Primary and Acquired Immunodeficiency Syndromes Flashcards

A set of vocabulary flashcards covering primary and acquired immunodeficiency syndromes, including specific genetic etiologies, clinical manifestations, and HIV replication mechanisms.

Inborn errors of immunity

Another name for Primary Immunodeficiency Syndromes (PID) classified by immunologic mechanisms and clinical presentation.

B-cell Deficiency Infection Type

Deficiency in this cell type primarily leads to bacterial infections, accounting for $53\,\%$ of PID disorder distribution.

T-cell Deficiency Infection Type

Deficiency in this cell type primarily leads to viral and fungal infections.

Central Tolerance

The elimination of cells with potential to react strongly with self antigens, occurring in the thymus and initiated during fetal development.

Peripheral Tolerance

The process occurring in the bone marrow and spleen where autoreactive B cells are negatively selected and naive autoreactive cells are removed from peripheral lymphoid tissue.

DiGeorge Syndrome Etiology

A disorder resulting from a heterogeneous mutation in $TBX1$, leading to decreased T cells and a high $CD4:CD8$ ratio.

Severe Combined Immunodeficiency (SCID)

A life-threatening PID resulting from mutations such as $ADA$ deficiency (autosomal recessive) or the X-linked recessive gamma chain of $IL-2$.

Chronic Mucocutaneous Candidiasis (CMC)

A defect in cell-mediated immunity where T cells fail to recognize Candida antigen, often screened using a toll-like receptor (TLR) function assay.

Bruton X-Linked Agammaglobulinemia

A disease-causing variant in the gene for Bruton tyrosine kinase ($BTK$) that arrests B-cell development at the pre-B-cell stage.

Common Variable Immune Deficiency (CVID)

A heterogeneous group of disorders with defective antibody formation characterized by frequent sinopulmonary infections and prevalent intestinal giardiasis.

Hyper IgM Syndrome

A condition with X-linked inheritance ($Xq24-Xq27$) featuring extremely low concentration of $IgG$ and $IgA$ but high concentrations of polyclonal $IgM$.

Selective IgA Deficiency

A deficiency associated with rare alleles and deletions of $MHC$ class III, often making patients susceptible to transfusion reactions due to anti-$IgA$ antibodies.

Hereditary Ataxia-Telangiectasia (ATX)

An autosomal recessive disorder characterized by a defect in DNA repair linked to the Ataxia-telangiectasia mutated ($ATM$) gene and the presence of a butterfly rash.

Wiskott-Aldrich Syndrome (WAS)

An X-linked recessive disorder caused by a defect in $WASp$ expressed in hematopoietic cells, presenting with thrombocytopenia, purpura, and skin eczema.

Retroviridae

The family of viruses to which $HIV$ belongs, specifically a type D retrovirus in the lentivirus subfamily.

gp120

The $HIV$ virion glycoprotein that binds to the T-cell $CD4$ receptor and undergoes a conformational change to bind chemokine receptors like $CCR5$ or $CXCR4$.

gp41

The $HIV$ glycoprotein that contains a fusion peptide which inserts into the T-cell membrane to allow fusion of viral and cell membranes.

Postexposure Prophylaxis (PEP)

Prompt treatment for health care workers exposed to $HIV$ that should begin within $1$ to $2\,\text{hours}$ after exposure to decrease infection risk by more than $80\,\%$.

NRTIs and NNRTIs

Nucleoside reverse transcriptase inhibitors and nonnucleoside reverse transcriptase inhibitors used in combination as drug therapy for $AIDS$.