Detailed Study: Primary vs Secondary Immunodeficiency Diseases

This assignment solution provides a detailed overview of primary and secondary immunodeficiency, highlighting the key differences, causes, and symptoms of each. Primary immunodeficiencies are genetic disorders affecting the immune system, often diagnosed in childhood, while secondary immunodeficiencies are acquired due to environmental factors like infections, malnutrition, or chemotherapy. The solution also explains the importance of isotype controls in flow cytometry for accurate cell staining and discusses the roles of antigens, antibodies, and substrates in Enzyme Multiplied Immunoassay Technique (EMIT), used for rapid detection of hormones and drug metabolites. The document references several key immunology texts, ensuring a comprehensive and well-researched explanation of these complex topics. Desklib provides access to similar solved assignments and past papers for students.

Section A
1. b
2. a, b, c
3. d
4. a, c, d, e
5. b
6. a, b, e
7. c, e
8. c
9. ace
10. d
11. as
12. A, d, e
13. cytokines, large, lipopolysaccharides small, antibodies, memory
14. dendrocyte, innate, cytokines, strong, IgG, memory
15. c, d, e
16. a, c, e
17. b, d
18. a, c
19. b, d
20. d, e
21. autoimmune, immune, joints, monoclonal, inflammatory, TNF alpha
22. d
23. b
24. a

25. e
26. b
27. e
28. b
29. b
30. b
31. b
32. c
33. b
34. c
35. d
36. d
37. c
38. b, c
39. c
40. b
41. b
42. a
43. e
44. a, c
45. d
46. e
47. c
48. b
49. d

50. c, e
51. c
52. b
53. b
54. b
55. width FL4
56. photons detector, lasers
57. linear, mean
58. fc receptor, Fab region
59. emission
60. 21-60, 71-80
61. 2,424,00
62. a, d, b
63. c
64. b
65. b
66. a, d
67. c
68. d, b
69. d, b
Section B
Question 1
Primary immunodeficiency are disorders in which part of immune system of the body is missing
or does not function (Picard et.al 2015 pp. 696-726). Most of the primary immunodeficiency are
genetic disorders and are usually diagnosed during childhood although some may be diagnosed

during adulthood. They are mainly due to intrinsic congenital defect of the immune system.
Many are X-linked and present mostly in male. Females are mainly carries and the have defects
in important immune function genes. Primary immunodeficiency mainly occurs due to a defect
in innate and acquired immunity. Symptoms of primary immunodeficiency depends on type but
symptoms that lead to diagnosis are recurrent or persistent infections or developmental delay as a
result of infections (McCusker and Warrington 2011 p.11). Particular organ diseases can also
result such as diseases involving the heart and skeletal system. Some tumors such as lymphomas
can also predispose to development of autoimmune diseases. The leading symptoms are upper
and lower respiratory tract infections accounting for 91%, skin accounting for 21% and
gastrointestinal tract accounting for 13% (Modell et.al 2011, p. 61). Main causative organism for
these infections are pyogenic bacteria causing pus formation, diarrhea and respiratory problems.
According to Murphy and Weaver (2016) Secondary immune deficiency disease occurs when the
immune system is interfered due to environmental factors. They are more common than primary
immunodeficiency. Some of these factors include severe burns, HIV, chemotherapy or
malnutrition. Secondary immunodeficiency is acquired and are triggered after birth. Most of
them are due to an underlying condition. Immune system of people with secondary
immunodeficiency vary regularly in competence as individuals shift in spectrum from health to
disease. Secondary immunodeficiency is caused by emotional and physical stress such as
infections (Rice 2012, pp. 22-42). Protein malnutrition, gut diseases, tumors and endocrine
disorders such as liver failure are some of the causes. Others include; kidney disease,
immunosuppressive drugs, splenectomy and irradiation therapy.
Question 2
Isotope control are primary antibodies which does not have specificity to the target however they
match type and class of the primary antibody used in application. They function as negative

