Combined B and TCell or Primary TCell Deficiencies

Severe Combined Immunodeficiency (SCID) is a group of congenital immune disorders in which both T-cell and B-cell development and function are disrupted. Several gene defects resulting in SCID have been isolated, including IL-

2 receptor 7 chain, Janus kinase 3 (JAK3), adenosine deaminase, and recombinase activating genes (RAG-1 and 2). Because SCID patients have few or no circulating B- and T-cells, they are susceptible to bacterial and opportunistic infections. SCID patients generally present in the first year of life with severe, recurrent bacterial and/or viral infections. Standard treatment is bone marrow transplant or enzyme replacement (in the case of adenosine deaminase deficiency) (IUIS Committee, 1999).

Ataxia telangiectasia (AT) is an autosomal recessive disorder usually presenting between ages 2 and 5 years with ataxia and telangiectasias of the nose, conjunctiva, ears, or shoulders. These patients have T-cell defects secondary to thymic hypoplasia, and IgA deficiency occurs in 50% of patients. A defect in the ATM gene, a protein kinase involved in cell cycle control and DNA repair, is the culprit in this disorder and also leads to the increased risk of malignancy (IUIS Committee, 1999). DiGeorge Syndrome is the result of a congenital defect in migration of the third and fourth branchial arches, leading to thymic hypoplasia and other developmental abnormalities. The severity of the T-cell defect corresponds to degree of thymic aplasia, and those patients with severe T-cell defects are susceptible to opportunistic infections. Wiskott-Aldrich syndrome (WAS) is an X-linked recessive disorder resulting from a defect in the WAS protein, which is involved in intracellular signaling and actin polymerization. Patients usually present with eczema, thrombocytopenia, impaired T-cell function, and recurrent infections.

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How To Deal With Rosacea and Eczema

How To Deal With Rosacea and Eczema

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