(4.3) PRIMARY IMMUNE DEFICIENCIES

A group of disorders characterized by a reduced ability to produce antibodies, making individuals vulnerable to extracellular bacterial infections.

Problems with B-cells, a type of white blood cell, which significantly impact antibody production, making up over 80% of human immunodeficiency diseases.

The most common immunodeficiency, characterized by abnormally low levels of IgA, an antibody type, but normal levels of other antibodies. It can be caused by multiple gene defects and might involve faulty isotype switching.

A disorder where B cells fail to switch to producing other antibody types besides IgM, leading to a high level of IgM but very low levels of IgG, IgA, and IgE.

A severe disorder where B cells cannot mature beyond the pre-B cell stage due to a defective Bruton's tyrosine kinase (BTK) gene.

T-cells are crucial for activating naive and memory B-cells which leads to antibody production.

Problems with phagocytes (cells that engulf and destroy pathogens) increase susceptibility to bacterial infections. These defects affect phagocytic function.

A genetic disorder where phagocytes (cells that fight infection) are unable to kill microbes effectively, leading to recurrent bacterial infections..

A genetic condition where red blood cells are unable to produce sufficient amounts of G6PD, leading to damage and premature destruction. Favism is a symptom.

Genetic defects in complement components increase susceptibility to infections and sometimes autoimmune issues.

A specific complement deficiency causing severe recurrent infections and immune complex-mediated diseases, due to the crucial role of C3 in all complement pathways.

Defects in these pathways result in increased susceptibility to bacterial infection.

Defects in these components do not significantly increase susceptibility to general infections, except for encapsulated bacteria.

Deficiencies cause poor immune complex clearance, raising the risk of type III hypersensitivity diseases and damage to organs (kidneys, joints, etc.).

Result in accumulation of complement complexes, like the Membrane Attack Complex (MAC), on host cell membranes and cell injury.

Genetic disorders affecting the immune system's ability to fight infection. They can be caused by dominant, recessive, or X-linked gene defects and result in recurrent or chronic infections.

A group of genetic disorders characterized by a profound deficiency in both B and T cells, making individuals highly susceptible to infections.

In SCID, defects in genes responsible for DNA rearrangements (e.g., RAG-1, RAG-2) interfere with the creation of variable regions in antibodies and T-cell receptors.

Some SCID cases result from abnormalities in cytokine receptors or cell-to-cell interaction molecules needed for activating immune cells.

A metabolic immunodeficiency disorder that causes SCID. ADA deficiency is mainly caused by mutations in the ADA gene.

In some immunodeficiencies, problems arise with producing, activating, or maintaining normal numbers of B and T cells within the lymphatic system.

Defects in T-cells, either in number or function, can impact the immune response.

A group of genetic disorders where the immune system doesn't function properly due to a defect in one or more genes.

Immunocompromised conditions caused by environmental factors after birth, like infections, treatments, or malnutrition.

A newer term used to describe primary immunodeficiency disorders, highlighting the genetic nature of these conditions.

Frequent or chronic infections that are a common sign of immunodeficiency, often resistant to standard treatments.

Infections caused by unusual or rare pathogens that a healthy immune system usually handles easily.

Antibiotics fail to clear an infection, suggesting an underlying immunodeficiency is present.

Problems with how the immune system develops, usually occurring during fetal development (in utero).

A group of genetic disorders severely impairing both B and T cell function, making individuals highly susceptible to infections.

Defects in genes like RAG-1 and RAG-2, which control DNA rearrangement, lead to faulty antibody and T-cell receptor production.

Some SCID cases are due to problems with cytokine receptors or cell-cell communication proteins, disrupting immune cell activation.

A metabolic immunodeficiency disorder, often causing severe combined immunodeficiency (SCID), due to a deficiency in the enzyme Adenosine Deaminase.

Problems with producing, activating, or maintaining the appropriate numbers of B and T lymphocytes.

Problems with the number or function of T cells, hindering the immune response.

Problems with cells that engulf and destroy pathogens, increasing susceptibility to bacterial infections.

A genetic disorder where phagocytes can't kill microbes effectively, causing recurrent bacterial infections.

A genetic condition affecting red blood cells' ability to produce enough G6PD, leading to damage and premature destruction.

An impaired ability of phagocytes to produce reactive oxygen species, thus failing to kill pathogens.

An enzyme critical for the production of reactive oxygen species, a process required to kill pathogens within phagocytes.

Frequent infections caused by bacteria and fungi, often a sign of an immune system problem.

A group of disorders where T-cells have abnormal numbers or function, impacting the body's ability to fight infections.

A T-cell disorder caused by a defect in TAP (transporter associated with antigen processing), leading to reduced MHC class I expression and impaired CD8 T-cell function.

A group of molecules on all nucleated cells that present processed antigens to CD8 T cells.

A type of T-cell that helps recognize and destroy infected or cancerous cells.

Frequent fungal infections, a symptom potentially indicating a problem with cells that fight fungi.

An immune response that fights fungi and other pathogens