Pediatric Hepatitis C
Introduction
Introduction to children with viral hepatitis C Viral hepatitis (viral hepatitis) is a contagious disease caused by hepatitis C virus (HCV), which is mainly caused by liver damage. It was once the main pathogen of hepatitis after transfusion. Because of its insidious onset, it has a high probability of becoming chronic, easily lead to cirrhosis and induced hepatocellular carcinoma, so the prognosis is poor, and the composition ratio of viral hepatitis is less than 15%. . The incidence of children is not high and can be spread by mothers and children and close contact. basic knowledge Sickness ratio: 0.001%-0.002% Susceptible people: young children Mode of transmission: mother-to-child transmission Complications: cirrhosis
Cause
The cause of hepatitis C virus in children
Causes:
Hepatitis C virus (HCV) belongs to the family Flaviviridae. The genome is a single positive-stranded RNA with envelope and nucleocapsid. There are mainly 5 genotypes, and their distribution is regional. China has type II and III. Mainly, HCV is difficult to proliferate in cell culture. Chimpanzee is the only ideal model animal. It can be inactivated by heating with ultraviolet light, 20% hypochlorous acid and chloroform at 100 ° C for 10 min.
Pathogenesis:
The pathogenesis of hepatitis C is not completely clear. It is believed that HCV has direct cytopathic effect and can induce immune damage. Specific CTL is the main mechanism for the body to clear HCV, and it is direct or indirect. An important reason for the destruction of infected hepatocytes, Fas antigen-mediated infection of hepatocytes is also involved in the mechanism of hepatocyte necrosis.
Liver pathological changes are characterized by fatty degeneration, lymphocyte aggregation in the portal area, loss of bile duct or disappearance of bile duct, and hepatocyte necrosis is light.
Prevention
Pediatric hepatitis C prevention
Strict blood donor screening and blood product management and disinfection management of medical equipment can reduce HCV infection transmitted by transfusion products and iatrogenic pathways. There are no active and passive immunization measures.
1. The route of transmission of HCV: mainly through blood transmission, HCV infection among blood donors is one of the main sources of infection, so strengthen the management of blood donors, strengthen the management of blood components such as blood cells in single pulping institutions and Quality control, eliminate the source of cross-infection, strictly control the screening of blood donors, carefully carry out anti-HCV and transaminase screening, establish quality control of HCV diagnostic reagents, carry out more sensitive HCV gene diagnostic methods, and improve screening positive rate We will vigorously promote voluntary blood donation and eliminate the system of paid blood donation.
2. Strengthen the management of blood products: Each production unit strictly selects blood, supplies safe blood products, makes product identification, strengthens blood screening and product quality supervision of production units, and strictly controls the indications for applying blood and blood products. The medical units are strict. Comply with and against abuse to reduce HCV infection.
3. Promote the use of disposable syringes and infusion devices, and strengthen the quality control of disposable injection, infusion device production and sales, strengthen the disinfection management of surgical instruments, endoscopy and dialysis equipment, and divide the room for HCV infection. Equipment surgery, examination and dialysis to reduce the chance of cross-infection.
4. Strengthen the prevention of mother-to-child transmission, and list anti-HCV and HCV RNA as routine examination items for pregnant women. The equipment for anti-HCV and HCV RNA positive pregnant women should be strictly disinfected to minimize neonatal injury and maternal blood pollution.
5. Strengthen research on hepatitis C vaccine: There is no active immunization and passive immunization measures to prevent HCV infection, and hepatitis C vaccine is actively being developed.
(1) Recombinant HCV protein vaccine: The HCV genome encodes a macromolecular polyprotein precursor, which is cleaved by proteases (including protein C, E1, E2 protein and non-structural protein), and the above protein components are expressed by recombinant techniques. Immunization, and can induce cellular immunity to produce specific killer T lymphocytes (CTL) involved in HCV clearance.
(2) Recombinant HCV gene vaccine: The DNA encoding HCV was constructed into eukaryotic expression vector, encoding HCV core, E1, E2 and C and E1, E2 and C and E1, E2 chimera, amplified by Escherichia coli After purification, 293 cells were transfected. It has been confirmed that 293 cells can express HCV antigen and then extract plasmid DNA to prepare vaccination. This DNA immunization will be important for the development of both prophylactic and therapeutic HCV vaccines. effect.
Complication
Pediatric hepatitis C complications Complications cirrhosis
Can develop into hepatitis cirrhosis, hepatocellular carcinoma.
Symptom
Children with viral hepatitis C symptoms Common symptoms Liver function check bilirubin... Single ALT increased jaundice liver pain appetite decreased abdominal distension liver large hard nausea
The incubation period is 2 to 26 weeks, with an average of 8 weeks. The following clinical types and characteristics are common:
1. Acute hepatitis C: multiple onset of concealment, mild symptoms, common fatigue or decreased activity tolerance, anorexia, abdominal discomfort, etc., about 25% of jaundice, mostly mild, mild to moderately enlarged liver, splenomegaly Rarely, ALT can be manifested as a single-phase or multi-phase type increase, the latter type indicates that liver damage is serious or easy to develop into a chronic type, the course of disease is about 3 to 6 months or longer, and there is a tendency to become chronic, about 40%. ~60% converted to chronic hepatitis.
2. Chronic hepatitis C: Classification with hepatitis B, viremia can be persistent or intermittent, the former is more common, the possibility of natural recovery is very small, some children can develop hepatitis cirrhosis.
