Immunology Questions and Answers – Primary Immunodeficiency Disorders

This set of Immunology Multiple Choice Questions & Answers (MCQs) focuses on “Primary Immunodeficiency Disorders”.

1. Which of the following is NOT a primary immunodeficiency disorder?
a) Pneumonia
b) Ear infections
d) Meningitis
View Answer

Answer: c
Explanation: Primary immunodeficiency disorders (PIDs) are the disorders of the immune system itself. These disorders are caused due to inherited (genetic) defects and it mostly occurs in infants and children but the signs and symptoms may not appear in childhood and can be seen in late childhood or early adulthood. Pneumonia, ear infections as well as meningitis are examples of PID while AIDS is an example of secondary immunodeficiency disorder (SID).

2. People with Primary immunodeficiency are likely to have autoimmune disorders. True or False?
a) True
b) False
View Answer

Answer: a
Explanation: It is true that people having primary immunodeficiencies are prone to have autoimmune disorders as well as blood disorders. This is because people having PI are associated with the immune system. The defects in the immune system can be due to genetic disorders or any health problem that causes genetic disorder. This can further lead to having autoimmune disorders like Addison disease, Deletion syndrome, etc.

3. Which of the following is NOT a risk factor of sinus infection?
a) Previous cold
b) Seasonal allergies
c) Weak immune system
d) Consumption of cold food items
View Answer

Answer: d
Explanation:  Sinus infection is one of the PID. It happens when fluid builds up in the air-filled pockets in the sinuses which eventually gives a way for the germ growth. Risk factors can be previous cold, seasonal allergies/pollen allergies as well as having a weak immune system. Smoking can also lead to sinus infection in some people. People having a long-term sinus infection can have a different structure of sinus than normal.

4. Ataxia telangiectasia is associated with which part of the body?
a) Lungs
b) Cerebellum and Spinal Cord
c) Liver
d) Digestive system
View Answer

Answer: b
Explanation: Ataxia telangiectasia (AT) is a primary immunodeficiency autosomal disorder which takes place in cerebellum and spinal cord. It even results in weakening of the immune system and does not allow the repair of damaged/broken DNA. This can even lead to cancer. Cerebellum is one of the most important part of the brain which is responsible for the coordination of voluntary movements. It even helps in speech, recognition and regulation of muscular activity.  AT can be caused due to genetic disorders in early stages of life. The most observable symptom seen in children is when they get confused between words or stammer while talking. 

5. Which of the following is NOT a symptom of Chronic Granulomatous Disease?
a) Inflammation of tissue
b) Swelling of lymph nodes
c) Cold and cough
d) Chronic runny nose
View Answer

Answer: c
Explanation: The people suffering from Chronic Granulomatous Disease do not have a good functioning immune system. Due to the weak immune system, the patient’s body is quite prone to get in contact with bacteria and fungi. The symptoms start showing in childhood itself. It is not a normal disorder hence cough and cold cannot be considered as a symptom for this disorder. Medical tests are to be done to check whether there is inflammation of tissue, changes in lymph nodes or having a chronic runny nose which means to have problem in breathing while still having runny nose. 

6. Which chromosome number shows defect in DiGeorge Syndrome?
a) Chromosome no. 17
b) Chromosome no. 20
c) Chromosome no. 21
d) Chromosome no. 22
View Answer

Answer: d
Explanation: DiGeorge syndrome is a deletion syndrome in children and it comes under the PID category as this syndrome is caused due to the genetic disorders. In children, a small piece of chromosome 22 goes missing or shows a defect. This can cause various health problems from heart defects to seizures. There can be changes in their structure of eyes, ears and nose. This is a very rare syndrome and it totally depends on the genetic disorders or defects.

7. Which of the following is NOT a complication of IgA deficiency?
a) Sinusitis
b) Autoimmune disorders
c) Chronic Granulomatous Disease
d) Skin, eyes and ear infection
View Answer

Answer: c
Explanation: IgA is an antibody isotype which is a blood protein and a major part of the immune system. IgA deficiency can either mean low levels of IgA or no IgA in the blood. In such cases, a patient suffering from IgA deficiency, can face problems like sinus or arthritis. This is also a type of an autoimmune disorder which can be caused due to weakness of immune system. If there is no IgA in the blood at all, it can cause infections near skin, eyes as well as ears. On the other hand, chronic granulomatous disease is nowhere related to IgA deficiency and is associated with chronic disorders. 

