Glossary of Immunological Terms
A
Adhesion Molecule: These are chemicals on cell surfaces (Proteins or Phospholipids) that enable cells to stick or bind together. These are important on the surface of placental cells to allow them to attach to the uterus and to allow the placental cells to join together to make the placenta.
Allele: This is the product of a gene. The gene contains information for the DQ molecule or antenna. Once the antenna or molecule is expressed on the cell surface, it is called an Allele or an antigen.
Allergen: Any substance that induces an allergy (mold, grasses, antibiotics, etc.).
Allergy: This is a condition that involves an immunity in the body against a variety of things that can come into the body including grasses, pollens, molds, etc. The immunity that results is a special one involving an antibody called IgE. This antibody when it combines with the allergen (pollen, mold, antibiotics) causes the immune system to make inflammation that can result in itching, asthma, red eyes, etc.
Alloantibody: An antibody in an individual that is directed against another individual of the same species. Blocking antibodies produced during pregnancy are antibodies of this type.
Alloantigen: This is the chemical that induces the immune response in the woman during pregnancy. The alloantigen is provided by the father to the baby’s placenta.
Alloimmunity: A condition characterized by a specific antibody reaction to another human being. Recognition is usually mediated by small polypeptide chains on the cell membrane. Rh sensitivity is set up by this type of immunity.
Amniocentesis: A procedure in which a small amount of amniotic fluid (fluid around the baby) is removed through a needle from the fluid-filled sac, in which the baby is living. It is done at about 16 weeks of pregnancy. The fluid is studied for chromosomal and other biochemical abnormalities that may affect the health and well-being of the baby.
ANA (Antinuclear Antibody): This test checks for problems similar to lupus and rheumatoid arthritis or other similar immunological diseases that are associated with pregnancy losses or infertility. This test becomes weakly positive in women with infertility and women with recurrent pregnancy losses. This antibody causes inflammation in the body or the uterus when a baby attaches. It is usually reported as ANA positive with a titer of 1:40 or higher with a speckled pattern. This pattern is not typical of lupus, rheumatoid arthritis, or other immunological disorders.
Anaphylaxis: This is an acute, emergency immune reaction that occurs in some patients with allergies. It results in the release of toxins by the immune system that cause the person to pass out, stop breathing, develop asthma, and in some cases go into shock and die.
Antibody: See immunoglobulin.
Anti-DNA/Histone antibody: If a woman reacts to the broken down DNA (histones) and it is a speckled pattern, then she is showing a reaction to her embryos.
Antigen: The chemical that is introduced into a person that starts and completes an immune response. When you are vaccinated (measles), the measles virus is the antigen that results in the antibody that protects you from developing measles.
APA (Antiphospholipid Antibody): These are antibodies in the blood that attach to phospholipids and are structures on the surfaces of all cells. A positive APA test indicates that the woman’s blood clots too fast cutting off blood flow to the baby. These antibodies can also cause the placenta to attach too weakly to the uterus. The usual treatment is baby aspirin and heparin (a blood thinner). Heparin is given as an injection. Both medications are started before pregnancy during the cycle of conception; these are the least controversial of all the treatments for infertility or recurrent pregnancy losses.
Autoimmunity: A condition characterized by a specific antibody (antiphospholipid antibody or antibodies to DNA) or cells (such as Natural Killer Cells) that react with molecules or constituents of the body’s tissue and cause diseases such as rheumatoid arthritis and lupus.
C
Cardiolipin: This is a phospholipid. Some individuals make an antibody to cardiolipin and this causes the blood to clot too quickly. Patients who lose pregnancies through miscarriage sometimes have a false positive test for syphilis because they have antibodies to cardiolipin that were manufactured when the pregnancy miscarried.
CD (Cluster of differentiation): This is a designation used to catalog surface molecules (antennae) on lymphocytes (white blood cells). It tells what the cell is and how activated it is. For example, Natural Killer cells have CD 56+. B lymphocytes express CD 19+ and produce antibodies that sometimes can damage a pregnancy.
