congenital thymic hypoplasia
Introduction
Introduction to congenital thymic hypoplasia Congenital thymic hypoplasia is also known as DiGeorge syndrome or the third and fourth pairs of pharyngeal sac syndrome. It is a congenital immune deficiency caused by abnormalities of the pharyngeal sacs in the first to sixth stages of the embryo. In the 6th to 10th week of the embryo, the thymus, parathyroid gland and part of the face, aortic arch and cardiac tuberculosis develop from the first to the sixth cell components of the pharyngeal sac. By the 12th week of pregnancy, the thymus migrates to the chest, as before. Embryonic tissue development abnormalities cause the intrinsic, the disease is scattered, it is speculated that it is not caused by genetic defects, may be caused by abnormal embryonic environment, such as mother alcoholism may be one of the pathogenic factors. Pathological examination revealed thymus and thyroid absent or hypoplasia. There were no gender differences in the patients. basic knowledge The proportion of illness: 0.001% Susceptible people: infants and young children Mode of infection: non-infectious Complications: juvenile rheumatoid arthritis autoimmune hemolytic anemia thyroiditis
Cause
Congenital thymic hypoplasia
Congenital immunodeficiency (35%):
The cause of this disease is congenital immunodeficiency caused by dysplasia of the pharyngeal sac in the early embryonic stage. In the 6th to 10th week of the embryo, the thymus, parathyroid gland and part of the face, aortic arch and cardiac tuberculosis are from 1st to the 1st 6 The cell components of the pharyngeal sac developed and formed. By the 12th week of pregnancy, the thymus migrated to the chest, which was previously caused by abnormal development of these embryonic tissues.
Prevention
Congenital thymic hypoplasia prevention
Pregnant woman health care
It is known that the occurrence of some immunodeficiency diseases is closely related to embryonic dysplasia. If pregnant women are exposed to radiation, receive certain chemical treatments or develop viral infections (especially rubella virus infections), they can damage the fetal immune system. Especially in the early pregnancy, it can affect multiple systems including the immune system. Therefore, it is very important to strengthen the health care of pregnant women, especially in the early pregnancy. Pregnant women should avoid receiving radiation, use some chemical drugs with caution, and inject rubella vaccine to prevent as much as possible. Virus infection, but also to strengthen the nutrition of pregnant women, timely treatment of some chronic diseases.
2. Genetic counseling and family survey
Although most diseases cannot determine the genetic pattern, genetic counseling for diseases with defined genetic patterns is valuable if genetically immunodeficiency in adults will provide the developmental risk of their children; if a child has autosomals Recessive genetic or sexually linked immunodeficiency disease, it is necessary to tell parents that their next child is likely to be sick, for patients with antibodies or complement deficiency patients should check the antibody and complement levels to determine the family disease For some diseases that can be genetically mapped, such as chronic granulomatosis, parents, siblings and their children should be genetically tested. If a patient is found, it should also be performed among his or her family members. Check that the child's child should be carefully observed at the beginning of the birth for any disease.
3. Prenatal diagnosis
Some immunodeficiency diseases can be prenatally diagnosed, such as cultured amniotic fluid cell enzymology can diagnose adenosine deaminase deficiency, nucleoside phosphorylase deficiency and some combined immunodeficiency diseases; fetal blood cell immunological test can be Diagnosis of CGD, X-linked no-gammaglobulinemia, severe combined immunodeficiency disease, thereby terminating pregnancy and preventing the birth of the child.
Complication
Congenital thymic dysplasia complications Complications juvenile rheumatoid arthritis autoimmune hemolytic anemia thyroiditis
The main complication of this disease is secondary infection due to immunodeficiency.
Symptom
Congenital thymic hypoplasia Symptoms Common symptoms Hypocalcemia Eye widening Heart malformation convulsions
1. Can appear after birth:
1 special features, such as wide eye distance, small jaw, low auricle and other deformities.
2 stubborn hypocalcemia, simple calcium can not be corrected.
3 aortic arch abnormalities, such as the right aorta, Fallot's quadruple sign.
Examine
Examination of congenital thymic hypoplasia
Laboratory examination
(1) Lymphocytes decrease in peripheral blood, especially T cells decrease, and the percentage of B cells increases.
(2) Cellular immune function has been reduced to varying degrees.
(3) The humoral immune function is variable, and serum immunoglobulin is often not low.
(4) The blood calcium content is lowered.
(5) The level of parathyroid hormone is lowered.
2. X-ray inspection
Shows that the thymus is shrinking or absent.
3. Lymph node biopsy
Lymphocyte deficiency in the paracortical area is shown.
Diagnosis
Diagnosis and diagnosis of congenital thymic hypoplasia
Diagnosis can be based on medical history, clinical symptoms, and laboratory tests. This disease should be distinguished from other causes of thymic dysfunction, the disease is a genetic disease, that is, thymic dysplasia, but not combined with parathyroid function insufficiency. After the neonatal period, repeated infections of viruses, fungi or Pneumocystis carinii, or infections are chronic processes, and the inoculation of various live attenuated vaccines such as vaccinia, BCG and measles vaccines often causes serious reactions and even death. Severe patients are prone to bacterial infections.
