Myelodysplastic neoplasms
MDS with increased blasts (MDS-IB)
Also called Myelodysplastic neoplasm with increased blasts
If you or someone you love has just heard this diagnosis, start here. This guide explains what the condition is, how it is usually treated and where a transplant fits.
MDS with increased blasts is a myelodysplastic neoplasm with a raised proportion of immature blood cells. It is often treated as higher-risk MDS, and a donor stem cell transplant may be considered for eligible people.
Other names and abbreviations
MDS-IB, MDS-EB, RAEB (historical), myelodysplastic syndrome, MDS, refractory anemia with excess blasts, MDS with excess blasts, refractory anaemia with excess blasts (historical)
In short
- MDS with increased blasts is a marrow cancer with a raised share of immature cells, called blasts. There are also too few working blood cells.
- Treatment can include azacitidine or decitabine, plus transfusions and infection care. Some people get stronger treatment or join a clinical trial.
- For eligible people, a donor transplant from a relative, registry volunteer or cord blood is often considered. It offers a chance of cure but has serious risks.
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Underlined words open a short explanation. See all terms
Where transplant fits
Allogeneic transplantationComing from another person. In an allogeneic, or donor, transplant, the stem cells come from a relative or an unrelated volunteer whose cells are a close enough match to the patient's. has curative potential and is often considered for eligible people with higher-risk MDSA group of cancers in which the bone marrow does not make enough healthy blood cells and abnormal cells appear in the blood or marrow. Also called myelodysplastic syndromes (MDS). Sometimes they turn into acute myeloid leukemia.. Donor choice and timing depend on the complete disease and health assessment.
Treatment depends on the exact diagnosis, disease stage, prior treatment and the person’s health.
Some patients need a donor who is not a relative.
See if you can joinKey facts
- Who it affects
- MDS mainly affects older adults; increased-blast disease can occur at other ages and needs assessment of the full risk profile.
- How common
- Slightly more than 10,000 people a year are diagnosed with MDS of any type, about 4.4 to 4.6 per 100,000. In an older WHO grouping, MDS with excess blasts made up about 40% of all MDS.United States, all MDS types, as summarized by NCI PDQ (updated September 2024); the 40% share is for the older RAEB category Source: How common
- Cells used in a transplant
- Donated blood-forming cells for allogeneic transplantation. Marrow, peripheral blood or cord blood and donor type are selected for the patient and transplant approach.
- Where a donor fits
- Donor transplant option
The condition
What it is
Myelodysplastic neoplasms, also called myelodysplastic syndromes (MDS), are cancers of blood-forming stem cellsYoung cells that can grow into every type of blood cell: red cells that carry oxygen, white cells that fight infection and platelets that help blood clot. They are found in the bone marrow and the bloodstream.. Abnormal development means the marrowThe soft, spongy tissue in the center of most bones. Red bone marrow holds the blood-forming stem cells that make red blood cells, white blood cells and platelets. does not reliably produce enough working blood cells. MDS can cause serious problems without ever progressing to acute myeloidHaving to do with the bone marrow, or with certain blood-forming cells made there. Also called myelogenous. Acute myeloid leukemia (AML) is a fast-growing cancer that starts in these cells. leukemia (AML).
BlastsYoung blood cells that have not finished developing. In leukemia and some related diseases, abnormal blasts build up in the marrow and blood and leave less room for healthy blood cells. Doctors count blasts to help identify the disease. are immature blood cells. Their proportion helps distinguish MDS subtypes and contributes to relapseWhen a disease comes back after a period of getting better. Relapsed disease has returned after treatment helped for a time. and progression risk. WHO and International Consensus Classification terminology differ around the boundary between MDS and AML; certain genetic findings also affect classification, so a blast percentage is not the only rule.
Marked as affected: blood stem cells, red blood cells, platelets and granulocytes.
- Blood stem cell, Affected, In the bone marrow
- Myeloid line
- Red blood cells, Affected
- Platelets, Affected
- Granulocytes, Affected
- Monocytes
- Lymphoid line
- B cells
- Plasma cells, Develop from B cells
- T cells
- NK cells, Natural killer cells
- Myeloid line
What causes it
MDS usually develops through acquired genetic changes in blood-forming cells, and the underlying cause is often unknown. Age, previous chemotherapy or radiation, smoking and some chemical exposures can increase risk.
Inherited predisposition can contribute in a minority of patients. Personal and family history may prompt genetic evaluation, which can also affect the suitability of related donors. MDS is not contagious.