CD4 T Helper Cell: This is a T lymphocyte that helps activate CD3 cells in an immunity response by producing cytokines that cause proliferation, differentiation, and growth of other cells necessary for completing the immune reaction. These are usually high normal in women with infertility and recurrent pregnancy losses.
Cell-mediated Immunity: This is immune destruction caused by killer cells, not antibodies. Natural Killer Cells can become activated in infertile women or women who lose pregnancies through miscarriage. These activated cells produce Tumor Necrosis Factor that kills placental cells.
Chorionic villus sampling (CVS): A procedure in which a small sample of cells is taken from the placenta through a small catheter placed up through the vagina and the cervix. This is done earlier in pregnancy than amniocentesis and is used to test for chromosomal and other biochemical abnormalities that may affect the health and well-being of the baby.
Chromosomes: These are a part of DNA. They are rod-shaped structures (genes) located in the center of all cells. These contain the hereditary, genetic material given by both mother and father to the baby. Human beings typically have 23 pairs of chromosomes (46 total). Two of these chromosomes are the sex chromosomes that are called X and Y. Baby girls have 2 X chromosomes and boys have one X and one Y chromosome.
Cryopreserved: This refers to the slow safe freezing of embryos, sperm, or white blood cells for future use. At present, unfertilized eggs do not freeze well. Freezing seems to damage them and make them difficult to fertilize at a later time.
Cytokine: These are hormones produced by white blood cells (lymphocytes) that communicate with other cells of the immune system, recruiting them to perform more aggressive roles in the fighting off of infection or in the rejection of something from the body such as a baby, a kidney or a bone marrow transplant.
Cytotrophoblast: This is a specialized cell of the placenta (also a trophoblast) whose function is to attach the baby to the mother’s uterus. It provides the anchor. It grows deeply into the lining of the uterus (decidua) and firmly attaches to the placenta for the duration of pregnancy.
D
Donor Egg: These are unfertilized eggs taken from a donor woman and then donated to another woman who needs them. This procedure requires assisted reproductive technology procedure using IVF or GIFT.
Down Syndrome: This is a genetic disorder caused by the presence of an extra chromosome 21. (Called trisomy 21). Affected children have mental retardation and characteristic features of the body, face, and limbs. Affected children also have many medical problems such as heart defects.
E
Early Menopause: This is also called premature ovarian failure. (The ovaries run out of eggs too early). The average age of menopause is 51 years of age. Premature menopause occurs before the age of 40. It is often an indicator of autoimmune problems in the woman and is often associated with a long history of infertility or pregnancy loss through miscarriage or IVF.
Egg Donation: The process of taking eggs from a donor, fertilizing them with the male partner’s sperm in the laboratory dish, and transferring the resulting embryos back to the female partner’s uterus. The female partner will not be biologically related to the child but will be the birth mother of record. The male partner will be the biological father of the child.
ELISA (enzyme-linked immunosorbent assay): This is a laboratory test method to analyze blood for the presence and the amount of antibodies in the woman to DNA, phospholipids, and other things. The test tubes are coated with a substance such as the phospholipid. Then the serum to be tested is added. If there are antibodies in the serum against the phospholipid, they attach and in the process of attachment, a color (dye) is released that turns the fluid in the test tube a different color. The intensity of the color tells you how high the immunity is (how much antibody is present).
Embryo: The earliest stage of development of a baby after the egg is fertilized by the sperm.
Endometriosis: A disease condition of women when the tissue that normally lines the uterus each month preparing for a baby (endometrium) leaks out of the uterus inside the body cavity and begins to grow (and menstruate) in locations such as the ovaries, fallopian tubes, bowel, bladder, and abdominal cavity. This causes pain, inflammation, scar tissue, and autoimmunity response in the woman which may make it difficult for her to become pregnant.
Endometrium: The lining of the uterus that is shed through menstruation each month as the menstrual period. As the monthly cycle progresses, the endometrium thickens into zones (seen on ultrasound) and provides a nourishing place for the embryo to attach and begin the process of placental development.
