Deciphering Your Routine HIV Blood Tests

What the Tests Mean and Why They're Important to Your Good Health

Sample Hematology Report. Image © James Myhre

In order to properly manage your HIV, a number of blood tests are routinely performed with each doctor visit. When shown the results of these tests, most people will look their CD4 count and viral load and pretty much skim over the rest. And even if some of the names or figures make sense, it's often difficult to understand what they mean or how they apply to you as an individual.

The bottom line is that these routine tests are just as important as your HIV-specific one.

They can be predictive of a developing infection or measure a person's response to a prescribed medication—detecting or preventing side effects that sometimes occur.

By gaining a basic understanding of a few of the key tests, you'll be better able to participate in the ongoing management of your HIV in a way that is both proactive and informed.

What Is a "Normal" Result?

When reading a lab report, results are generally expressed in a numeric value. These values are then compared to the "normal" range outlined on the report, which are indicated with a high and a low value. Attention is given to values that fall outside of the normal range, as this may suggest a potential concern. Abnormal values are sometimes highlighted in bold, or indicated with "H" for high and "L" for low.

The normal range is based on the values one would expect to find within the general population of your specific region of the world.

As such, they don't always reflect what would be "normal" for a person living with HIV. If a result falls outside of the expected range, it shouldn't necessarily cause alarm. Simply discuss the with your doctor, who can better determine its relevance.

It's also important to note that results can vary from lab to lab, either because testing methods or testing equipment.

Therefore, it's best to use the same lab for all your tests.

At the same time, try to perform your tests at more-or-less the same time each visit. Serological values can naturally fluctuate during the course of a day (as they can if a person is ill, worn out, or was recently vaccinated). If you are not feeling well on the day of rescheduled test, you may want to consider rescheduling for another day when you are feeling better.

Complete Blood Count (CBC)

What These Tests Are About: The complete blood count (CBC) examines the chemistry and makeup of your blood. The panel of tests looks at the cells responsible for the transporting of oxygen and carbon dioxide in the body, as well as those that fight infection and help stop bleeding. (See sample report.)

Why They Are Important: A CBC can aid in the diagnosis of an infection, anemia, autoimmune disease, and a range of other health concerns. Anemia is also one of the side effects associated with Retrovir (AZT), for example, the test of which can identify levels of bone marrow suppression caused by the drug.

Among the components of a CBD:

  • Hemoglobin (Hb) - This is a protein found in red blood cells that binds with oxygen and delivers it directly to tissues. Low hemoglobin values are associated with anemia. Iron supplements are sometimes prescribed in milder cases of iron deficiency anemia.
  • Platelets (PLT) - These cells are responsible for helping to stop bleeding. Although people with HIV often have lower PLT values than the general population, when mild, these values are usually not a concern. Both nucleoside reverse transcriptase (NRTI) and HIV itself can be associated with the decreased PLT levels (called thrombocytopenia), as well as HIV-related diseases such as lymphoma and mycobacterium avium complex (MAC).
  • White blood cell count (WBC) - White blood cells (leukocytes) are the body of cells that fight infection. While a lower WBC is not uncommon in people with HIV, markedly lower levels may be a sign of serious infection. CD4 lymphocytes are among the cells that comprise the WBC. Others include neutrophils (which target bacteria and other foreign bodies), eosinophils (parasites, allergies), and basophils (responsible for releasing histamines during a cold or allergy).

Blood Fats (Lipids)

What These Tests Are About: These tests are performed to measure the level of different fats (or "lipids") in the blood, including cholesterol and triglycerides.

Why They Are Important: HIV itself is linked with increased levels of triglyceride and LDL cholesterol ("bad cholesterol"), as well as decreased levels of HDL cholesterol ("good cholesterol"). Some antiretroviral drugs, such as protease inhibitors (PIs), can affect lipid levels as well. Monitoring these values is especially important for people with HIV, as they have an almost 50% greater chance of developing cardiovascular disease than the general population.

  • Low-density lipoprotein cholesterol (LDL): Low-density lipoprotein carries cholesterol from the liver to other parts of the body, and is associated with the clogging of arteries. If a person has raised LDL levels, dietary changes and/or cholesterol-reducing drugs may be indicated, particularly for those on PIs.
  • High-density lipoprotein cholesterol (HDL): Conversely, this type of cholesterol decreases the risk of heart disease by helping to remove bad cholesterol from the tissues and carrying it back to the liver for metabolism.
  • Triglycerides: This is a form of fat that the body stores for energy. High levels of triglycerides are typically associated with the metabolic syndrome or pancreatitis.

