IgG level increases and decreases in severe malnutrition and lymphoid aplasia, respectively.

Hepatitis B vaccine is a virus-like particle based vaccine. Virus-like particle vaccines consist of viral proteins derived from the structural proteins of a virus. These proteins can self-assemble into the virus-like particles which are noninfectious as they lack viral nucleic acid.

Level of IgM increases during actinomycosis. Actinomycosis is an infectious bacterial disease caused by Actinomyces species.

Vaccination confers active artificial adaptive immunity. It is artificial because it develops through deliberate action of vaccination. It is active because immunity is induced in the host and lasts longer. It is adaptive because it is specific in action.

Plaque psoriasis causes raised, inflamed and reddend skin covered with silvery-white scales. These patches may itch and burn and may be seen on elbows, knees, scalp and lower back.

Autoimmune hemolytic anemia (AHA) causes the premature destruction of red blood cells. It causes fatigue, pale skin, shortness of breath and dark urine. AHA is a type of acquired haemolytic anemia.

Artificial passive immunisation is done for immediate protection.

IgE plays an important role in parasitic helminth diseases. Since serum IgE levels rise in parasitic diseases, measuring IgE levels is helpful in diagnosing parasitic infections.

Passive transfer of cell mediated immunity is used to treat some kinds of cancer. Passive or adoptive transfer of cell-mediated immunity is conferred by the transfer of sensitised or activated T-cells from one individual into another.

Synctiotrophoblasts are giant cells which hinder the passage of mother's WBC to reach foetal side of the placenta. If they were to reach the foetal side of the placenta, many foreign proteins will be recognised and it will trigger an immune reaction.

Immunoglobulins can be divided into five different classes based on differences in the amino acid sequences in the constant region of the heavy chains. They are IgD, IgM, IgE, IgA and IgG.

When IgA is found in secretions, it has another protein associated with it. This protein is called the secretory piece or T-piece. It is the protein to which two monomeric units of IgA get conjugated.

IgD present on the surface of B-cells has some extra amino acids at C-terminal end for anchoring it to the membrane.

Myasthenia gravis or muscle weakness is caused by circulating antibodies that block acetylcholine receptors at the postsynaptic neuromuscular junction. It inhibits the excitatory effects of neurotransmitter acetylcholine on nicotinic receptors at neuromuscular junctions.

Swelling and destruction of myelin sheath over the nerves occurs in CIDP. Symptoms of this disease include weakness, paralysis and/or impaired movement in arms and legs.