Estradiol: The female hormone that is produced by cells that live in the follicle (nest) around the developing egg. There are three estrogens Estrone E-1, Estradiol E-2, and Estriol E-3.
Estrogen: These are a family of three hormones produced by the ovaries which are responsible for the development of the female sex characteristics. Estrogens are responsible along with progesterone for preparing the uterine lining (endometrium) to thicken for pregnancy. Estrogens are also important for healthy bones, sexual drive, overall health, and well-being. A small amount of estrogen is also produced in males. These do not result in the development of the female sex characteristics for the male hormone testosterone counteracts these effects.
F
Fibrinolysins: These are special proteins in the blood of all normal persons that help blood clots dissolve.
Flow Cytometry: This is a laboratory method where blood is placed into a machine that separates blood cells by size, shape, density, and epitope (antennae) on their surface. The immunophenotype assay and the NK assay are tested by using this machine. Each cell in the machine passes a laser eye and the reflected light is analyzed by the machine. Each type of cell reflects light differently. An NK ( CD 56+) cell gives a different reflection than a B cell (CD 19+).
Follicle Stimulating Hormone (FSH): This brain hormone is produced in the pituitary gland deep in the brain. It is responsible for making the ovary grow and produce eggs. It also tells the ovary when to release the egg (ovulate) and when to begin the production of estrogen by the ovary. In the male FSH does a similar thing to the testicles. It stimulates them to produce and release the sperm to the site where they are ready to be ejaculated.
G
Gamete intrafallopian transfer (GIFT): An assisted reproductive technology that involves removing eggs from a woman’s ovary at surgery, combining the eggs with sperm and immediately injecting both the eggs and the sperm directly into the fallopian tubes of the uterus. Fertilization then takes place on its own inside the tube. One disadvantage of GIFT is that neither the doctor nor the couple knows whether or not fertilization has taken place if the woman does not become pregnant.
H
Heparin: It is a drug that when injected in the proper dosage is a blood thinner and prevents the blood from clotting. It is a natural substance in the body of all persons produced by the liver and lungs.
Hepatitis B and C: These are viruses that may be sexually transmitted, or transmitted by contact with blood and other body fluids that cause infection of the liver leading to jaundice and liver failure.
Histocompatibility: This is a term used to determine how identical two unrelated individuals are. Identical twins are fully histocompatible (same tissues). Brothers and Sisters are semi-histocompatible. The chances of unrelated individuals being histocompatible like identical twins is one in 3 million.
HLA (Human Leukocyte Antigen): These are molecules on the surface of human cells that determine a person’s white blood cell type. Ten numbers make up this system. There are two A numbers, two B numbers, two C numbers, two DR numbers, and two DQ numbers. One number at each locus (A, B, C, DR, and DQ) comes from your mother the other one comes from your father.
Human chorionic gonadotropin (hCG): A hormone that increases early in pregnancy. It is produced by the cells of the placenta that attach the baby to the uterus. Its detection is the basis of all pregnancy tests. It is also used as a drug given to the woman to time ovulation. Once this drug is given, the woman predictably ovulates in 36-40 hours.
Human immunodeficiency virus (HIV): This is a retrovirus that causes acquired immune deficiency syndrome (AIDS), a disease that destroys the body’s ability to protect itself from infection and disease. It is transmitted by the exchange of body fluids or blood transfusions.
Humegon: This drug is used to stimulate ovulation. It contains biologically active FSH and LH. Humegon and hCG are given sequentially for induction of ovulation. It, like Pergonal, is also used in men to treat testicular dysfunction.
Hypothalamus: This is a thumb-sized gland near the base of the brain that controls the pituitary gland. It releases messages called releasing hormones that stimulate the pituitary gland to release its hormones (FSH and LH) in the proper amounts to achieve ovulation. In some women, the hypothalamus is dysfunctional, resulting in infertility.
