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Significant attention has been paid to myelodysplastic syndromes (MDS) and aplastic anemia, but less attention to when they appear together. Amy DeZern, MD of Johns Hopkins Kimmel Cancer Center answers questions about the far rarer incidence of both disease occurring that the same time.

Aplastic Anemia and MDS Overlap Syndrome

How common is one of these diseases coexisting with the other?

This is a complicated topic because the bone marrow failure overlap syndromes are in fluid motion in the diagnostic pathway. Classically, MDS has a hypercellular marrow – too many cells. In contrast, aplastic anemia has a hypocellular marrow, showing a very low number of cells. But there is a subset of MDS called hypocellular MDS. This means there’s a low number cells, but it is still more like MDS than aplastic anemia – and the two diseases are closely linked. What is most often thought of as the defining difference between hypocellular MDS and aplastic anemia would be the presence of chromosomal abnormalities observed when the karyotype of the bone marrow is examined, with MDS being far more likely to have these chromosomal abnormalities. Aplastic anemia has these more rarely.

Are there overlapping symptoms of these two disease that would initially be cause for confusion or misdiagnosis?

Despite the difference I mentioned, the symptoms of both are very similar. Patients with either disease often have low red cells, low white cells, and low platelets. Thus, the confusion could lie in the similar blood counts, but the reason for these low blood counts is different. In aplastic anemiam there are no cells to make new blood, but in MDS,  there are too many bad cells that are not effective in making blood,crowding out the good ones. 

Are cases as a dual diagnosis such as these counted along with the individually diagnosed cases or are they regarded as a separate category?

This is an area of a lot of scientific debate. Usually, they’re more often as classified as MDS if they have the chromosomal abnormality I have mentioned. Aplastic anemia, with a normal karyotype and an empty marrow, is really the only condition that is categorized this way.  Once there has been an evolution – a changing of the chromosomes, this moves away from aplastic anemia to MDS, some call that the overlap syndrome but they are usually treated more as an MDS patient. Hypocellular MDS is often treated initially like aplastic anemia,  with immunosuppressive therapy.

Is treatment each disease any different than when they appear separately?

The first line treatment for an older adult with pure aplastic anemia is immunosuppressive  therapy. In older adults with hypocellular MDS, immunosuppressive therapy could be considered, but would never be considered in MDS where the standard of care should be hypomethylating agents, azacitidine (Vidaza®) and decitabine (Dacogen®), which of course are not used in aplastic anemia.

Should patients who have been diagnosed for one of these diseases be tested for the other?

The testing is same for both. A bone marrow biopsy is performed and chromosomal abnormalities are looked for in both. The observation of dysplasia would be checked for in both diseases.  Measurements of the earliest progenitor cells (or blasts) that are CD34 positive can be helpful to distinguish as well.

Amy E. DeZern, MD, MHS

Position / Title: 
Assistant Professor of Oncology and Medicine
Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins
Primary Disease Area of Focus: 
  • acute myeloid leukemia (AML)
  • aplastic anemia
  • myelodysplastic syndromes (MDS)
  • myeloproliferative neoplasms (MPN)
  • paroxysmal nocturnal hemoglobinuria (PNH)

Dr. Amy DeZern is a hematologist and medical oncologist at the Sidney Kimmel Comprehensive Cancer Center and is an Assistant Professor of Oncology and Medicine at the Johns Hopkins University School of Medicine. She received her medical degree in 2005 from the Johns Hopkins University School of Medicine and her Master in Clinical Investigation (M.H.S.) from the Johns Hopkins Bloomberg School of Public Health. She completed residency training in internal medicine as well as fellowships in medical oncology and hematology at Johns Hopkins.  Dr. DeZern sees patients at the Sidney Kimmel Comprehensive Cancer Center.

Dr. DeZern’s primary clinical and research interests are focused on bone marrow failure disorders.  She has expertise in the diagnosis and treatment of myelodysplastic syndromes (MDS), aplastic anemia - both inherited and acquired, paroxysmal nocturnal hemoglobinuria (PNH), and acute leukemias.  She sees clinic patients weekly with these diagnoses as well as patients in need of bone marrow transplants.  Dr. DeZern greatly enjoys taking care of patients with bone marrow failure and hematologic malignancies and is dedicated to improving the care and outcomes of patients with these conditions.  To that end, she is an active clinical researcher who specializes in clinical studies of diagnostics and maintains a database of samples and clinical information for outcomes research in marrow failure and leukemia. She is the principal investigator of a number of clinical protocols for patients with MDS as well as a unique clinical trial treating patients with severe aplastic anemia using a specialized bone marrow transplant regimen at Johns Hopkins.  Her work has resulted in multiple publications in the scientific literature and presentations at national meetings.  She is also involved with the Aplastic Anemia & MDS International Foundation and serves as one of the six principal investigators for the Edward P. Evans MDS Clinical Research Consortium.

Practice Location: 
Johns Hopkins Sidney Kimmel Comprehensive Cancer Center
401 N. Broadway
Baltimore , MD 21231
Physician Status: 
  • accepting new patients
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