RH Negative Blood Dictionary
*A work in progress and updated when I write a new article.
ABO – Refers to human blood groups, A, B, AB, O
ABO compatability-Used as a blood transfusion term. A person is ABO compatible with another person when their blood doesn’t carry A or B antigens that will provoke a response in the other person’s serum. In transfusion terms, a person is compatible with another person if his blood can be transfused into the other without provoking an immune reaction also known as a transfusion reaction.
Agglutinate- verb used to describe red blood cells when they clump. This clumping is how the body responds to the antigens (proteins).
Allele- is an alternative form of a pair or series or genes at the same locus.
Amorph- a gene that is silent, NULL because it produces no detectable effect.
Antibody – An immunoglobulin produced by B lymphocytes (white blood cells made in the bone marrow). Antibodies bind to antigens and foreign molecules to inactivate them or mark them for destruction.
Antigen – Cell surface markers that are either a sugar or protein. Antigens causes the production of antibodies. Antigens can be introduced into the body or it may be formed from within. They provoke an immediate body reaction. The blood factors A, B, and Rh are antigens and typically most antigens are proteins. What Landsteiner refers to as factors or X factors are called antigens today.
Antigen-Antibody reaction – The result of a combination of molecules from an antigen with one or more molecules of its specific antibody that produces an immune response.
Anti-human antibody reaction- Is produced when human serum is injected into other animals like rabbits, guinea pigs, and goats. They recognize it as foreign and produce antihuman-antibody, nowdays called, antihuman globulin. This is known as Coombs serum.
Anti-Rh antibody – Antibodies formed in Rh negative people (Rhd) in response to the Rh factor (RhD) , which negative people don’t have. These antibodies form with the sole purpose to attack and destroy all red blood cells that are RhD (positive).
Anti-sera – Clear serum containing antibodies
Anti-species antibodies – Antibodies common to every species that are active against other species. The strength of the reaction depends on their place on the phylogenetic distance.
Antithetical- Refers to alternative forms of and antigen produced by the alleles. E, e, K, k.
Autoimmune hemolytic anemia – A hemolytic anemia due to antibodies arising against membrane glycoproteins or the patient’s own red blood cells usually against P or the Rh antigens.
Blood factors – an inherited antigen present on the surface membrane of red blood cells of some individuals but not on others. Landsteiner called these X factors in his day.
Blood Group – synonym for blood type. Immunologically distinct class of blood distinguished by absence or presence of antibodies
Blood Group System – Per ISBT definition-A system controlled at a single gene locus or by very closed linked genes
Bilirubin – The orange or yellowish pigment found in bile. It is carried into the liver by the blood. It’s also signals the breakdown of hemoglobin when red blood cells are destroyed.
CDE – Alternative term in the medical literature used for many years to mean Rh blood group system.
Chromosone – An extremely long DNA molecule that carries the genes
Complement – A heat stable system of proteins that takes part in host defense by causing lysis or phagocytocis
Congenital idiopathic anemia – A severe and progressive reduction in hemoglobin soon after birth now known as HDN
Coombs Test – A lab test for hemolytic disease of the newborn. Rh positive blood cells after incubation with serum being screened for anti D (Rhd) are washed with isotonic saline. The washing removes all proteins or antigens except anti-D. The washed red blood cells are then suspended in the animal anti-human globulin. If the red cells are coated with anti-D, agglutination occurs, and the test is positive.
Double incompatibility – Used when a fetus is both ABO blood type and Rh Factor type incompatible with its mother. A fetus that is blood group B+ is doubly incompatible with its A- mother.
Erythroblast- A young or precursor nucleated red blood cell.
Erythroblastosis – The presence of erythroblasts in circulation.
Erythroblastosis fetalis – Horrific disease of fetus and newborns. It occurred when red blood cells from an Rh positive fetus cross the placenta and provokes an immune response in the Rh negative mother. The mothers anti-Rh antibodies then cross over to the fetus, destroying the baby’s red blood cells and creating an abnormally high number of immature red blood cells. It once was a leading factor in fetus and newborn death until the advent of RhoGAM. Now part of the disease process of HDN.
