Human Health and Diseases

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

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.

Asthma is a part of the atopy syndrome. 

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

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

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.

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.

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.

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.

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

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

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.

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.

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.

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

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 I involves mast cells which have specific receptors for IgE.

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.

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.

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.

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.

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

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

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.

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.

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.

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.