Advanced Immunology and Immunopathology Quiz

1. What is responsible for the immediate reaction to a bee sting and what is responsible for the delayed response?

*Leukotrienes are responsible for the immediate reaction and histamine is responsible for the delayed response.

*IgG antibodies are responsible for the immediate reaction and cytokines are responsible for the delayed response.

*Histamine release is responsible for the immediate reaction and prostaglandins are responsible for the delayed response.

This question focuses on the mechanisms involved in immediate and delayed reactions to bee stings, specifically highlighting the role of preformed antibodies (IgE) in the rapid response and de novo synthesized leukotrienes in the delayed response. The incorrect answers provided offer variations in the immune mediators involved to test the understanding of these concepts.

Explanation

This question focuses on the mechanisms involved in immediate and delayed reactions to bee stings, specifically highlighting the role of preformed antibodies (IgE) in the rapid response and de novo synthesized leukotrienes in the delayed response. The incorrect answers provided offer variations in the immune mediators involved to test the understanding of these concepts.

2. What lab test should you order first when suspecting a patient has an autoimmune disease?

Thyroid function tests (TFTs)

Complete blood count (CBC)

Liver function tests (LFTs)

3. A baby with recurrent bacterial pneumonia at the age of 9 months has a defect in?

Production of antibodies by plasma cells

Maturation of neutrophils in the bone marrow

Maturation of T cells in the thymus

The correct answer is based on the given information about the lack of mature B cells in plasma and defective BTK leading to a maturation defect in B cells. This defect predisposes the patient to bacterial infections after 6 months of age.

Explanation

The correct answer is based on the given information about the lack of mature B cells in plasma and defective BTK leading to a maturation defect in B cells. This defect predisposes the patient to bacterial infections after 6 months of age.

4. Why do patients who are matched for MHC(DP, DQ, DR) have lower complications of renal transplants?

MHC2 mismatch is not important in renal transplants.

Matching for MHC(DP, DQ, DR) has no impact on the complication rate of renal transplants.

Matching for MHC(DP, DQ, DR) leads to higher complications in renal transplants.

Matching for MHC(DP, DQ, DR) in renal transplants is crucial to prevent CD4+ mediated damage, which can reduce complications. MHC2 mismatch can lead to issues, but it is not a problem in Bare Lymphocyte syndrome.

Explanation

Matching for MHC(DP, DQ, DR) in renal transplants is crucial to prevent CD4+ mediated damage, which can reduce complications. MHC2 mismatch can lead to issues, but it is not a problem in Bare Lymphocyte syndrome.

5. A male infant with multiple viral and bacterial infections had normal levels of T and B cells. Without specifying which Ig's are high or low, the labs provided show elevated IgM levels. What might be the mechanism of disease?

Defective CD3 on T cells

Defective CD19 on B cells

Defective CD40 receptor on B cells

In this scenario, the elevated IgM levels along with normal T and B cells suggest a defect in the CD40-CD40 Ligand interaction, as seen in Hyper IgM syndrome. This defect is crucial for isotype switching from non-specific IgM to other immunoglobulins, leading to low levels of other immunoglobulins and recurrent infections.

Explanation

In this scenario, the elevated IgM levels along with normal T and B cells suggest a defect in the CD40-CD40 Ligand interaction, as seen in Hyper IgM syndrome. This defect is crucial for isotype switching from non-specific IgM to other immunoglobulins, leading to low levels of other immunoglobulins and recurrent infections.

6. A female presents with symmetric proximal muscle weakness, violaceous eruption on upper eyelids with periorbital edema, fever, morning stiffness, and dysphagia of solid and liquids in upper esophagus. Endomysial inflammation with CD8+ T cells is observed. What is the most likely diagnosis?

SLE (Systemic Lupus Erythematosus)

Dermatomyositis characterized by perimysial inflammation with CD4+ cell involvement

Rheumatoid Arthritis

Patients with Polymyositis typically present with the described symptoms and endomysial inflammation with CD8+ T cells. Dermatomyositis, SLE, and Rheumatoid Arthritis do not typically present with the specific findings mentioned in the question.

