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Department Translational Hematology and Oncology Research
Primary Location Cleveland Clinic Main Campus
Type of Doctor Adults Only
Languages English, German, Polish, Russian
Surgeon No
Cleveland Clinic Main Campus
Primary Location

Cleveland Clinic Main Campus

Specialties & Treatments

Treatment & Services

  • Bone Marrow Transplantation
  • Cancer Center
  • Chemotherapy
  • Clinical Trials
  • Experimental Therapeutics
  • General Hematology
  • Hematology
  • Medical Oncology
  • Molecular Diagnostics
  • Molecular Therapy
View all 10 Treatment & Services +

Specialty in Diseases & Conditions

  • Acute Lymphocytic Leukemia (ALL)
  • Anemia
  • Aplastic Anemia
  • Autoimmune Neutropenia
  • Benign Hematology
  • Blood Clots
  • Blood Disorders
  • Bone Marrow Failure Disorders
  • Cancer
  • Chronic Anemia
  • Chronic Neutropenia
  • Congenital Amegakaryocytic Thrombocytopenia (CAMT)
  • Congenital dyserythropoietic Anemia
  • Congenital Neutropenia
  • Cytopenia
  • Diamond Blackfan Anemia (DBA)
  • Dyskeratosis Congenita
  • Fanconi Anemia
  • Hematologic Malignancies
  • Large Granular Lymphocytic Leukemia
  • Leukemia
  • Leukopenia
  • LGL
  • Myelodysplasia
  • Myelodysplastic Syndrome (MDS)
  • Paroxysmal Nocturnal Hemoglobinuria
  • PNH
  • Pure Red Cell Aplasia
  • Rare Cancer and Blood Disease Program
  • Shwachman-Diamond Syndrome (SDS)
  • T-Cell Large Granular Lymphocyte Leukemia (LGL)
  • Thrombocytopenia Absent Radii Syndrome (TAR)
View all 32 Specialties +


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About Jaroslaw Maciejewski, MD, PhD

Jaroslaw P. Maciejewski, MD, PhD, FACP, is Staff Physician in the Cleveland Clinic Department of Hematologic Oncology and Blood Disorders and is board certified in hematology and internal medicine. He is also Chairman of the Department of Translational Hematology and Oncology Research at the Taussig Cancer Institute and has an academic rank of Professor of Medicine at the Cleveland Clinic Lerner College of Medicine of Case Western Reserve University. Recognized for his scholarly achievement in biomedical research, Dr. Maciejewski is an elected member of The American Society for Clinical Investigation (ASCI).

His clinical areas of expertise include bone marrow failure syndromes (including aplastic anemia, myelodysplastic syndrome, large granular lymphocyte leukemia, paroxysmal nocturnal hemoglobinuria), and myeloid malignancies. His research deals with the molecular pathogenesis of these disorders and deals with various specific aspects of stem cell biology, genetics, cytogenetics and immunobiology. He has developed multiple whole genome scanning technologies for laboratory and diagnostic use, including SNP-arrays, methylation arrays and viral chips.

Dr. Maciejewski attended medical school at the Medical School Charite, Humboldt University, Berlin, Germany receiving his medical degree and doctorate from the Institute for Medical Immunology at Humboldt University Medical School. He completed his internal medicine residency at the University of Nevada, School of Medicine in Reno, NV and Hematology Fellowship at the National Institutes of Health Medical Center, Bethesda, MD. He also completed his postdoctoral research fellowship at the Hematology Branch of the National Heart, Lung and Blood Institute (NHLBI) in Bethesda, MD where he later served as Staff Scientist before joining Cleveland Clinic in 2001 as Staff Physician and Section Head of Experimental Hematology. In January 2009, Dr. Maciejewski was appointed Chairman of the newly created Department of Translational Hematology and Oncology Research at the Taussig Cancer Institute.

Dr. Maciejewski has a distinguished track record in research relating to the hematology and pathophysiology of hematologic diseases including bone marrow failure syndromes (BMFS). His extensive list of publications (over 150 peer-reviewed journal articles and book chapters) demonstrates his success as an accomplished translational physician-scientist. As Principal Investigator, Dr. Maciejewski has acquired notable grant funding from federal, foundation and industry sponsors since joining Cleveland Clinic in 2001. His most recent achievement is a $1.9 million grant award from the National Institutes of Health’s Transformative R01 program. The Transformative R01 grants are awarded for "exceptionally innovative, high-risk and unconventional research projects that have the potential to create or overturn fundamental paradigms.” This funding will help support Dr. Maciejewski’s research related to whether viruses could be the cause of certain types of bone marrow cancers and other blood disorders. In addition to bench translational research, he leads the Cleveland Clinic Bone Marrow Failure Program that conducts various clinical trials based on investigator-initiated protocols involving the application of targeted immune therapies.

