Phagocytosis deficiency

Introduction to phagocytic deficiency Degenerative deficiencies, including chronic granulomatosis and Chediak-Higashi syndrome, phagocytic defects will lead to increased susceptibility to pathogenic microorganisms, and various infections of pyogenic bacteria and conditional pathogens often occur. Defects in primary phagocytosis refer to innate or hereditary endogenous phagocytic insufficiency. basic knowledge The proportion of sickness: 0.00001% Susceptible people: no specific population Mode of infection: non-infectious complication:

Phagocytosis

(1) Causes of the disease

The cause of phagocytic function deficiency is mostly hereditary diseases. For example, CGD is mainly a chromosomal genetic disease, but it can also be inherited in an autosomal recessive manner. For this reason, girls can also develop disease, so children with white blood cells are experimental. In the chamber test, it can be proved that the phagocytic bacteria do not increase the oxygen consumption of leukocytes, do not form peroxide or hydrogen peroxide, the bacteria are not killed, and there are also leukocytes lacking peroxidase, or lack of glucose dehydrogenation of 6-phosphate. Enzyme, or lack of pyruvate kinase, lack of 6-phosphate glucose dehydrogenase, can not kill catalase-positive bacteria; lack of pyruvate kinase, the ability to kill staphylococcus, chronic granulomatosis is X-linked Recessive inheritance, a few are autosomal recessive, Chédiak-Higashi syndrome is a genetic disease of autosomal recessive genes, and its etiology is still not clear.

(two) pathogenesis

Chronic granulomatosis is X-linked recessive inheritance, a few are autosomal recessive, and Chédiak-Higashi syndrome is a genetic disease of autosomal recessive genes, and its pathogenesis is still unknown.

The pathogenesis of phagocytic defects may be neutropenia, and the function of phagocytic cells is insufficient.

Neutropenia

Congenital hereditary neutropenia is rare. The number of polymorphonuclear leukocytes in these children is less than 5.0×108/L, showing frequent infection, and periodic neutropenia is 15 to 35 days. Repeated reduction of one cycle (average 21 days), reduction period of several days, the number can be reduced to 5.0 × 107 / L, accompanied by pancreatic insufficiency of neutropenia (Shwachman syndrome or systemic disseminated sarcoidosis) The child is stunted, showing symptoms such as fatty spasm and repeated infection. The number of neutrophils is reduced to 2.0 to 4.0×108/L. Patients are often accompanied by mild diabetes. These children have poor prognosis for viral infection. Neutropenia with low immunoglobulin is a group of more common diseases. These children may have elevated IgM at the same time. Children with lazy leucocyte syndrome have neutropenia. Respiratory tract infections, gingivitis, stomatitis, etc., patients with white blood cells can not move to chemotactic stimuli in vitro; there is no cohesion in the skin window test; after giving fresh plasma, this abnormal reaction can not be changed.

The cause of leukopenia is mostly hereditary disease, or a family history can be detected. Cyclic neutropenia is a defect of bone marrow stem cells. During neutropenia, monocytes increase. The increase in granulocyte colony-stimulating factor excreted from the urine indicates that it is not an obstacle to the production of granulocyte-forming hormone.

2. Insufficient function of phagocytic cells

(1) chronic granulomatous disease (CGD): the disease is mainly seen in male children, usually in the following years after birth, recurrent purulent infection, sputum and cellulitis are the most common, often complicated by lymph node suppuration, and then Caused by osteomyelitis, the white blood cells of these patients devour bacteria, but they can not kill them, but they are protected by white blood cells, not affected by their antibodies, complements and drugs.

(2) Chédiak-Higashi syndrome: This is a rare syndrome in which the number of polymorphonuclear leukocytes is reduced, and the normal function is lacking. The response to chemotaxis is poor, the bactericidal ability is low, and the patient repeatedly has severe suppuration. Sexual infections, accompanied by skin pigmentation, shame, hepatosplenomegaly, etc., can survive to adults rarely.

(3) Job syndrome: It is a phagocytic deficiency disease involving girls. It is mainly caused by the inability to remove invading staphylococci, accompanied by pigment deficiency and eczema.

The above-mentioned retarded leukocyte syndrome belongs to leukocyte function defects, and other chemotactic defects may detect complement deficiency or leukocyte antibodies.