Hysterosalpingogram (HSG): This is an x-ray test that involves the injection of a liquid dye into the uterus and the tubes. It allows the doctor to see the size and the shape of the uterus, whether there are any abnormalities, and whether the tubes are open to take the sperm to the egg and to deliver the fertilized egg into the uterus.
I
IgG (Immunoglobulin G): This is a protein in the blood produced by B lymphocytes (CD19+). It is an antibody that is present primarily in the lymph system. It is produced by IgM (Immunoglobulin) that resides in the blood. One IgM produces five IgG antibody molecules in a balanced system. It is a Y-shaped molecule consisting of two heavy and two light chains, each having variable and constant regions. The variable regions determine the fit with the antigen that initiated the response like a key-in-lock situation.
IL (Interleukin): This is a generic term for cytokines produced by white blood cells when they are activated and in the process of killing or rejecting something such as an embryo, a kidney transplant, or an infection. CD3-IL2 Receptor + cells are T cells in the process of rejection in the body. They should be below 5% of the total T cells in the immunophenotype testing.
Immunization: This is synonymous with vaccination. A substance is introduced by injection (measles) that then stimulates an immunity response with the formation of antibodies to measles. These antibodies protect the person against getting the infection. Immunization occurs naturally during a successful pregnancy. The woman immunizes herself against her husband’s HLA antigens, and she produces blocking antibodies that protect and aid in the growth of the placenta. Women with recurrent pregnancy losses fail to produce these protective antibodies because they are too similar to their husbands. Immunization (vaccination) with paternal or donor lymphocytes corrects this problem and results in subsequent live-born babies when a pregnancy is established.
Immunoglobulin class: There are five different classes or families of antibodies (immunoglobulins). IgM is the first antibody produced when an immune response is initiated. It lives in the blood system. IgG lives in the lymphatic system and is made by IgM. IgA lives in the organs and protects them. IgD is present as a memory antibody in the blood once a person is immune or immunized. IgE is the antibody that causes allergies and asthma. It is present throughout the body.
In vitro fertilization (IVF): This is a method of assisted reproduction that involves combining an egg with a sperm in a laboratory dish. If the egg fertilizes and begins to divide, the resulting embryo is transferred back into the woman’s uterus where it will hopefully implant and develop. IVF may be performed in conjunction with medications that stimulate the ovaries to produce many eggs to increase the chances of successful fertilization and implantation. IVF bypasses the fallopian tubes and is often the treatment needed by women whose tubes are surgically removed or tied.
Intradermal: Within the top layer of skin. An intradermal injection is an injection in which the medication or the substance used in the immunization is placed within the top layers of the skin, like a mosquito bite.
IVIg (Intravenous Immunoglobulin G Infusion): This gamma globulin preparation is made just like Rhogam, the gamma globulin that is given to Rh-negative women during pregnancy. It is made from pooled blood that is washed and processed (it comes out clear in the end). It takes approximately 2-4 hours to administer in the vein.
K
Killer Cells: These are a family of cells including Natural Killer Cells that destroy target cells (like placental cells and embryos) in a “kiss of death” type encounter.
L
Laparoscopy: The insertion of a long, thin, lighted, telescope instrument called the laparoscope into the body cavity through an incision usually in the navel. During this procedure, the body cavity is pumped full of gas and this allows the doctor to inspect the contents of the pelvic and abdominal cavities. Sometimes other incisions may be made and additional instruments need to be inserted to allow correction of any abnormalities such as removal of endometriosis, ovarian cysts, pregnancies that are in the tubes, etc. A surgeon can also remove scar tissue and open closed tubes during this procedure. He can also flush the tubes to see if they are open. Many times the doctor also looks inside the uterus with a specially designed instrument called the hysteroscope.
Leukocyte Antibody Detection (Cross Match): This is the assay to measure humoral immune responses (antibody production) in the mother (or mother-to-be) against her husband. This immunity is achieved naturally during a normal pregnancy. Women with recurrent pregnancy losses or infertility tend to have lower antibody levels.