Explanation

Patients with Polymyositis typically present with the described symptoms and endomysial inflammation with CD8+ T cells. Dermatomyositis, SLE, and Rheumatoid Arthritis do not typically present with the specific findings mentioned in the question.

7. In a female with Raynaud's phenomenon who developed extremely high BP (Malignant hypertension), rising creatinine, and BUN, what would an ANA antibody test show?

Centromere pattern

Speckled pattern

Homogeneous pattern

The correct answer is nucleolar pattern as it is commonly associated with scleroderma. Scleroderma is characterized by AntiDNA toposiomerase I antibodies and can present with malignant hypertension. Nodular glomerulosclerosis may be seen on kidney biopsy in patients with scleroderma and can contribute to malignant hypertension.

Explanation

The correct answer is nucleolar pattern as it is commonly associated with scleroderma. Scleroderma is characterized by AntiDNA toposiomerase I antibodies and can present with malignant hypertension. Nodular glomerulosclerosis may be seen on kidney biopsy in patients with scleroderma and can contribute to malignant hypertension.

8. Tender irregular radish, itchy rash develops in a guy who traveled to North America, this rash got worse in next few days but disappeared after few weeks, what type of hypersensitivity?

Type II - Cytotoxic hypersensitivity involving antibodies targeting specific cell surface antigens.

Type III - Immune complex-mediated hypersensitivity involving antibodies forming immune complexes that deposit in tissues.

Type I - Immediate hypersensitivity involving IgE antibodies and mast cell activation.

Type IV hypersensitivity is characterized by a delayed response involving T cells, while Type I, Type II, and Type III hypersensitivities involve different mechanisms and immune components.

Explanation

Type IV hypersensitivity is characterized by a delayed response involving T cells, while Type I, Type II, and Type III hypersensitivities involve different mechanisms and immune components.

9. What test you order in a patient who developed Edema, induration, pain at the site of injection of vaccine?

Electrocardiogram.

Skin prick testing.

Complete blood count.

10. Which protein from which gene serves as a transcription factor involved in the transcription and regulation of TREGS?

CD28

TGFB

IL10

The correct protein from the gene FOXP3 is a transcription factor essential for regulating TREGS, which play a crucial role in self-tolerance to prevent autoimmune diseases such as IPEX syndrome.

Explanation

The correct protein from the gene FOXP3 is a transcription factor essential for regulating TREGS, which play a crucial role in self-tolerance to prevent autoimmune diseases such as IPEX syndrome.

11. In which part of LN are T, B lymphocytes, macrophages, and Plasma cells?

*T cells are in Paracortex*Bcells are in Cortex.*Plasma cells-Medullary CORDS*Macrophages-Medullary Sinus.

The correct locations of T cells, B cells, Plasma cells, and Macrophages within the lymph node (LN) are crucial for the understanding of lymph node structure. T cells are primarily found in the Paracortex, B cells populate the Cortex, Plasma cells are located in the Medullary CORDS, and Macrophages reside in the Medullary Sinus. Understanding these locations aids in grasping the immune responses and interactions that occur within the lymph node environment.

Explanation

The correct locations of T cells, B cells, Plasma cells, and Macrophages within the lymph node (LN) are crucial for the understanding of lymph node structure. T cells are primarily found in the Paracortex, B cells populate the Cortex, Plasma cells are located in the Medullary CORDS, and Macrophages reside in the Medullary Sinus. Understanding these locations aids in grasping the immune responses and interactions that occur within the lymph node environment.

12. What is the mechanism of specific tissue damage in Type 2 Hypersensitivity?

Direct action of T cells leading to destruction of tissues

Activation of alternate complement pathway leading to cell lysis

Release of histamine causing vasodilation and smooth muscle contraction

13. Why is the relationship between NF-kB and IkB not a basic science concept?

Because IkB acts as a transcription factor for cytokines, enhancing the inflammatory response.

Because NF-kB promotes apoptosis of T and B lymphocytes, leading to immune suppression.