Exchange transfusions – The infusion of Rh negative blood into a newborn’s vein while simultaneously, withdrawing old blood through another. At first, the ankle/wrist, or the skull and wrist were used until doctors settled on using the umbilical cord. The term “exchange transfusion” was coined by Alexander Weiner and became accepted practice for newborns born with Rh hemolytic disease.
Fetus- an unborn child between eight weeks and delivery, before that it’s called an embryo.
Gamma Globulin – Proteins found in blood serum and where antibodies are made. GG is in everyone’s blood. The ability to resist infections is directly relatable to g. globulin also called immunoglobulin.
Gene – an inherited unit of the genetic code that is the blueprint for a specific property of a cell. Each gene has a defined location on a chromosome.
Genotype – The overall genetic makeup of a plant or animal. Specifically the makeup at a particular locus that is responsible for a blood group antigen.
Glycoprotein – A protein containing at least one carbohydrate group.
HDN – See Hemolytic Disease of the Newborn
Heme – See Bilirubin
Hematopoiesis – The process of making blood cells.
Hemoglobin – The iron containing pigment of the red blood cells. It carries oxygen from the lungs to the tissues.
Hemolysis – Destruction of the red blood cells and the release of hemoglobin into the serum. See in snake bite reactions as well as when antibodies provoke the immune response.
Hemolytic Disease of the Newborn or HDN – Currently known as a disease of the fetus and newborn. Characterized by red blood cell destruction due to the mothers IgG antibodies to the child’s red cell antigens crossing the placenta. The consequences of HDN are anemia, jaundice, kernicterous, erythroblastosis, hydrops, and death.
HLA – Human leukocyte antigen.
Hydrops – The most severe form of Erythroblastosis fetalis. The baby is born waterlogged, swollen, and dead.
Homologous – Having a similar position, structure, or function.
Icterus – Yellowing of the skin caused by bilirubin. Occurs when red blood cells are destroyed and the breakdown products accumulate in the body.
Icterus gravis neonatorium – A manifestation of HDN. A severe jaundice of the newborn appearing a few hours after birth and rapidly progressing.
IgG – Abbreviation of immunoglobulin G, one of the five types of immunoglobulin found in higher vertebrates. They are abundant and active against the Rh antigen and can cross the placenta.
IgM – Abbreviation of immunoglobulin M, which is the first type of antibody made by the B lymphocyte, and the first major type secreted into the blood at the first exposure of an antigen. Doesn’t pass into the placenta.
IgSF – Immunoglobulin superfamily of cell surface proteins that enable cells to adhere, bind, and recognize other cells.
IL – Interleukins – Proteins produced by the body.
Immunoglobulin – Antibodies. See IgM and IgG.
Immune response or reaction – A self-protecting response by the body by creating an antibody against the invading antigen. Symptoms occur as the two react from minor to life threatening depending on the response. In the tests of Landsteiner & Weiner, the rabbit formed antibodies against the rhesus monkey blood (antigen). The rabbits antibodies were then used to test for clumping which signaled a new protein (antigen).
Immunization – Process of inducing immunity. Once the system is primed by exposure to an antigen, it will respond to all invading challenges with enough antibodies to destroy the foreign substance.
In utero – In the uterus of the body ( fetus).
In vitro – In glass like a test tube.
In vivo – In the body, not the lab.
ISBT – International Society of Blood Transfusion.
Jaundice – Yellowing of the skin and seen first in the whites of the eyes. A sign that red blood cells are being destroyed.
Kernicterus – A form of hemolytic disease of the newborn when the brain and spinal cord becomes stained with yellow pigment. Develops between the 2-8 day of light and prognosis is very poor.
L-W- The LW blood system was first described by Landsteiner and Wiener in 1940 and called the Rhesus factor or Rh factor. Once it was determined that two different systems were at work, Rh factor changed to LW in 1982. The protein system causing disease is now the Rh system. This was done to prevent confusion. To learn more go to Wikipedia and type in ICAM4. LW is carried on chromosome 19. LW isn’t associated with anemia or disease.
Locus – Precise place on a gene or chromosome.
Natural antibodies – Old documents used this term for the antibodies anti-A and anti-B because scientists thought they weren’t stimulated. In 1959 it was discovered they were stimulated but this term stuck. It’s obsolete now.
Natural knockouts – Term used for the null phenotypes like Rh null, which has no genes from the Rh system.
