Key Points Primary immunodeficiencies are a group of disorders where the defect lies within the immune system; most of them are caused by single-gene defects. Because of the complexity of diagnosing a primary immunodeficiency, the cooperation of the clinician, the…
Key Points The major histocompatibility complex (MHC) genomic region contains many genes with immune-related functions, including the human leukocyte antigen (HLA) genes. Identification of genes within the MHC has increased the possibility of defining the genetic basis of immunity. The…
Key Points The major histocompatibility complex (MHC) is one of the most diverse and polymorphic genetic systems in humans. It consists of human leukocyte antigen (HLA) class I molecules (HLA-A, -B, and -C) and class II molecules (which include HLA-DRB1,…
Key Points Cytokines are soluble proteins released by cells to facilitate communication and interaction between cells, to modulate the immune response, to direct cell differentiation, and to orchestrate associated inflammatory and reparative activities. Adhesion molecules are complex cell surface glycoproteins…
Key Points The complement system is a group of circulating proteins that promote inflammation and host defense. Unregulated tissue damage is a possible complication of complement activation; a large variety of circulating and membrane-bound proteins exist to regulate complement activity.…
Key Points Five different classes of antibody are known—immunoglobulin (Ig) M, IgG, IgA, IgD, and IgE—each with a distinct heavy chain. Two different light-chain types have been identified: κ and λ. Antigens react with antibodies at the Fab region, which…
KEY POINTS Humoral immune tests assess production of specific antibody responses to past or recent infections, and cellular immune assays measure current immune responses. The immune system changes with age and nutritional status. Differences in immune responses of test subjects…
Key Points Antigens can have a wide variety of types of chemical composition such as proteins, carbohydrates, and lipids. They can range in size from very small molecules, such as hormones, to very large ones on viral or bacterial particles.…
Key Points The immune system consists of cellular and humoral components that defend the body against invading microorganisms. Deficiency of individual factors of the immune system can leave an individual susceptible to different infections. The lymphoid cells of the immune…
Key Points Warfarin has historically been the most commonly used oral anticoagulant. It is a vitamin K antagonist and blocks γ-carboxylation of a series of glutamic acid residues during the synthesis of factors II, VII, IX, and X, and proteins…