HIV Biochemical Tests

Urea

M>50 (3.0-8.5 mmol/L) 
F>50 (2.5-7.5 mmol/L)  

Urea is a waste product that is produced when the body breaks down protein from food or tissue. Urea is normally filtered by the kidneys and excreted in the urine. The urine urea nitrogen test measures the amount of urea in the urine and reflects the protein intake and metabolism of the body. A decrease in urine urea nitrogen can indicate a low protein intake, malnutrition, kidney disease, impact of certain medications or increased fluid intake. However, it can also be caused by some infections that affect the kidneys or the urinary tract. 

Metabolic Acidosis: A bicarbonate level below the normal range (usually <22 mmol/L) suggests that the body is experiencing an excess of acid or a loss of bicarbonate. This can occur due to various reasons including gastrointestinal losses such a diarrhea.  Conditions such as diarrhea can lead to significant bicarbonate loss, contributing to lower serum levels.

Serum sodium is a measure of the concentration of sodium ions in the blood, typically expressed in milliequivalents per liter (mEq/L). Sodium is a crucial electrolyte that plays several key roles in the body, including:

Fluid Balance: Sodium helps regulate the amount of fluid in and around cells, maintaining proper hydration levels.

Nerve Function: It is essential for transmitting electrical signals in nerves and muscles, facilitating communication throughout the body.

Blood Pressure Regulation: Sodium levels influence blood volume and pressure, making it important for cardiovascular health.

Blood Profile

Infections: Both pneumonia and gastroenteritis are infections that can cause an increase in WCCs as the body mounts an immune response to fight off the pathogens causing these conditions.

HIV: While HIV can lead to a decrease in certain types of white blood cells (like CD4 cells), it can also cause periods of elevated WCCs, especially during opportunistic infections or when the immune system is highly active.

Inflammation: Infections and other conditions can cause inflammation, which in turn can lead to an elevated WBC count as the body responds to the inflammatory signals.

Stress Response: The physical stress of multiple infections and the body’s effort to combat them can also lead to an increase in WCC production.

Red blood cells (RBCs) are primarily a measure of the oxygen-carrying capacity of the blood. They contain hemoglobin, a protein that binds to oxygen in the lungs and transports it to tissues throughout the body. Here are some key points about what RBC counts indicate:

Oxygen Delivery: The number of RBCs directly affects how much oxygen can be delivered to the body’s tissues. A higher count generally means better oxygen transport.

Anemia Detection: A low RBC count can indicate anemia, which may result from various factors such as nutritional deficiencies (like iron, vitamin B12, or folate), chronic diseases, or bone marrow disorders.

Overall Health Assessment: RBC counts are part of a complete blood count (CBC) and can help diagnose various conditions, including infections, dehydration, and blood disorders.

Response to Conditions: Changes in RBC levels can reflect the body’s response to different conditions, such as high altitude (where RBC counts may increase) or chronic illnesses (where they may decrease).

A platelet count measures the number of platelets in your blood, which are essential for blood clotting and wound healing. 

Low platelet count (thrombocytopenia) can indicate an increased risk of excessive bleeding and may suggest underlying issues such as bone marrow disorders, infections, or autoimmune diseases.

High platelet count (thrombocytosis) may raise the risk of abnormal blood clotting, which can lead to complications like heart attacks or strokes, often due to conditions like inflammation or certain cancers.

Hemoglobin lab values indicate the amount of hemoglobin in the blood, which is crucial for transporting oxygen throughout the body. 

Low Hemoglobin: This can indicate anemia, which is common in individuals with chronic infections like HIV and tuberculosis. It may result from nutritional deficiencies, bone marrow suppression, or chronic disease effects.

High Hemoglobin: Elevated levels might suggest dehydration or a response to chronic hypoxia, which can occur in patients with lung complications or other chronic health issues

Ferritin lab tests measures the level of ferritin in the blood, which is a protein that stores iron in the body. This test helps determine how much iron is available for use in various bodily functions, particularly in the production of red blood cells.

Low Ferritin Levels: Indicate iron deficiency, which can lead to conditions like iron deficiency anemia. This may result from inadequate dietary intake, chronic blood loss, or malabsorption issues.

