Stem cell transplantation

Disease Description (Causes and Symptoms)

• Definition: Hematopoietic stem cell transplantation (HSCT) is a treatment (procedure) in which hematopoietic stem cells from the bone marrow, peripheral blood, or umbilical cord blood are transplanted into the patient to regenerate normal blood cells.
• Indications (main diseases treated): Hematologic cancers and blood disorders such as acute and chronic leukemia, myelodysplastic syndromes, malignant lymphoma, multiple myeloma, and aplastic anemia; some congenital immunodeficiencies and metabolic diseases; and certain high- or low-grade solid tumors (in some cases), among others.
• Brief pathophysiology: High-dose chemotherapy and radiation (conditioning) are used to eliminate the patient’s diseased cells, and infusion of the graft reconstitutes a new hematopoietic system. In allogeneic transplantation, the graft-versus-tumor (GVT) effect may contribute to the antitumor effect, but graft-versus-host disease (GVHD) may occur in cases of immunologic mismatch.
• Symptoms: The transplant itself does not cause symptoms (asymptomatic)—however, treatment side effects (nausea, vomiting, hair loss, infection, bleeding, etc.) and complications (GVHD, infection, organ toxicity, etc.) may occur before and after transplantation.

Treatment Methods

• Types of transplantation
  • Allogeneic: HLA-matched sibling, unrelated donor, umbilical cord blood, or haploidentical (half-matched, haplo) donor, etc. The GVT effect may be expected, but there is a risk of GVHD.
  • Autologous: The patient’s own hematopoietic stem cells are collected and stored, then reinfused after high-dose treatment. Relative disadvantages include the risk of relapse (due to residual cancer cells), infection, and delayed engraftment.
  • Syngeneic: Transplantation from an identical twin donor (rare).
• Sources of hematopoietic stem cells
  • Bone marrow (bone marrow harvesting), peripheral blood (large-volume collection after growth-factor mobilization), and umbilical cord blood (blood from a newborn’s umbilical cord).
• Preparation (conditioning) therapy
  • Myeloablative or reduced-intensity conditioning (RIC)—selected according to the patient’s age, underlying diseases, and disease status.
• Immunosuppression and GVHD prevention
  • Cyclosporine, tacrolimus, methotrexate, and mycophenolate are mainly used. Steroids are the first-line treatment when GVHD occurs.
• Infection prevention and management
  • Prophylactic antiviral, antifungal, and antibacterial therapy; isolation and hygiene management before neutrophil recovery; and regular specimen testing (CMV, EBV, etc.).
• Supportive care
  • Transfusions, growth factors (e.g., G-CSF), nutritional support, rehabilitation, and psychosocial support.
• Long-term follow-up
  • A revaccination plan; endocrine (fertility), pulmonary, cardiac, and liver function tests; and monitoring for cancer recurrence.
• Precautions and risk of complications
  • Acute complications: Infection (sepsis), bleeding, mucositis, organ toxicity (such as hepatic veno-occlusive disease), rejection, or graft failure.
  • Chronic complications: Chronic GVHD (involvement of the skin, liver, mouth, or respiratory tract), infertility, secondary malignancies, and reduced organ function.
  • Counseling is needed regarding pregnancy planning, vaccination schedules, and long-term cancer and endocrine complications.

Checklist Before an Outpatient Visit (Including Example Questions)

• Items to bring
  • A list of all medications currently being taken (including prescription medications, OTC medications, herbal medicines, and supplements)
  • Copies of previous test results (CBC, bone marrow examination, HLA testing, liver and kidney function tests, electrocardiogram, chest examinations, etc.)
  • A history of previous hospitalizations, surgeries, and infections (especially recent viral infections, tuberculosis, etc.)
  • Vaccination history (especially rubella, chickenpox, and Helicobacter, etc.), whether pregnancy is possible (women), and reproductive plans
  • Social support situation (availability of a donor, caregiver, and housing environment)
• Items to check at the outpatient visit
  • Current symptoms (fever, bleeding, gum bleeding, mucositis, shortness of breath, etc.)
  • Recent weight changes, nutritional status, cough, and degree of fatigue
  • Documents related to the donor (HLA test results)
• Example questions (items for the patient to ask the doctor during the outpatient visit)
  • "Why is one type of transplantation (allogeneic vs. autologous) recommended in my case?"
  • "What are the expected length of hospitalization and recovery time?"
  • "Are there any medications I am currently taking that I need to stop?"
  • "What measures should I take at home to prevent infection?"

General Example Questions to Ask the Doctor

• What preparation and tests are needed before transplantation? (HLA testing, infection testing, cardiopulmonary function evaluation, etc.)
• What are the advantages and disadvantages of the conditioning recommended in my case (myeloablative vs. reduced-intensity)?
• What are the major side effects of immunosuppressants, and what needs to be monitored during long-term use?
• What medications should I take to prevent infection after transplantation, and for how long?
• What are the major factors affecting the long-term prognosis (survival rate and risk of relapse)?

Examples of Disease-Specific Questions

• Regarding the donor: "If the donor is not a fully HLA-matched donor (such as a haploidentical donor or umbilical cord blood), how much difference can I expect in my risk of complications and prognosis?"
• Regarding fertility and family planning: "How will transplantation affect fertility (eggs/sperm), and through what procedures are preservation options (sperm, eggs, embryos, ovaries/testes) available?"