Immunodeficiency 71 with inflammatory disease and congenital thrombocytopeniaD81.9

Immunodeficiency 71 with inflammatory manifestations and congenital thrombocytopenia and combined T- and B-cell immunodeficiency (IMD71) is an autosomal recessive inherited immune disorder characterized by the presence of recurrent bacterial and viral infections and inflammatory manifestations such as vasculitis, bronchial asthma, eczema in infancy or early childhood.

Laboratory findings vary but usually show thrombocytopenia, sometimes with abnormal platelet morphology; elevated serum IgE, IgA, or IgM; leukocytosis; decreased or increased T lymphocytes; and increased eosinophils.

Detailed studies show impaired neutrophil and T-cell chemotaxis and impaired T-cell activation due to defects in polymerization of F-actin.

1. Brigida I et al (2018) T-cell defects in patients with ARPC1B germline mutations account for combined immunodeficiency. Blood 132: 2362-2374.
2. Kahr WH et al. (2017) Loss of the Arp2/3 complex component ARPC1B causes platelet abnormalities and predisposes to inflammatory disease. Nature Commun. 8: 14816
3. Kuijpers TW et al (2017) Combined immunodeficiency with severe inflammation and allergy caused by ARPC1B deficiency. J Allergy Clin Immun 140: 273-277.
4. Thaventhiran JED et al (2020) Whole-genome sequencing of a sporadic primary immunodeficiency cohort. Nature 583: 90-95.