Transplantation And Hla Matching MCQ Assessment

HLA-DR, -DP and -DQ antigens are encoded for by class II genes. These genes are part of the major histocompatibility complex (MHC) in humans. Class II genes are responsible for encoding proteins that play a crucial role in the immune system, specifically in presenting antigens to T cells. The HLA-DR, -DP, and -DQ antigens are important for immune recognition and response, and their encoding genes are classified as class II genes.

HLA antigens are encoded for by genes found on chromosome six. The HLA system, also known as the human leukocyte antigen system, is a group of genes that play a crucial role in the immune system. These genes are located on chromosome six, which is one of the 23 pairs of chromosomes found in humans. The HLA antigens are important for immune recognition and the ability to distinguish between self and non-self cells. By being encoded on chromosome six, these genes ensure that the HLA antigens are properly expressed and function effectively in the immune response.

HLA-A, -B, and -C antigens are encoded for by class I genes.

MHC molecules are glycoprotein complexes, meaning they are proteins that have attached carbohydrate molecules. These complexes are encoded for by genes found on chromosome 6. This indicates that the genes responsible for producing MHC molecules are located on chromosome 6. Therefore, the correct statement is that MHC molecules are glycoprotein complexes encoded for by genes found on chromosome 6.

This statement correctly describes the process of serum cross-matching and PRA. When anti-HLA antibodies bind to HLA antigens on donor cells, it triggers the activation of complement, a part of the immune system. This activation leads to the formation of the membrane attack complex, which can cause damage to the donor cells. This process is important in determining compatibility between a donor and recipient in organ transplantation.

The correct answer is that MCH class II molecules are encoded for by HLA-A-, HLA-B and HLA-DR genes. This statement is incorrect because MHC class II molecules are actually encoded for by HLA-DR, HLA-DP, and HLA-DQ genes. The HLA-A and HLA-B genes encode for MHC class I molecules, while the HLA-C genes also encode for MHC class I molecules. MHC class III molecules, on the other hand, encode various components of complement.

Based on the information provided, 40 out of 50 wells show cell death and take up the dye. This means that 80% (40/50) of the population is experiencing cell death and taking up the dye. Therefore, it can be estimated that 80% of the population are unsuitable donors.

The human leukocyte antigens are also referred to as MHC, which stands for major histocompatibility complex. MHC molecules are proteins found on the surface of cells that play a crucial role in the immune system by presenting antigens to T cells. These antigens are recognized by T cells, which then initiate an immune response against foreign substances or infected cells. Therefore, MHC molecules are essential for immune recognition and response.

There are three different classes of HLA molecule. HLA molecules are proteins found on the surface of cells that play a crucial role in the immune system. These molecules are responsible for presenting antigens to immune cells, which helps in the recognition of foreign substances and initiation of an immune response. The three classes of HLA molecules are HLA class I, HLA class II, and HLA class III. Each class has a distinct function and is involved in different aspects of the immune response.

For kidney transplants, it is essential to match HLA-A, HLA-B, and HLA-DR antigens. These antigens are part of the human leukocyte antigen (HLA) system, which plays a crucial role in the immune response. Matching these antigens helps to minimize the risk of rejection by ensuring compatibility between the donor and recipient. HLA-A, HLA-B, and HLA-DR antigens are highly polymorphic, meaning they have many different variations. Matching these antigens increases the likelihood of a successful transplant and reduces the chances of graft rejection.

The HLA-DR locus has one mismatch. This means that there is a difference or variation in one specific region or allele of the HLA-DR gene. This mismatch could be due to a genetic mutation or variation in the DNA sequence of the HLA-DR gene. It is important to note that mismatches in the HLA-DR locus can have implications for organ transplantation and immune responses.

The HLA-B locus refers to a specific region of the human leukocyte antigen (HLA) gene complex. Mismatches in this locus occur when there are differences between the alleles present in two individuals. The answer states that there are two mismatches for the HLA-B locus, indicating that there are two instances where the alleles between two individuals differ at this specific gene region.

Familial matching refers to the likelihood of a complete match between siblings. The correct answer states that there is a 25% chance of a complete match between siblings. This means that siblings share, on average, 25% of their HLA alleles, which are important for immune system compatibility. This percentage indicates the probability of a complete match between siblings in terms of these specific alleles.

