The Clinic Visit

Once HIV is diagnosed, it is very important to have frequent follow up visits with a doctor who specializes in the treatment and management of HIV. This is usually an infectious disease doctor. It is recommended that young children and adolescents see a pediatric infectious disease specialist. Sometimes it will be necessary for your infectious disease doctor to call on other specialists to assist in the management of complications that may arise from the HIV.

During a typical outpatient clinic visit, your child will be weighed and measured. This is very important as the HIV may slow a child's growth. Vital signs will be monitored since medications can affect these, particularly blood pressure.Your child will then be examined by the doctor. Other specialists that may meet with the family include the dietary specialist or nutritionist, social worker or a doctor from a different specialty. After the examination, it is usually necessary for most children to have laboratory or blood tests drawn. These tests are to monitor the amount of virus activity in the child and how much destruction is occurring to the immune system. Other blood tests are performed to monitor for side effects of the HIV medications. HIV medications can cause serious side effects on body organs, such as the liver and pancreas. It is extremely important for your child to be examined and to have labs monitored on a frequent basis. The frequency of visits will be determined by your health care team.

The following blood tests are those most frequently monitored:

• Complete Blood Count (CBC) - This test monitors the number and function of red blood cells, white blood cells, and platelets.
  1. White Blood Cells - these cells are produced by the immune system and help defend the body against infection. There are several types of white blood cells and each one works differently. A high white blood cell count might be a sign of infection somewhere in the body. A low white blood cell count might be the result of HIV infection or another serious illness or disease.
  2. Hemoglobin - this is a measure of red blood cells in the body. Red blood cells deliver oxygen throughout the body. A low red blood cell count might indicate anemia, which can cause a person to feel tired or have decreased energy. Anemia can sometimes be caused by a chronic or longstanding disease such as HIV or by the medications used to treat HIV such as AZT.
  3. Platelets - platelets are produced by the bone marrow. They help the blood to clot. Some antiretroviral medications can cause a low platelet count.

• The Blood Chemistry Screen - Sodium, potassium, chloride, bicarbonate, phosphate, calcium, and magnesium are all electrolytes. Electrolytes are substances in the body that play an important role in the operation of the cells in the body and heart. A person with HIV who is having diarrhea or vomiting can have an electrolyte imbalance. The BUN and creatinine are tests to evaluate the function of the kidneys. The kidneys are responsible for getting rid of the body's waste products through the urine. Many medications are processed through the kidney and passed through the urine. This can affect kidney function. Liver function is also monitored (SGOT/SGPT) since the liver also helps process many of the medications. The pancreas can also be irritated by the HIV and/or its medications, and its function is monitored by checking the enzymes amylase and lipase levels in the blood.

• The Immune Function Screen - this group of tests will measure the amount of HIV in the body as well as its effect on the immune system. This will help determine when to start medication and then will determine the effectiveness of the medications.
  1. CD4 or T4 count - the CD4 cell (also called the T4 or helper T cell) is one type of white blood cell that is an important part of the immune system. They help to protect the body against infection. The CD4 cell leads the attack against infection. HIV infects the CD4 cell making it unable to fight infection. The HIV then begins to destroy other T cells. When the CD4 cell count gets low, the immune system is being weakened.

     The lower the CD4 cell count, the more likely the child will get sick. Other things can affect the CD4 cell count as well such as stress, illness, and recent immunizations. Because of this, the doctor does not make medication changes based on just one CD4 cell measurement, but looks at the trend over a few measurements obtained at different times. However, if the CD4 cell count remains low over several lab draws, it may indicate progression of disease or that the medications are no longer effective. This might require a change in medication.

     Understanding the meaning of T cell counts can be difficult since they can vary as mentioned above. Normal counts also depend upon the age of the patient, so interpretation of counts should be done with your doctor.

  2. Viral Load - The viral load (also called the PCR) measures the amount of virus found in the body. As the disease worsens, the amount of HIV in blood and body tissues increases. The viral load is reported in "copies". If there is so little HIV in the blood that it is not detected by this test, it is reported as undetectable (<400 copies). However that does not mean that the virus is not present anywhere in the body or that the patient is cured. Even when HIV is not spilling over into the blood, it is still present in other body sites and tissues including the central nervous system, the spleen, and lymph nodes. As the disease progresses untreated or as the virus becomes resistant or less responsive to medication, the viral load will rise.

When evaluating for treatment, the doctor will look at the CD4 count as well as the viral load and symptoms to decide on a management plan. Generally, routine blood tests are ordered every 1-3 months for monitoring. This may be done more frequently during changes in the treatment plan or as the disease progresses. Although blood tests can be an uncomfortable experience for a child, they are very important in helping to monitor the progression of the HIV, immune function, body organ function, and the success of medications and their side effects.