Leukocyte: A white blood cell, i.e. a lymphocyte
LIT (Lymphocyte Immunization Therapy): Lymphocyte immune therapy is used in women with recurrent spontaneous abortions. This immunization is made from the father-to-be’s blood or sometimes from a donor’s blood. It is injected under the skin of the mother’s forearm. This is done twice, separated by one month. Testing to see that it has worked is done one month after the second treatment. Common reactions to this treatment include: swelling, irritation, and itching at the injection site. Some women run a fever after this treatment.
Luteinizing hormone (LH): This pituitary hormone works in concert with FSH. FSH starts the development of the egg, and LH finishes the development and starts progesterone production. FSH is important to stimulate the cells of the follicle to produce Estrogen. LH is important to stimulate the cells of the follicle that produce Progesterone during the second half of the menstrual cycle. A certain ratio of FSH to LH tells the ovary when to release the egg (ovulation). In the male, LH stimulates the testicles to produce the male hormone testosterone.
Lymph node: This is a gland that is composed of a collection of lymphocytes that are connected to lymphatic vessels that circulate the lymph in the body. These serve as a sort of filter that looks for something that has entered the body like a germ, virus, pollen, mold, or chemical. It is in this gland that the immunity response is begun. This often causes swelling of the gland because many of the lymphocytes are reproducing and increasing their numbers to assist in the battle that will eliminate the foreign interloper.
Lymph: This is the fluid-like plasma in blood, that contains the lymphocytes of the immunity system.
Lymphocyte: This is a white blood cell that is in charge of starting antigen-specific immunity responses. There are many types of lymphocytes in the immune family. These consist of T cells, B cells, granulocytes, basophils, mast cells, eosinophils, Natural Killer Cells, etc. Each cell type has a CD designation.
M
Menopause: The natural cessation of ovulation and menstruation. Menopause can occur between 42 and 56 years of age but usually occurs around the age of 51 when the ovaries stop producing eggs and estrogen production stops. Many women may experience symptoms of hot flashes and sweats when this process is underway.
Metrodin: This drug contains FSH. It is given sequentially with hCG for ovulation induction.
MHC (Major histocompatibility complex): A genetic system of man that determines the antennae (cell surface molecules) on lymphocytes that are responsible for antigen presentation to T lymphocytes in the elicitation and the expression (the beginnings) of an immune response. This genetic system is responsible for the rapid rejection of grafts between individuals that are not appropriately matched.
N
Natural Killer Cell Assay: This test determines the killing power of a woman’s Natural Killer Cells in the test tube.
Necrosis: This is the death of tissue. It may refer to the death of a cell, the death of clusters of cells (tissue), or the death of an entire organ (for example, liver necrosis).
O
Oocytes: These are the eggs produced by the ovary before fertilization.
P
Pergonal: This is a drug used to stimulate ovulation. It contains equal amounts of FSH and LH. It is administered by injection and is used to stimulate the development of the follicle and the egg in the ovary in women undergoing ovulation induction. This preparation is also used in men with infertility due to primary or secondary problems of sperm production to stimulate sperm production.
Perinatologist: This is an obstetrician/gynecologist who has had extra training in maternal-fetal medicine. They treat high-risk pregnant women and manage their pregnancies and deliveries.
Pituitary Gland: A small hormone-producing gland just beneath the hypothalamus at the base of the brain. The hormones produced control the ovaries, the thyroid, and the adrenal glands of a woman. FSH, LH, and TSH are some of the hormones produced. Disorders of this gland lead to irregular or absent ovulation in the female and abnormal or absent sperm production in the male.
PLI (Paternal Lymphocyte Immunization): See LIT (Lymphocyte Immunization Therapy).
Prednisone: This is a steroid that blocks inflammation of an allergic reaction. A common reaction to this drug is bloating. It is a drug that can cause many side effects. Ask your doctor many questions about its many side effects.
Premature ovarian failure: Cessation of menstruation due to failure of the ovaries before the age of 40. This condition is also called early menopause. It is often associated with autoimmune abnormalities and a history of infertility, IVF failures, or recurrent pregnancy losses.