He serves on the Medical Advisory Board of the International Aplastic Anemia and Myelodysplastic Syndrome Foundation, the editorial board of Blood and has also been a reviewer on various study sections for the NIH. He served on the International Scientific Committee at the 10th International Symposium on Myelodysplastic Syndromes held in Patras, Greece in 2009 and was presented with the Celgene Young Investigator Award for Clinical Research in Hematology at the 50th Annual ASH Meeting in San Francisco in 2008. Dr. Maciejewski is also committed to his role as mentor. His K24 Career Development award from the NIH has enabled him to actively continue mentoring medical students, postdoctoral/clinical fellows and junior faculty through his Bone Marrow Failure Training Program for physician-scientists.

Education & Professional Highlights

Education & Professional Highlights


Education & Fellowships

Fellowship - National Heart, Lung and Blood Institute
Bethesda, MD USA

Residency - University of Nevada School of Medicine
Internal Medicine
Reno, NV USA

Medical Education - Humboldt University Berlin, Medical School (Charite)

Medical Education - Humboldt University Berlin, Medical School (Charite)

Professional Highlights

  • Department Chair, Translational Hematology and Oncology Research
  • Member, Medical Advisory Board, Aplastic Anemia and MDS International Foundation
  • Professor of Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University


  • Internal Medicine - Hematology

Specialty Interests

Bone marrow failure syndromes including aplastic anemia, myelodysplastic syndrome, large granular lymphocyte leukemia, paroxysmal nocturnal hemoglobinuria, autoimmune neutropenia, pure red cell aplasia and other refractory anemias, cytopenias, acute lymphocytic leukemia

Awards & Honors

  • American Society of Clinical Investigation
  • America's Best Doctors
  • Fellow in FACP since 7/1/09 from the Ohio Chapter


  • American Society of Clinical Investigation
  • American Medical Association
  • American Society of Hematology
Research & Publications

Research & Publications

See publications for Jaroslaw Maciejewski, MD, PhD.

(Disclaimer: This search is powered by PubMed, a service of the U.S. National Library of Medicine. PubMed is a third-party website with no affiliation with Cleveland Clinic.)

Industry Relationships

Industry Relationships

Cleveland Clinic physicians and scientists may collaborate with the pharmaceutical or medical device industries to help develop medical breakthroughs or provide medical expertise or education. Cleveland Clinic strives to make scientific advances that will benefit patient care and support outside relationships that promise public benefit. In order for the discoveries of Cleveland Clinic physicians' and scientists' laboratories and investigations to benefit the public, these discoveries must be commercialized in partnership with industry. As experts in their fields, Cleveland Clinic physicians and scientists are often sought after by industry to consult, provide expertise and education.

To assure professional and commercial integrity in such matters, Cleveland Clinic maintains a program that reviews these collaborations and, when appropriate, puts measures in place to minimize bias that may result from ties to industry. Cleveland Clinic publicly discloses the names of companies when (i) its physicians/scientists receive $5,000 or more per year (or, in rare cases, equity or stock options) for speaking and consulting, (ii) its physicians/scientists serve as a fiduciary, (iii) its physicians/scientists receive or have the right to receive royalties or (iv) its physicians/ scientists hold any equity interest for the physician's/scientist's role as inventor, discoverer, developer, founder or consultant.* In publicly disclosing this information, Cleveland Clinic tries to provide information as accurately as possible about its physicians' and scientists' connections with industry.

As of 9/23/2021, Dr. Maciejewski has reported the financial relationships with the companies listed below. In general, patients should feel free to contact their doctor about any of the relationships and how the relationships are overseen by Cleveland Clinic. To learn more about Cleveland Clinic's policies on collaborations with industry and innovation management, go to our Integrity in Innovation page.

Consulting and/or Speaking. Dr. Maciejewski receives fees of $5,000 or more per year as a paid consultant, speaker or member of an advisory committee for the following companies:

  • Regeneron Pharmaceuticals, Inc.
  • Celgene Corporation (a wholly-owned subsidiary of Bristol-Myers Squibb)
  • Roche (Hoffman-La Roche, Ltd.)

