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Human Health and Diseases

Description: This test will help the students to revise the related topics of health and diseases and thus will boost their knowledge about the concern topic.
Number of Questions: 27
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Tags: Autoimmune disorders Inverse Trigonometric Functions Trigonometric Ratios and Identities Active and Passive Immunity Immunity Allergies:Cause and Symptoms Immune System of Human Body Auto Immune Diseases
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Which of the following statements about food allergy is correct?

  1. In children, it is often due to cow's milk.

  2. Food allergy can be diagnosed by skin prick testing.

  3. Migraine is a common presenting feature.

  4. Food allergy is a common cause of irritable bowel syndrome.

  5. Most children will ‘grow out’ of nut allergy by the age of 11 years.


Correct Option: A
Explanation:

Cow's milk is a common cause of food allergy in infants. Many affected children are able to tolerate dairy products later in life.

An antigen is a substance that causes the immune system to produce antibodies against itself. Which type of cells are known to be involved in the initial presentation of antigen to T lymphocytes?

  1. Dendritic cells

  2. Plasma cells

  3. Neutrophil polymorphonuclear leucocytes

  4. Erythrocytes

  5. Platelets


Correct Option: A
Explanation:

Dendritic cells are professional antigen processing cells. They have a number of receptors that enhance the uptake of antigens, and they specialise in converting these antigens into MHC-peptide complexes that can be recognised by lymphocytes.

Which one of the following diseases is a part of the atopy syndrome?

  1. Oral allergy syndrome

  2. Nut allergy

  3. Asthma

  4. Urticaria

  5. Food intolerance


Correct Option: C
Explanation:

Asthma is a part of the atopy syndrome. 

In a human body, the primary lymphoid organs are involved in the production and early clonal selection of lymphocyte tissues. Which one of the following is/are the primary lymphoid organ(s)?

  1. Lymph nodes

  2. Spleen

  3. Peyer's patch

  4. Tonsils

  5. Thymus


Correct Option: E
Explanation:

T-cells are derived from bone marrow stem cells and differentiate into immunocompetent cells in the thymus.

Peanuts are among the most common allergy-causing foods for human beings. Which one of the following statements is false for peanut allergy?

  1. Peanut allergy is an example of immediate hypersensitivity.

  2. Atopy is a risk factor in peanut allergy.

  3. Anaphylaxis can occur on first exposure.

  4. IgG is believed to be centrally involved in anaphylaxis to peanut antigens.

  5. Self administered adrenaline can be life saving.


Correct Option: D
Explanation:

Peanut allergy is an example of an IgE-mediated hypersensitivity.

Lymphocytes are an important part of the immune system. Which of the following specialised cell types are involved in the entry of lymphocytes into the lymph nodes?

  1. M-cells

  2. Mesangial cells

  3. PALS

  4. HEV endothelial cells

  5. Selectins


Correct Option: D
Explanation:

The high-walled endothelium of the post-capillary venules (HEV) in lymph nodes express vascular addressins which are recognised by homing receptors on lymphocytes passing through the afferent lymphatics and which mediate entry of the lymphocytes into the lymph nodes.

Immunosuppression involves an act that reduces the activation or efficacy of the immune system. Which one of the following agents is not immunosuppressive?

  1. Levamisole

  2. Corticosteroids

  3. Thalidomide

  4. Aspirin

  5. Total lymphoid irradiation


Correct Option: D
Explanation:

This is an anti-inflammatory drug. Aspirin is part of a group of medications called non-steroidal anti-inflammatory drugs (NSAIDs) and has antipyretic, anti-inflammatory and analgesic properties but does not affect immunity. Aspirin inhibits the enzyme, cyclooxygenase.

Anaphylaxis is a severe whole-body allergic reaction to a chemical that has become an allergen. Systemic anaphylaxis is not caused by which one of the following substances?

  1. Wasp venom

  2. ACE inhibitors

  3. Penicillin

  4. Nut ingestion

  5. Latex


Correct Option: B
Explanation:

An ACE inhibitor (or angiotensin-converting-enzyme inhibitor) is a pharmaceutical drug used primarily for the treatment of hypertension. It can provoke angioedema but does not progress to anaphylaxis, though angioedema in the throat can be dangerous.

A wasp's stinger contains venom that is transmitted to humans during a sting. Which of the following statements regarding wasp venom desensitisation is correct?

  1. Wasp venom desensitisation is only indicated if there is a history of two or more severe reactions to wasp stings.

  2. Wasp venom desensitisation is associated with adverse reactions in less than 30% of treated patients.

  3. It is effective after a 5-week course of injections.

  4. It is only successful in those in whom total serum IgE levels are reduced.

  5. It is probably effective by increasing levels of antigen specific Tregs.


Correct Option: E
Explanation:

Wasp venom desensitisation is probably effective by increasing levels of antigen specific Tregs (as well as the production of specific blocking IgG antibodies) and so inhibiting CD4 T cells in their production of IL-4 and IL-13 that aid IgE production.

