Imm 9 - Immunodeficiencies Flashcards
What are two B cell deficiencies?
Bruton agammaglobulinemia. Selective immunoglobulin deficiencies.
What are 4 T cell deficiencies?
Thymic aplaisa (DiGeorge syndrome). Chronic mucocutaneous candidiasis. Hyper IgM syndrome. IL-12 receptor deficiency.
What are three combined B and T cell deficiencies?
Severe combined immunodeficiency. Wiskott-Aldrich syndrome. Ataxia-telangiectasia.
What are 4 phagocyte disorders?
Chronic granulomatous disease. Chediak-Higashi disease. Hyperimmunoglobulin E (Job Syndrome). Leukocyte adhesion deficiency syndrome.
What is Bruton agammaglobulinemia?
X-linked (Boys) disorder causing B cell deficiency caused by defective tyrosine kinase gene that causes low levels of all immunoglobulins. This results in recurrent bacterial infections after 6 months of age.
What is the most common immunoglobulin deficiency?
Selective IgA deficiency.
What is Selective IgA deficiency?
Appear healthy but causes lots of sinus and lung infections (1/600 European descent). Associated w/ atopy, asthma. Possible anaphylaxis to blood transfusions and blood products.
What is Thymic aplasia (DiGeorge)?
The third and fourth pouches fail to develop, causing no thymus (leading to no mature T cells), and no parathyroids (causing tetany from low Ca2+). Associated w/ congenital defects in heart/great vessels. Predisposed to recurrent viral, fungal, protozoal infections. 90% have a chromosome 22q11 deletion (detect w/ FISH).
What PE can be done to check for hypocalcemia?
Chvostek sign: Tapping patient’s cheek will cause facial muscle spasm. Trousseau sign: Tighten BP cuff on arm and will cause carpopedal spasm.
What is mucocutaneous candidiasis?
T cell dysfunction vs C.albicans. Tx is ketoconazole.
What is Hyper-IgM syndrome?
Lots of IgM but decrease in all other immunoglobulins. There are 3 ways that can be inherited: X-linked (no CD40 ligand on T cell), AR (B cells do not have CD40), NEMO deficiency.
What does IL-12 receptor deficiency lead to?
Increased mycobaterial infections.
What is Severe Combined Immunodeficiency (SCID)?
Defect in early stem cell differentiation causing B and T cell deficiency. Can be caused by at least 7 different gene defects (Adenosine deaminase deficiency is the most important). This leaves NK cells as last defense. No thymic shadow on newborn CXR.
What is the triad of Severe Combined Immunodeficiency (SCID)?
Triad of Severe infection, chronic diarrhea, and Failure to thrive. The severe infection portion includes chronic mucocutaneous candidiasis, fatal or recurrent RSV, VZV, HSV, measles, flu, parainfluenza, and Pneumocystis jirovecii pneumonia (PCP).
What 2 disease would not be able to see thymic shadow on newborn CXR?
Severe combined immunodeficiency (SCID). DiGeorge.
What is Wiskott-Aldrich syndrome?
An X-linked disease that causes B and T cell immunodeficiencies. There is no IgM vs capsular polysaccharides of bacteria, causing low IgM and high IgA.
What are the symptoms of Wiskott-Aldrich syndrome?
[WAITER] Wiskot, Aldrich, Immunodeficiency, Thrombocytopenia and purpura, Eczema (on the trunk), Recurrent pyogenic infections.
What are the X-linked immunodeficiencies?
[WACH] Wiskott-aldrich. brunton Agammaglobulinemia. (+/-) Chronic granulomatous disease. (+/-) Hyper-IgM syndrome.
What is Ataxia-Telangiectasia?
A combined immunodeficiency, there is IgA deficiency and low levels of T cells. Causes radiation sensitivity (try to avoid x-rays) due to defective DNA repair. (+/-) increased AFP in children above 8 months. Average age of death is 25 y.o.
What are the symptoms of Ataxia-Telangiectasia?
Cerebellar ataxia and poor smooth pursuit of moving target w/ eyes. Telangiectasias of face in children above 5 y.o. Increased risk of lymphomas and leukemias.
What is Chronic Granulomatous disease (GCD)?
A phagocyte disorder, the lack of NADPH oxidase activity causing impotent phagocytes. Patients are susceptible to organisms w/ catalase (S.aureus, E.coli, Klebsiella spp., Asperillus spp., Candida spp.)
How do we diagnose Chronic Granulomatous Disease?
A negative nitroblue tetrazolium (NBT) dye (No yellow to blue-black oxidation): NBT is added to sample of patients blood, where normally the phagocytes ingest the dye and the oxygen free radicals will oxidize it from yellow to blue-black color.
What is the treatment for Chronic Granulomatous disease?
Prophylactic TMP-SMX. IFN-gamma is also helpful.
What is Chediak-Higashi disease?
A phagocyte disorder, it is caused by defective LYST gene (lysosomal transport gene, important in getting enzymes into the lysosomes), causing defective phagocyte lysosome. They engulf things but cannot do anything with it, causing giant cytoplasmic granules in PMNs, which are diagnostic.