controls to aid in differentiating specific antibody signal from the non-specific background
signal. Isotype control are recommended in flow cytometry for surface staining and intracellular
staining (Givan, 2013). This is because isotope control antibodies are developed to suit cell
surface staining protocols and to aid in assessment of the background staining that is inherent in
the cell-antibody binding. Isotype control are also a better place to begin in optimizing flow
cytometer settings and determining range of data for general autofluorescence from a cell labeled
with a conjugated antibody.
Non-specific signaling may develop from both the interaction with off-target proteins and fc
receptor binding, including when the background level is isotype-specific. Selecting the
appropriate isotype control minimize background effects and give chance for interpretation of
true signals. Immunoprecipitation experiments also use isotype controls and other non-specific
whole molecule immunoglobulins as negative controls. For an isotype to be useful, it should be
the same isotype (Sharp, 2017). This is in regard to species, light chain (lambda or kappa) and
heavy chains (IgG, IgA, IgD, IgM or IgE) class, similar fluorochrome and the same F:P ratio
which is a measurement of the number of fluorescent contained on each antibody. F:P ratio is the
fluorescent to protein ratio. This ratio represents the amount of fluorochrome that is bound to the
antibody. It is however necessary for one to know the F/P ratio of both the the isotype control
and target antibody because the differences seen in staining and florescence may be due to the
F/P difference
Question 3
Role of antigen, antibody and substrate in EMIT

The principle showing the use of the enzyme is as below. The binding of the antibody to the
antigen is detected by the enzyme label. The enzyme normally acts on the colorless substrate in
order to produce a colored product that can be detected. Also the antigen presence is detected by
use of the enzyme labelled antibody and the quantity of colored product is proportional to both
concentrations of enzyme and antigen. Enzyme multiplied immunoassay technique is a
homogeneous assay system where there is no separation. Elimination of this step is
advantageous. The reaction of the binding of antigen and antibody changes the activity of the
enzyme label (Hermanson, 2013). Enzyme mostly used is isocitrate dehydrogenase and glucose -
6-phosphate dehydrogenase. Their activity can be measured by checking the alteration in
absorbance at 340nm as a result of NAD converting to NADH. This system can activate or
inhibit these enzymes and has utilized antigens conjugated to the enzyme substrate. The substrate
for the other enzyme is produced by one enzyme and any activity of enzyme that is significant
can only be detected when both are in near approximation (Copeland, 2013). It occurs mostly
when the associated epitopes in specific antigen are bounded their respective antibodies. Cells
usually present intracellular proteins fragments to T cell lymphocyte, this cell detects tissues of
foreign pathogens like virus, toxins and bacteria. Immediately after detection immune response is
initiated and there is production of antibodies by B lymphocytes that binds to the same proteins
(Delves, Martin, Burton, and Roitt 2017). EMIT is used in rapid detection of hormones and
drugs metabolites in human fluids. Antibodies against the drugs abused are synthesized in labs in
order to be recognized. They are attached to a protein of high molecular weight to form a
conjugate of an antigen. This conjugate is injected in the host animal whose immune system
produce drug specific antibodies that can either be monoclonal or polyclonal. Once desired blood
level of antibodies is obtained they are purified.

References
Copeland, R.A., 2013. Evaluation of enzyme inhibitors in drug discovery: a guide for medicinal
chemists and pharmacologists. John Wiley & Sons, New York
Delves, P.J., Martin, S.J., Burton, D.R. and Roitt, I.M., 2017. Essential immunology. John Wiley
& Sons, New York.
Hermanson, G.T., 2013. Bioconjugate techniques. Academic press, London
Givan, A.L., 2013. Flow cytometry: first principles. John Wiley & Sons, New York.
McCusker, C. and Warrington, R., 2011. Primary immunodeficiency. Allergy, Asthma & Clinical
Immunology, 7(1), London, p. S11.
Modell, V., Gee, B., Lewis, D.B., Orange, J.S., Roifman, C.M., Routes, J.M., Sorensen, R.U.,
Notarangelo, L.D. and Modell, F., 2011. Global study of primary immunodeficiency diseases
(PI)—diagnosis, treatment, and economic impact: an updated report from the Jeffrey Modell
Foundation. Immunologic research, 51(1), p.61.
Murphy, K. and Weaver, C., 2016. Janeway's immunobiology. Garland Science.
Picard, C., Al-Herz, W., Bousfiha, A., Casanova, J.L., Chatila, T., Conley, M.E., Cunningham-
Rundles, C., Etzioni, A., Holland, S.M., Klein, C. and Nonoyama, S., 2015. Primary
immunodeficiency diseases: an update on the classification from the International Union of
Immunological Societies Expert Committee for Primary Immunodeficiency 2015. Journal of
clinical immunology, 35(8), Springer US, Switzerland, pp.696-726.

Rice, V.H., 2012. Theories of stress and its relationship to health. Handbook of stress, coping,
and health: Implications for nursing research, theory, and practice, pp.22-42.
Sharp, Z. (2017). Principles of stable isotope geochemistry.