Liver Function Tests (LFT)

What These Tests Are About: This is a panel of tests that measures how well the liver is functioning. The liver is the organ responsible for the metabolism of fat, carbohydrates, and proteins, as well as producing biochemicals needed for digestion. These tests can assist with identifying liver disease or hepatitis, as well as damage caused by the use of drugs, alcohol or other toxic substances.

Why They Are Important: The liver recognizes medications as a toxic substance and, as such, processes them as part of its detoxification function. This can occasionally "overwork" the liver, leading to damage (called hepatotoxicity). Some patients on the HIV drugs Viramune (nevirapine) or Ziagen (abacavir) may experience a hypersensitive reaction that can result in hepatotoxicity, usually within the first weeks or months of starting treatment. Additionally, nearly a third of Americans with HIV are co-infected with either hepatitis B (HBV) or hepatitis C (HCV). Monitoring LFTs is key to identifying these infections.

  • Alanine aminotransferase (ALT): ALT is an enzyme found in the liver. This test is used to detect liver impairment or long-term disease. Elevated ALT levels may indicate an active hepatitis infection. In addition to viral hepatitis, over-the-counter drugs and herbal remedies can sometimes cause increased ALT levels, as well as alcohol, recreational drugs, and even high-dose vitamin A.
  • Aspartate aminotransferase (AST): AST is an enzyme produced in muscles and tissues throughout the body, including the liver. This test is used along with the ALT to identify active or chronic liver problems. If elevated levels of both are found, liver damage of some sort is likely present.
  • Alkaline phosphatase (ALP): One of the liver's key functions is to produce bile, which assists in digesting fat. ALP is an enzyme found in the bile duct of the liver. When the bile flow is slowed or obstructed, ALP levels are increased. Markedly raised ALP levels may indicate a liver or gall bladder problem, caused either by an obstruction (such as gall stones) or an infection. Elevated alkaline phosphate levels can also indicate a bone problem. The medical provider will aim to understand why levels are high, and whether the increase is due to liver or bone.
  • Bilirubin: Bilirubin is a yellowish substance found in bile. Raised bilirubin levels cause the jaundice seen in active hepatitis infection. The HIV drug Reyataz (atazanavir) can also cause raised bilirubin levels in some, resulting in the yellowing of skin and eyes. While this is generally not considered harmful or indicative of a liver problem, it can be distressing to those it affects.

Renal Function Tests

What These Tests Are About: These are the tests that measure kidney function, which is integral to the urinary system, acting as filters to the blood and assisting with regulating electrolytes, body pH levels, and blood pressure. These tests can identify nephropathy (the damage or disease of the kidneys), or diagnose dysfunctions caused by medication and other substances.

Why They Are Important: HIV-related nephropathy is associated with the increased risk of death, with an incidence rate of around 12% worldwide. Many medications can affect the kidneys, which is why the kidney function should be monitored on a regular basis. This is particularly relevant for any HIV drug that contains tenofovir (e.g., Truvada, Atripla) as it is known to cause kidney impairment and even failure in some.

  • Creatinine: Creatinine is a by-product of muscle metabolism, produced at a fairly consistent rate and excreted through the kidneys. Changes in creatinine levels may indicate a problem with the kidneys, but can be the result of the use of certain drugs or over-the-counter supplements (such as creatinine boosters popular with performance athletes).
  • Urea: Urea is a by-product of protein metabolism, which is excreted from the body in urine. High urea levels may be suggestive of renal dysfunction, kidney toxicity, or dehydration.
  • Estimated glomerular filtration rate (eGFR): This test estimates the amount of blood the kidneys filter per minute. Diminishing values are indicative of renal impairment. Monitoring these values is particularly important for those on any medications that can affect the kidneys


Islam, F.; Wu, J.; Jansson, J.; et al. "Relative risk of cardiovascular disease among people living with HIV: a systematic review and meta-analysis." HIV Medicine. March 13, 2012; 13(8):453-468.

Alter, M. "Epidemiology of viral hepatitis and HIV co-infection." Journal of Hepatology. Division of Viral Hepatitis, U.S. Centers for Disease Control and Prevention (CDC),Atlanta, GA. 2006; 44(1):S6-S6.

Joint United Nations Programme on HIV/AIDS (UNAIDS). "2015 UNAIDS Report on Global AIDS Epidemic." Geneva, Switzerland; ISBN: 978 92 4 1508934.

Continue Reading