Dermatologic Manifestations of Wiskott-Aldrich Syndrome Workup

Updated: Aug 13, 2019
  • Author: Akimichi Morita, MD, PhD; Chief Editor: Dirk M Elston, MD  more...
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Laboratory Studies

In Wiskott-Aldrich syndrome (WAS), thrombocytopenia is persistent in the range of 1,000-80,000 platelets/µL. The platelets are small and fail to aggregate normally. Their survival is shortened. No antiplatelet antibodies can be detected.

Blood analysis shows Coombs-positive hemolytic anemia, leukocytopenia, lymphopenia, and eosinophilia.

Total serum gammaglobulin levels are usually in the reference range. The immunoglobulin M level is low, but immunoglobulin A, IgE, and immunoglobulin D levels are usually elevated. The immunoglobulin G level is in the reference range in almost all cases. This distinctive immunoglobulin pattern may not be present until the patient is several years of age.

The number of T cells and responses to mitogens in vitro may be normal in early life but often decreases in older age.

Natural killer cell–mediated cytotoxicity is deficient.

CD43 expression on the surface of lymphocytes is low. This finding can be detected by flow cytometry or western blot analysis.

The expression of WAS protein from peripheral blood mononuclear cells by flow cytometry or Western blot analysis help in making the diagnosis prior to mutational analysis. The level of WAS protein correlates with the phenotype of affected patient and the clinical course. [15]

After the above screening methods, the mutational analysis of the WASP gene is important to make a definitive diagnosis.


Other Tests

Delayed hypersensitivity skin testing results, such as Candida and purified protein derivative of tuberculin, are reduced.


Histologic Findings

A lesional skin specimen from a Wiskott-Aldrich syndrome patient shows findings similar to those of atopic dermatitis.