Immunology Flashcards
What cells do the common lymphoid progenitor cells give rise to?
T cells, B cells and NK cells
What cells do the Common Myeloid Progenitors give rise to?
Megakaryocyte/erythrocyte progenitor, dendritic cells and granulocyte/macrophage progenitor cells which differentiate into neutrophils, monocytes, eosinophils and basophils.
2008A Q5
Which of the following vaccines is least likely to induce long term immunologic memory?
A. Bacille Calmette-Guérin (BCG).
B. Diphtheria-tetanus-pertussis.
C. Haemophilus influenzae type B conjugate.
D. Hepatitis B.
E. Pneumococcal polysaccharide.
E. Pneumococcal polysaccharide.
What causes Graft Vs Host Disease?
Immune cells transplanted from a non-identical donor (the graft) recognize the transplant recipient (the host) as foreign, thereby initiating an immune reaction that causes disease in the transplant recipient.
The pathogenesis of GVHD is a complex, multistep process, but is primarily a T cell mediated process.
What medications are used in preventiion and treatment of GVHD?
Non-specific immunosuppressive drugs, such as corticosteroids and methotrexate,
as well as more specific T cell immunosuppressive drugs, such as cyclosporine and tacrolimus
Which virus is most likely to trigger Haemophagocytic Lymphohistiocytosis (HLH) in X-linked lymphoproliferative disease?
Epstein-Barr virus
What is mechanism of Staph aureus exacerbating atopic eczema dermatitis?
T-cell stimulation
What medications taken by atopic individuals should be ceased prior to skin prick testing?
Loratadine and other antihistamines
Steroids are okay to continue.
The gene defect in chronic granulomatous disease affects which protein?
NADPH oxidase
CGD is characterised by recurrent life threatening fungal and bacterial infections.
Inability of phagocytes to destroy certain microbes
Once a peanut allergy develops, it often persists lifelong. How many will spontaneously resovle and at what age? At what age does it usually present?
20% resolve at adolescence.
Presents at 6-24 months
If there is a FHx of SCID in a newborn, what should you look for in cord blood?
Reduction in lymphocytes is diagnostic.
All forms of SCID have deficiency of T lymphocytes.
A baby having episodic attacks of angiodema of hands and feet without pruritis is likely to have what disorder?
It is a deficiency of what?
Hereditary Angiodema
C1 Esterase deficiency
In children with immunodeficiency, the purpose of routine irradiation of administered blood products is to decrease the risk of:
A. Alloimmunization.
B. Cytomegalovirus (CMV) infection.
C. Graft-versus-host disease.
D. Transfusion related acute lung injury (TRALI).
E. Variant Creutzfeld-Jakob disease (vCJD).
C. Graft-versus-host disease.
Leukoreduced red cells — White blood cells (WBCs) can be removed from blood products by highly efficient filters that reduce the number of WBCs by more than 99.9 percent, generally to <1 x 106 WBCs per red cell unit [6]. The few that remain are capable of replication and can cause transfusion-associated-graft-versus-host disease (TA-GVHD).
Irradiated red cells — Transfusion-associated graft-versus-host disease (TA-GVHD) is caused by viable donor lymphocytes that are transfused into a patient who either does not recognize these cells as foreign or does not have the capacity to destroy them. TA-GVHD usually begins 8 to 10 days following transfusion and is almost inevitably fatal.
At a standard dose, gamma irradiation of the blood product prior to transfusion stops proliferation of foreign lymphocytes, which entirely prevents TA-GVHD. However, the dose of radiation used for cellular blood products is not sufficient to kill viruses. Thus, irradiation does not provide a CMV-safe product, and does not eliminate the need for either leukoreduction or CMV-seronegative blood products if a CMV-safe product is required. Conversely, leukoreduction does not eliminate all viable donor lymphocytes, and a leukoreduced product can cause TA-GVHD disease if it was not irradiated.(Uptodate)
How does chronic granulomatous disease tend to present?
Presents in first 3 years of life with skin infections, pneumonias, osteomyelitis (esp small bones), abscesses, presistent lymphadenopathy and hepatosplenomegally, and uncommon organisms.
Confirmed by NBT Test (Nitroblue tetrazolium test)
