Posted by: Indonesian Children | January 14, 2009

WORK UP DIAGNOSIS AND TEST : HIV – AIDS IN CHILDREN

Lab Studies

  • Prompt diagnosis of HIV infection is critical. As such, the CDC recommends prenatal HIV testing as the standard of care for all pregnant women in the United States. Diagnosis of HIV infection in infants is aided by HIV culture or DNA/RNA PCR; positive results are confirmed by repeating the test. In suspected cases, HIV testing should occur immediately in the newborn period (ie, before the infant is aged 48 h), at age 1-2 months, and again at age 3-6 months. Testing at age 14 days may allow for earlier detection of HIV in infants who had negative test results within the first 48 hours of life. By approximately age 1 month, PCR testing has a 96% sensitivity and 99% specificity to identify HIV.
    • The 2006 Working Group recommendations for diagnosing infants are as follows:
      • Because of the persistence of the maternal HIV antibody, infants younger than 18 months require virologic assays that directly detect HIV in order to diagnose HIV infection.
      • Virologic diagnostic testing in infants with known perinatal HIV exposure is recommended at birth to 14 days, at 1–2 months, and at 3–6 months. Preferred virologic assays include HIV DNA PCR and HIV RNA assays.
      • An antibody test to document seroreversion to HIV antibody–negative status in uninfected infants is recommended at age 12–18 months.
      • In children 18 months and older, HIV antibody assays can be used for diagnosis.
         
    • The Working Group does not recommend use of the currently approved HIV p24 antigen assay for infant diagnosis in the United States because the sensitivity and specificity of the assay in the first months of life is less than that of other HIV virologic tests.
       
  • Monitor CD4+ levels or percentages in infants or patients newly diagnosed with HIV at 3- to 4-month intervals to assess patients’ immune status. In children younger than 6 years, the 2006 Working Group recommends using CD4 percentages over absolute CD4 counts for monitoring disease progression because of inherent age-related changes in absolute CD4 counts.
  • Monitor for opportunistic infections.
    • Perform a CBC count with differential and a urinalysis every 1-3 months in infants. Older child can be screened every 3-6 months (CBC count) or yearly (urinalysis).
    • Culture urine samples monthly for the presence of cytomegalovirus (CMV) until age 2 months and then at 2-month intervals until age 12 months.
       
  • Assess HIV RNA levels twice at baseline and then every 3-4 months. (Consistently use the same HIV RNA assay method to monitor a particular patient.) More frequent testing of HIV RNA levels and CD4 counts may be necessary for children who have virologic or clinical deterioration or when initiating or changing antiretroviral therapy.
  • If the mother is HIV positive, use serologic tests to screen the infant for hepatitis B, hepatitis C, syphilis, and toxoplasmosis.
  • Decreased levels of albumin, serum immunoglobulin G, and CD8+ T cells are linked with fatality in children.
  • Monitor laboratory studies in accordance with drug therapy protocols and clinical status (eg, lipid profile in a patient with lipodystrophy).

Imaging Studies

  • Perform chest radiography, CT scanning, MRI, echocardiography, and ECG for baseline determinations and subsequently as clinically indicated.

Other Tests

  • Perform history and physical examinations at regular intervals (eg, every 2 wk initially in infancy, with an increase in intervals as the child ages and the immune status stabilizes).
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  • Obtain an audiologic evaluation at age 2 years or sooner if concern exists.
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  • Obtain dental examinations at age 1-2 years.
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  • Obtain a neurodevelopmental evaluation every 3-6 months.
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  • Obtain an ophthalmologic evaluation for CMV, tuberculosis, and toxoplasmosis infections, as well as for corneal ulceration, which is often secondary to underlying nutritional deficits.
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  • Obtain a cerebrospinal fluid analysis in patients with neurologic disease (based on risk factors of the area and the clinical presentation of the child).

