Study of Factors Regulating Mast Cell Proliferation

This study will examine growth factors that promote and inhibit mast cell proliferation resulting in mastocytosis, a disease of excessive mast cells in the body. These cells can release chemicals that cause itching, blisters, flushing, bone pain and abdominal pain. Patients up to 80 years of age with mastocytosis may be eligible for this 1-day study. Participants will have one visit at NIH lasting up to 8 hours, during which they will undergo the following tests and procedures: * Medical history and physical examination. * Laboratory studies, if medically indicated. * Blood tests to identify genetic changes important in the growth, development, and functioning of mast cells. * Bone marrow aspiration and biopsy. For the bone marrow procedure, the skin over the hipbone and the outer surface of the bone itself are numbed with local anesthesia. Then, a special needle is inserted into the hipbone and about 1 tablespoon of bone marrow is drawn into a syringe. Another needle is inserted into the same area to collect a small piece of the bone marrow. Additional procedures may include allergen testing, urinalysis, and 24-hour urine collection. Participants will receive an evaluation of their mastocytosis.

Sex

All

Minimum age

1 Day

Maximum age

80 Years

* PATIENT PARTICIPANT INCLUSION CRITERIA:

Participants with mastocytosis zero to 80 years of age may participate in telehealth visits, and two to 80 years of age may participate on-site at NIH Clinical Center

Histologic evidence of increased mast cell number by bone marrow and/or skin biopsy or documentation of mastocytosis in the skin

supported with a photograph of diagnostic skin lesions

Must be under the care of a primary care physician to be enrolled.

Ability to provide informed consent.

PATIENT PARTICIPANT EXCLUSION CRITERIA:

Anemia with hemoglobin \< 8 g/dL, hematocrit \< 24.

Any condition that in the opinion of the investigator contraindicates participation in this study.

RELATIVE INCLUSION CRITERIA:

Two to 80 years of age.

A biological relative without the diagnosis of mastocytosis by skin examination or histologic evidence in a skin or bone marrow biopsy

Participant has a primary medical care provider outside the NIH

Ability to provide informed consent.

RELATIVE EXCLUSION CRITERIA:

Any condition that in the opinion of the investigator contraindicates participation in this study.

• BACKGROUNDCarter MC, Metcalfe DD, Komarow HD. Mastocytosis. Immunol Allergy Clin North Am. 2014 Feb;34(1):181-96. doi: 10.1016/j.iac.2013.09.001. Epub 2013 Oct 7. PMID 24262698
• BACKGROUNDChan EC, Bai Y, Kirshenbaum AS, Fischer ER, Simakova O, Bandara G, Scott LM, Wisch LB, Cantave D, Carter MC, Lewis JC, Noel P, Maric I, Gilfillan AM, Metcalfe DD, Wilson TM. Mastocytosis associated with a rare germline KIT K509I mutation displays a well-differentiated mast cell phenotype. J Allergy Clin Immunol. 2014 Jul;134(1):178-87. doi: 10.1016/j.jaci.2013.12.1090. Epub 2014 Feb 28. PMID 24582309
• BACKGROUNDCruse G, Metcalfe DD, Olivera A. Functional deregulation of KIT: link to mast cell proliferative diseases and other neoplasms. Immunol Allergy Clin North Am. 2014 May;34(2):219-37. doi: 10.1016/j.iac.2014.01.002. Epub 2014 Mar 12. PMID 24745671
• DERIVEDKrausfeldt LE, Cao V, Rodrigues R, Henderson WA, Eisch R, Scott LM, Metcalfe DD, Komarow HD. Evidence for dysbiosis in the gut microbiome of patients with systemic mastocytosis. J Allergy Clin Immunol Glob. 2025 Oct 9;5(1):100578. doi: 10.1016/j.jacig.2025.100578. eCollection 2026 Jan. PMID 41583012
• DERIVEDWilson TM, Maric I, Simakova O, Bai Y, Chan EC, Olivares N, Carter M, Maric D, Robyn J, Metcalfe DD. Clonal analysis of NRAS activating mutations in KIT-D816V systemic mastocytosis. Haematologica. 2011 Mar;96(3):459-63. doi: 10.3324/haematol.2010.031690. Epub 2010 Dec 6. PMID 21134978