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From Blood Draw to Infusion: How Your NK Cells Are Prepared in Japan

Published 2026.10.03 7 min read

Hello, I am Dr. Hidenori Shimada of Grand Green Osaka Umekita Clinic in Osaka, Japan.

If you are researching NK cell therapy from abroad, you may wonder what actually happens to your cells between the day blood is drawn and the day they are returned to you. This article walks through that journey at a conceptual level, so you can ask better questions before a consultation at Grand Green Osaka Umekita Clinic in Osaka.

The short answer: your own cells take a round trip

In NK cell therapy, a small amount of blood is collected in the same way as a standard blood test. The NK (natural killer) cells in that blood are then activated and expanded at a specialized cell processing facility, and the resulting cells are returned to you by intravenous infusion. The aim is to increase the number and activity of NK cells, which are innate immune cells that help detect and attack abnormal cells.

Because the cells come from you, the therapy is described as autologous. The procedure itself involves only a blood draw and an infusion, so it does not require hospitalization. However, it is a self-funded treatment in Japan, not covered by public health insurance, and whether it is appropriate for you must be decided by a doctor after an individual consultation.

Step 1: The blood draw and what happens right after

The process begins with a blood collection at the clinic. The volume and the schedule are set by the treating doctor, and the sample is handled according to the clinic’s procedures and the requirements of the facility that will process it. Before collection, you will normally be asked about your medical history, current treatments, and any infections that could affect cell handling.

It is reasonable to ask how the clinic makes sure that the cells prepared for you are the cells returned to you. If you are traveling from overseas, it is worth asking in advance how the schedule between collection and infusion is arranged, because the culture period takes time.

Step 2: Activation and expansion at a licensed facility

At the processing facility, NK cells are separated from the rest of the blood and cultured with substances that stimulate them to multiply and become more active. This takes place in a controlled environment where the cells are monitored for quality. Japan’s regenerative medicine law requires that clinics offering this kind of treatment submit a treatment plan that is reviewed and accepted, and that cell processing is carried out at facilities that meet legal standards.

Patients are often curious about exact cell numbers or culture details. These can vary by protocol and by individual blood samples, so it is reasonable to ask your doctor what information the clinic can share about the process used for you. Be cautious about any source that promises specific numerical results, since a higher cell count does not by itself mean a better outcome for any individual.

Step 3: Quality checks before the cells are returned

Before infusion, the prepared cells are checked according to the facility’s quality control procedures. These checks typically look at things such as cell viability and sterility, to confirm that the cells meet the standards set for release. If a batch does not meet those standards, it should not be used, and your doctor can explain what would happen to the schedule in that case.

This is also a good moment to ask how the clinic handles unexpected situations, such as a delayed culture or a change in your health on the planned day. Clear answers to these practical questions help you plan travel, accommodation, and time away from work with more confidence, and they give you a better basis for deciding whether to proceed.

Step 4: The infusion and what to expect afterward

The cells are returned by an intravenous drip in the clinic. As the therapy uses a blood draw and an infusion, patients generally do not need to be admitted to hospital. Temporary fever or fatigue may occur after infusion, and your doctor will explain which symptoms to watch for and when to get in touch.

Because NK cell therapy can be used alongside surgery, chemotherapy, or radiation therapy, and does not replace them, your doctor may coordinate with the medical institution providing your standard cancer treatment. Please keep your oncology team informed about any additional therapy you consider, and bring your latest medical summary to the consultation, ideally in English or with a translation, so that the doctor can understand your situation accurately.

Questions to ask before you decide

How many blood collections and infusions are planned, and over what period?
Which facility processes the cells, and under which regenerative medicine plan is the treatment provided?
What are the fees, and what do they include? Treatment is self-funded and not covered by insurance.
What are the possible risks and side effects, and what are the limits of the evidence for my type of cancer?
How will treatment be coordinated with my current oncologist?

Grand Green Osaka Umekita Clinic offers consultations for international patients, and an information page in multiple languages is available to help you prepare. Costs, risks, side effects, and suitability should always be confirmed directly with a doctor at the consultation. It also helps to write down your questions in advance and to ask for the answers to be explained in a language you are comfortable with, so that your decision is made with a full understanding of what is, and is not, known about this treatment.

Key points to remember

Between the blood draw and the infusion, your own NK cells are collected, activated, expanded, quality-checked, and returned. Each step has its own questions worth raising with your doctor. NK cell therapy is a self-funded option offered under Japan’s regenerative medicine framework; it is not a substitute for standard cancer treatment, and its effects vary from person to person and cannot be promised. A consultation is the right place to discuss whether it fits your situation.

From Blood Draw to Infusion

1ConsultationDoctor reviews your situation
2Blood drawStandard blood collection
3Cell processingActivation and expansion
4Quality checksBefore the cells are returned
5IV infusionYour own cells, no hospital stay

This figure is a conceptual summary of the article content

Learn more about NK Cell Therapy

References

Supervising Physician

Director, Medical Corporation Shimada Clinic
Head of Clinical Practice, Grand Green Osaka Umekita Clinic

Hidenori Shimada

Graduated from the University of Tokushima Faculty of Medicine in 2005. After his initial residency, he obtained U.S. medical certification (ECFMG) and trained as a sub-intern in general surgery at the University of Washington. After completing the doctoral program at Kyoto University Graduate School of Medicine and working as a researcher at the Center for iPS Cell Research and Application (CiRA), Kyoto University, he founded Shimada Clinic in 2013. At Grand Green Osaka Umekita Clinic (https://umekitaclinic.org), he is engaged in a wide range of care, from internal medicine and pediatrics to cell therapy and aesthetic medicine.

* The physician supervision of this article covers its academic content only and does not constitute a recommendation of any specific treatment or product.

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