Phagocytic deficiency prevention

1. Prevention of hereditary immunodeficiency

The genetic factors of immunodeficiency account for a large proportion, especially in severe cases. Therefore, for people with immunodeficiency, such as repeated episodes of multiple suppuratives, diarrhea without obvious infectious agents, antibiotics, antibiotics, etc. Before marriage, immunological examination should be carried out, and the immune laboratory should be submitted to the immune laboratory for the detection of immune cells, serum immune factors and related cytokines, as well as in vitro and in vivo immune function tests. At the same time, genetic inquiry should be made, including the personal history of both men and women. , family history, malformations, etc., for cleft palate, cleft lip can further check the function of thymus and thymus; skin whitening should check its relationship with Wiskott-Aldrich syndrome.

2. Prevention of teratogenic infant immunodeficiency

In order to avoid the immunodeficiency caused by fetal teratogenicity, in addition to the previous personal history, family history, malformations, etc. of the parents of the fetus, it is necessary to prevent the mother from being infected with rubella virus, cytomegalovirus, etc. during pregnancy to prevent the use of teratogenic tendency. Drugs, to prevent harmful rays, such as gamma rays, X-ray irradiation, etc., in the prenatal examination, should pay attention to whether the fetus is deformed, deformed children can interrupt the pregnancy.

3. Prevention of secondary immunodeficiency

Strengthen physical exercise, maintain physical and mental health, prevent excessive fatigue and malnutrition, actively treat infectious diseases that may lead to immunodeficiency, correctly use therapeutic drugs, immunosuppressive agents or immunomodulators; if necessary, supplement missing immune factors to ensure immune function normal.

Phagocytic defect Complication

1. Chronic granulomatosis can be complicated by hepatosplenomegaly, deep abscess and pneumonia, and other rhinitis, conjunctivitis, dermatitis, liver abscess and so on.

2. Chédiak-Higashi syndrome, which can be complicated by albinism (melanocytes), nervous system diseases (neural cells) and hemorrhage (platelets).

Symptoms of phagocytic deficiency disease Common symptoms Granuloma lymphadenopathy Repeated infection of hepatosplenomegaly abscess

1. Chronic granulomatous disease (CGD), mostly in childhood, often has significant lymphadenopathy, hepatosplenomegaly, deep abscess and pneumonia, pathogenic bacteria are mostly peroxidase-negative, such as Staphylococcus epidermidis, Staphylococcus aureus, Serratia, Escherichia coli and Pseudomonas, other symptoms include rhinitis, conjunctivitis, dermatitis, liver abscess, etc., patients generally have delayed development.

2. Chédiak-Higashi syndrome, a rare genetic disease involving autosomal recessive genes involving multiple organs, clinical manifestations: recurrent pyogenic infection, partial eye and skin albinism, central nervous system abnormalities Organs have non-malignant lymphocyte infiltration, abnormal lysosomes in many tissue cells, leading to infection (neutrophils), albinism (melanocytes), nervous system diseases (neural cells) and hemorrhage (platelets).

Examination of phagocytic deficiency

1. Laboratory examination of chronic granulomatosis

White blood cell count may increase due to infection, but may not produce hydrogen peroxide due to lack of NADP oxidase activity, superoxide and other reactive oxygen species, other granulocyte proteins may also be lacking, granulocyte tetrazolium blue (NBT) reduction test Missing, abnormal sterilization test.

2.Chédiak-Higashi syndrome

Laboratory examination: patients with neutropenia, chemotaxis and bactericidal power, NK cell activity decreased, but killing T cell activity was normal.

Chédiak-Higashi syndrome, under the light microscope, visible neutrophils, monocytes, lymphocytes in the cytoplasm and platelets have larger particles, this abnormal lysosome fusion.

Diagnosis and identification of phagocytic deficiency

diagnosis

1. Chronic granulomatosis can be diagnosed based on clinical manifestations and low neutrophil bactericidal function.

2. Chédiak-Higashi syndrome can be diagnosed based on clinical manifestations and laboratory tests.

Differential diagnosis

1. Chronic granulomatosis needs to be differentiated from hepatosplenomegaly, deep abscess and pneumonia, and other rhinitis, conjunctivitis, dermatitis, liver abscess.

2. Chédiak-Higashi syndrome needs to be differentiated from albinism (melanocytes) and nervous system diseases (neural cells).

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