3. Subclinical hepatitis C: It is a common clinical type in pediatrics. Children with no symptoms of hepatitis often find hepatitis during physical examination or other medical treatment. Further investigation of the pathogen can be diagnosed. In the acute phase, and some have entered the chronic phase.
4. Virus carrying status: From no hepatitis symptoms, no regular liver size and texture abnormalities, no elevation of ALT, liver biopsy was normal or mild lesions.
5. Characteristics of infant HCV infection
(1) Dominant infection: jaundice is prone to occur, and splenomegaly is more common in older children.
(2) Infection by mother-to-child transmission: Infants may present with transient viremia, that is, viremia disappears after several months of birth, and anti-HCV is often negative.
6. HCV mixed infection with other viruses
(1) Mixed infection with HIV: Studies on mother-to-child transmission of mixed-infected infants have shown that the two viruses have synergistic pathogenic effects: HIV infection progresses faster and HCV viremia levels increase significantly.
(2) Mixed infection with HBV: can aggravate liver damage and increase the risk of developing severe hepatitis and hepatocellular carcinoma. HCV replication is often dominant.
Examine
Examination of pediatric hepatitis C virus
Pathogenic diagnosis:
1.HCV:RNA (RT-PCR method) Take serum or liver tissue for qualitative or quantitative detection. Within 1 to 2 weeks after infection, the viral gene in the serum can be detected, which can be used for early rapid diagnosis. An effective indicator of the efficacy of the virus.
2. Serum anti-HCV (including antibodies against structural and non-structural antigens): often detected anti-HCV IgG, positive indicates that HCV has been infected or is being infected; its IgM type antibody can appear before, at the same time, or even after IgG Those who do not regress for more than half a year often turn to chronic hepatitis, and are often positive during the active period of chronic liver disease. 3. HCV antigen test can directly detect the diagnosis of serum, body fluid or liver tissue HCV antigen, and has established immuno-PCR method, which can be detected. Low level expression of HCV antigen.
3. Do abdominal B ultrasound to understand the liver, spleen and so on.
Diagnosis
Diagnosis and diagnosis of viral hepatitis C in children
Diagnose based on
1. Clinical exclusion method: Anyone who does not meet the diagnostic criteria for type A, type B, and type E viral hepatitis, and excludes cytomegalovirus symptomatic infection, EB virus and other known causes of hepatitis, such as drug-induced hepatitis, alcoholic hepatitis , autoimmune liver disease, etc., epidemiological suggestion for non-digestive tract infections may be suspected to be hepatitis C.
2. Specific diagnosis: serum anti-HCV positive, and confirmed liver or extrahepatic tissues such as salivary glands, spleen, peripheral blood mononuclear cells and T lymphocytes positive for HCVAg or HCV RNA, can be diagnosed, due to immunological detection of HCV Antibodies require long-term continuous detection, and nearly 40% of acute hepatitis C has not detected anti-HCV, and unstandardized PCR detection of HCV RNA may have false positives, if both anti-HCV and HCV RNA are positive, or Continuous HCV RNA 2 times positive is more significant.
3. Determining the diagnosis: Where the clinical diagnosis is acute, chronic, severe hepatitis or post-hepatitis cirrhosis, patients diagnosed with hepatitis C virus by pathogenic or serological specific diagnosis are considered as confirmed cases, and there is one in children. Overlapping or co-infection of the above viruses requires a distinction.
Differential diagnosis
Infectious toxic disease
Because the biotransformation function of the liver of children is not perfect, it lacks sufficient inactivation and attenuation ability for drugs or other toxic substances entering the body, or metabolically active substances or terminal products produced in the body, so liver damage and liver function are prone to occur. Abnormal, infectious diseases such as sepsis, typhoid fever, infectious mononucleosis, leptospirosis, toxic hepatitis, parasitic diseases, etc. often complicated by liver dysfunction, so it is primary liver disease or secondary liver damage It is a problem often encountered in clinical practice, and attention should be paid to the difference.
2. Infant hepatitis syndrome
Neonatal hepatitis syndrome or infant hepatitis syndrome is possible as a clinical name, but pathogenically includes hepatitis B virus, hepatitis C virus (HCV), and hepatitis G virus (HGV), which can be transmitted through mother to child. Cytomegalovirus (CMV), Epstein-Barr virus, various enteroviruses, paramyxoviruses, herpes simplex virus, Toxoplasma gondii, etc. It is quite difficult to make a clear pathogen diagnosis due to various clinical limitations. Fortunately, most neonatal hepatitis The clinical experience is good.
3. Nutritional diseases
The local symptoms of chronic hepatitis in children are not obvious. Sometimes, only general health and growth and development are not good. In consideration of common diseases such as malnutrition, liver conditions and HBV serum markers should be examined. On the other hand, there have been many cases in recent years. Obese children with overnutrition are also misdiagnosed as hepatitis due to abnormal biochemical tests of liver function.
4. Metabolic disease
Infants with occasional e antigen-positive mothers develop severe hepatitis and liver failure. At this time, it is necessary to identify with some rare congenital metabolic abnormalities such as tyrosinemia, citrullineemia, and glycogen storage disease. , galactosemia, hepatolenticular degeneration, etc., children also have clinical manifestations of hepatomegaly and liver failure, because HBsAg of severe hepatitis B virus is often negative, which increases the difficulty in diagnosis of hepatitis B, when the pathogenic diagnosis cannot rely on HBsAg, at this time HBV DNA, anti-HBc IgM detection has greater significance.
It is necessary to synthesize epidemiological characteristics and clinical manifestations, mainly relying on experimental methods for specific diagnosis.