Passive antibodies – Antibodies made after injection of an antigen. Vaccines are an example.
Phenotype – The characteristics of a person or organism that can be appraised biochemically or objectively measured such as blood group A for example.
Placenta – An organ with the sole purpose to sustain the life of a child in the uterus. Named by the ancient Romans.
Plasma – The liquid part (clear) of the lymph system. Seen in blood tubes when the red blood cells clump and drop to the bottom while the clear plasma rises to the top. Does not carry oxygen to the cells, but is a volume expander. Plasma helps blood flow through the blood vessels.
Post-partum – Time after delivery of a baby.
Reagent – A chemical used in a lab to test for another chemical. Anti-B antibody is a reagent that tests for B red blood cells by clumping them.
Recessive – The allele that is not expressed when the dominate allele is present.
Red blood cells – Cells that carry hemoglobin and oxygen to the body and give it their red color. The outer membrane of red blood cells carries the blood factors or antigens.
Rh compatible – When one person’s blood doesn’t provoke an immune response with another person’s blood. People with Rh negative blood are compatible with all people, including Rh negative and Rh positive people. Rh positive people are compatible with only other Rh positive people.
Rh Factor – An antigen found on the outer membrane of red blood cells in about 85% of people. It was named in 1940 after a similar protein found on rhesus monkey cells. It was wrongly thought that the agglutinating antibodies produced in the mother’s serum in response to her husbands RBCs were the same specificity as antibodies produced in various animals’ serum in response to RBCs from the Rhesus monkey. In error, the paternal antigen (Rh+) was named the Rhesus factor. By the time it was discovered that the mother’s antibodies were produced against a different antigen from the one discovered by Landsteiner and Weiner, the rhesus blood group terminology was being widely used. Therefore, instead of changing the name, it was abbreviated to the Rh blood group.
Rh hemolytic disease – see HDN
Rh negative blood – Red blood cells that don’t carry the Rh factor.
Rh null blood – Rare blood with currently 2015 less than 50 people identified world wide. They are Rh null because the gene for the entire Rh system is missing. This causes fragile blood cells and chronic anemia. People who are Rh null can only receive a transfusion from someone with Rh null blood. They are encouraged to donate for themselves in case of an emergency.
Rh positive blood – Red blood cells that carry the Rh factor.
RhoGAM – Ortho’s registered trademark for Rh vaccine
Rh System – The Rh blood group system is one of thirty-three current human blood group systems. It is the most important blood group system after ABO. At present, the Rh blood group system consists of 50 defined blood-group antigens, among which the five antigens D, C, c, E, and e are the most important. The word Rhesus has been dropped.
Rh vaccine (generic definition) – Potent Rh antibody, in the form of the 7S fraction of the gamma globulin. It’s administered to the Rhd woman after she delivers a baby or has a miscarriage, to prevent her from developing immunity to the Rh factor. If she doesn’t get the vaccine after delivering an Rh positive baby or miscarriage, the next baby, if also Rh positive could be born with major health problems or even dead.
RHAG – The official name of this gene is “Rh- associated glycoprotein. This protein encoded by this gene is red blood cell specific. It’s believed to be part of a membrane channel that transports ammonium and carbon dioxide across the red blood cell membrane. Associated with Rh – hemolytic anemia. It is located on chromosme 6.
RHD — Rh blood group, D antigen, also called Rh polypeptide 1. The RHD gene codes for the RhD red blood cell protein known as Rh factor (antigen) of the Rh blood group system. It is similar to RHCE, RhAG, RhBG, and RhCG. These 5 genes constitute the Rh family gene set and are active in hemolytic anemia.
Serum – The clear liquid part of blood that separates from red blood cells in the test tube. It carries the antibodies.
7S – Found in the serum inside gamma globulin where antibodies exist. 7S is a small molecule of gamma globulin that can pass through the placenta from mother to child.
Titer – The concentration of a substance, usually an antibody, in solution.
Tranfuse – Literally the pouring of blood from a bag into a person.
Transfusion reaction – A body’s reaction to mismatched blood. There is immediate or delayed hemolysis due to an allergic response with urticaria, fever, bronchospasm. inflammation, and possible heart failure.
Umbilical vein – The vein that links a fetus to the placenta.