Pediatric Acquired Immune Deficiency Syndrome Nephropathy

Introduction to Pediatric Acquired Immunodeficiency Syndrome Nephropathy Chronic serious disease caused by human immunodeficiency virus (HIV), causing kidney damage and glomerular sclerosis. HIV infection in humans mainly causes damage to helper T lymphocytes, namely CD4+ T lymphocytes, and reduces health search, and causes damage to other immune functions, causing various opportunistic infections and tumors, eventually leading to death. AIDS has become popular in countries all over the world. Because of its poor prognosis and high mortality rate, there is no cure at all, which has already caused serious consequences. basic knowledge The proportion of illness: 0.0024% Susceptible people: children Mode of transmission: mother-to-child transmission Complications: renal insufficiency

Pediatric acquired immunodeficiency syndrome nephropathy

(1) Causes of the disease

Infants and children are infected through the mothers of their AIDS carriers and blood transfusions, so the transmission of AIDS in children is mainly through menstrual blood transmission and vertical transmission. The incidence of blood and blood products with AIDS virus is high in newborns or children. Especially in children with hemophilia A, the prevalence rate was 30% after the input of factor VIII; 57 cases were counted and 12 cases were related to blood transfusion. Pediatric cases account for about 1% of AIDS cases. Since the discovery of the human immunodeficiency virus (HIV), the pathogen of AIDS in 1983, new progress has been made in the diagnosis and treatment of this disease.

(two) pathogenesis

1. Pathogenesis The pathogenesis of HIV-associated nephropathy is still unclear. It has been reported that HIV-N is a disease limited to glomeruli. Whether glomerular sclerosis associated with HIV infection is directly caused by the virus invading the kidney, or indirectly through other mechanisms to promote glomerular hypertrophy, remains to be further explored. Studies have suggested that either hemodynamics or infection-related circulatory factors, such as acute phase reactants or interleukins, may be important factors in altering glomerular permeability. It has been noted that there are disorders of interleukin metabolism in HIV-infected patients, especially high circulating (IL-1) beta and TNF levels; early renal dysfunction associated with HIV infection may be associated with glomerular permeability Defect-related and evidence of poor tubule dysfunction.

2. Pathological changes When glomerular proteinuria occurs, renal biopsy should be carefully considered. Renal biopsy showed that the histology of the kidney was different, except for mild mesangial hyperplasia, focal glomerular sclerosis, minimal lesions, focal necrotic glomerulonephritis and other glomerular pathological changes, in the interstitial The homologous unique proteinaceous substance is filled in the dilated renal tubules, and the atrophied tubular epithelium and interstitial cell infiltration are all visible. Acute tubular necrosis, allergic interstitial nephritis, kidney infection, tumor, vascular damage, and renal calcium deposition are all seen. Autopsy and biopsy revealed a small tubuloreticular inclusion bodies (TRI) in the glomerular capillary endothelial cells. IgM and C3 are present in immunofluorescence, and IgA is deposited in the mesangial area.

Pediatric acquired immunodeficiency syndrome nephropathy prevention

Mainly to prevent HIV infection, use disposable syringes, prudent blood transfusions and blood products to prevent HIV-infected women from becoming pregnant. Consultation on HIV and voluntary HIV testing are common among all pregnant women, helping early treatment of pregnant women themselves and prevention of perinatal infections. Treatment of HIV patients can reduce their risk factors for developing kidney disease.

Pediatric acquired immunodeficiency syndrome nephropathy complications Complications, renal insufficiency

Commonly associated with serious infections, such as Pneumocystis carinii pneumonia, lymphocytic interstitial pneumonia, repeated bacterial infections (including tuberculosis, etc.), enteroviral meningitis, arbovirus encephalitis, also cause nerve roots Neuropathy and vascular disease (stroke). All children have progressive weight loss, diarrhea and growth retardation. Children with this disease have progressive renal insufficiency, multiple system, multiple organ damage.

Pediatric acquired immunodeficiency syndrome nephropathy symptoms common symptoms repeated infection fever nephrotic syndrome slow growth nephrogenic edema lymphadenopathy proteinuria diarrhea