Symptoms and effects
Anemia can cause fatigue, breathlessness or difficulty with ordinary activities. Low neutrophilsA type of white blood cell that is one of the first to respond to germs such as bacteria. Low neutrophil levels raise the risk of serious infection. increase infection risk, and low plateletsTiny pieces of cells in the blood that help form clots to slow or stop bleeding. They are made in the bone marrow. Too few platelets can cause easy bruising and bleeding. can cause bruising or bleeding. Some people first learn about MDS through a routine blood test.
Blood counts, marrow findings and molecular tests help track the disease. The subtype name and the overall risk score answer different questions: prognosis depends on the combination of genetic findings, blast count and blood-cell shortages, not a single label.
Diagnosis and treatment
How MDS with increased blasts is diagnosed
Diagnosis usually starts with a complete blood count (CBC) that shows low red cells, white cells or platelets. A blood smear checks the size and shape of the cells and looks for immature cells called blasts. Blood tests also check vitamin B12 and folate levels, which are usually normal in MDS.
A bone marrow aspiration and biopsy, from the hipbone or breastbone, is needed to count blasts. Under the WHO's 2022 rules, MDS-IB1 means 5 to 9% blasts in the marrow or 2 to 4% in the blood. MDS-IB2 means 10 to 19% in the marrow, 5 to 19% in the blood, or rod-shaped clumps inside blasts called Auer rods. The biopsy also shows any scarring (fibrosis). When blasts are raised and the marrow is scarred, the WHO calls it MDS with fibrosis (MDS-f).
Chromosome tests (cytogenetics and FISH), flow cytometry and gene sequencing are done on marrow or blood. The results feed into risk scores such as the Molecular International Prognostic Scoring System (IPSS-M), which uses blood counts, chromosome findings and changes in 31 genes. A pathologist typically sends a biopsy report within about 10 days, and some test results may come in separate reports.
How it is treated
Treatment aims to manage low blood counts, reduce the abnormal cell population and address the risk of progression. Azacitidine or decitabine may be used, with transfusionsPutting blood, or parts of blood such as red cells or platelets, into a person's bloodstream through a vein. Some people with blood disorders need regular transfusions., infection treatment and other supportive care. Selected patients receive more intensive therapy or enter clinical trialsA research study that tests how well a new medical approach works in people. Trials can test new ways to screen for, prevent, diagnose or treat a disease..
Allogeneic transplantation is the established treatment with curative potential for MDS. For a person with higher-risk disease who can tolerate it, early assessment is important. Whether to give treatment before transplantA treatment that gives a patient healthy blood-forming stem cells through a vein. The cells travel to the bone marrow and replace faulty marrow or marrow damaged by treatment. They can come from the patient or a donor. depends on blast burden, expected benefit, donor timing and medical fitness.
The decision is individualized because transplantation can also cause serious complications or treatment-related death, and MDS can return afterward. A diagnostic subtype alone cannot establish that the benefits exceed those risks.
Kinds of treatment described for MDS with increased blasts (MDS-IB): supportive care, medicines, a donor stem cell transplant (for some people) and clinical trials (for some people).
After diagnosis, the options described here
Supportive care
Transfusions, infection treatment and other supportive care help with low blood counts.
Medicines
Azacitidine or decitabine may be used, and some people get more intensive therapy.
Donor stem cell transplant, For some people
For eligible people, a donor transplant offers a chance of cure, but it has serious risks.
What a transplant involvesClinical trials, For some people
Some people join a clinical trial.
These are the kinds of treatment this page describes, not a plan. Which ones fit, in what order and whether they are combined differs from person to person.
When transplant specialists are usually consulted
NMDP and ASTCT guidance recommends high-resolution HLA typingA lab test that finds a person's tissue type (HLA markers). It starts with a blood draw or a cheek swab. Doctors compare a patient's results with those of relatives, registry donors and cord blood units. at diagnosis for anyone with MDS and an intermediate or high IPSS or IPSS-R score, or a moderate, high or very high IPSS-M score. Early typing lets testing of relatives and a donor search start sooner.
Read the guidanceWhat a transplant involves
- Step 1
: Finding a donor
Relatives are tested first to see whether their tissue type (HLA) matches. If none match, the team searches donor registries and cord blood banks.
- Step 2
: Conditioning
Chemotherapy, sometimes with radiation, prepares the body for the new cells.