On entering a germinal center, the primary B-blasts grow exponentially to form which cell type in the dark zone?

  1. Secondary B-blasts

  2. Centrocytes

  3. Centroblasts

  4. Memory B-cells

  5. Plasma cells


Correct Option: C
Explanation:

Centroblasts are found in the dark zone and are highly mitotic cells with no surface IgD and very little surface IgM.

CD4+ T cells are generally treated as having a pre-defined role as helper T cells within the immune system. These cells help in the identification of which of the following?

  1. HLA B27

  2. HLA class III antigen

  3. Processed peptides from antigen

  4. CD8 antigen

  5. Surface immunoglobulin


Correct Option: C
Explanation:

Only if the T cell has the correct antigen specificity in the TCR and the same HLA class II antigens.

Which among the following structures are mainly confined to the paracortical area of lymph nodes?

  1. Follicular dendritic cells

  2. Plasma cells

  3. Macrophages

  4. B-cells

  5. T-cells


Correct Option: E
Explanation:

T-cells are mainly confined to the paracortical (thymus-dependent) area of lymph nodes, and in nodes taken from children with selective T-cell deficiency. The paracortical region is virtually devoid of lymphocytes.

Which among the following tingible bodies are present inside the germinal center macrophages of the immune system?

  1. DNA fragments

  2. Phagocytosed foreign antigen

  3. A sign of macrophage apoptosis

  4. Bacterial cell wall components resistant to degradation

  5. VLA molecules


Correct Option: A
Explanation:

There is very extensive apoptotic cell death amongst light zone centrocytes and the resultant DNA fragments are visible as 'tingible bodies' within the macrophages which have phagocytosed the apoptotic lymphocytes.

Immunoglobulin E (IgE) is a type of antibody that is present in minute amounts in the body but plays a major role in allergic diseases. Which of the following types of cells produce IgE?

  1. Mast cells

  2. Eosinophils

  3. Basophils

  4. Plasma cells

  5. T lymphocytes


Correct Option: D
Explanation:

A plasma cell is a mature B lymphocyte that is specialised for antibody (immunoglobulin) production. Plasma cells are rarely found in the peripheral blood. They comprise 0.2% to 2.8% of the bone marrow white cell count. These cells produce immunoglobulins of all isotypes, including IgE.

Monocytes and macrophages are critical effectors and regulators of inflammation and the innate immune response of the body. Which of the following cells are not thought to be of monocyte-macrophage lineage?

  1. Neutrophils

  2. Follicular dendritic cells of lymph nodes

  3. Kupffer cells in liver

  4. Histiocytes in tissues

  5. Monocytes in blood


Correct Option: A
Explanation:

These are of the myeloid lineage which separates from the monocyte-macrophage lineage after the pluripotent stem cell stage.

The lymphoid tissues in the adult immune system serve as primary and secondary depots of cells being involved in the immune response. Which of the following lymphoid tissues is unencapsulated?

  1. Thymus

  2. Lymph node

  3. Spleen

  4. Tonsil

  5. MALT


Correct Option: E
Explanation:

The respiratory, alimentary and genitourinary tracts are guarded immunologically by subepithelial accumulations of lymphoid tissues which are not constrained by a connective tissue capsule. These may occur as diffuse collections of lymphocytes, plasma cells and phagocytes throughout the body and the lamina propria of the intestinal wall, or as more clearly organised tissue with well-formed follicles as found in the Peyer's patches.

Type 1 hypersensitivity reaction is an allergic reaction provoked by re-exposure to a specific type of antigen referred to as an allergen. Which among the following is associated with Type 1 hypersensitivity?

  1. IgM

  2. IgD

  3. Macrophages

  4.  IgE

  5. Enterocytes


Correct Option: D
Explanation:

Type I involves mast cells which have specific receptors for IgE.

Phagocytosis is a process by which certain living cells ingest or engulf other cells or particles. Which of the following cell types are phagocytic in nature?

  1. Hepatocytes

  2. Lymphocytes

  3. Monocytes

  4. Erythrocytes

  5. Plasma cells


Correct Option: C
Explanation:

Phagocytosis is the process of uptake of microbes and particles followed by digestion and destruction of this material. Monocytes can perform phagocytosis using intermediary (opsonising) proteins such as antibodies or complement that coat the pathogen, as well as by binding to the microbe directly via pattern-recognition receptors that recognise pathogens.

HLA-DR2 is a broad antigen serotype. It is regarded as a risk factor for which of the following autoimmune diseases?