8. Prenatal test is done for what purpose?
a) To check the history of Primary immunodeficiency disease
b) To check blood purity
c) To detect measles
d) To detect immunity of pregnant women
View Answer

Answer: a
Explanation: In families with a known history of PID, prenatal test is taken by pregnant women to detect for any genetic problems in the developing baby. This test monitors the health and development status of the baby. Some factors like gestational diabetes or preeclampsia in women can lead to a risky pregnancy. Prenatal tests include a group of tests like ultrasound, amniocentesis, urine test, etc. 

9. Which of the following is NOT an immune-modifying drug?
a) Thalidomide
b) Lenalidomide
c) Pomalidomide
d) Sedalidomide
View Answer

Answer: d
Explanation: Immune-modifying drugs are the drugs prescribed by doctor which help in recognizing cancer cells. These drugs help the immune system to target the cancer-causing cells. These drugs are also termed as Immunomodulators. The most 3 important immune-modifying drugs are Thalidomide, Lenalidomide and Pomalidomide. Thalidomide was first used to treat myeloma while lenalidomide and pomalidomide are the new drugs for detecting and attacking multiple myeloma. 

10. What method can be used to replace the defective immune system?
a) Organ transplantation (healthy organs for better working of the body)
b) Stem cell transplantation
c) Removal of cancel cells
d) Consumption of drugs for increasing immune power
View Answer

Answer: b
Explanation: Stem cell transplantation can be used to replace the defective immune system in patients with severe or life-threatening types of primary immunodeficiency disease. This requires a stem cell donor that biologically matches to the patient. However, stem cell transplantation has a number of risks and is not always successful but it still can offer some patients a permanent cure.

11. What is Agammaglobulinemia also termed as?
a) XLA
b) YLA
c) X-YLA
d) Y-XLA
View Answer

Answer: a
Explanation: XLA stands for X-linked Agammaglobulinemia. This disorder is an X-linked disorder hence the name, XLA. It causes deficiencies on a genetic level which causes weakness in patients in order to produce antibodies and proteins that are required by the immune system. Due to this disease, there are some changes that occur in the gamma globulin fractions of blood. This disease was first studied and examined by Dr Ogden Bruton hence it is also named after him as Bruton’s Agammaglobulinemia.   

12. Which of the following diagnosis method is used for detecting chromosomal changes in patients suffering from DiGeorge Syndrome?
a) X-ray 
b) Stress test
c) Echorcardiography
d) Fluorescent in situ hybridization
View Answer

Answer: d
Explanation: DiGeorge syndrome is a genetic disorder that shows deletion of chromosome no. 22. To detect this syndrome, a number of tests are done like blood tests (to look for immune system problems), X-ray (to examine tissues, bones and organs), Echocardiography (to check the structure of heart and its working). However, the Fluorescent in situ hybridization test majorly tests whether there is any deletion in the chromosomal sequences. In cases where this cannot be identified, a whole chromosome study is done.

13. Which one of the following is the most common symptom of Wiskott-Aldrich Syndrome?
a) Bloody diarrhoea 
b) Respiratory infections
c) Thrombocytopenia
d) Eczema
View Answer

Answer: a
Explanation: Although all of the above options are the symptoms of Wiskott-Aldrich Syndrome, the most common and primary syndrome is Bloody diarrhoea. This is followed by the secondary symptoms like respiratory infections, eczema and thrombocytopenia. This occurs if there are decreased levels of T and B cells and their functions are nearly weak. If there are elevated levels of IgE and IgA more than required, it can also cause this syndrome. 

14. Which immunoglobulin is majorly involved in causing Transient Hypogammaglobulinemia of Infancy (THI)?
a) IgM
b) IgE
c) IgG
d) IgA
View Answer

Answer: c
Explanation: THI is a primary immunodeficiency disorder as it can either be genetically associated or can be caused due to weak immune system. In this case, the baby does not get the maternal IgM, IgA and IgE. However, the major loss is caused by IgG. Lower the levels of IgG, higher is the risk of THI. When the baby is in the mother’s womb, maternal IgG helps the baby to build up its immune system. However, at the time of birth, the baby starts building its own immune system by generating IgG. But if the baby does not generate moderate amounts of IgG on its own, it might result in THI. 

15. Which blood test is taken for diagnosis of Chronic Granulomatous Disease?
a) Nitrobule tetrazolium test
b) Calcium blood test
c) Folate test
d) Liver function test
View Answer

Answer: a
Explanation: If a patient has symptoms of Chronic Granulomatous Disease, medical attention is a must. A specialised blood test called as the nitrobule tetrazolium test can be done to confirm the results and reports of the suffering patient. This test measures the ability of immune system to convert the colourless nitrobule tetrazolium to dark blue. This test determines whether or not the immune cells are making toxic substances that body uses to fight the infections.

Sanfoundry Global Education & Learning Series – Immunology.

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Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

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