- Step 3
: Transplant day, Day 0
The donor’s cells are given through a vein, like a transfusion.
- Step 4
: Engraftment
The new cells settle in the marrow and start making blood cells, usually within weeks.
- Step 5
: Recovery
The immune system rebuilds over months. The team watches for infection, graft-versus-host disease (donor immune cells attacking the body) and relapse.
Daily life and the donor’s role
Living with the condition and treatment
Repeated blood tests, clinic visits and sometimes marrow samples are part of care. Some people need regular transfusions or medicines to support blood production. The practical burden depends on the degree of anemia, infection risk, treatment schedule and other health conditions.
If transplant is considered, discussions include the chance of disease control, treatment-related risks, recovery support and personal goals. A donor search can take place while these decisions and other treatment continue.
The role of a blood stem cell donor
An unrelated donor can be an important source of cells for a person with MDS who is proceeding to allogeneic transplantation. Autologous transplantationComing from the patient's own body. In an autologous transplant, the patient's own stem cells are collected and stored, then given back after high-dose treatment. It does not use a donor. is not a standard way to treat the abnormal marrow clone.
When allogeneic transplantation is selected, the graftThe blood-forming stem cells given to a patient in a transplant. In a donor transplant, the graft comes from the donor's bone marrow or blood, or from donated cord blood. comes from another person. A matched relative, unrelated registry donor or an appropriate alternative donor may be suitable. HLA compatibilityMarkers on most cells that make up a person's tissue type. Doctors test a patient's and donor's HLA to see how well they match. The more markers they share, the better the chance the body accepts the donor's cells., donor age and availability, patient health and the transplant approach all matter; no donor category is best for every person.
Highlighted here: a relative, an unrelated volunteer and donated cord blood.
The person’s own cells
Autologous transplant, no donor
Collected from the person before treatment, then given back.
A relative
Donor transplant (allogeneic)
A brother or sister may be a full match. Parents and children can be half-matched donors.
An unrelated volunteer
Donor transplant (allogeneic)
Found through a donor registry.
Donated cord blood
Donor transplant (allogeneic)
Collected from a baby’s umbilical cord after birth and stored in a public bank.
Some patients rely on a volunteer donor they have never met. Joining your country’s registry could make you that person for someone.
Join the registryFinding a donor and the outlook
How a donor is found
When a transplant from a donor is planned, the team usually tests brothers and sisters first. Each full sibling has about a one in four chance of being a full match.
Most patients do not have a matched relative. In the words of NMDP, the U.S. registry, “75% of patients don’t have a fully matched donor in their own family.” The team then searches registries of volunteer donors around the world and banks of donated cord blood. In some transplants, a half-matched parent, child or sibling can also be the donor.
8 of 8
All eight markers match. Doctors call this a full match.
8 of 8: the donor matches the patient at all eight markers, two each for HLA-A, HLA-B, HLA-C and HLA-DRB1.
7 of 8
One marker differs. Some transplants use a donor like this.
7 of 8: the donor matches at seven of the eight markers. One HLA-C marker differs.
Half-matched
One set, inherited together from one parent, matches. The rest may or may not.
Half-matched: the donor matches the four markers the patient inherited from one parent. The other four may or may not match.
- Matches
- Differs
- May or may not match
- Top row: from one parent. Bottom row: from the other.
- DR means HLA-DRB1
Doctors can look at up to 12 HLA markers, and usually aim to match 8 to 10 of them. This drawing shows the 8 that transplant guidelines count, and it reads each one as simply matching or not.
Matching depends on inherited tissue markers called HLA, so a patient is most likely to match someone who shares their ancestry. Every person who joins makes the search a little more likely to succeed, especially for patients from groups that are underrepresented on registries.
Looking ahead
Outlook for MDS with increased blasts
Outlook depends on more than the blast count. Care teams combine blasts with blood counts, chromosome results and gene changes, using scores such as the IPSS-M. General health also shapes which treatments, including transplant, are possible. On average, MDS-IB2 is more serious than MDS-IB1.
Timing matters. A donor transplant is the only treatment that can cure MDS. In a U.S. trial of people aged 50 to 75 with higher-risk MDS, those who had a matched donor found within 90 days were more likely to be alive 3 years later than those without one. When azacitidine or decitabine stop working, survival is often short: the National Cancer Institute cites a median of only 4 to 6 months from older studies.
