Btk is the protein affected in XLA, a disease identified as a B cell differentiation defect. Btk is crucial for B cell differentiation and activation, but its role in other cells is not fully understood. This review focuses on the function of Btk in monocytes, neutrophils, and platelets and the receptors and signaling cascades in such cells with which Btk is associated.

https://jlb.onlinelibrary.wiley.com/doi/pdf/10.1189/jlb.0513307

Bruton's tyrosine kinase--an integral protein of B cell development that also has an essential role in the innate immune system.

To determine the prevalence and clinical characteristics of patients with in Japan, we conducted a nationwide survey of primary immunodeficiency disease (PID) patients for the first time in 30 years. Questionnaires were sent to 1,224 pediatric departments and 1,670 internal medicine departments of Japanese hospitals. A total of 1,240 patients were registered. The estimated number of patients with PID was 2,900 with a prevalence of 2.3 per 100,000 people and homogenous regional distribution in Japan. The male-to-female ratio was 2.3:1 with a median age of 12.8 years. Adolescents or adults constituted 42.8% of the patients. A number of 25 (2.7%) and 78 (8.5%) patients developed malignant disorders and immune-related diseases, respectively, as complications of primary immunodeficiency disease. Close monitoring and appropriate management for these complications in addition to prevention of infectious diseases is important for improving the quality of life of PID patients.

/pdf/nationwide-survey-of-patients-with-primary-immunodeficiency-27fxb508rk.pdf

Nationwide Survey of Patients with Primary Immunodeficiency Diseases in Japan

Lung Disease in Primary Antibody Deficiencies.

X-linked agammaglobulinemia is a primary humoral immunodeficiency characterized by hypogammaglobulinemia and increased susceptibility to infection. Although there is increased awareness of autoimmune and inflammatory complications in X-linked agammaglobulinemia (XLA), the spectrum of gastrointestinal manifestations has not previously been fully explored. We present a case report of a family with two affected patients with XLA. Given the gastrointestinal involvement of the grandfather in this family, we performed a retrospective descriptive analysis of XLA patients with reported diagnoses of GI manifestations and inflammatory bowel disease (IBD) or enteritis registered at the United States Immunodeficiency Network, a national registry of primary immunodeficiencies. In this cohort of patients with XLA, we found that up to 35% had concurrent gastrointestinal manifestations, and 10% had reported diagnoses of IBD or enteritis. The most commonly reported mutations were missense, which have been associated with a less severe XLA phenotype in the literature. The severity of symptoms were wide ranging, and management strategies were diverse and mainly experimental. Patients with XLA may require close monitoring with particular attention for GI manifestations including IBD and infectious enteritis. Further studies are needed to improve diagnosis and management of GI conditions in XLA patients.

/pdf/gastrointestinal-manifestations-in-x-linked-3si569yt26.pdf

Gastrointestinal Manifestations in X-linked Agammaglobulinemia

Clinical characteristics and genetic profiles of 174 patients with X-linked agammaglobulinemia: Report from Shanghai, China (2000-2015).

https://esid.org/content/download/492/2389/file/XLA_MolImm_2009.pdf

Aurica Rugina

Papers

Genetic and demographic features of X-linked agammaglobulinemia in Eastern and Central Europe: A cohort study