Public Health Service-Reportable Financial Conflicts of Interest. Cleveland Clinic scientists and physicians engage in basic, translational and clinical research activities, working to solve health problems, enhance patient care and improve quality of life for patients. Interactions with industry are essential to bringing the researchers' discoveries to the public, but can present the potential for conflicts of interest related to their research activities. Click here to view a listing of instances where Cleveland Clinic has identified a Public Health Service (PHS)-Reportable Financial Conflict of Interest and has put measures in place to ensure that, to the extent possible, the design, conduct and reporting of the research is free from bias.

* Cleveland Clinic physicians and scientists subscribe to the guidance presented in the PhRMA Code on Interactions with Healthcare Professionals and the AdvaMed Code of Ethics on Interactions with Health Care Professionals. As such, gifts of substantial value are generally prohibited.

Patient Satisfaction Reviews

80 Patient Satisfaction Reviews

The Patient Satisfaction Rating is an average of all responses to the care provider related questions shown below from our nationally-recognized Press Ganey Patient Satisfaction Survey. Patients that are treated in outpatient or hospital environments may receive different surveys, and the volume of responses will vary by question.

Responses are measured on a scale of 1 to 5 with 5 being the best score.

The comments are submitted by patients and reflect their views and opinions. The comments are not endorsed by and do not necessarily reflect the views of Cleveland Clinic.

Overall Star Ratings
4.9 out of 5
Explains 4.9
Courtesy, Respect & Concern 4.9
Patient Rating of Doctor 4.9

18 Patient Comments

Reviewed on Oct 20, 2021

I always enjoy my discussion with Dr. M

Reviewed on Aug 18, 2021

I put my trust in Dr Macijewski's depth of knowledge with my diagnosis and treatment. He spends time and answers my questions and concerns.

Reviewed on Jul 28, 2021

Honestly Dr. M is one of the funniest characters I've come across In my health journey and my husband and I love hanging out with him as much as we respect his expertise in my care.

Reviewed on May 12, 2021

Dr Maciejewski and Dr Zawit are both very knowledgeable and spent a long time discussing my condition during my visit. Highly recommend Cleveland Clinic and Dr Maciejewski to others.

Reviewed on May 5, 2021

Dr. Maciejewski and his Fellow are easy to work with.

Reviewed on Apr 21, 2021

I learned in the Marine Corps that an organization takes on the character of its leader. I have been Dr. Maciewski's patient for more than 10 years, and that axiom has proven true.

Reviewed on Apr 21, 2021

When I relocated from New York, I was resigned to an early death. Dr. Maciewski put the optimism and energy back into my life.

Reviewed on Apr 21, 2021

I 100% Recommended Dr M to anyone.

Reviewed on Apr 14, 2021

Dr. M always explains things thoroughly, asks how I feel about suggestions he makes, and makes me feel very cared about! i recommend him to others when i can!

Reviewed on Apr 7, 2021

Dr. Maciejewski is an excellent physician He is kind, thorough, and extremely knowledgeable He has saved my life

Reviewed on Mar 3, 2021

Dr. Maciejewski and his fellow, Dr. Zuwet, were the utmost of professional. They were thorough and caring and explained everything very well. We could not have asked for anything more.

Reviewed on Mar 3, 2021

Dr. M and Zuwet are incredible!

Reviewed on Feb 17, 2021

I have a great deal of confidence in Dr. M. He always explain everything, is very pleasant and answers all my questions. Great Doctor

Reviewed on Feb 17, 2021

Dr. Maciejewski and his resident stay in touch weekly to oversee my leukemia care. I feel supported and safe, despite distance.

Reviewed on Feb 17, 2021

As I mentioned, Dr Maciejewski's team is in touch with me weekly in response to labs drawn locally in Austin TX for my LGL leukemia. No local doc is experienced with this and your team makes me feel supported and safe, even with severe neutropenia. I'm grateful for their care.

Reviewed on Nov 11, 2020

I particularly appreciated the concern and attention Dr. Maciejewski paid to the concerns of my children and wife, the clarity with which he explained my condition and possible treatments, and the guidance he provided my children concerning their own genetic testing

Reviewed on Nov 11, 2020

Dr. Zawit, Dr. Maciejewski's fellow, and Carrie, his assistant, have been unfailingly helpful and responsive.

Reviewed on Nov 11, 2020

great experience and very knowledgeable doctor!!!!

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