These are group figures, and many people in them were diagnosed years ago. They cannot predict one person's course. Half of the people in each group lived longer than the median, and a transplant cures some people.
About these numbers. Each one says which group of people it comes from, and the place and years where the source gives them. It describes what happened across that group, not what will happen to any one person. And a figure measured among people who had a transplant is not the same as the number of people who need one.
- 27 months (MDS-IB1); 19 months (MDS-IB2)Median survival from diagnosis
213 people with MDS-IB1 and 279 with MDS-IB2 in the Düsseldorf MDS registries, Germany, diagnosed 1969 to 2023 (85% before 2020), all treatments combined; published 2026
Read the source: Median survival from diagnosis - 48% when a matched donor was found vs 27% when none was foundAlive 3 years after joining the trial
384 people aged 50 to 75 with higher-risk de novo MDS (IPSS intermediate-2 or high) at 34 U.S. centers, enrolled 2014 to 2018 (BMT CTN 1102); not limited to MDS-IB; published 2021
Read the source: Alive 3 years after joining the trial
Median means half the group lived longer and half lived less long.
Common questions
What does "increased blasts" mean in MDS?
Blasts are immature blood cells. In MDS with increased blasts, they make up a raised share of cells: under the WHO's 2022 definitions, 5% to 19% in the bone marrow or 2% to 19% in the blood. The blast share helps doctors tell MDS subtypes apart and is one factor in the risk of progression to acute myeloid leukemia. Genetic findings and the severity of low blood counts also shape the outlook.
Is MDS with increased blasts the same as MDS with excess blasts?
Mostly, yes. MDS with increased blasts is the name used in the WHO's 2022 classification. Reports may instead say MDS with excess blasts (MDS-EB), the term used by the International Consensus Classification, or refractory anemia with excess blasts (RAEB), an older name. Near the line with acute myeloid leukemia, the two systems differ: the ICC calls 10% to 19% blasts MDS/AML.
Can MDS with increased blasts turn into leukemia?
It can, but not always. MDS is already a cancer of blood-forming cells, and it can cause serious problems without ever becoming acute myeloid leukemia (AML). A raised share of blasts adds to the risk of progression. The line between MDS and AML depends partly on which classification system is used and on certain genetic findings, not only on the blast percentage.
Is MDS with increased blasts curable?
Sometimes. A donor stem cell transplant, called an allogeneic transplant, is the only treatment that can potentially cure MDS. It is often considered for eligible people with higher-risk MDS, a group that often includes this subtype. But a transplant can cause serious problems, including death from treatment, and MDS can come back afterward. Whether the benefits outweigh the risks is decided person by person.
Does MDS with increased blasts always need a bone marrow transplant?
No. Treatment aims to manage low blood counts, reduce the abnormal cells and lower the risk of progression. Medicines such as azacitidine or decitabine may be used, along with transfusions and treatment for infections, and some people join clinical trials. For eligible people with higher-risk disease, European transplant guidance supports moving to transplant without long delay; these medicines are often used to control MDS while a donor is arranged.
Can a brother or sister be the donor?
Yes, a matched brother, sister or other relative may be suitable. So may an unrelated volunteer from a registry, or another type of donor the team thinks is right. Tissue match (HLA), donor age and availability, and the patient's health all matter. No donor type is best for everyone. If an inherited risk is suspected, genetic testing can also affect whether a relative can donate.
For your next appointment
MDS with increased blasts (MDS-IB)
From the Jada Bascom Foundation disease library, jadabascomfoundation.org. Printed .
Questions to bring to your care team
- Is it MDS-IB1 or MDS-IB2, and what is my IPSS-M risk group once the gene results are in?
- Has a preliminary search for an unrelated donor started, and how long might it take?
- Would you give azacitidine or decitabine before transplant, or go straight to transplant?
- If I have Medicare, how does its March 2024 coverage change for transplant in MDS apply to me?
- What is the goal of each treatment you are suggesting?
- Is a transplant being considered? Why now, or why not yet?
- Should brothers and sisters have HLA typing, and when does a donor search start?
- What happens if a fully matched donor is not found?
- Where can our family find support during treatment?
A one-page list to take to the next appointment, with room for notes.
Supporting someone with a diagnosisSupport for patients and families
These independent organizations offer information and support. JBF is not affiliated with them.