High Ferritin Levels: May suggest iron overload conditions, such as hemochromatosis, or can be associated with inflammation, liver disease, or certain cancers. Elevated ferritin can also occur in response to chronic diseases or infections.

Serum albumin is a key biomarker that reflects various aspects of health, particularly related to liver function, nutritional status, and inflammation. It is the most abundant protein in blood plasma and plays crucial roles in maintaining oncotic pressure, transporting hormones, vitamins, and drugs, and acting as an antioxidant.

Chronic inflammation associated with HIV can lead to altered protein metabolism. Typically, an inflammatory state, such as during chronic illess, can produce pro-inflammatory cytokines and decrease albumin synthesis in the liver, hereby contributing to lower serum levels.

Prealbumin is a negative acute-phase protein, meaning that its levels can decrease in the presence of inflammation or acute illness.  Pre-albumin measurements are important indicators of nutritional status, particularly protein levels in the body. Here’s what they indicate:

Nutritional Assessment: Prealbumin is a sensitive marker for assessing protein malnutrition. 

Monitoring Nutritional Support: Prealbumin levels are often used to monitor patients receiving nutritional support, 

Response to Treatment: Because prealbumin has a short half-life (about 2 days), it can quickly reflect changes in nutritional status. 

Clinical Outcomes: Studies have shown that prealbumin levels correlate with patient outcomes, including recovery rates and hospital stays. 

Serum protein lab tests measure the total amount of protein in the blood, primarily focusing on two main components: albumin and globulin. Here’s a brief overview of what these measurements indicate:

Nutritional Status: Total protein levels can help assess a person’s nutritional health. Low levels may suggest malnutrition or inadequate protein intake.

Liver Function: Since the liver produces most blood proteins, abnormal levels can indicate liver disease or dysfunction. High levels might suggest liver inflammation or chronic infections.

Kidney Health: These tests can also reveal kidney issues. High protein levels in urine (proteinuria) can indicate kidney damage or disease.

Immune Response: Globulin levels reflect immune function. Elevated globulin can indicate chronic inflammation, infections, or certain cancers, while low levels may suggest immune deficiencies.

Disease Monitoring: Changes in protein levels can help monitor various conditions, including liver disease, kidney disease, and certain cancers.

The immunological classification of HIV based on CD4 count is crucial for understanding the progression of the disease and guiding treatment decisions. Here’s a summary of the classification according to CD4 T-lymphocyte counts:

Category 1: CD4 count ≥ 500 cells/mm³

This indicates a healthy immune system. Patients in this category are generally asymptomatic and have a low risk of opportunistic infections.

Category 2: CD4 count 200-499 cells/mm³

This range suggests moderate immune suppression. Patients may start to experience some symptoms or opportunistic infections, and closer monitoring is necessary.

Category 3: CD4 count < 200 cells/mm³

This level indicates severe immune suppression and is associated with a high risk of opportunistic infections and AIDS-defining conditions. Patients in this category require immediate medical intervention and often prophylactic treatments to prevent infections.

An undetectable viral load in the context of HIV is typically defined as having fewer than 20 to 50 copies/mL of HIV RNA in the blood, depending on the sensitivity of the testing method used. When a person achieves an undetectable viral load, it means that the virus is effectively suppressed to a level that standard tests cannot detect. This is a crucial goal of antiretroviral therapy (ART), as it significantly reduces the risk of HIV transmission and helps maintain the patient’s health.

An elevated viral load in a patient with HIV who is on antiretroviral therapy (ART) suggests a few key points:

Active Viral Presence: This level indicates that the virus is not completely suppressed, showing that the virus is replicating in the body.

Adherence Concerns: This result may raise questions about how consistently the patient is taking their medications. Inconsistent adherence can lead to detectable viral levels.

Resistance Possibility: If the viral load remains elevated, it could signal the development of resistance to the current treatment. This might necessitate testing to determine if the virus has adapted to the medications being used.

Need for Close Monitoring: This finding should prompt more frequent monitoring of the patient’s viral load and possibly a review of their treatment plan. Regular follow-ups are crucial to assess whether the viral load is increasing, decreasing, or remaining stable.

Contextual Factors: It’s important to consider the patient’s overall health and any recent changes that might affect their viral load, such as new infections or stressors.