Because NF-kB directly activates IkB, causing a positive feedback loop.

The relationship between NF-kB and IkB is not a basic science concept because IkB inhibits NF-kB, leading to its deactivation and subsequent inflammatory response. NF-kB does not directly activate IkB, it does not promote apoptosis of T and B lymphocytes, and IkB does not act as a transcription factor for cytokines.

Explanation

The relationship between NF-kB and IkB is not a basic science concept because IkB inhibits NF-kB, leading to its deactivation and subsequent inflammatory response. NF-kB does not directly activate IkB, it does not promote apoptosis of T and B lymphocytes, and IkB does not act as a transcription factor for cytokines.

14. What type of hypersensitivity is the mechanism for the condition where a female who is Rh- had a child with an Rh+ male without receiving RHOGAM at 28th week of pregnancy?

Type 4 hypersensitivity in fetus due to Rh incompatibility

Type 1 hypersensitivity in fetus due to Rh incompatibility

Type 3 hypersensitivity in fetus due to Rh incompatibility

The correct answer is Type 2 hypersensitivity in fetus due to Rh incompatibility, as the Rh- mother forms antibodies against the Rh+ RBCs of the fetus, leading to severe issues like Erythroblastosis fetalis. The other types of hypersensitivity reactions are not specifically linked to Rh incompatibility in the context of pregnancy.

Explanation

The correct answer is Type 2 hypersensitivity in fetus due to Rh incompatibility, as the Rh- mother forms antibodies against the Rh+ RBCs of the fetus, leading to severe issues like Erythroblastosis fetalis. The other types of hypersensitivity reactions are not specifically linked to Rh incompatibility in the context of pregnancy.

15. Female with Menorrhagia(Heavy menstrual flow)+Petechia+Purpura was diagnosed with ITP(Most common cause of thrombocytopenia in children and adults), what is the mechanism?

Type 3 Hypersensitivity

Type 4 Hypersensitivity

Type 1 Hypersensitivity

In this case, the correct mechanism is Type 2 Hypersensitivity where IgG antibodies against fixed platelet surface antigens coat platelets leading to their removal by macrophages in the spleen and liver. This phenomenon results in decreased platelet count and characteristic symptoms like petechiae and purpura. Type 1, 3, and 4 hypersensitivity reactions do not exhibit the same pathophysiology seen in ITP.

Explanation

In this case, the correct mechanism is Type 2 Hypersensitivity where IgG antibodies against fixed platelet surface antigens coat platelets leading to their removal by macrophages in the spleen and liver. This phenomenon results in decreased platelet count and characteristic symptoms like petechiae and purpura. Type 1, 3, and 4 hypersensitivity reactions do not exhibit the same pathophysiology seen in ITP.

16. Which type of Hypersensitivity can indirectly cause Macrocytic Megaloblastic Anemia?

Type 1

Type 3

Type 4

Pernicious anemia is an example of Type 2 hypersensitivity and involves Destruction of Parietal cells leading to B12 deficiency, which can cause Macrocytic Megaloblastic Anemia.

Explanation

Pernicious anemia is an example of Type 2 hypersensitivity and involves Destruction of Parietal cells leading to B12 deficiency, which can cause Macrocytic Megaloblastic Anemia.

17. Patient most likely has Goodpasture's disease as a result of IgM and IgG antibody formation against Protein in Basement membrane of Alveoli and glomeruli. Which type of hypersensitivity is involved?

Type I Hypersensitivity

Type III Hypersensitivity

Type IV Hypersensitivity

In Goodpasture's disease, antibodies attack specific proteins in the basement membrane of alveoli and glomeruli, leading to damage in these organs. This mechanism is characteristic of Type II Hypersensitivity reactions, where antibodies target specific antigens on host cells or tissue.

Explanation

In Goodpasture's disease, antibodies attack specific proteins in the basement membrane of alveoli and glomeruli, leading to damage in these organs. This mechanism is characteristic of Type II Hypersensitivity reactions, where antibodies target specific antigens on host cells or tissue.

