Immunoglobulin (Ig) class switch recombination (CSR) deficiencies are rare primary immunodeficiencies characterized by the lack of switched isotype (IgG/IgA/IgE) production. In some cases, CSR deficiencies can be associated with abnormal somatic hypermutation. Analysis of CSR deficiencies has helped reveal the key functions of CSR-triggering molecules, i.e., CD40L, CD40, and effector molecules ...

Seven patients with gastrointestinal disorders and deficiencies of serum and secretory immunoglobulins were evaluated clinically, microbiologically, and immunologically. Five patients had generalized deficiencies of immunoglobulins; two were selectively deficient. Diarrhoea and malabsorption in six of the seven patients were at least partially explained. Four of the five patients with generaliz...

The primary antibody deficiency syndromes are a rare group of disorders that can present at any age, and for which delay in diagnosis remains common. Replacement therapy with immunoglobulin in primary antibody deficiencies increases life expectancy and reduces the frequency and severity of infection. Higher doses of immunoglobulin are associated with reduced frequency of infection. Late diagnos...

Tansient hypogammaglobulinemia of infancy (THI) is characterized by an abnormal delay in the onset of immunoglobulin synthesis. In the present study, clinical and immunological data and outcome of 30 patients with THI are presented. Between 1995-2001, 464 patients with frequent upper and lower airway infections admitted to the Pediatric Immunology and Allergy outpatient clinic; 30 of them (aged...

What is the test? Immunoglobulins are protein molecules. They contain antibody activity and are produced by the terminal cells of B-cell differentiation known as 'plasma cells'. There are five classes of immunoglobulin (Ig): IgG, IgM, IgA, IgD and IgE. In normal serum, about 80% is IgG, 15% is IgA, 5% is IgM, 0.2% is IgD and a trace is IgE. Quantitative serum immunoglobulin tests are used to de...

The review of non-cystic fibrosis bronchiectasis by Smith elegantly highlights the lack of evidence available in some areas. In particular, approach to immunological testing is varied. Table 2 on page 134 in this review describes the diagnostic features required for immunodeficiency (including immunoglobulin G [IgG] subclass 2 deficiency amongst other IgG subclass deficiencies). However, IgG su...