The immune systems are cells and many other biological structures that are responsible for immunity. This functions as the defense of organisms to protect the body from external biological influences such as recognizing and killing pathogens.
The immune system forms a body defense system that later it against foreign substances such as microorganisms, potentially toxic molecules, or abnormal cells. This system attacks foreign substances or antigens and also gives a warning about that. Repeated exposure to the same material will give a faster and multilevel reply. The immune system will produce antibodies, white blood cells, and various substances. These are all can destroy foreign substances such as bacteria and viruses. Besides, the immune system also consists of:
- Tonsils (tonsils) and thymus that function to make antibodies in the body.
- Lymph nodes, they are responsible for the circulation of lymph fluid and consists of white blood cells that function to protect the body from infection.
- Bone marrow, characterized as soft tissue found in long bones, such as the arms, legs, spine, and pelvic bones. This network serves to produce red blood cells, platelets, yellow marrow, and several types of white blood cells.
- Spleen, an organ in the body to filter and destroy old or damaged red blood cells and platelets, and help the immune system to destroy various foreign substances that can cause inflammation in the body.
- White blood cells, formed in soft bone tissue that have the main function to protect the body from infection.
Development of Fetal Immunology
In pregnancy, the antibodies produced by the fetus are less to respond to the invasion of maternal antigens / bacterial invasion. From the 20th week of pregnancy, the fetal immune response to antigens begins to increase. The fetal response is aided by the transfer of antibody molecules from the mother to the fetus. This is used to provide passive protection lasting up to several weeks. The birth process itself, starting from the rupture of the sealed amnion pouch and then make the fetus exposed to new microorganisms. Candida alicans, gonococcus, and herpes viruses can be found in the vagina. In the case of diagnosed herpes infections, vaginal delivery is not permitted. Babies are prone to get Staphylococcus aureus, a microorganism where the baby’s resistance to its tent to a very small.
To compensate for the immunological status, careful antenatal supervision, examinations to rule out the possibility of infection or therapy to treat infection are very important actions. Also, take the consideration of techniques for giving birth aseptic without including microorganisms and careful care by taking into account all aspects of handling newborns.
Passive Immune System in Fetus
In its development, the fetus can be protected from dangerous environments. Generally, pathogenic germs cannot penetrate the placental barrier. However, in newborns without antibodies, the baby will be very easily infected. Mature babies have acquired maternal antigens and passive immunity to certain types within 6 weeks or more before being born. However, babies who leave a sterile environment suddenly interact with many microorganisms and other antigens. It takes several weeks before active immunity is formed.
Here are several maternal passive immunization processes:
The fetal immune system is strengthened by channeling immunoglobulins through the placenta from the mother to the fetus. This process is through the bloodstream carrying antibodies and channeling through milk. Immunoglobulin profiles are channeled through the placenta and secreted through milk depend on the specific transport mechanism for various classes of immunoglobulins.
Maternal IgG penetrates the placenta into the fetal circulation through a specific active mechanism, which is effective from around 20 weeks ‘gestation, but its activity increases rapidly from 34 weeks’ gestation. The mother will produce an immune response to the antigen she encountered by producing IgG. This later can cross the placenta. Even in lower levels of maternal IgG, it will still be channeled through the placenta. This means that the fetus will receive passive immunization against large pathogens found in the environment after birth. This passive immunity provides important postnatal temporary protection until the babies have a complete system and produce its antibodies.
Changes in the Immune System
- Changes in the Intrauterine Immune System
In the 8th week of pregnancy, there has been an occurrence of immunity in the presence of lymphocytes around the site of the thymus. By the increasing age of the pregnancy, the number of lymphocytes in peripheral blood increases and begins to form lymph follicles. The number of the most lymph of lymphocytes forms at the end of pregnancy. For example, we can find them in lymph, shows red tissue.
Lymphoid cells from the gamma G immunoglobulin molecule is a combination of gamma A and gamma M immunoglobulin. Gamma G is formed mostly after 2 months after the baby is born. Gamma G fetal globulin can be obtained from the mother through the placenta. When an infection occurs, the fetus carries out a reaction with plasmacytosis, adding additional lymphoid follicles and synthesizing immunoglobulin M gamma. Gamma A immunoglobulin can be formed in 2 months pregnancy and found soon after birth, especially secretions from the digestive tract, respiratory, salivary gland, pancreas, and urogenital tract.
Immunoglobulin gamma M increases as soon as the baby is born equal to the state of normal flora in the digestive tract. However, the baby is only protected by Gamma G immunoglobulin from the mother. This is also limited in level as well as the lack of Gamma A immunoglobulin. This immunoglobulin causes the neonate to be more susceptible to infection and sepsis. In the advanced pregnancy, it is also found selimfoit nests that were getting bigger and bigger. Humoral deterrents are formed by lymphoid cells, consisting of symmetric polypeptide pairs. Gama-G is found in adults, a little in the late fetus and formed in the second month after the baby is born. Gama-Globulin comes from the mother which is channeled through the phallus by pinocytosis called passive immunity.
Distribution of immunoglobin G gamma from mother to fetus is not always beneficial for the fetus, such as in Rh isoimmunized rhesus. Maternal gamma G immunoglobin crosses the placenta and damages fetal erythrocytes resulting in erythroblastosis retails. The fetus contains the elements of its father and the place of implantation of the placenta. This is known as allograft rejection. The formation of a deterrent object was found at 5 months’ gestation. Immunoglobulin M gamma production increases after the baby are born. The weakness of newborns is only protected by gamma G maternal immunoglobin to a limited degree and less gamma A immunoglobin.
- Changes in Extra -uterine Immunity System
The immune system of a newborn is still immature, causing the neonate to be susceptible to various infections and allergies. A mature immune system will provide natural and acquired immunity. Natural immunity consists of the body’s defense structures that prevent or minimize infection. After birth, the baby must get exclusive breastfeeding from the mother, since the breast milk contains complete antibodies. They are immunoglobulin A, D, E, G, and M.
Here are some examples of natural immunity:
- Protection by the skin of the mucous membrane
- Airway filter function
- The formation of microbial colonies by the skin and intestines
- Chemical protection by the stomach acid environment
Natural immunity is also provided at the cellular level by blood cells that help newborns kill foreign microorganisms. But in newborns, these blood cells are still immature, it means that the newborn baby has not been able to localize and fight infection efficiently.