  1. Insulin-dependent (type I) diabetes

  2. Multiple sclerosis

  3. Ankylosing spondylitis

  4. Rheumatoid arthritis

  5. Myasthenia gravis


Correct Option: B
Explanation:

Individuals with HLA-DR2 are more at risk of developing multiple sclerosis than those with other HLA-DR specificities. Thus, a higher frequency of HLA-DR2 is found in MS patients versus the normal population.

After a thorough checkup, the doctor told Mr. Mehra that he was suffering from one of the severe systemic autoimmune diseases. Which of the following is a non-organ-specific (systemic) autoimmune disease of humans?

  1. Myasthenia gravis

  2. Systemic lupus erythematosus (SLE)

  3. Hashimoto's thyroiditis

  4. Pernicious anemia

  5. Insulin-dependent diabetes mellitus


Correct Option: B
Explanation:

SLE is a disease involving antibodies to non-organ specific antigens such as DNA and induces immune complexes, which deposit in the vascular bed causing kidney, skin, joint and cerebral lesions.

Cryptic T-cell epitopes are capable of triggering autoimmune diseases in human beings. Which among the following statements regarding the cryptic T-cell epitopes is correct?

  1. They dominate the normal immune response.

  2. They negatively select T-cells.

  3. They are unable to bind in the MHC groove.

  4. They can be derived by antigen processing.

  5. They are presented by MHC class I but not MHC class II molecules.


Correct Option: D
Explanation:

In order to be T-cell epitopes, i.e. peptides, they must be derived by antigen processing. Qualitative and/or quantitative alterations in processing can lead to greatly increased production of cryptic peptides and thus, may trigger autoimmune disease.

Mrs. Verma is suffering from pernicious anemia. She is most susceptible to which of the following?

  1. Addison's disease of the adrenal glands

  2. Multiple sclerosis

  3. Autoimmune hemolytic anemia

  4. Rheumatoid arthritis

  5. Graves' disease


Correct Option: E
Explanation:

Graves' disease is a fairly frequent organ-specific disease and is often found in association with pernicious anemia.

Which of the following regarding the 'natural antibodies' in human body is false?

  1. Natural antibodies are autoreactive in nature.

  2. Natural antibodies are polyspecific in nature.

  3. Natural antibodies react with bacterial carbohydrates.

  4. Natural antibodies posses high affinity immunoglobin, IgG.

  5. Natural antibodies are produced by CD5+ B-cells.


Correct Option: D
Explanation:

This statement is false. The 'natural antibodies' are low affinity IgM.

Which among the following indicates the autoantigen selection of responding B-cells during an infection in the body?

  1. Germ line configuration of the antibody

  2. High affinity antibody

  3. Expression of a public idiotype

  4. A monoclonal antibody response

  5. A response to many different autoantigens


Correct Option: B
Explanation:

The mutation of the antibody variable region genes in B-cells in the germinal center produces a range of antibody affinities, and those B-cells bearing higher affinity antibody will be favourably selected for further stimulation by the antigen.

Antiphospholipid syndrome occurs when the immune system mistakenly attacks some of the normal proteins in the blood. The antiphospholipid syndrome is associated with which of the following?

  1. Infertility

  2. Severe anemia

  3. Wegener's granulomatosis

  4. Raised platelet levels

  5. Recurrent fetal loss


Correct Option: E
Explanation:

Recurrent fetal loss is characteristic of the antiphospholipid syndrome. In the experimental situation, passive transfer of cardiolipin antibodies into mice also results in recurrent fetal loss.

Exophthalmos is defined as a protruding eyeball anteriorly out of the orbit. This disorder is often associated with which of the following?

  1. Hashimoto's disease

  2. Primary myxedema

  3. Graves' disease

  4. Idiopathic thrombocytopenic purpura

  5. Autoimmune hemolytic anemia


Correct Option: C
Explanation:

In Graves' disease, there is a hyperthyroidism due to stimulating autoantibodies to the TSH receptor which continuously mimic the effect of TSH but which are not subject to the feedback mechanisms which lower the level of TSH once sufficient thyroid hormone has been produced. Graves' disease is often associated with exophthalmos, which involves marked hypertrophy of the extra-occular muscles. This association may be caused by autoantibodies against an antigen present on both eye muscle and thyroid.

Neonatal myasthenia occurs in about 12% of babies whose mother has myasthenia gravis. Neonatal myasthenia gravis is caused by

  1. an inherited genetic defect

  2. transplacental transfer of maternal IgG against the TSH receptor

  3. anti-idiotype to maternal IgG

  4. transplacental transfer of maternal IgG against the acetylcholine receptor

  5. maternal T-cells transferred across the placenta


Correct Option: D
Explanation:

Transient neonatal autoimmune diseases are seen due to the transplacental transfer of maternal IgG autoantibodies in those diseases in which IgG is the effector component of the autoimmune response. The disease will be of the same type as seen in the mother because the autoantibodies will determine the target organ specificity. The neonatal disease resolves after a few weeks as the maternal IgG is catabolised.

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