Summary Background. Primary immunodeficiencies (PIDs) are inherited disorders in which one or several components of immune system are defected. Moreover, affected patients are at high risk for developing recurrent infections, particularly pulmonary infections. The spectrum of pulmonary manifestations in PIDs is broad, and includes acute and chronic infection, structural abnormalities (eg, bronc...

X-linked agammaglobulinemia (XLA) is an immunodeficiency caused by mutations in the Bruton tyrosine kinase (Btk) gene. In order to identify the mutations in Btk gene in Iranian patients with antibody deficiency, 13 male patients with an XLA phenotype from 11 unrelated families were enrolled as the subjects of investigation for Btk mutation analysis using PCR-SSCP followed by sequencing. Five di...

Immunoglobulin replacement therapy is the essential treatment of B-cell deficiencies. Because of the high expense of therapy, optimal dose, infusion intervals and serum IgG levels should be well defined. Data of 19 X-linked agammaglobulinemia (XLA), 7 hyper-IgM syndrome (HIM) and 20 common variable immunodeficiency (CVID) patients were analyzed. Infection frequencies and hospitalization require...

Bruton's tyrosine kinase (Btk) plays critical roles in B cell development and activation. Mutations of Btk cause X-linked agammaglobulinemia (XLA) in humans and X-linked immunodeficiency in mice. An Src homology domain 2-kinase linker region exists in all Src, Abl, ZAP70/Syk and Btk/Tec non-receptor tyrosine kinase families. Missense mutations in the Btk linker region can cause XLA, supporting ...

X-linked agammaglobulinemia (XLA) is a human immunodeficiency caused by mutations in Bruton tyrosine kinase (Btk) and characterized by an arrest in early B-cell development, near absence of serum immunoglobulin, and recurrent bacterial infections. Using Btk- and Tec-deficient mice (BtkTec(-/-)) as a model for XLA, we determined if Btk gene therapy could correct this disorder. Bone marrow (BM) f...

Defects in the gene for Bruton's tyrosine kinase (Btk) result in the disorder X-linked agammaglobulinemia (XLA). Whereas XLA is characterized by a profound defect in B-cell development, Btk is expressed in both the B lymphocyte and myeloid cell lineages. We evaluated a patient with XLA who had reduced amounts of Btk transcript but no abnormalities in his coding sequence. A single base-pair subs...

Controversy exists in the literature concerning the potentiating effect of heparin on the inactivation rate of factor Xla by antithrombin Ill (AT Ill) in both purified systems and in plasma. We have analyzed the factors that could influence this reaction and found that ionic strength of the medium, as well as the type and concentration of the heparin preparations accounted for the major discrep...

Most polyreactive and antinuclear antibodies are removed from the human antibody repertoire during B cell development. To elucidate how B cell receptor (BCR) signaling may regulate human B cell tolerance, we tested the specificity of recombinant antibodies from single peripheral B cells isolated from patients suffering from X-linked agammaglobulinemia (XLA). These patients carry mutations in th...

The pathogenic role of B cells in rheumatoid arthritis (RA) has recently gained much interest by the marked clinical responses of anti-CD20 therapy in RA. We describe a patient with X-linked agammaglobulinemia (XLA) who presented with an erosive symmetrical polyarthritis with histological features of RA including formation of a destructive pannus. Furthermore, the patient also developed subcuta...