B cell-intrinsic deficiency of the Wiskott-Aldrich syndrome protein (WASp) causes severe abnormalities of the peripheral B-cell compartment in mice.

Wiskott Aldrich syndrome (WAS) is caused by mutations in the WAS gene that encodes for a protein (WASp) involved in cytoskeleton organization in hematopoietic cells. Several distinctive abnormalities of T, B, and natural killer lymphocytes; dendritic cells; and phagocytes have been found in WASp-deficient patients and mice; however, the in vivo consequence of WASp deficiency within individual blood cell lineages has not been definitively evaluated. By conditional gene deletion we have generated mice with selective deficiency of WASp in the B-cell lineage (B/WcKO mice).

DiGeorge Syndrome: a not so rare disease.

Introduction: The DiGeorge Syndrome was first described in 1968 as a primary immunodeficiency resulting from the abnormal development of the third and fourth pharyngeal pouches during embryonic life. It is characterized by hypocalcemia due to hypoparathyroidism, heart defects, and thymic hypoplasia or aplasia. Its incidence is 1:3000 live births and, despite its high frequency, little is known about its natural history and progression.

Neutropenia in antibody-deficient patients under IVIG replacement therapy.

Patients with antibody deficiencies are more prone to develop acute neutropenic episodes even during immunoglobulin replacement. The aims of this study were to evaluate the presence of acute neutropenia in 42 patients with primary antibody immunodeficiencies, currently receiving intravenous immunoglobulin (IVIG), and to describe the clinical and laboratory findings during neutropenic episodes. Of all patients, 10 (23.

[Evaluation of factors associated with recurrent and/or severe infections in patients with Down's syndrome].

Objective: To evaluate epidemiological, clinical and laboratorial aspects of patients with Down syndrome, who present recurrent and/or severe infections, as well as to evaluate the presence of immunodeficiency in this population.

Methods: Patients with Down syndrome diagnosed by chromosome analysis with recurrent and/or severe infections, followed at the Allergy and Immunology Unit of Children's Institute from 1990 to 1999, were submitted to an epidemiological, clinical and laboratorial protocol, including immunological aspects.

Results: Sex distribution was 1.

Prevalence of Toxocara infection in schoolchildren from the Butantã region, São Paulo, Brazil.

Visceral larva migrans syndrome by Toxocara affects mainly children between 2 and 5 years of age, it is generally asymptomatic, and the seroprevalence varies from 3 to 86% in different countries. A total of 399 schoolchildren from 14 public schools of the Butantã region, São Paulo city, Brazil, were evaluated by Toxocara serology (enzyme-linked immunosorbent assay). Epidemiological data to the Toxocara infection obtained from a protocol were submitted to multiple logistic regression analysis for a risk profile definition.