Progesterone: A female hormone secreted by the ovary after ovulation during the second half of the menstrual cycle (luteal phase). The cells producing the hormone are called luteal cells. The body producing the progesterone in the ovary is called the corpus luteum. Adequate progesterone production is essential for the success of all pregnancies.
R
Recipient: A person who receives donated eggs, sperm, or embryos.
Reproductive Immunophenotype: This checks for the presence of Natural Killer Cells. In most cases, Natural Killer Cells are good because they reduce the likelihood of developing cancer. These tests measure the following CD (Cell Designation) levels:
Rh-negative: This is part of a person’s blood type. Rh refers to rhesus. 15% of women lack this antenna on their red blood cells and are called Rh-negative. Those who have this antenna on their red blood cells are called Rh-positive. It is called the rhesus factor because it was first described in rhesus monkeys. Rh-negative women who are carrying an Rh-positive child can make an antibody against the Rh-positive antenna and destroy the baby's red blood cells. This condition is prevented by giving the women Rh-immunoglobulin (Rhogam) during pregnancy.
Rheumatoid factor: An antibody that reacts with Ig (an immunoglobulin) found particularly in patients with rheumatoid arthritis.
Rhogam: The immunoglobulin, very similar to IVIg, that is given to Rh-negative women carrying Rh-positive infants to prevent her body from developing an immunity against the baby's red blood cells.
S
Semen analysis: The examination of the ejaculation (semen) under the microscope. It determines the sperm count and evaluates their shape and their ability to move correctly and in the proper direction.
Superovulation with timed intrauterine insemination: A procedure to facilitate fertilization. The woman is given drugs to induce ovulation of multiple eggs. When the eggs are ready to be released, the woman is inseminated with her partner’s sperm which has been washed and concentrated. This is usually inserted directly into the uterus through a small plastic tube.
Surrogate: A traditional surrogate is a woman who is inseminated with the sperm of a man who is not her partner to conceive and carry a child to be reared by the biological genetic father and his partner. In this procedure, the surrogate is genetically related to the child. The biological father and his partner must usually adopt the child after its birth. Another type of surrogate is a gestational carrier. This process involves implanting a fertilized egg into the surrogate’s uterus. In this procedure, the surrogate does not provide the egg and is therefore not biologically genetically related to the child. This type of surrogate provides what is often referred to as a host uterus.
Syncytiotrophoblast: This is a specialized cell of the placenta (also a trophoblast) that acts like a dialysis membrane between the mother's blood and the baby's blood, feeding the baby as well as removing waste products from the baby's blood.
T
Testosterone: This is primarily a male hormone produced by the testicles which is responsible for the development and the release of sperm, male physical characteristics, and sexual drive. Small amounts of testosterone are also produced in women by the ovaries and the adrenal glands.
Transvaginal ultrasound aspiration: An ultrasound-guided technique for egg retrieval. A long, thin needle is passed through the vagina into the ovary. When the follicle is entered, suction is applied to retrieve the eggs. It is also known as ultrasound-guided egg aspiration and transvaginal egg retrieval.
Trophoblast: These are the cells of the embryo that become the placenta and attach the baby to the mother’s uterus. These cells provide an armor of protection completely around the baby in the uterus. They also serve to nourish the baby carrying food from the mother’s blood to the baby's blood. These are the cells that are biopsied during a chorionic villus biopsy (CVS) to determine if the baby is genetically normal.
U
Ultrasound: A picture of internal organs produced by high-frequency sound waves viewed as an image on a monitor screen; used to monitor the growth of follicles or a fetus and to retrieve eggs. Ultrasound can be performed abdominally or vaginally.
W
WBC: This refers to white blood cells.
Wheel and flare reaction: This is an immune reaction in the skin that occurs when one has a positive tuberculin skin test or has a positive test when allergy testing is done. It is characterized much like a mosquito bite with an area of central redness in the skin, local swelling (wheal) and the subsequent appearance of a red rim outside the wheal called a flare.