Chronic granulomatous disease

Introduction to chronic granulomatosis Chronic granulomatous disease (CGD) is a hereditary granulocyte bactericidal deficiency characterized by extensive granulomatous lesions in the skin, lungs and lymph nodes. Most patients are male. X-linked recessive inheritance; a few are autosomal recessive inheritance, both sexes can occur. Clinical manifestations are characterized by repeated severe infections and the formation of pigmented granuloma at sites of repeated infection. basic knowledge The proportion of illness: 0.002% Susceptible people: no special people Mode of transmission: mother-to-child transmission Complications: pneumonia, empyema, lung abscess, colitis, enteritis, anal fistula, rhinitis, chronic diarrhea, lupus erythematosus, juvenile rheumatoid arthritis

Causes of chronic granulomatosis

Genetic factors (78%):

The disease is X-linked recessive inheritance, and a few are autosomal recessive inheritance, both of which can be ill. The main drawback is that the hydrogen peroxide produced by the host phagocytic system is insufficient to kill the catalase-positive bacteria, causing widespread spread of infection. Granuloma is a response to contrast-induced purulent infections, often with pigmented lipid tissue cells infiltrating and wrapping.

Pathogenesis

Normal granulocytes phagocytose bacteria, degranulate to produce hydrogen peroxide, and release new ecological oxygen after phagocytosis, oxidize iodine and chlorine compounds into free iodine and chlorine to form complete hydrogen peroxide-peroxidase-iodine Ion sterilization system, due to the lack of NAPDH oxidase, this disease can not produce hydrogen peroxide, so that bacteria that can not produce hydrogen peroxide such as Staphylococcus aureus, Candida albicans, Klebsiella, E group Escherichia coli, sticky The bactericidal function of Serratia, etc., but the streptococcus which can produce hydrogen peroxide, pneumococci still have a killing effect. In short, there is a disease caused by the lack of bactericidal activity of granulocytes.

Chronic granulomatosis prevention

1. Avoid close marriage, pregnant women with a family history, early intervention, it is recommended to do prenatal examination.

2. Strengthen care and nutrition to improve patient resistance and immunity.

3. To prevent infection, attention should be paid to isolation to minimize contact with pathogens.

Chronic granulomatosis complications Complications Pneumonia, empyema, lung abscess, colitis, enteritis, anal fistula, chronic diarrhea, lupus erythematosus, juvenile rheumatoid arthritis

Complications of the disease:

1. Repeated infections such as pneumonia, empyema, lung abscess, enteritis and colitis, can go to the anal fistula, common in the liver, spleen, lung and bone abscess, the occurrence of Aspergillus abscess in the brain, esophagus, small intestine and ureter can block.

2. rhinitis;

3. Gastric sinus stricture;

3. Chronic diarrhea;

4. Delayed development of sick children, often resulting in short stature, with lupus erythematosus, juvenile rheumatoid arthritis.

Chronic granulomatosis symptoms Common symptoms Diarrhea Brain abscess Liver splenomegaly Gastric sinus stricture Skin granulomatous Eczema

Generally in childhood, characterized by repeated infections of the skin, lungs and lymph nodes, the pathogens are often catalase-producing bacteria such as Staphylococcus aureus, Serratia, Escherichia coli and Pseudomonas, And cause purulent lymphadenitis, rhinitis, conjunctivitis, lung and chronic dermatitis, liver abscess and osteomyelitis are also more common, gastric stenosis can cause gastric sinus stenosis, in addition, can cause retinal damage, chronic diarrhea, Perianal abscess and brain abscess, etc., may have skin granuloma, eczema dermatitis, liver, spleen, in each affected organ, granuloma formed by tissue cells containing pigment lipids can be seen, and the disease is generally delayed.

Examination of chronic granulomatosis

1. Tetrazolium blue test (NBT): chemiluminescence test and oxidase activity assay NBT can be used as a screening for CGD, and can also be used to screen female X-linked CGD carriers. Chemiluminescence test is a sensitive but An indicator that is not specific for the production of superoxide ions. Neutrophils in CGD patients do not produce chemilumines, while X-linked female carriers produce only a moderate amount of chemiluminescence. In addition, flow cytometry is used. The production of superoxide ions to determine the activity of the oxidase.

2. Neutrophil bactericidal function test: Determination of the bactericidal ability of neutrophils to catalase-positive bacteria such as Staphylococcus aureus or Escherichia coli can be used as a preliminary screening test for the diagnosis of CGD.

3. Identification of CGD types: Genetic analysis found that mutations or deletions can confirm CGD and can understand the different types of CGD.

4. Prenatal diagnosis: At present, molecular analysis of fetal DNA by molecular hybridization, PCR and restriction fragment polymorphism analysis (RFLP) can be used for prenatal diagnosis of CGD.

5 other: white blood cell count may increase due to infection; but may not produce hydrogen peroxide, superoxide and other reactive oxygen species due to lack of nisin adenine dinucleotide phosphate (NADP) oxidase activity; other granulocytes Proteins (such as cytochrome b245) may also be lacking, often with anemia, and bone marrow smears can be seen in dark blue tissue cells.

According to clinical manifestations, symptoms, signs, choose to do ECG, B-ultrasound, X-ray, biochemical examination.

Diagnosis and diagnosis of chronic granulomatosis

According to the repeated occurrence of skin, organ purulent infection, and hepatosplenomegaly in infants and young children, granulocytes increase and NBT function is reduced, which can be diagnosed.

Molecular genetic analysis of myeloid cDNA or genomic DNA can assist in diagnosis and typing, and can identify the site of mutation. DNA can be extracted from fetal chorionic or amniotic cells for prenatal diagnosis. In the absence of the above methods, the tetrazolium blue test can be used. And take placental blood analysis.

Differential diagnosis

It is mainly distinguished from those with repeated infections with hepatosplenomegaly. The tetrazolium blue test should be used to screen leukocyte function and should be identified with the following diseases:

1. G-6-PD deficiency: the patient's leukocyte G-6-PD activity is also reduced, generally about 80% of normal, this patient is prone to hemolytic anemia and repeated infection, due to lack of enzymes, white blood cells are not measured To the metabolic activity of the hexose monophosphate bypass, it cannot be corrected for methylene blue, which is different from CGD.

2. Leukocyte glutathione peroxidase deficiency: The condition is milder than CGD, and there are no heterozygous patients in the family.

3. Family lipoprotein histiocytosis: late onset, only female onset, its granulocyte defects are similar to CGD.

4. Chronic granuloma around the appendix should be distinguished from ascending colon cancer: located in the retroperitoneal appendix, due to long-term chronic inflammation of the appendix, appendix exudation, peritoneal tissue wrapping, repeated exudation and gradually increase, absorption The process of chronic granuloma formed around the appendix, from the appearance, texture, the naked eye is difficult to distinguish from malignant tumors, but retrospective fever, right lower quadrant pain and diarrhea and other medical history, are consistent with the clinical manifestations of chronic granuloma around the appendix.

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