WT - Immunodeficiencies Flashcards
B cell disorders
- X-linked agammaglobulinemia (Bruton’s)
- Selective IgA deficiency
- Common variable immunodeficiency
T cell disorders
- Thymic aplasia (DiGeorge)
- Hyper-IgE syndrome
- Chronic mucocutaneous candidiasis
- IL-12 r. deficiency
B and T cell disorders
- SCID
- Ataxia Telangiectasia
- Hyper-IgM syndrome
- Wiskott-Aldrich Syndrome
Innate immunity disorders (Phagocyte dysfunction)
- Leukocyte adhesion deficiency
- Chediak Higashi Syndrome
- Chronic-Granulomatous DIsease
Regulatory T-cell Disorders
IPEX (immune dysregulation, polyendocrinopathy, enteropathy, X-Linked)
X-linked agammaglobulinemia (Bruton’s)
- B-cell precursors fail to become B cells (via Bruton tyrosine kinase defect)
- light chains not prod
- NO mature B cells –> absent Abs of ALL classes
- underdeveloped germinal centers of lymph nodes (live vaccines contraindicated)
- NO tonsillar tissue
- XLR
sx:
- recurrent rest bac infec (after 6 mo. due to dec maternal Ig)
- loss of opsonic by Abs
- H flu, step pneumonia
classic: recurrent otitis media
tx: IVIG
common variable immunodeficiency
similar to SCID but older pt (ADULTS, 20-45), and females too
- defect B cell maturation
- NORMAL B cell count
- absent plasma cells, Ig
- usu unknown MOA
assoc: inc risk of AI disease, bronchiectasis, pernicious anemia, lymphoma, sinopulmonary infections
selective IgA deficiency
- defective IgA B cells
- usu asymp
- unknown MOA
- MOST COMM PRIMARY IMMUNODEFICIENCY
sx:
- Airway infec, recurrent sinusitis
- otitis media, PNA
- recurrent diarrheal illness from Giardiasis
- Anaphylaxis in blood transfusions (forms IgE against IgA)
- susceptibility to GIARDIASIS
- false + b-hCG
assoc: AI disease (SLA, RA)
dx: low IgaA, nml IgG, IgM
All B cell disorders present with these types of infec
sinopulmonary
GI
thymic dysplasia (DiGeorge syndrome)
- 3rd/4th pharyngeal pouch failure
- 22q11 deletion
DiGeorge triad: loss of thymus, parathyroid glands, congenital heart defects
Velocardiofacial triad: cleft palate, facial/mandible probs, cardiac defects
-recurrent viral infec, fungal/thrush
dx:
- circ B cells=OK, nml CD20
- T cells=REDUCED, dec CD3+
- dec PTH
- hypOCa, tetany
- no thymus shadow
- underdeveloped PARACORTEX in lymph nodes and peri-arteriolar sheath in spleen white pulp
hypER-IgE syndrome
- rare
- STAT3 mut –> Th17 deficiency –> dec IL-17
- impaired neutrophil recruitment to infection sites
- immune sx w/ skin and bone findings
sx:
- derm (eczema)
- cold abscesses (Staph)
- recurrent sinusitis/otitis W/O FEVER
- facial deformities (broad nasal bridge)
- retained primary teeth (2 rows of teeth)
- fractures from minor trauma
dx:
- inc IgE
- inc EOS
- dec IFN-gamma
chronic mucocutaneous candidiasis
-defects in AI regulator genes (AIRE) –> normally responds to candida and also promotes neg selective in thymus
sx:
- recurrent candida infec (thrush/skin/esophagitis)
- T-cell dysfxn (absent in vitro response to candida)
dx:
- dysfx Th1 CKs
- dec IL-2, IFN-gamma
- inc IL-10
NOT due to Ab or B cell dysfxn
assoc: endocrine dysfxn (hypOparathyroidism, adrenal failure)
IL-12 r. deficiency
- dec TH1 response, may present post BCG vaccine
- AR
- most comm cause of mendelian susceptibility to mycobacterial diseases (MSMD)
sx:
-disseminated mycobacterial and fungal infections
dx:
-dec IFN-gamma
SCID
- purely an immune system disorder
- loss of cell mediated + humoral immunity
- usu primary T-cell problem
- loss of B-cells, Abs is secondary
- ANERGY
via
- XLR (IL-2 r mut) * most common
- adenosine deaminase gene deficiency –> inhib ribonucleotide reductase *2nd most comm
- RAG mut (VDJ recomb defect)
sx: INFANTS
- chronic diarrhea, failure to thrive, thrush
- BUBBLE BABIES
dx:
- loss of thymic shadow (but nml Ca/heart)
- loss of germinal centers
- dec T-cell r excision circles (nml DNA found in T cells in thymus) –> measure this bc maternal T cells may cause false nml counts
tx: will DIE unless BMT
ataxia telangiectasia
- defective ATM gene –> defective NHEJ
- AR
triad: ataxia, spider telangiectasia, IgA deficiency (sinus/respiratory infec)
- inc sensitivity to radiation
assoc: inc risk lymphomas
dx:
- inc AFP
- dec IgA, IgG, IgE