Question

In tissue typing for organ transplant, which of the following is matched?
(a)HLA proteins
(b)HLA alleles
(c)Human leukocyte antigens
(d)Haplotypes

Answer 1

Hint: Tissue typing is a group of procedures to determine the type of histocompatibility antigens on a person's cells or tissues, so that when an organ is transplanted to any other patient with the need. The body for the other patient must be able to accept the foreign organ.

Complete answer:
The human leukocyte antigen (HLA) system or complex is studied in tissue typing for the organ transplant. HLA is an important part of the immune system and is controlled by the genes located on the 6th chromosome. The gene is responsible for the formation of cell surface molecules (proteins) that are specialized to present antigenic peptides to the T-cell receptor (TCR) on T cells (plays a central role in immune response). If the patent’s T-cells or receptors are not compatible with the receiving tissue, the antigen and antibody reaction will take place leading to internal damage and death of the recipient.
This procedure is used before transplantation of tissues or organs from the donor to the recipient. In tissue typing HLA (human leukocyte antigen) is matched to see whether they are compatible or not.
The skin, cornea, mucosa of the respiratory, gastrointestinal, and genitourinary tracts form the first line of defense forming a physical barrier. T-cells develop in the bone marrow stem cells and travel to the thymus gland, where they go through rigorous selection. There are 3 main types of T-cell: Helper, regulatory and cytotoxic cells. Only T-cells can recognize non-self-antigens.
So, the correct answer is, ‘Human leukocyte antigens.’

Note: Our immune system can distinguish the self-cells from foreign cells and eliminates any potentially harmful non-self molecules and cells from the body. The immune system also can recognize and destroy abnormal cells that are derived from the host tissues. Any molecule capable of being recognized by our immune system (T-cells) is considered as an antigen (Ag).