Children with AIDS nephropathy should be asked in detail about their medical history, including their mother's medical history, history of sexually transmitted diseases, drug dependence and history of drug use, and whether or not children have blood transfusions and blood products. Adult AIDS has the characteristics of long incubation period, relatively long course of disease and complicated condition. However, children's AIDS, especially in infants and young children, is very different from adult AIDS. The incubation period is relatively short and the disease progresses rapidly. In children with HIV-N, a urine test abnormality occurs after the diagnosis of HIV infection, mainly proteinuria. It is characterized by an increase in the ratio of microalbumin/creatinine in the urine, which is a manifestation of nephrotic syndrome proteinuria, which is one of the important clinical features of HIV-N. Mostly, it is a manifestation of nephrotic syndrome, proteinuria, edema, and hypoproteinemia. Normal blood pressure, progressive azotemia, and enlarged kidneys show an acute progression, which can progress to end stage renal disease (ESRD) and does not respond to treatment. The clinical performance of children with AIDS depends to a large extent on the location and type of opportunistic infection that occurs. Vertically transmitted HIV infections, the main clinical manifestations of growth stagnation, lymphadenopathy, chronic cough and fever, recurrent lung infections, and persistent diarrhea. Pulmonary diseases can be found in more than 80% of pediatric AIDS patients, which is the main cause of complications and death. The three children reported by Beijing Children's Hospital all had long-term and repeated cough as the main clinical manifestations, including 1 case of pneumonia 6 times. In addition, these children have progressive wasting, diarrhea and growth retardation. Pulmonary infections are mainly Pneumocystis carinii pneumonia (PCP), lymphocytic interstitial pneumonia (LIP), and repeated bacterial infections, including tuberculosis. PCP is the most common opportunistic infection of AIDS in infancy, and its main clinical manifestations are shortness of breath, hypoxia and X-ray examination. The early stages of LIP are asymptomatic and have bilateral lung shadows. Infections of the central nervous system include acute self-limiting diseases such as enteroviral meningitis, severe diffuse or focal infections that cause destructive sequelae (eg, arbovirus encephalitis). All clinical manifestations of CNS infection are secondary to toxic mediators such as the release of cytokines. These factors are neurotoxic and cause clinical manifestations of encephalopathy, such as motor abnormalities and paralysis. Many of these diseases also cause radiculopathy and vascular disease (stroke). Some manifestations of oral and facial pediatric HIV-infected patients, including candidiasis, herpes simplex virus infection, linear gingival erythema, oral hairy leukoplakia.

Pediatric acquired immunodeficiency syndrome nephropathy

HIV counseling and voluntary HIV testing for all pregnant women to detect perinatal HIV infection early also contributes to early treatment and perinatal infection prevention in pregnant women themselves.

Virological examination

For suspected HIV-infected infants, HIV virology should be performed as soon as possible (within 48 hours of birth), including virus isolation or PCR detection of HIV DNA or RNA. After the first test results are obtained, the second time (as in 14 days after birth) should be checked as soon as possible to determine if there is HIV infection. Virological testing should also be repeated at 1 to 2 months of age and 3 to 6 months of age. The use of PCR to examine HIV DNA is the most appropriate method of testing for HIV infection in infancy. PCR detection of HIV RNA may also be useful in the diagnosis of perinatal HIV infection, but with limited data. The sensitivity of HIV isolation is similar to that of PCR for detecting HIV DNA, but the isolation and culture process is complex and expensive. For infants under 1 month of age, it is not advisable to use HIV p24 antigen alone to diagnose or rule out HIV infection, because at this stage the test has a high frequency of false positive results. When collecting specimens, cord blood should not be used because it may be contaminated by maternal blood. Within 48h or 48h after the birth of the baby, the virological test positive is an intrauterine infection; and the virological test is negative within 1 week after birth, but then becomes positive at birth, which is the infection at birth. The number of copies of HIV RNA after 1 month of age in intrauterine infections and those born at birth is more valuable for prognosis and disease progression. Infants with a history of HIV exposure should repeat the test at 1 to 2 months of age, even if the initial virological test results are negative. If the result is negative, the test should be repeated at 3 to 6 months of age. If the virological test results of both specimens are positive, the diagnosis can be confirmed. Two or more test results are negative, two times within one month of age, and one test at 4 months or older and the result is negative, HIV infection can be ruled out.

2. Classification check

At the same time as the diagnosis is established, the patient should be classified; this is important for the selection of treatment measures and the judgment of prognosis. Classification is done in three ways: infection status, immunological status, and clinical status.

(1) Infection status: divided into HIV infection and non-HIV infection. 1 HIV infection: HIV IgG antibodies alone are not sufficient to make a diagnosis of HIV infection because HIV IgG antibodies from mothers can be 18 months old in infants. The most sensitive and specific method for detecting HIV infection is to detect HIV DNA or RNA by PCR, or to isolate HIV from plasma, mononuclear cells or cerebrospinal fluid by virus isolation. Because these methods can detect 30% to 50% of HIV-infected infants within a short period of time after birth; almost 100% of HIV-infected infants can be detected at 3 to 6 months of age. The detection of p24 antigen is not sensitive enough, especially when the level of HIV antibody is high, a considerable amount of p24 antigen binds to the antibody to form an antigen-antibody complex, and thus is not easily detected. However, the use of certain techniques to dissociate the antigen-antibody complex can increase the sensitivity of antigen detection. 2 No HIV infection: HIV infection can be ruled out in the following cases: A. Infants with HIV-infected mothers undergo seroconversion after 6 months of age (ie, HIV antibodies are converted from positive to negative). B. Other laboratory test evidence for no HIV infection. C. Does not meet the criteria for the definition of AIDS surveillance cases (the main point is: non-umbilical blood samples collected from two HIV-infected mothers within 18 months of age, respectively, by PCR, virus isolation or p24 antigen detection) .

