Immunoproliferative and Immunodeficiency Diseases

Vocabulary flashcards covering immunoproliferative diseases, primary immunodeficiencies (B-cell, T-cell, and combined), and diagnostic screening tests.

Immunodeficiency

A dysfunction in body defense that causes a failure to detect foreign antigens and produce antibodies against these foreign (non-self) substances.

Immunoproliferative diseases

Malignancies of the immune system that involve cell lymphoid lineage.

Polyclonal Hypergammaglobulinemia

Elevation of several classes of immunoglobulins to several specific antigens, resulting in a broad spike in the gamma region on serum protein electrophoresis.

Monoclonal Hypergammaglobulinemia

A malignant transformation of a clone of $B$ cells that produce identical antibodies, causing a narrow peak in serum protein electrophoresis.

Multiple Myeloma (Kahler disease)

A lymphoproliferative disease where plasma cells produce high concentrations of $IgG$, $IgA$, and light chains, with monoclonal light chains excreted in urine as Bence Jones proteins.

Bence Jones proteins

Monoclonal light chain fragments found in the blood and excreted in the urine of patients with Multiple Myeloma.

Waldenstrom macroglobulinemia

A condition characterized by infiltration of lymphoplasmatic cells into the bone marrow and proliferation of a clone of $B$ cells that synthesize homogenous $IgM$.

Heavy-chain disease (Franklin disease)

A disorder characterized by the presence of monoclonal proteins composed of the heavy-chain portion of the immunoglobulin molecule.

Primary Amyloidosis

A monoclonal plasma cell disorder where insoluble proteins are deposited in tissues (skin, liver, heart, etc.), resulting in progressive loss of organ function.

Chronic Granulomatous Disease (CGD)

A defect in the $NADPH$ oxidase system that causes neutrophils to fail in producing reactive oxygen intermediates.

Myeloperoxidase Deficiency

An autosomal recessive trait on chromosome $17$ that results in a mild to moderate defect in bacterial killing and a marked defect in fungal killing.

Chediak-Higashi Syndrome

A rare familial disorder inherited as an autosomal recessive trait expressed as abnormal granulation (giant granules) of neutrophils with impaired chemotaxis.

Leukocyte Adhesion Deficiency (LAD)

A defect in the $CD18$ protein, a component of adhesion receptors, leading to abnormal adhesion, motility, and chemotaxis of leukocytes.

Specific Granule Deficiency

A failure to synthesize specific granules and some contents of other granules during the differentiation of neutrophils in the bone marrow.

Transient Hypogammaglobulinemia

A condition presenting at $2-6$ months of life characterized by slow development of $T$ helper function and deficiency in all immunoglobulins, especially $IgG$.

Bruton's X-linked Agammaglobulinemia

A block in the maturation of pre-$B$ cells into lymphocytes due to a deficiency of Bruton tyrosine kinase ($Btk$), leading to absent or reduced antibody isotypes.

Selective IgA deficiency

The most common congenital immunodeficiency, characterized by an arrest in $B$ cell development leading to small amounts or absence of serum and secretory $IgA$.

Common Variable Immunodeficiency

The most common primary immunodeficiency with a severe clinical syndrome, typically presenting as hypogammaglobulinemia of both $IgG$ and $IgA$.

Hyper-IgM Syndrome

An X-linked genetic disease caused by a defect in the $CD40$ ligand on $T$ helper cells, resulting in increased $IgM$ and markedly decreased $IgG$ and $IgA$.

DiGeorge syndrome (Congenital thymic hypoplasia)

A developmental abnormality of the third and fourth pharyngeal pouches that affects thymic development and leads to insufficient mature $T$ cells.

Purine nucleoside phosphorylase deficiency

A defect in purine metabolism leading to the accumulation of the toxic metabolite deoxyguanosine triphosphate, which decreases $T$ cell numbers.

Chronic mucocutaneous candidiasis

A condition where $T$ cells fail to produce macrophage migration inhibiting factor ($MIF$) in response to Candida antigen.

Bare lymphocyte syndrome (T-cell expression)

A deficiency in the expression of $MHC$ class $II$ on the $T$-cell surface.

Severe Combined Immune Deficiency (SCID)

A group of serious congenital immunodeficiencies (e.g., Adenosine deaminase deficiency) affecting both $T$ and $B$ cell function and purine metabolism.

Wiskott-Aldrich Syndrome

A mutation in the gene coding for $WASP$, a protein for cytoskeletal reorganization, preventing $T$ helper cells from delivering lymphokines to target cells.

Ataxia-telangiectasia

A combined deficiency where levels of $IgG2$, $IgA$, and $IgE$ are often low/absent, and the number of circulating $T$ cells is often decreased.

Nezelof Syndrome

A combined deficiency characterized by deficient $B$ and $T$ cells, abnormal thymus morphology, and paracortical lymphocyte depletion in peripheral lymphoid tissues.

Nitro-blue tetrazolium (NBT) test

A screening test used to detect phagocytic defects.

Hemolytic titration assay (CH50)

A screening test used to evaluate the classical complement pathway.