Diseases of children (pediatrics)

Combined T and B-cell immunodeficiencies

Combined immunodeficiencies are syndromes characterized by the absence or reduction of the number and/or function of T-lymphocytes and severe impairment of other components of adaptive immunity. Even with normal B-cell levels in the peripheral blood, their function is usually suppressed due to the lack of assistance from T-cells.

Hyperimmunoglobulinemia syndrome M

Hyper-IgM syndrome (HIGM) is a group of primary immunodeficiencies characterized by normal or elevated serum immunoglobulin M concentrations and a marked decrease or complete absence of immunoglobulins of other classes (G, A, E). Hyper-IgM syndrome is a rare immunodeficiency, with a population frequency of no more than 1 case per 100,000 newborns.

Hyper-IgM syndrome associated with CD40 deficiency (HIGM3): symptoms, treatment

Autosomal recessive variant associated with CD40 deficiency (HIGM3) is a rare form of hyper-IgM syndrome (HIGM3) with an autosomal recessive type of inheritance, so far described in only 4 patients from 3 unrelated families. The CD40 molecule is a member of the tumor necrosis factor receptor superfamily, constitutively expressed on the surface of B lymphocytes, mononuclear phagocytes, dendritic fibers and activated epithelial cells.

Autosomal recessive hyper IgM syndrome: causes, symptoms, diagnosis, treatment

Following the discovery of the molecular basis of X-linked hyper-IgM syndrome, descriptions of male and female patients with normal CD40L expression, increased susceptibility to bacterial but not opportunistic infections, and, in some families, an autosomal recessive inheritance pattern appeared. In 2000, Revy et al. published the results of a study of such a group of patients with hyper-IgM syndrome, which revealed a mutation in the gene encoding activation-inducible cytidine deaminase (AICDA).

X-linked hyper-IgM syndrome type 1 (HIGM1)

More than 10 years ago, a gene was discovered, mutations in which lead to the development of the HIGM1 form of the disease. In 1993, the results of the work of five independent research groups were published, showing that mutations in the CD40 ligand gene (CD40L) are a molecular defect underlying the Xt-linked form of hyper-IgM syndrome. The gene encoding the protein gp39 (CD154) - CD40L, is localized on the long arm of the X chromosome (Xq26-27). The CD40 ligand is expressed on the surface of activated T-lymphocytes.

Transient infantile hypogammaglobulinemia: symptoms, diagnosis, treatment

Transient infantile hypogammaglobulinemia (TIH) is defined as a significant decrease in IgG levels with or without deficiency of other immunoglobulin classes in a child older than 6 months, provided that other immunodeficiency conditions have been excluded.

IgG subclass deficiency: causes, symptoms, diagnosis, treatment

A condition in which a deficiency of one of the IgG subclasses is determined with a normal or reduced level of total immunoglobulin G is called selective IgG subclass deficiency. A combination of deficiencies of several subclasses is often encountered.

Selective immunoglobulin A deficiency: symptoms, diagnosis, treatment

Among the known immunodeficiency conditions, the most common in the population is selective immunoglobulin A (IgA) deficiency. In Europe, its frequency is 1/400-1/600 people, in Asian and African countries the frequency is somewhat lower.

Common variable immune deficiency: symptoms, diagnosis, treatment

Common variable immune deficiency (CVID) is a heterogeneous group of diseases characterized by a defect in antibody synthesis. The prevalence of CVID varies from 1:25,000 to 1:200,000, with an equal sex ratio.

Agammaglobulinemia in children

Agammaglobulinemia in children is a typical disease that is accompanied by isolated antibody deficiency. This disease manifests itself in frequent recurrent bacterial infections.