18. Which antibodies are involved in the pathogenesis of Guillain-Barre Syndrome?

Antibodies play a role in Guillain-Barre Syndrome, but it is an example of type 4 hypersensitivity.

Only T cells and macrophages are involved in the pathogenesis of Guillain-Barre Syndrome.

No, antibodies are not involved in Guillain-Barre Syndrome.

Guillain-Barre Syndrome is an autoimmune condition that follows infections like Influenza or Campylobacter jejuni. It results in ascending paralysis and involves peripheral and cranial nerve segmental demyelination and edema, which are examples of type 2 hypersensitivity reactions.

Explanation

Guillain-Barre Syndrome is an autoimmune condition that follows infections like Influenza or Campylobacter jejuni. It results in ascending paralysis and involves peripheral and cranial nerve segmental demyelination and edema, which are examples of type 2 hypersensitivity reactions.

19. Which HLA subtype is associated with ALL Types of Hypersensitivity reactions?

HLA-DQ2

HLA-DR4

*HLA-DR2 which has been associated with Hay fever(type1),SLE(Type3),Goodpasture syndrome(Type2),Multiple Sclerosis(NO ANTIBODIES involved only here-Type 4 hypersensitivity)

HLA-B27

HLA-DR2 is the only HLA subtype that has been associated with all different types of hypersensitivity reactions, making it the correct answer.

Explanation

HLA-DR2 is the only HLA subtype that has been associated with all different types of hypersensitivity reactions, making it the correct answer.

20. Does Graft Versus Host Disease(Good for treating leukemia) involve Antibodies?

GVHD is a result of an overactive antibody response by the recipient's immune system.

Yes, GVHD involves the production of antibodies that attack the host's tissues.

In GVHD, the primary cells involved are B cells that produce antibodies against the donor's cells.

GVHD is an example of type 4 hypersensitivity reaction where T cells from the donor attack the recipient's tissues. This reaction does not involve antibodies, unlike other types of hypersensitivity reactions. Therefore, options stating involvement of antibodies or B cells are incorrect.

Explanation

GVHD is an example of type 4 hypersensitivity reaction where T cells from the donor attack the recipient's tissues. This reaction does not involve antibodies, unlike other types of hypersensitivity reactions. Therefore, options stating involvement of antibodies or B cells are incorrect.

21. A patient who had group A streptococcal pharyngitis develops reddish macules on the trunk that spread outward coalesce but spare face (Erythema marginatum) with subcutaneous nodules, chorea, large joint pain, increased ESR, and dies due to myocarditis. Which type of hypersensitivity is involved?

Type 1 hypersensitivity

Type 3 hypersensitivity

Type 4 hypersensitivity

Rheumatic fever involving Type 2 hypersensitivity is the correct answer due to the autoimmune response against M protein mimicking self-antigen leading to myocarditis. Type 1 hypersensitivity involves immediate hypersensitivity reactions like anaphylaxis. Type 3 hypersensitivity involves immune complex deposition leading to diseases like post-streptococcal glomerulonephritis. Type 4 hypersensitivity is mediated by T cells and is mainly seen in delayed-type hypersensitivity reactions.

Explanation

Rheumatic fever involving Type 2 hypersensitivity is the correct answer due to the autoimmune response against M protein mimicking self-antigen leading to myocarditis. Type 1 hypersensitivity involves immediate hypersensitivity reactions like anaphylaxis. Type 3 hypersensitivity involves immune complex deposition leading to diseases like post-streptococcal glomerulonephritis. Type 4 hypersensitivity is mediated by T cells and is mainly seen in delayed-type hypersensitivity reactions.

22. A patient with fever, hypertension, melena (SMA involvement), myalgia, and neurologic dysfunctions that has renal microaneurysms and no pulmonary involvement is likely to have which type of vasculitis and which type of hypersensitivity is the mechanism of the disease?

Kawasaki Disease - involves medium-sized vessel vasculitis and primarily affects children. Type 1 hypersensitivity is the mechanism of the disease.

23. What are characteristics of Local Type3 hypersensitivity and how would you test for it?

Itching, Rash, Fever with no complement activation. Test: Western Blot.

