Newborn screening for kappa-deleting-recombination-excision circles (KRECs) reliably identifies classical X-linked agammaglobulinaemia (XLA) patients with profound B-cell lymphopenia at birth but has not been evaluated in patients with residual BTK function.
After exclusion of acquired immunodeficiency, genetic tests were performed: they detected deletion of exons 8-9-10 of Bruton Tyrosine Kinase gene on X chromosome, leading to the diagnosis of XLA.
X-linked agammaglobulinemia (XLA) is a primary antibody disorder due to a mutation in the Bruton tyrosine kinase gene that requires lifelong immunoglobulin replacement resulting in a significant economic burden and treatment abandonment.
Patients with X-linked agammaglobulinemia due to hereditary Btk deficiency do not show bleeding, but a mild bleeding tendency is observed in high dose therapy of B-cell malignancies with ibrutinib and novel second-generation irreversible Btk inhibitors (acalabrutinib and ONO/GS-4059).
X-linked agammaglobulinemia (XLA) is a primary immunodeficiency disorder caused by germline mutations in the Bruton tyrosine kinase (BTK) gene on X chromosome.
The regulation and activation of Bruton's tyrosine kinase (Btk) is known as a pivotal step of B cell antigen receptor (BCR) signaling in TI humoral immunity, as observed in patients with X-linked agammaglobulinemia (XLA) experiencing a high incidence of encapsulated bacterial infections.
Mutations in BTK, Bruton's tyrosine kinase, lead to X-linked agammaglobulinemia, a disease characterized by recurrent respiratory tract infections, including pneumonia.
A novel Bruton tyrosine kinase gene variation was found in an adult with X-linked agammaglobulinemia during blood cross-matching prior to surgical operation.
TLRs are in close interaction with Bruton's tyrosine kinase which has been found mutated and malfunctioned in the prototype antibody deficiency disease named X-linked agammaglobulinemia (XLA).
BTK was initially shown to be defective in the primary immunodeficiency X-linked agammaglobulinemia (XLA) and is essential both for B cell development and function of mature B cells.
Bruton's tyrosine kinase (BTK) is an intracellular signaling molecule first identified as the molecule affected in X-linked agammaglobulinemia (XLA) patients, who almost completely lack peripheral B cells and serum immunoglobulins.
Here we show that BTK is a critical regulator of NLRP3 inflammasome activation: pharmacologic (using the US Food and Drug Administration-approved inhibitor ibrutinib) and genetic (in patients with XLA and Btk knockout mice) BTK ablation in primary immune cells led to reduced IL-1β processing and secretion in response to nigericin and the Staphylococcus aureus toxin leukocidin AB (LukAB).
In this study, we show that XLA patients had an increased frequency of the intermediate monocytes subset and that BTK-deficient monocytes and PMN had a normal expression of receptors involved in the activation and cellular responses.
This study provides significant finding on the regulation of BTK gene in monocytes and the potential for development of innovative biomarkers and therapeutic monitoring strategies to increase the quality of life in XLA patients.
Owing to its role, Btk has been established as an important therapeutic target for a vast range of disorders related to B-cell development and function, such as the X-linked agammaglobulinemia, various B-cell malignancies, inflammation, and autoimmune diseases.