(2) Immunological status: Mainly classified according to CD4 T lymphocyte count. Because normal CD4 T lymphocyte counts vary from adult to adult at different ages, the US CDC has different classification criteria for different age groups (Table 2). In the CD4 cell index, the percentage change in CD4 cells is more important than its absolute number. In HIV infection, CD4 cells decrease with the progression of infection; those with lower CD4 cells have a poorer prognosis. Once the diagnosis of HIV infection is established, CD4 cells should be examined every 3 months thereafter.

3. Detection of viral load

HIV viral load has a guiding role in antiviral therapy. The viral load is generally determined by quantitative detection of HIV RNA. The results of the assay are expressed in terms of the copy number of HIV RNA. Adult data indicate that HIV RNA levels will decrease by a considerable margin (102 to 3) 6 to 12 months after acute HIV infection, reflecting the interaction of the body's immune system with the virus. After that, a certain steady state is reached. However, the HIV infection obtained during the perinatal period is different from that of adults, and the high copy number of HIV RNA lasts for a long time. The number of copies at birth is generally below 10,000/ml, up to 100,000/ml at 2 months of age, and up to 10 million/ml at 2 months. Slowly lower later. For infants under 1 year of age, if the copy number of HIV RNA is above 2.99×105/ml, it may be related to disease progression or even death; when the copy number is above 100,000/ml and the CD4 cells are less than 15%, May indicate the possibility of disease progression and death. When the methods of quantitative detection of HIV RNA are different, the results are different. When the same specimen is tested by different methods, the results can be 2 times different. Usable methods include quantitative PCR (such as Amplicor HIV-1 Monitor of Luo Diagnostic System), branched-strand DNA detection (Quantiplex of Chiron Corporation, USA), and detection of plasma RNA (NASBA of Organon Technika Co., Ltd.) based on amplification of nucleic acid sequences. It is important to always use the same technology after selecting a technology from a particular manufacturer in order to continuously monitor the viral load. The above three detection techniques have different requirements for the amount of specimens. The smallest amount of blood specimens (100 l) is NASBA technology, followed by Amplicor's HIV-1 Monitor (200 l), while Quantiplex requires 1 ml of plasma. Another noteworthy phenomenon is that HIV RNA varies over the same day or on different days, with a range of up to three times. In infants or children, the scope of this change may be even greater. Therefore, after repeated testing, viral load should be considered only when the change in HIV RNA copy number is more than 5 times (ie, 0.7 log 10) in children under 2 years of age, and more than 3 times (ie 0.5 log 10) in children over 2 years of age. Clinical and biological changes. In order to eliminate the occurrence of detection technology, one sample can be divided into two parts, and the average value is used as the detection value. For a treatment plan, it is not possible to make changes based on only one test result, and the test can be changed after repeated test confirmation. Conventional imaging examinations such as B-ultrasound, X-ray film and brain CT often found that the whole body lymph nodes were swollen, and pulmonary inflammation lesions were found, and obvious central nervous system occupying lesions were found. Pulmonary infection is a major cause of common complications and death, mainly PCP, LIP, bacterial pneumonia and tuberculosis. PCP is the most common opportunistic infection of AIDS in infancy. Chest X-rays show reticular, flocculent and cord-like blurred shadows around the hilum. As the disease progresses, small patches of blurring and knots appear. The knotted shadows can also be merged into larger flaky shadows. Nodular shadows are often multiple. Pulmonary lesions generally develop from the two lungs along the bronchus to the periphery, and the two lung tips and lung base are rarely affected or affected less. The early stages of LIP are asymptomatic and have bilateral lung shadows. The lungs have increased texture or dot-like shadows, and the lungs are obviously feather-like. The late stage is interstitial fibrosis, which is a honeycomb lung shadow. Infections in the central nervous system can cause severe diffuse or focal infections, causing clinical manifestations of encephalopathy, such as motor abnormalities and paralysis, as well as radiculopathy and stroke.

Diagnosis and diagnosis of nephrotic acquired immunodeficiency syndrome in children

The clinical diagnosis of children with AIDS nephropathy includes a history of sexually transmitted diseases, drug dependence and drug abuse in the mother, or a history of application of blood transfusions and blood products. After laboratory tests confirmed the presence of HIV infection, multiple systemic damage and urine test abnormalities, urine microalbumin / creatinine ratio increased, you can confirm the disease.

Diagnostic principles for HIV infection in infants born to HIV-infected mothers:

1. 18 months of infants with a confirmed diagnosis with ELISA detection antibody 2 positive and confirmatory test (immunoblot or fluorescence-free detection) 1 positive; or 2 different virus detection tests in different samples (HIV isolation, HIV gene and p24 Positive for antigen determination; or there is a pediatric AIDS definition disease (see clinical typing). Presumed diagnosis of infants 18 months: Have a virus test (ibid.) positive (except cord blood).

2. The <18-month-old baby's definitive diagnosis is positive for any two viral test tests (ibid.) in different samples; or there is a pediatric AIDS-defining disease.

3. Except for congenital immunodeficiency disease.

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