Flashcards in Immunodeficiency Deck (11):
Primary immunodeficiency diseases:
Conditions characterized by intrinsic deficits within the immune system and are caused by inherited or de novo genetic defects.
Antibody deficiency pattern of infections:
- Bacteria: pneumococcus, H. flu, moraxella, staph aureus, meningococcus, pseudomonas, campylobacter, mycoplasma, ureaplasma.
- Virus: common respiratory especially enteroviruses, rotavirus.
- Protozoa: giardia, cryptosporidium.
Combined immunodeficiency pattern of infections:
- Bacteria: listeria, enteric flora.
- Virus: herpesviruses, RSV, influenza, parainfluenza, measles.
- Fungi: pneumocystis, candida, cryptococcus, histoplasma.
- Protozoa: toxoplamsa, cryptosporidium.
Cellular immunodeficiency pattern of infections:
- Mycobacteria, especially atypical and including BCG.
- Herpes viruses.
Phagocyte defects pattern of infections:
- Bacteria: Catalase positive; mycobacteria including BCG.
- Fungi: candida, aspergillus, paecilomyces.
- Susceptibility: pygoenic infections, viral meningo-encephalitis, vaccine strain poliomyelitis, mycoplasma arthritis.
- Features: infancy/childhood with recurrent sinopulmonary pygenic infections, 25% with neutropenia.
- Inheritance: X-linked.
- Diagnosis: Absent B cells, family history, IgG < 100 mg/dl, B cells < 2% of lymphocytes, normal T cell number and function.
Common variable immunodeficiency:
- Susceptibility: bacteria, common respiratory and enteroviruses, rotavirus, giardia, cryptosproidium.
- Features: recurrent sinopulmonary infections, bronchiectasis, diarrhea, arthritis, giardia, autoimunity, asthma, lymphoproliferative disease, gastric CA and lymphoma.
- Inheritance: sporadic, autosomal recessive.
- Diagnosis: hypogammaglobulinemia, B cells present. Impaired antibody response.
Severe Combined Immunodeficiency (SCID):
- Susceptibility: all infectious organisms including vaccine strains and opportunistic infections.
- Features: failure to thrive, chronic diarrhea, erythroderma or other skin eruption. Specific gene defects may have associated features.
- Inheritance: X-linked or autosomal recessive.
- Diagnosis: lymphopenia in most, diminished or absent T cells in most, poor/absent in vitro mitogen-induced T cell proliferation in all.
Treatment of SCID:
Stem cell transplantation.
Chronic granulomatous disease:
- Susceptibility: catalase positive organisms, indolent fungal infections.
- Features: recurrent infections. Granulomas of skin, liver, lungs, lymph nodes, viscera, bones, joints. GI/GU obstruction secondary to granulomas.
- Diagnosis: neutrophil oxidative burst assay by flow cytometry using DHR or nitroblue tetrazolium.
- Tx: prophylactic antibiotics, gamma interferon, bone marrow transplantation.