Advanced Immunology and Immunopathology Quiz

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.

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.

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.

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.

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.

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.

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.

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.