This article is the first in a three-part series that discusses kidney disease in people with HIV, including causes, symptoms, and treatment options. Part 1 covers causes, symptoms, and diagnosis. Part 2 covers treatment options for people with HIV and kidney disease. Part 3 discusses new research on kidney transplants in people with HIV.

Kidney disease is a common problem for people with HIV, particularly as they get older. Depending on how severe the kidney disease is, a variety of options are available, ranging from diet changes to a kidney transplant. Some choices, such as a kidney transplant, were once thought to be too risky, but are now increasingly available to people with HIV.

Growing rates of kidney disease and other chronic conditions are both good news and bad news for people with HIV. Highly active antiretroviral therapy (HAART) has been very effective in prolonging lifespans and decreasing mortality from HIV and other related diseases.

However, this also means that HIV-positive individuals are now more likely to die of chronic diseases, such as kidney disease.

“Organ failure is increasingly the cause of [death] in HIV-infected individuals, as improvements in antiretroviral therapy have led to longer life spans and much less death due to opportunistic disease,” said Dr. Jonah Odim, a medical officer in NIAID’s Division of Allergy, Immunology and Transplantation and Dr. Larry Fox, a medical officer in NIAID’s Division of AIDS, in correspondence with The AIDS Beacon.

Kidney disease is estimated to affect about 30 percent of people with HIV and cause more than 10 percent of HIV-related deaths.

What Is Kidney Disease?

The kidneys perform the necessary functions of regulating the body’s fluids and filtering the blood to eliminate waste products and toxic substances.

Kidney disease occurs when the kidneys lose the ability to perform these functions. As a result, water, waste, and toxins build up in the body. Chronic kidney disease is defined by evidence of kidney damage or decreased kidney function for at least three months.

There are five different stages of kidney disease, based on how well or poorly the kidneys are working. The fifth and final stage is referred to as end stage renal (kidney) failure (ESRF) or sometimes just kidney failure. When patients are in ESRF, their kidneys shut down and are almost completely unable to function properly.

Kidney disease can cause other health conditions such as heart disease, nerve damage, bone disease, and anemia (a decrease in red blood cells that prevents the body from getting enough oxygen).

People with HIV are at an increased risk of kidney disease because the virus interferes with the kidneys’ ability to function correctly. People with advanced HIV who have a low CD4 (white blood cell) count and a high viral load (amount of virus in the blood) are at greater risk for developing kidney disease. Older people with HIV are also at greater risk of kidney disease.

Symptoms

Some symptoms of kidney disease may include:

• Urinating pale urine more often than usual, darker urine less often, or urinating foamy, bubbly or bloody urine
• Difficulty urinating, or waking often at night to urinate
• Swelling in the legs, feet, ankles, face, and hands
• Excess fatigue
• Itching or rash
• Shortness of breath
• Lack of appetite or a metallic taste in the mouth
• Nausea and vomiting
• Fainting, dizziness, or difficulty concentrating
• Feeling excessively cold
• Leg, back, or side pain.

Causes

The two most common causes of kidney disease are high blood pressure (hypertension) and diabetes, a condition in which the body cannot properly manage its blood sugar levels.

Certain factors beyond a patient’s control, such as family history, premature birth, and trauma or injury may be factors in kidney disease. African-Americans and Hispanics are also at higher risk of kidney disease.

HIV itself can cause damage to the kidneys, called HIV-Associated Nephropathy. It is thought to be caused by the virus infecting and damaging cells in the kidneys. Kidney damage from HIV can occur even in people taking antiretroviral drugs.

Medications for HIV and HIV-related health problems are also harsh on the kidneys and may, over time, contribute to kidney disease.

Antiretroviral drugs that have been associated with kidney disease include Viread (tenofovir), Crixivan (indinavir), Reyataz (atazanavir), and possibly Kaletra (lopinavir/ritonavir). Selzentry (maraviroc) is not recommended for people with severe kidney disease or ESRF.

Other medical conditions that may increase the risk of kidney disease are hepatitis C infection; kidney stones, which cause the urinary tract to become blocked; glomerulonephritis, an inflammatory immune response to infections such as strep throat that can damage the kidneys; and allergic reactions to antibiotics such as penicillin and vancomycin.

The use of drugs such as heroin and cocaine and excessive use of painkillers containing ibuprofen (Advil, Motrin), naproxen (Aleve), aspirin, or acetaminophen (Tylenol) may also contribute to kidney disease.

Diagnosis

There are several tests used to determine if a person has kidney disease. The most common are blood and urine tests that measure kidney function.

Blood tests monitor blood pressure (which can increase in people with kidney disease) and the amount of a substance called creatinine in the blood. Creatinine is a waste product of metabolism and should be filtered from the blood by the kidneys.  High creatinine levels in the blood can indicate kidney dysfunction.

Urine tests monitor the levels of protein in the urine. When the kidneys are not functioning well, proteins start to build up in the urine, along with red and white blood cells. If high protein levels or blood cells are found in the urine, this also usually indicates kidney disease.

Additional tests might include an ultrasound, MRI, or CAT scan to image the kidneys. In some cases a kidney biopsy might be performed, in which a small piece of the kidney is taken and examined under a microscope.

According to the National Kidney Foundation, people with HIV who have any additional risk factors for kidney disease should be tested for kidney disease at least once a year.

For more information on treatment of kidney disease, please see Part 2 of this series. For more information on kidney transplants for people with HIV, please see Part 3 of this series.