Glossary | Blood Stem Cell

Cell Source

Where the blood-forming cells used for transplant are collected from.

Bone marrow, the soft spongy tissue found inside of bones, produces blood-forming cells for the body. The bone marrow for a transplant is collected from a donor's pelvic bone during a surgical procedure in a hospital.
Peripheral blood stem cells (PBSC) are found circulating in the bloodstream. Normally, the bone marrow releases a small number of blood-forming cells into the bloodstream. A donor receives injections of a medication that increases the number of blood-forming cells in the blood. Then, the donor's blood is collected in a non-surgical procedure done in an outpatient clinic.
Umbilical cord blood contains a large number of blood-forming cells. Cord blood is collected from the umbilical cord and placenta in a hospital after a baby is born.

Disease Status

A measure of how the disease responded to treatment before the patient received a bone marrow, peripheral blood, or umbilical cord blood transplant. The disease status can help predict the likelihood of a better or worse survival outcome after transplantation.

In these reports, disease status is included only for leukemias, lymphomas, myelodysplastic syndromes (MDS), myeloproliferative neoplasms (MPN), and multiple myeloma.

Leukemia Disease Statuses

For chronic myelogenous leukemia (CML):

1st chronic phase—Patients have low level clinical evidence of leukemia. Includes patients who are undergoing initial treatment for CML who have not progressed to more advanced disease.
2nd or subsequent chronic phase or accelerated phase—Patients with low level of clinical evidence of leukemia after being treated for more progressive disease or more advanced disease.
Blast phase—Patients with more advanced disease in the blood or marrow.

For acute myleogenous leukemia (AML) or acute lymphoblastic leukemia (ALL):

1st remission—The disease responded well to treatment. There is no clinical evidence of leukemia.
2nd or subsequent remission—The disease recurred after responding well to initial treatment; the disease came back after being in remission one or more times. After further treatment, there is no clinical evidence of leukemia.
Not in remission—The disease is not responding to treatment. There is still some evidence of leukemia.

Lymphoma Disease Statuses

1st remission—The disease responded well to treatment. There is no clinical evidence of lymphoma.
2nd or subsequent remission—The disease recurred after responding well to initial treatment; the disease came back after being in remission one or more times. After further treatment, there is no clinical evidence of lymphoma
Partial Response—The disease has responded reasonably well to treatment, but there is some disease remaining.
Active Disease (Not in remission)—The disease is not responding to treatment. There is still evidence of lymphoma.

Myelodysplastic Syndromes (MDS) and Myeloproliferative Neoplasms (MPN) Disease Statuses

In remission—The disease responded well to treatment. There is no clinical evidence of disease.
Not in remission—The disease is not responding to treatment. There is still evidence of disease.
No data—The disease status was not available.

Multiple Myeloma Disease Statuses

Partial response or better, transplanted after 1 year of diagnosis—The disease has responded reasonably well to treatment, but there is some disease remaining. The patient was transplanted more than a year after being diagnosed.
Partial response or better, transplanted within 1 year of diagnosis—The disease has responded reasonably well to treatment, but there is some disease remaining. The patient was transplanted less than a year after being diagnosed.
Stable/progressive disease or relapse, transplanted after 1 year of diagnosis—The patient’s disease has either not responded well to therapy, or has progressed or came back after treatment. There is active disease that is either stable or worsening. The patient was transplanted more than 1 year after being diagnosed.
Stable/progressive disease or relapse, transplanted within 1 year of diagnosis—The disease has not responded to therapy but has not progressed or there is active disease that is worsening. The patient was transplanted less than a year after being diagnosed.

Donor Type

Biological relationship between the patient and the donor who provided the blood-forming cells.

Autologous—The patient's own cells were collected, stored, and infused back into the patient.
Allogeneic—Another person donated bone marrow, peripheral blood, or an umbilical cord blood unit. These cells match the patient’s human leukocyte antigen (HLA) type. Specific allogeneic types include:
- HLA-identical sibling—The brother or sister who donated cells is the patient's biological sibling who matches the patient’s HLA type.
- HLA-identical twin – The brother or sister who donated cells is the patient’s monozygotic twin who shares the patient’s DNA.
- Other related donor—The family member who donated cells is related biologically to the patient and is not included in the HLA-matched sibling or identical twin category. The donor might have variable degrees of mismatch to the patient.
- Unrelated—The person who donated cells is not biologically related to the patient.

Human Leukocyte Antigen (HLA)

Proteins on cells that make each person's tissue type, which varies from person to person.

HLA typing is used to match patients and donors for a bone marrow, peripheral blood, or umbilical cord blood transplant. A person's HLA type is identified by testing a blood sample or swab of cheek cells.

95% Confidence Interval

A range of numbers that represents the statistical certainty of the survival probability estimate, based on the data reported.

For example, a 95% confidence interval of 65 - 75% means there is 95% certainty that the survival probability estimate is between 65% and 75%.

Number of Patients Evaluated

Number of patients for whom medical information was analyzed at 100 days after their bone marrow or umbilical cord blood transplant and was voluntarily reported to the Center for International Blood and Marrow Transplant Research® (CIBMTR).

Patient Age

Age of a patient at the time of a bone marrow or umbilical cord blood transplant. These reports provide the age in 10-year intervals.

“Unknown” means the age was not reported.

Patient Sex

A patient’s sex is either male or female, and is based on their genetics and anatomy (which organs their body has). (Not to be confused with gender, which is based on how someone identifies or expresses themselves.)

“Unknown” means the sex was not reported.

Patient Race

Race of a patient.

The U.S. Patient Survival Report

These reports have only two categories:

White, for Caucasian (non-Hispanic).
Non-white, for all other races.

U.S. Transplant Data by Disease Report

The race of the patient is categorized as:

American Indian or Alaska Native
Asian
Black or African American
Native Hawaiian or Other Pacific Islander
White

Survival Probability Estimate

The best estimate of the chance that a person will be alive at a specified time after transplant. This estimate is based on the data reported. View an example.

Date Last Reviewed:

June 2023