Immunodeficiency

Immunodeficiency

A state of increased susceptibility to infections due to deficiencies or defects in one or more components of the immune system.

Primary Immunodeficiency (PI)

Immunodeficiency due to intrinsic defects, either congenital or acquired, typically manifesting at an early age, and is non-contagious.

Secondary Immunodeficiency

Immunodeficiency acquired due to underlying diseases or medications, occurring at any age and representing over 90% of cases.

Bruton’s Disease

An X-linked agammaglobulinemia characterized by hypogammaglobulinemia due to mutations in the Bruton tyrosine kinase (BtK), leading to a lack of antibodies.

IgA Deficiency

The most common primary immunodeficiency with serum IgA levels < 0.05 g/L, and 50% of patients experience respiratory tract infections.

Common Variable Immunodeficiency (CVID)

A condition characterized by low serum IgG levels (<5 g/L) with variable IgA and IgM levels, often requiring immunoglobulin replacement.

Severe Combined Immunodeficiency (SCID)

A serious condition caused by defects in lymphocyte lineage affecting both T and B cell functions, often presenting in the first 3 months.

Neutropenia

A condition characterized by low levels of neutrophils, which can be persistent or cyclical.

C1 Esterase Inhibitor Deficiency

A condition causing hereditary angioedema leading to tissue and mucosal swelling, which can be life-threatening if untreated.

Warning Signs of Immunodeficiency

Include 8 or more new ear infections in a year, recurrent pneumonia, persistent thrush after age 1, and family history of primary immunodeficiency.

Diagnosis of Primary Immunodeficiency

Involves quantification of blood cells, tests for T and B cell functions, phagocyte function tests, and complement testing.

Treatment of Primary Immunodeficiency

Includes passive supplementation of deficient components, bone marrow transplantation, and genetic engineering.

HIV Infection and AIDS

HIV specifically infects CD4 receptor-expressing cells, including T helper cells, leading to immune system evasion.

Rules for Managing Immunodeficiency

Important guidelines include early suspicion and diagnosis, avoiding live vaccines in immunocompromised patients, and consulting an immunologist.

Chronic Granulomatous Disease (CGD)

A condition where patients cannot kill phagocytosed bacteria due to failure of respiratory burst.