, its role in maintaining immune strength and its application as an anti-aging treatment are garnering interest, and sustained administration is also feasible as part of a comprehensive approach to health and well-being.
Our clinic provides treatment plans tailored to each patient's needs. Through an initial consultation, we recommend optimal treatment methods and perform procedures prioritizing safety.