Biology

Human Immunity and Blood

2,096 Questions

Human immunity and blood questions cover the physiological mechanisms protecting the body against diseases and the components of blood. Topics include blood groups, cell mediated immunity, monoclonal antibodies, and blood coagulation. These biology topics frequently appear in general science sections of competitive exams.

Blood groupsCell mediated immunityMonoclonal antibodiesBlood coagulationCancer immunology

Human Immunity and Blood Questions

Multiple choice

Autoantigen selection of responding B-cells during tumor formation in the body is indicated by

  1. germ line configuration of the antibody

  2. high affinity antibody

  3. expression of a public idiotype

  4. a monoclonal antibody response

  5. a response to many different autoantigens
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The mutation of the antibody variable region genes in B-cells in the germinal center produces a range of antibody affinities, and those B-cells bearing higher affinity antibody will be favourably selected for further stimulation by antigen.

Multiple choice

Which of the following statements about IgA deficiency is FALSE?

  1. IgA deficiency is defined as a blood level < 0.07 g/l.

  2. IgA deficiency is the most common of the primary immune deficiencies.

  3. Many patients with IgA deficiency are healthy throughout their lives.

  4. Patients with IgA deficiency may suffer from an increased prevalence of allergies.

  5. There is a defined problem with the class switch mechanisms for IgG in such patients.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

There is no known problem with the class switch mechanisms for IgG in most IgA deficient patients (as yet) but a small proportion, usually those who present with infections, have poor responses to either carbohydrate or protein antigens +/- low IgG subclass levels. There is linkage with MHC class II and class III genes but almost certainly this is not the whole story; the precise mechanisms are not known.

Multiple choice

Chronic lymphocytic leukaemia (CLL) is a type of slow growing blood cancer that affects developing B-lymphocytes. Chronic lymphocytic leukaemia is commonly associated with which of the following features?

  1. Invariably rapid demise

  2. Slow but progressive course

  3. Overwhelming bleeding

  4. Hepatitis

  5. Thymoma
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Patients are usually over 50 years of ageand the life expectancy is 15 years, depending on the stage of disease at presentation.

Multiple choice

Chronic granulomatous disease is a disorder that causes the immune system to malfunction, resulting in a form of immunodeficiency. Which of the following is the primary defect in chronic granulomatous disease (CGD)?

  1. Neutrophil production in the bone marrow

  2. Neutrophil chemotaxis

  3. Neutrophil intracellular killing of organisms

  4. Opsonisation

  5. Cytotoxic T-cell activity
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Neutrophils from patients with CGD fail to produce super-oxide that enables an influx of potassium ions to activate the intracellular enzymes that kill organisms.

Multiple choice

Which of the following statements relating to anti-TNF monoclonal antibody therapies is FALSE?

  1. The risk of latent TB is assessed routinely in immunosuppressed patients by interferon release assays on whole blood.

  2. Clinical characteristics of TB in the setting of anti-TNF therapy include a preponderance of extra-pulmonary disease and poor granuloma formation on histology.

  3. Therapeutic TNF inhibition is associated with significant risk of reactivation of Mycobacterium tuberculosis.

  4. Infliximab is a soluble TNF receptor.

  5. The success of TNF blockade in rheumatoid arthritis (RA) underlines the pivotal proinflammatory role of TNF in this disease.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Etanercept is the soluble TNF receptor. Infliximab is a monoclonal antibody - as indicated in the last part of the name InflixiMAB. TNF blockade can be achieved by either the use of a chimeric anti-TNF antibody (infliximab, adalimumab) or a soluble TNF receptor (etanercept).

Multiple choice

Which of the following proteins are contained in specific granules of neutrophils?

  1. Cathepsin and gelatinase

  2. Myeloperoxidase, bactericidal/permeability-increasing proteins (BPI), defensins, serine proteases neutrophil elastase and cathepsin G

  3. Alkaline phosphatase, lysozyme, NADPH oxidase, collagenase, lactoferrin and cathelicidin

  4. Cytokines such as IL-1, IL-2, IL-4, IL-5, IL-6, IL-8, IL-13 and TNF alpha
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Alkaline phosphatase, lysozyme, NADPH oxidase, collagenase, lactoferrin and cathelicidin are contained in the specific granules (or secondary granules) of neutrophils.