Leukocyte adhesion molecule deficiency type I in children
Introduction
Brief introduction of type I leukocyte adhesion molecule defect LADI is a rare primary immunodeficiency disease. The clinical manifestations are delayed umbilical cord detachment, repeated soft tissue infection, chronic periodontitis and peripheral blood leukocytes, which often die in the neonatal period. basic knowledge The proportion of illness: 0.001% Susceptible people: children Mode of infection: non-infectious complication:
Cause
Pediatric leukocyte adhesion molecule deficiency type I etiology
(1) Causes of the disease
The integrin 2 (CDL8) subunit is the three integrins, phagocytic-associated antigen-1 (Mac-1, CDL16), lymphocyte function-associated antigen-1 (LFA-1, CDL1a) and p150, 95 molecules (CDL1c). As a common component, the ITBG2 gene encoding CDL8 is located at 21q22.3. The ITBG2 gene mutation types, including point mutations, deletions, insertions and splicing mutations, result in loss of CDL8 function and autosomal recessive inheritance.
(two) pathogenesis
CDL8 is expressed on the surface of all leukocytes and plays an important role in the directed movement of leukocytes and adhesion to vascular endothelial cells. CDL8 deficiency prevents leukocytes from passing through vascular endothelial cells and displacing to the inflammatory part, which is the cause of LADI.
The pathological features of this disease are that the various tissues are completely deficient in neutrophils, and no local purulent substances are produced, but the pulmonary inflammation is normal.
Prevention
Pediatric leukocyte adhesion molecule defect type I 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, preventing the birth of children, leukocyte adhesion molecule deficiency type I is a rare primary immunodeficiency disease, early Accurate diagnosis, early delivery of specific treatment and provision of genetic counseling (prenatal diagnosis or even intrauterine treatment) are very important.
Complication
Pediatric leukocyte adhesion molecule deficiency type I complications Complication
Causes a serious systemic infection, or the wound does not heal for a long time.
Symptom
Pediatric leukocyte adhesion molecule deficiency type I symptoms common symptoms umbilical cord infection repeated infection soft tissue infection fungal infection
It is mainly caused by repeated bacterial infection of skin mucosa, characterized by painless necrosis, ulceration, progressive enlargement or systemic infection, and delayed umbilical cord detachment due to umbilical cord infection. The most common pathogen is Staphylococcus aureus. Gram-negative bacteria in the intestines, followed by fungal infections; viral infections are not common, and no pus formation at the site of infection is characteristic of this disease.
The expression of CDL8 molecules in severely deficient children is less than 1% of normal people, and the condition is serious. It often dies from repeated infections in infants and young children. CDL8 is moderately deficient in 2.5% to 30% of normal people. The condition is mild and severe. Gingivitis and periodontitis, trauma or surgical wounds can not heal for a long time, can survive to adulthood.
Examine
Pediatric leukocyte adhesion molecule defect type I examination
Peripheral blood neutrophils are significantly increased, especially in infection, up to 5 to 20 times higher than normal, the proliferation of T cells and B cells is decreased, serum immunoglobulin levels are in the normal range, T cell-dependent antigen phage x174 The antibody response is reduced, the cause of which is unclear, neutrophil chemotactic function is weakened, ic3b-conditioning particles bind and phagocytic dysfunction, and neutrophil-mediated antibody-dependent cytotoxicity is absent.
Flow cytometry can be used to analyze the positive rate of CDL8 in peripheral blood neutrophils. ITGB2 gene analysis can find various types of gene mutations, thus confirming the diagnosis, conducting prenatal diagnosis and discovering carriers of the disease.
Chest X-ray and B-ultrasound are often required, and are generally selected according to clinical needs.
Diagnosis
Diagnostic diagnosis of leukocyte adhesion molecule defects in children
Repeated soft tissue infections, chronic ulcers of the skin and mucous membranes, and infants with peripheral neutrophils should consider the possibility of this disease. Most have a history of delayed umbilical corditis and umbilical cord loss. Flow cytometry measures neutral granules. The positive rate of CDL8 in the cells can confirm the disease.
LADI should be differentiated from leukocyte adhesion molecule type II (LADII).
