Original Paper

Diagnostic and Subdiagnostic Accumulation of Mast Cells in the Bone Marrow of Patients with Anaphylaxis: Monoclonal Mast Cell Activation Syndrome
Karoline Sonneck^a, Stefan Florian^a, Leonhard Müllauer^b, Friedrich Wimazal^a, Manuela Födinger^c, Wolfgang R. Sperr^a, Peter Valent<sup>a

a</sup>Division of Hematology and Hemostaseology, Department of Internal Medicine I,
^bDepartment of Clinical Pathology and
^cClinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Vienna, Vienna, Austria

Address of Corresponding Author

Int Arch Allergy Immunol 2007;142:158-164 (DOI: 10.1159/000096442)

  Key Words

• Anaphylaxis
• CD2
• CD25
• KIT mutation
• Mastocytosis
• Tryptase

  Abstract

Background: Patients with mastocytosis may suffer from severe hypotension after wasp or bee stings. In these patients, no specific IgE is detectable, but they usually have skin lesions and an elevated serum tryptase level. Methods: We report on 6 patients who were referred to our department because of severe hypotension following bee or wasp stings without cutaneous lesions. Results: In 3 patients, the baseline serum tryptase level was elevated (26, 36, and 67 ng/ml, respectively), and investigation of their bone marrow revealed systemic mastocytosis (SM). In the remaining 3 patients, serum tryptase levels were <20 ng/ml, and bone marrow histology and tryptase immunohistochemistry did not reveal diagnostic mast cell infiltrates. However, in 1 patient, three minor SM criteria were demonstrable leading to the diagnosis SM, and in the 2nd patient, two minor SM criteria, including an aberrant mast cell phenotype, were found. In the 3rd patient, no minor SM criteria were detected. Conclusions: All patients with unexplained hypotension after hymenoptera stings should undergo a thorough investigation for major and minor SM criteria regardless of the tryptase level or presence of skin lesions, in order to diagnose or exclude SM or a related subdiagnostic condition (1 or 2 minor SM criteria) tentatively termed monoclonal mast cell activation syndrome.

Copyright © 2007 S. Karger AG, Basel

  Author Contacts

Correspondence to: Dr. Peter Valent
Division of Hematology and Hemostaseology, Department of Internal Medicine I
Medical University of Vienna, Währinger Gürtel 18-20
AT-1090 Vienna (Austria)
Tel. +43 1 40400 4416, Fax +43 1 402 6930, E-Mail peter.valent@meduniwien.ac.at

  Article Information

Received: May 8, 2006
Accepted after revision: July 27, 2006
Published online: October 20, 2006
Number of Print Pages : 7
Number of Figures : 1, Number of Tables : 2, Number of References : 42