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- Tuovinen, EA, et al.
(författare)
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Novel Hemizygous IL2RG p.(Pro58Ser) Mutation Impairs IL-2 Receptor Complex Expression on Lymphocytes Causing X-Linked Combined Immunodeficiency
- 2020
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Ingår i: Journal of clinical immunology. - : Springer Science and Business Media LLC. - 1573-2592 .- 0271-9142. ; 40:3, s. 503-514
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Tidskriftsartikel (refereegranskat)abstract
- Hypomorphic IL2RG mutations may lead to milder phenotypes than X-SCID, named variably as atypical X-SCID or X-CID. We report an 11-year-old boy with a novel c. 172C>T;p.(Pro58Ser) mutation in IL2RG, presenting with atypical X-SCID phenotype. We also review the growing number of hypomorphic IL2RG mutations causing atypical X-SCID. We studied the patient’s clinical phenotype, B, T, NK, and dendritic cell phenotypes, IL2RG and CD25 cell surface expression, and IL-2 target gene expression, STAT tyrosine phosphorylation, PBMC proliferation, and blast formation in response to IL-2 stimulation, as well as protein-protein interactions of the mutated IL2RG by BioID proximity labeling. The patient suffered from recurrent upper and lower respiratory tract infections, bronchiectasis, and reactive arthritis. His total lymphocyte counts have remained normal despite skewed T and B cells subpopulations, with very low numbers of plasmacytoid dendritic cells. Surface expression of IL2RG was reduced on his lymphocytes. This led to impaired STAT tyrosine phosphorylation in response to IL-2 and IL-21, reduced expression of IL-2 target genes in patient CD4+ T cells, and reduced cell proliferation in response to IL-2 stimulation. BioID proximity labeling showed aberrant interactions between mutated IL2RG and ER/Golgi proteins causing mislocalization of the mutated IL2RG to the ER/Golgi interface. In conclusion, IL2RG p.(Pro58Ser) causes X-CID. Failure of IL2RG plasma membrane targeting may lead to atypical X-SCID. We further identified another carrier of this mutation from newborn SCID screening, lost to closer scrutiny.
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| 3. |
- Lawrence, Monica G, et al.
(författare)
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Undetectable Serum IgE Is a Sensitive and Specific Marker of Common Variable Immunodeficiency (CVID)
- 2015
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Ingår i: Journal of Allergy and Clinical Immunology. - : Elsevier. - 0091-6749 .- 1097-6825. ; 135:2, s. AB275-AB275
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Common variable immunodeficiency (CVID) is characterized by antibody deficiency and recurrent infections as well as autoimmunity, lymphoproliferation, and hematologic malignancy. The current diagnostic criteria for CVID include reduction in serum immunoglobulin (Ig)G and either IgA or IgM and failure of antibody production. Serum IgE level is not currently considered in establishing the diagnosis of CVID. Methods: A cohort of 123 subjects from the University of Virginia Health Systems, Medical College of Wisconsin and Mount Sinai School of Medicine were diagnosed with CVID by an experienced immunologist on the basis of currently accepted diagnostic criteria, including clinical history, serum IgG, IgA and IgM, and antibody response to vaccinations. Serum IgE was measured in all of these subjects using the Phadia ImmunoCap system. Serum IgE was also measured in an unbiased control cohort of 963 healthy 17-18 year olds from northern Sweden. Results: The prevalence of undetectable (<2 IU/ml) total serum IgE in our cohort of 123 subjects with CVID was 84.6% and the prevalence of IgE <10 IU/ml was 97.6%. In comparison, IgE <2 IU/ml was found in only 3.8% of controls, in agreement with other published population estimates. Conclusions: The finding of an undetectable (<2 IU/ml) serum IgE has both a high sensitivity of 84.6% and a high specificity of 96.2% for the diagnosis of CVID. Based on this observation, measurement of serum IgE should be included as a part of the routine laboratory work-up for CVID, and an undetectable serum IgE included as a component of the diagnostic criteria.
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