Immunodeficiency & Tolerance MCQ Quiz | Immunology

Quiz Introduction

Welcome to this specialized multiple-choice quiz on Immunodeficiency and Immunological Tolerance, designed for MBBS students. This module is fundamental to understanding how the immune system maintains self-integrity and responds to pathogens. The following 25 questions will test your knowledge on primary and secondary immunodeficiencies, such as SCID, DiGeorge syndrome, and AIDS, as well as the intricate mechanisms of central and peripheral tolerance, including the roles of AIRE, FOXP3, and regulatory T cells. This quiz serves as an excellent tool for self-assessment and revision. After submitting your answers, you will see your score and a detailed breakdown of correct and incorrect responses. You can also download all the questions with their correct answers in PDF format for future reference. Good luck!

1. A defect in the common gamma chain (γc), a component of several cytokine receptors, is responsible for which primary immunodeficiency?

2. DiGeorge syndrome is primarily caused by a developmental failure of which embryonic structures?

3. A mutation in the Bruton’s Tyrosine Kinase (BTK) gene impairs B-cell development, leading to which condition?

4. The most common form of Hyper-IgM syndrome results from a defect in which molecule, crucial for T-cell help to B-cells?

5. Chronic Granulomatous Disease (CGD) is characterized by the inability of phagocytes to produce reactive oxygen species due to a defect in which enzyme complex?

6. The Human Immunodeficiency Virus (HIV) primarily targets which cell population, leading to the progressive failure of the immune system?

7. Negative selection of T cells, a key process in central tolerance, primarily occurs in which anatomical location?

8. Mutations in the Autoimmune Regulator (AIRE) gene cause a breakdown of central tolerance, leading to which syndrome?

9. Which transcription factor is the master regulator for the development and function of regulatory T cells (Tregs)?

10. T-cell anergy is a state of peripheral tolerance induced when a T cell recognizes its antigen on an APC without receiving which crucial signal?

11. Which inhibitory receptor on T cells plays a critical role in peripheral tolerance by competing with CD28 for binding to B7 molecules?

12. Chediak-Higashi syndrome is an autosomal recessive disorder caused by a mutation in the LYST gene, leading to a defect in:

13. A patient with Wiskott-Aldrich Syndrome (WAS) typically presents with a classic triad of symptoms. Which of the following is NOT part of that triad?

14. Receptor editing is a mechanism of central B-cell tolerance where a self-reactive B cell attempts to change its antigen specificity by altering the:

15. The Fas-Fas Ligand (FasL) pathway is a major mechanism for inducing apoptosis in lymphocytes. This process is crucial for which immunological phenomenon?

16. Leukocyte Adhesion Deficiency (LAD) Type 1 is caused by a defect in the CD18 subunit of which class of molecules?

17. Deficiency in the late components of the complement system (C5-C9) significantly increases susceptibility to infections by which organisms?

18. What is the most common primary immunodeficiency disorder?

19. Ataxia-telangiectasia is a complex disorder caused by a mutation in the ATM gene, which is primarily involved in what cellular process?

20. Immune-privileged sites, such as the anterior chamber of the eye, maintain tolerance through several mechanisms. Which of the following is a key feature of these sites?

21. Common Variable Immunodeficiency (CVID) is primarily characterized by:

22. The phenomenon of inducing systemic unresponsiveness by feeding an antigen is known as oral tolerance. This is largely mediated by:

23. A patient presents with recurrent pyogenic bacterial infections and is found to have no circulating B cells and pan-hypogammaglobulinemia. T cell numbers and function are normal. This clinical picture is most consistent with:

24. The function of the Programmed Death-1 (PD-1) pathway in peripheral tolerance is best described as:

25. A self-reactive B cell in the bone marrow that recognizes a soluble, low-avidity self-antigen is most likely to undergo which tolerance mechanism?