immunodeficiency Flashcards

Question

Transcobalamin II deficiency (genetic, immunological , C/F and treatment)

Answer 1

• Genetic : autosomal recessive • Immunological: depleted plasma cells, diminished immunoglobulin levels & impaired phagocytosis. • C/F: patients show metabolic effects of vitamin B12 deficiency including Megaloblastic anaemia & intestinal villous atrophy. • Treatment :Vitamin B12

Answer 2

Features • increased susceptibility to intracellular microbes • Delay in growth and development • death at the early age • increased incidence of malignant tumours • Reduced numbers of peripheral blood B cells • block in the differentiation and development of the T cells

Answer 3

• Developmental defect 3rd & 4th pharyngeal pouches • Aplasia or hypoplasia of thymus & parathyroid glands. • intrauterine infection or other complications. • gene deletions in the DiGeorge chromosomal region at 22q11 • M=F • may be partial or complete. • Facial Defects: Infants’ low-set ears, fish-shaped mouth, midline facial clefts, a small receding mandible, hypertelorism, notched ear pinnae, antimongoloid slant • Congenital heart disorder • Thymic and parathyroid hypoplasia, causing T-cell deficiency • Recurrent infections begin soon after birth and T-cell function may improve spontaneously. • Immunological: Primarily involves CMI

Answer 4

• Abnormal immunological response to Candida albicans • C/F: Severe chronic candidiasis of mucosa, skin & nails. • Don’t show increased susceptibility to other infections • CMI to candida is deficient. • Delayed hypersensitivity to candida antigens is absent • Intracellular killing of candida is defective. • Treatment: Transfer factor therapy along with amphotericin B

Answer 5

• Enz PNP is involved in the sequential degradation of purines to hypoxanthine & finally uric acid • Genetic: autosomal recessive inheritance. • Immunological: decreased CMI . • C/F: Recurrent or chronic infection, usually present with hypoplastic anaemia & recurrent pneumonia, diarrhea & candidiasis • Diagnosis: A low serum uric acid

Answer 6

Severe combined immunodeficiencies (SCID) • autosomal recessive disorder • X-linked form (M>F) called primary lymphopenic ID • IL-2Rγ-chain defect is the most common that leads to defective signalling by the IL-2, IL-4, IL-7, IL-9 & IL-15. • characterized by CD 8+ T cell deficiency. (tyrosine kinase- ZAP-70) • Deficiency of recombinases RAG-1 & 2 • Immunological: decreased number of lymphocytes, thymus is either not developed or very poorly developed, a small number of T cells fail to respond to antigens & experimental mitogens

Answer 7

Features of SCID • Failure to thrive • Onset of infections in the neonatal period • Opportunistic infection • Chronic or recurrent thrush • Chronic rashes, Chronic didiarrhoea • aucity of lymphoid tissue • Immunity is so low that even the live attenuated vaccines are not tolerated- they can produce diseases. • prolonged by confinement into a sterile environment. • Treatment: gene therapy.

Answer 8

Wiscott-Aldrich syndrome • X-linked immunodeficiency which increases with age. • Genetic: defective CD43 protein gene on the short arm of X chromosome ( Xp11 ). • This gene encodes a glycoprotein called sialophorin • Immunological: CMI undergoes progressive deterioration • Serum IgM level is low, IgG & IgA levels are normal or elevated • humoral defect appears to be the specific inability to respond to polysaccharide antigens. • C/F: eczema, thrombocytopenic purpura & recurrent infections. • Treatment : BMT & transfer factor therapy.

Answer 9

ATAXIA-TELANGIECTASIA • cerebellar ataxia, telangiectasia, ovarian dysgenesis & chromosomal abnormalities. • Genetic: Gene responsible for chromosome 11. • role in DNA repair • ATM gene encodes Atm protein kinase • C/F : earliest signs- ataxia & choreoathetosis movements noticed in infancy. Telangiectasia involving the conjunctiva & face appears at 5 or 6 years of age. • Immunological : affect T&B cells IgA, IgE and IgG2 deficiency. T cell function is variably depressed. DTH & Graft rejection • Treatment : Transfer factor therapy & fetal thymus transplants.

Answer 10

Nezelof syndrome • depressed CMI is associated with selectively elevated, decreased or normal levels of ig • C/F: recurrent fungal, bacterial, viral & protozoal diseases associated with hemolytic anaemia. • Immunological: marked deficiency of T cell immunity & varying degrees of deficiency of B cell immunity. • Thymic dysplasia occurs with lymphoid depletion. • Abundant plasma cells (spleen, LN, intestines & elsewhere in body) • In spite of normal levels of immunoglobulins, antigenic stimuli don’t induce antibody formation. • Treatment: BMT, transfer factor & thymus transplantation.

Answer 11

Chronic granulomatous disease • Defect in generation of oxidative radicals needed phagocytic cells to kill the bacteria & other pathogens. • Genetic : Mutation in NADPH .X-linked congenital defect -70%, autosomal recessive form • Immunological : Besides free radical generation deficiency, there are also defects in mononuclear cells to function as APCs. • Both antigen processing & presentation are affected • C/F: recurrent infection with low grade pathogens, starting early in life progress & outcome fatal • Diagnosis : NBT ( Nitroblue tetrazolium )test • Treatment : Interferon gamma .

Answer 12

Endocrine- Diabetes mellitus GI- Hepatic insufficiency, hepatitis, intestinal lymphangiectasia, protein-losing enteropathy Hematologic-Aplastic anemia, cancer, graft-vs-host disease, sickle cell disease Iatrogenic- Chemotherapeutic drugs, immunosuppressants, corticosteroids, radiation therapy, splenectomy Infectious- Cytomegalovirus, Epstein-Barr virus, HIV, measles virus, varicella-zoster virus Nutritional- Alcoholism, undernutrition Physiologic- Infants due to immaturity of immune system, pregnancy Renal- Nephrotic syndrome, renal insufficiency, uremia Rheumatologic- Rheumatoid arthritis, systemic lupus erythematosus Other- Burns, chromosomal abnormalities (e.g. Down syndrome), congenital asplenia, critical and chronic illness, histiocytosis, sarcoidosis