Procedures

  • Perform endoscopy when esophageal candidiasis is suggested.
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  • Perform a Mantoux test for tuberculosis at age 6 months. (Test patients with control skin tests [eg, tetanus, mumps] to ensure absence of anergy.)
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  • Isolation of acid-fast bacteria in patients in whom pulmonary infection is suggested may be attempted with gastric lavage; it is sensitive in 32% and 48.8% of cases of pulmonary meningitis and tubercular meningitis, respectively.
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Histologic Findings

Biopsy may be considered to clearly determine the presence of an infectious or malignant cutaneous lesion. Maintain a high index of suspicion for a wide array of infections and malignancies, and the appropriate staining and tissue preparation should be requested.

Staging

  • Clinical categories are based on the 1998 CDC guidelines for antiretroviral treatment of pediatric AIDS (review and modification of the 1994 CDC HIV pediatric classification system for clinical categories in children younger than 13 y).
    • Category N: Children are asymptomatic. No signs or symptoms attributed to HIV infection are present, or patients have only 1 category A disorder.
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    • Category A: Children are mildly symptomatic. Patients have 2 or more of the following conditions but no category B or C condition:
      • Lymphadenopathy (³0.5 cm at more than 2 sites; bilateral = 1 site [ie, at the same anatomical location bilaterally])
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      • Hepatomegaly
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      • Splenomegaly
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      • Dermatitis
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      • Parotitis
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      • Recurrent or persistent upper respiratory tract infection, sinusitis, or otitis media

 

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    • Category B: Children are moderately symptomatic. Patients have symptomatic conditions not in category A or category C but that result from HIV infection. Some category B disorders are as follows:
      • Anemia (<8 g/dL), neutropenia (<1000/mL), or thrombocytopenia (<100,000/mL) persisting longer than 30 days
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      • Bacterial meningitis, pneumonia, or sepsis (single episode)
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      • Candidiasis, oropharyngeal (ie, thrush), persisting for longer than 2 months in children aged 6 months
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      • Cardiomyopathy
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      • CMV infection with onset before age 1 month
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      • Diarrhea (recurrent or chronic)
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      • Hepatitis
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      • HSV stomatitis (recurrent, ie, >2 episodes within 1 y)
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      • HSV bronchitis, pneumonitis, or esophagitis with onset before age 1 month
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      • Herpes zoster (ie, shingles) involving at least 2 distinct episodes or more than 1 dermatome
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      • Leiomyosarcoma
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      • Lymphoid interstitial pneumonia or pulmonary lymphoid hyperplasia complex
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      • Nephropathy
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      • Nocardiosis
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      • Fever lasting 1 month
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      • Toxoplasmosis with onset before age 1 month
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      • Varicella (disseminated, ie, complicated chickenpox)

 

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    • Category C: Patients are severely symptomatic. Patients have any condition listed in the 1987 surveillance case definition for AIDS, except for lymphoid interstitial pneumonia, which is now considered a category B condition.
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  • Immunologic categories with CD4+ T cell counts and percentages (based on CDC 1994 revised HIV pediatric classification system) are as follows:
    • Patients younger than 12 months
      • Nonsuppressed (category 1) – CD4+ count greater than 1500 cells/mL (³25%)
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      • Moderate suppression (category 2) – CD4+ count equal to 750-1499 cells/mL (15-24%)
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      • Severe suppression (category 3) – CD4+ count less than 750 cells/mL (<15%)
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    • Patients aged 1-5 years
      • Nonsuppressed (category 1) – CD4+ greater than or equal to 1000 cells/mL (³25%)
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      • Moderate suppression (category 2) – CD4+ count equal to 500-999 cells/mL (15-24%)
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      • Severe suppression (category 3) – CD4+ less than 500 cells/mL (£15%)
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    • Patients aged 6-12 years
      • Nonsuppressed (category 1) – CD4+ count greater than 500 cells/mL (³25%)
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      • Moderate suppression (category 2) – CD4+ equal to 200-499 cells/mL (15-24%)
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      • Severe suppression (category 3) – CD4+ less than 200 cells/mL (<15%)

REFERENCE


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