The correct answer is "panel reactive antibody". The PRA test estimates the percentage of the population that are likely to be unsuitable donors.

Gel electrophoresis is a technique used to separate molecules based on their electrical charge. In this process, an electrical field is applied to a gel matrix, causing charged molecules, such as DNA or proteins, to move through the gel. The movement of these ions is determined by their charge and size, allowing for the separation of different molecules based on their characteristics. Therefore, the statement "Gel electrophoresis describes the movement of ions across an applied electrical field" best applies to gel electrophoresis.

HLA typing can be done using serological and molecular methods. Serological methods involve testing for the presence of specific HLA antigens using antibodies, while molecular methods involve identifying specific HLA genes or alleles using techniques such as PCR or DNA sequencing. Both methods are used in HLA typing to determine an individual's HLA profile, which is important in various medical applications such as organ transplantation and disease susceptibility.

There are no mismatches for the HLA-A locus. This means that there is a perfect match between the alleles at this specific location.

Pre-transplant tests include ABO blood typing, HLA typing, serum cross-matching, and the PRA. These tests are performed to assess compatibility between the donor and recipient before a transplant procedure. ABO blood typing determines the blood group of the individuals involved. HLA typing identifies the human leukocyte antigen compatibility, which is crucial for successful transplantation. Serum cross-matching detects the presence of antibodies in the recipient's serum that may react with the donor's cells. The PRA (Panel Reactive Antibody) test measures the level of antibodies in the recipient's blood against a panel of potential donors. Therefore, the inclusion of "serum" and "serological" in the answer is appropriate as they refer to the tests and procedures involved in pre-transplant evaluation.

HLA alleles are expressed in a co-dominant fashion, meaning that both alleles in a heterozygous individual are fully expressed and contribute to the phenotype. This is in contrast to a dominant-recessive relationship, where one allele is dominant and masks the expression of the recessive allele. In co-dominance, both alleles are equally expressed, resulting in a combined phenotype that shows characteristics of both alleles. Therefore, the terms "co-dominant" and "codominant" can be used interchangeably to describe the expression pattern of HLA alleles.

Based on the given HLA types, the recipient has two different DR alleles (DR1 and DR4), indicating that they are heterozygous for the HLA-DR allele. On the other hand, the donor only has one A allele (A1) and no other A allele, indicating that they are homozygous for the HLA-A allele.

SSP-PCR stands for Sequence-Specific Primer Polymerase Chain Reaction. It is a molecular method used to detect specific DNA sequences. In SSP-PCR, specific DNA primers are used to target and amplify the desired DNA sequence. This method is commonly used in HLA typing, where it is used to assign a specific HLA tissue type. Therefore, the statement that SSP-PCR requires the use of specific DNA primers is correct.

SSP-PCR is a technique used for genotyping specific alleles. It involves a single cycle consisting of three stages: denaturation, annealing, and extension. The PCR process is used to amplify the DNA, and then a post-amplification step is performed to detect the specific alleles. If no amplification product is observed, it can be assumed that the individual does not express the specific allele being tested. Therefore, the statement "in the absence of an amplification product, it can be assumed that the individual does not express a specific allele" is correct.

Individuals that are antigenically similar are said to be histocompatible or compatible. Histocompatibility refers to the ability of cells or tissues to be accepted without an immune response. When individuals are histocompatible, it means that their antigens are similar enough that they can tolerate each other's cells or tissues without triggering an immune response. This is important in organ transplantation, where histocompatibility is crucial to prevent rejection of the transplanted organ. Compatibility, on the other hand, refers to the ability of two individuals to coexist or work well together. In the context of the question, both terms can be used interchangeably to describe the antigenic similarity between individuals.

HLA genes, also known as human leukocyte antigen genes, are located very close together on the chromosome. This means that they are inherited as a group, or en bloc. Each individual inherits two sets of these genes, one from each parent. These sets of genes are called haplotypes.

The correct answer is that smaller DNA fragments migrate faster towards the cathode. This statement is incorrect because in agarose gel electrophoresis, DNA fragments migrate from the cathode (negative electrode) to the anode (positive electrode). The negatively charged DNA is attracted to the positive electrode and moves towards it. Therefore, smaller DNA fragments will migrate faster towards the anode.