Immunodeficiencies

Question 1

immunodeficiency

Answer 1

impaired immune response resulting in increased susceptibility to opportunistic infections and obligate pathogens

Question 2

primary immunodeficiency

Answer 2

inherited (due to mutations in genes related to the immune system)

Question 3

secondary immunodeficiency

Answer 3

caused by disease, treatment, or other infection

Question 4

physiological causes of secondary immunodeficiency

Answer 4

elderly: t-cell oligoclonality, reduced t-cell output, reduced B cell repetoire; decreased functional T cell responses
young: immature lymphoid organs; low IgG levels (especially from 3-12 months after birth when its mostly IgM), decreased neutrophil and NK function; no memory cells

Question 5

iatrogenic- chemotherapy and radiation

Answer 5

decreased immune cell function (decreased cytokines, decreased phagocytosis, decreased chemotaxis) and decreased production of hematopoietic stem cells in the bone marrow

Question 6

iatrogenic- glucocorticoids

Answer 6

decreased t cell function (decreased cytokine production and decreased proliferation); decreased macrophage function (decreased phagocytosis and decreased fc receptor expression); viability of immune cells decreased (decreased apoptosis); inhibition of transcription factors (NKFB, NFAT, AP1)

Question 7

cyclosporin and tacrolimus are normally used for what

Answer 7

immunosuppresives (post organ transplant or to treat autoimmune inflammatory diseases like atopic dermatitis, psoriasis, eczema, rheumatoid arthritis, ulcerative colitis)

Question 8

cyclosporin and tacrolimus cause secondary ID by

Answer 8

inhibiting the function of T cells by inhibiting calcineurin, causing a secondary immunodeficiency similar to AIDS. normally, MHC presents antigen to T cell and it activates a signaling pathway that results in increased Ca2+. Ca2+ activates calcineurin which is a phosphatase that removes phosphate from NFAT to allow it to enter the nucleus and activate transcription factors for IL-2, IL-4, IFN gamma, TNF alpha, and IL-10. So without calcineurin, this is blocked

Question 9

iatrogenic: surgery

Answer 9

causes breaked in epithelial barrier–> inflammation (cytokines like Il-6 and TNF-alpha) and increased cortisol levels (a glucocorticoid)

Question 10

iatrogenic: splenectomy

Answer 10

increased susceptibility to infection with encapsulated bacteria OPSI (thats why they vaccinate before surgery)

Question 11

autoimmune diseases that cause secondary immunodeficiency

Answer 11

SLE, vasculitis

Question 12

paraneoplastic syndrome/ tumors

Answer 12

leukemia, paraneoplastic syndrome, multiple myeloma

Question 13

metabolic causes of secondary immunodeficiency

Answer 13

diabetes and kidney failure- cause increased fungal infections, increased bacterial and fungal respiratory infections and slow wound healing. This is because of hyperglycemia, impaired neutrophil and lymphocyte function, and vasculopathy that makes blood vessels thinner and decreases leukocyte mobility to site of infection

Question 14

malnutrition causes of secondary immunodeficiency

Answer 14

causes = insufficient protein uptake and insufficient uptake of vitamins (zinc, iron, folate, pyroxidine, and vitamin A)

Question 15

as a result of malnutrition….

Answer 15

diminished T cell number and function, specific B cell production impaired, and lack of cells in lymphoid organs