- MDS Foundation A global nonprofit offering MDS education, patient guides, patient forums and ways to connect with experts and other patients.Worldwide
- Aplastic Anemia and MDS International Foundation (AAMDSIF) Offers patient guides, a helpline, virtual support groups and a peer support network for people with MDS and related bone marrow diseases.United States
- MDS UK Patient Support Group A UK charity offering free membership, trusted information, online support meetings and one-to-one help for people with MDS or CMML and carers.United Kingdom
Sources and further reading
- Myelodysplastic Syndromes Treatment (PDQ), Health Professional Version
NCI, Accessed 2026-09-05 - Myelodysplastic Neoplasms/Syndromes (MDS)
EBMT Handbook / NCBI Bookshelf, Accessed 2026-09-05 - WHO fifth-edition classification: Myeloid and Histiocytic/Dendritic Neoplasms
WHO classification authors / Leukemia, Accessed 2026-09-05 - Indications for haematopoietic cell transplantation and CAR-T: 2025 EBMT practice recommendations
EBMT / Bone Marrow Transplantation, Accessed 2026-09-05 - Stem Cell and Bone Marrow Transplants for Cancer
NCI, Accessed 2026-09-05 - Donor and cord blood unit selection guidelines
NMDP / CIBMTR, Accessed 2026-09-05 - Join the registry
NMDP, Accessed 2026-09-24 - On modeling human leukocyte antigen-identical sibling match probability for allogeneic hematopoietic cell transplantation
Biology of Blood and Marrow Transplantation, March 2016 - Allogeneic Hematopoietic Cell Donor Selection: Contemporary Guidelines from the NMDP/CIBMTR
NMDP / CIBMTR, Transplantation and Cellular Therapy, 2025 - What is HLA? HLA basics, typing and matching
NMDP, Accessed 2026-09-26 - Matching with a patient
NMDP, Accessed 2026-09-26 - Myelodysplastic Syndromes Treatment (PDQ)–Patient Version
National Cancer Institute, Updated 2024-10-04; accessed 2026-09-24 - International Consensus Classification of Myeloid Neoplasms and Acute Leukemias: integrating morphologic, clinical, and genomic data
Blood (Arber DA, et al.), 2022; accessed 2026-09-24 - Germline predisposition traits in allogeneic hematopoietic stem-cell transplantation for myelodysplastic syndromes: a survey-based study and position paper
Lancet Haematology (Gurnari C, et al.; EBMT Chronic Malignancies Working Party), 2023; accessed 2026-09-24 - Molecular International Prognostic Scoring System for Myelodysplastic Syndromes
NEJM Evidence (Bernard E, et al.), 2022; accessed 2026-09-26 - Pathology Reports (fact sheet)
National Cancer Institute, 2022-08-08; accessed 2026-09-26 - Comparison of time to therapy initiation, therapeutic strategies and survival in patients with MDS IB1, IB2 and AML-MR using data of the duesseldorf registries
Annals of Hematology (Schulz F, et al.), 2026; accessed 2026-09-26 - Biologic Assignment Trial of Reduced-Intensity Hematopoietic Cell Transplantation Based on Donor Availability in Patients 50-75 Years of Age With Advanced Myelodysplastic Syndrome
Journal of Clinical Oncology (Nakamura R, et al.; BMT CTN 1102), 2021; accessed 2026-09-26 - Myelodysplastic syndromes (MDS): HCT consultation timing guidelines
NMDP, Accessed 2026-09-26
This information explains a condition and its treatments. It cannot diagnose an illness or recommend treatment for an individual. Your care team can explain how the evidence applies to you. Written and source-checked by the Jada Bascom Foundation. Each page lists the published sources it draws on.
Ways to help
Someone may be waiting for a match.
Some people with MDS with increased blasts (MDS-IB) are treated with a transplant from a donor. When no relative matches, that donor is often a stranger who joined a registry.
Join the registry
JBF points you to the official registry that serves your country. It explains who can join and what donation involves.
Help someone you love find a donor
If someone you love needs a donor, our family guide explains practical ways to help. A registration drive can add many potential donors at once, for them and for others.
Support this work
Gifts to the Jada Bascom Foundation support donor-awareness education like this page, community outreach, drive planning and referrals to official registries.
More in the library
Keep learning
Interactive storyWhy matching is hard: leukemiaHow leukemia affects blood production, when a donor transplant may help, and how inherited HLA markers shape the search for a suitable donor.Begin the storyPart of 2 diagnosis guides, each explaining how its subtypes fit together: Myelodysplastic syndromes (MDS) and Types of blood cancer.