Bruising, Itching, Inflammation with no complement activation. Test: PCR.

*Edema,Necrosis, Complement activation are characteristics of Arthus reaction, where antigen-antibody complexes deposit locally in the tissue.*TEST-IMMUNOFLUORESCENT STAINING.

Swelling, Redness, Pain with no complement activation. Test: ELISA Assay.

Local Type3 hypersensitivity reactions involve the deposition of antigen-antibody complexes in tissues, leading to inflammation and tissue damage. Testing for this type of reaction often involves techniques like immunofluorescent staining to visualize the complexes.

Explanation

Local Type3 hypersensitivity reactions involve the deposition of antigen-antibody complexes in tissues, leading to inflammation and tissue damage. Testing for this type of reaction often involves techniques like immunofluorescent staining to visualize the complexes.

24. What is the pathophysiologic mechanism of hyperacute rejection after transplant involving widespread thrombosis of graft vessels within minutes after transplant, leading to ischemia/necrosis of the transplanted organ? And which type of hypersensitivity is involved?

25. Can type 4 hypersensitivity and Humoral response both play a role in pathogenesis of transplant rejection?

Only type 4 hypersensitivity plays a role in transplant rejection, with no involvement of a Humoral response.

Humoral response is the only mechanism of transplant rejection; type 4 hypersensitivity is not involved.

No, type 4 hypersensitivity and Humoral response can never coexist in transplant rejection.

In the case of ACUTE rejection of a transplant, both Cellular and humoral components play a role. Cellular component corresponds to type 4 hypersensitivity involving CD8+T lymphocytes, while the Humoral component involves antibodies formed after transplantation, contributing to rejection. Therefore, both mechanisms can indeed coexist in transplant rejection.

Explanation

In the case of ACUTE rejection of a transplant, both Cellular and humoral components play a role. Cellular component corresponds to type 4 hypersensitivity involving CD8+T lymphocytes, while the Humoral component involves antibodies formed after transplantation, contributing to rejection. Therefore, both mechanisms can indeed coexist in transplant rejection.

26. Which type of rejection can last for Months-years and is characterized by Vascular Smooth muscle proliferation, Parenchymal atrophy, Interstitial Fibrosis (Not interstitial lymphocyte infiltrate) and Arteriosclerosis due to Cytokine release from CD4+ T cells?

Acute rejection

Antibody-mediated rejection

Hyperacute rejection

The characteristics described in the question are typical of Chronic rejection, which is different from Acute rejection, Hyperacute rejection, and Antibody-mediated rejection. CD4+ T cells play a key role in Chronic rejection, distinguishing it from other types of rejection.

Explanation

The characteristics described in the question are typical of Chronic rejection, which is different from Acute rejection, Hyperacute rejection, and Antibody-mediated rejection. CD4+ T cells play a key role in Chronic rejection, distinguishing it from other types of rejection.

27. Which type of hypersensitivity is involved in PPD test for ruling out TB?

Type 2 hypersensitivity involving cytotoxic antibodies.

Type 3 hypersensitivity involving immune complex deposition.

Type 1 hypersensitivity involving IgE antibodies and mast cells.

28. Newborn with Congenital infection will have rise in?

Maternal IgG levels transmitted through breast milk.

Decrease in white blood cell count.

Elevated levels of maternal antibodies.

Congenital infections are typically acquired in utero or during birth, leading to the presence of specific IgM antibodies in the newborn. Maternal IgG levels transmitted to the baby through breast milk do not signify a congenital infection. A decrease in white blood cell count is not a specific marker for congenital infection. Elevated levels of maternal antibodies are expected in a healthy infant due to the passive immunity transfer from the mother.

Explanation

Congenital infections are typically acquired in utero or during birth, leading to the presence of specific IgM antibodies in the newborn. Maternal IgG levels transmitted to the baby through breast milk do not signify a congenital infection. A decrease in white blood cell count is not a specific marker for congenital infection. Elevated levels of maternal antibodies are expected in a healthy infant due to the passive immunity transfer from the mother.