X-linked agammaglobulinemia (XLA) has been described as a disorder in which pre-B cells fail to differentiate into B cells. However, a small number of B cells have been seen occasionally in patients with this disorder. Because the phenotype of these cells might be helpful in defining the site of the defect in XLA, immunofluorescent staining techniques were used to characterize the B cells that ...

X-linked agammaglobulinemia (XLA) is a primary immunodeficiency disorder caused by germline mutations of B-cell tyrosine kinase (BTK) gene. It is characterized by decreased serum immunoglobulins levels and circulating mature B cells. This defect in humoral immunity leads to increased susceptibility to infection. Pyoderma gangrenosum (PG) is an uncommon, ulcerating, neutrophilic dermatosis. Here...

We describe a 35-year-old man with X-linked agammaglobulinemia who had refractory chronic pleurisy caused by a Helicobacter equorum-like bacterium. Broad-range bacterial PCR targeting the 16S and 23S rRNA genes and in situ hybridization targeting the 16S rRNA gene of H. equorum confirmed the presence of this pathogen in a human for the first time.

A boy with X-linked agammaglobulinemia experienced progressive global motor decline, cerebellar syndrome, and epilepsy. All standard polymerase chain reactions for neurotropic viruses were negative on cerebrospinal fluid and brain biopsy. Next-generation sequencing allowed fast identification of a new astrovirus strain (HAstV-VA1/HMO-C-PA), which led to tailor the patient's treatment, with enco...

Encephalitis is a major cause of death worldwide. Although >100 pathogens have been identified as causative agents, the pathogen is not determined for up to 75% of cases. This diagnostic failure impedes effective treatment and underscores the need for better tools and new approaches for detecting novel pathogens or determining new manifestations of known pathogens. Although astroviruses are com...

Introduction. X-linked agammaglobulinemia (XLA) is a primary immunodeficiency characterized by agammaglobulinemia requiring replacement treatment with immunoglobulin. The association of XLA and membranoproliferative glomerulonephritis (MPGN) is unexpected and, to our knowledge, only one case was previously published. Case Report. The authors report the case of a 10-year-old boy with family hist...

We describe the case of an eight-year-old boy with X-linked agammaglobulinemia who developed mild varicella despite regular intravenous immunoglobulin (IVIG) therapy. He maintained protective antibody levels against varicella and the previous batches of IVIG that he received had adequate varicella-specific IgG levels. The case illustrates that IVIG may not prevent VZV infection.

A plaque assay that detects human mononuclear blood cells producing immunoglobulin (Ig)M antibody to sheep erythrocytes was investigated for its usefulness in studying B-cell activation and regulation in 24 patients with humoral immunodeficiency. Cells from 3 of 15 patients with common variable agammaglobulinemia produced some plaques (range 40--160/10(6) cells; normal range 80--1240/10(6)), bu...

The human X chromosome is the favorite chromosome of many geneticists because of its peculiar inheritance pattern and unique biology. The peculiar inheritance pattern stems from its hemizygosity in males and gives rise to a disproportionately high number of Mendelian diseases associated with a human chromosome. As high as 70% of the genes with a known function on the X are associated with disea...

The most common of the primary immunodeficiency diseases are those that involve inadequate antibody production. The characteristic presentation of these disorders is recurrent sinopulmonary infections. An arrest in B cell development at the pre-B cell stage leads to agammaglobulinemia and an insignificant number of B cells. X-linked agammaglobulinemia is the most common of these developmental a...