Anemia: One-minute point-of-care test shows promise in new study

 

Erika Tyburski is shown with a prototype device for point-of-care testing of anemia. The device could enable more rapid diagnosis of the common blood disorder and allow inexpensive at-home self-monitoring of persons with chronic forms of the disease.

Credit: Gary Meek

 

The disposable self-testing device analyzes a single droplet of blood using a chemical reagent that produces visible color changes corresponding to different levels of anemia. The basic test produces results in about 60 seconds and requires no electrical power. A companion smartphone application can automatically correlate the visual results to specific blood hemoglobin levels.

By allowing rapid diagnosis and more convenient monitoring of patients with chronic anemia, the device could help patients receive treatment before the disease becomes severe, potentially heading off emergency room visits and hospitalizations. Anemia, which affects two billion people worldwide, is now diagnosed and monitored using blood tests done with costly test equipment maintained in hospitals, clinics or commercial laboratories.

Because of its simplicity and ability to deliver results without electricity, the device could also be used in resource-poor nations.

A paper describing the device and comparing its sensitivity to gold-standard anemia testing was published August 30 in The Journal of Clinical Investigation. Development of the test has been supported by the FDA-funded Atlantic Pediatric Device Consortium, the Georgia Research Alliance, Children's Healthcare of Atlanta, the Georgia Center of Innovation for Manufacturing and the Global Center for Medical Innovation.

"Our goal is to get this device into patients' hands so they can diagnose and monitor anemia themselves," said Dr. Wilbur Lam, senior author of the paper and a physician in the Aflac Cancer and Blood Disorders Center at Children's Healthcare of Atlanta and the Department of Pediatrics at the Emory University School of Medicine. "Patients could use this device in a way that's very similar to how diabetics use glucose-monitoring devices, but this will be even simpler because this is a visual-based test that doesn't require an additional electrical device to analyze the results."

The test device was developed in a collaboration of Emory University, Children's Healthcare of Atlanta and the Georgia Institute of Technology -- all based in Atlanta. It grew out of a 2011 undergraduate senior design project in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University. In 2013, it was among the winners of Georgia Tech's InVenture Prize, an innovation competition for undergraduate students, and won first place in the Ideas to SERVE Competition in Georgia Tech's Scheller College of Business.

Using a two-piece prototype device, the test works this way: A patient sticks a finger with a lance similar to those used by diabetics to produce a droplet of blood. The device's cap, a small vial, is then touched to the droplet, drawing in a precise amount of blood using capillary action. The cap containing the blood sample is then placed onto the body of the clear plastic test kit, which contains the chemical reagent. After the cap is closed, the device is briefly shaken to mix the blood and reagent.

"When the capillary is filled, we have a very precise volume of blood, about five microliters, which is less than a droplet -- much less than what is required by other anemia tests," explained Erika Tyburski, the paper's first author and leader of the undergraduate team that developed the device.

Blood hemoglobin then serves as a catalyst for a reduction-oxidation reaction that takes place in the device. After about 45 seconds, the reaction is complete and the patient sees a color ranging from green-blue to red, indicating the degree of anemia.

A label on the device helps with interpretation of the color, or the device could be photographed with a smartphone running an application written by Georgia Tech undergraduate student Alex Weiss and graduate student William Stoy. The app automatically correlates the color to a specific hemoglobin level, and could one day be used to report the data to a physician.

To evaluate sensitivity and specificity of the device, Tyburski studied blood taken from 238 patients, some of them children at Children's Healthcare of Atlanta and the others adults at Emory University's Winship Cancer Institute. Each blood sample was tested four times using the device, and the results were compared to reports provided by conventional hematology analyzers.

The work showed that the results of the one-minute test were consistent with those of the conventional analysis. The smartphone app produced the best results for measuring severe anemia.

"The test doesn't require a skilled technician or a draw of venous blood and you see the results immediately," said Lam, who is also an assistant professor in the Coulter Department of Biomedical Engineering. "We think this is an empowering system, both for the general public and for our patients."

Tyburski and Lam have teamed up with two other partners and worked with Emory's Office of Technology Transfer to launch a startup company, Sanguina, to commercialize the test, which will be known as AnemoCheck™. The test ultimately will require approval from the FDA. The team also plans to study how the test may be applied to specific diseases, such as sickle cell anemia -- which is common in Georgia.

The device could be on pharmacy shelves sometime in 2016, where it might help people like Tyburski, who has suffered mild anemia most of her life. "If I'd had this when I was kid, I could have avoided some trips to the emergency room when I passed out in gym class," she said.

About a third of the population is at risk for anemia, which can cause neurocognitive deficits in children, organ failure and less serious effects such as chronic fatigue. Women, children, the elderly and those with chronic conditions such as kidney disease are more likely to suffer from anemia.

 

 

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Georgia Institute of Technology. "Anemia: One-minute point-of-care test shows promise in new study." ScienceDaily. ScienceDaily, 12 September 2014. <www.sciencedaily.com/releases/2014/09/140912085108.htm>.

Vitamin deficiency anemia

Vitamin deficiency anemia is a lack of healthy red blood cells caused by lower than normal amounts of certain vitamins. Vitamins linked to vitamin deficiency anemia include folate, vitamin B-12 and vitamin C.

Vitamin deficiency anemia can occur if you don't eat enough folate, vitamin B-12 or vitamin C. Or vitamin deficiency anemia can occur if your body has trouble absorbing or processing these vitamins.

Not all anemias are caused by a vitamin deficiency. Other causes include iron deficiency and certain blood diseases. That's why it's important to have your doctor diagnose and treat your anemia. Vitamin deficiency anemia can usually be corrected with vitamin supplements and changes to your diet.

Signs and symptoms of vitamin deficiency anemia include:

• Fatigue
• Shortness of breath
• Dizziness
• Pale or yellowish skin
• Irregular heartbeats
• Weight loss
• Numbness or tingling in your hands and feet
• Muscle weakness
• Personality changes
• Unsteady movements
• Mental confusion or forgetfulness

Vitamin deficiencies usually develop slowly over several months to years. Vitamin deficiency symptoms may be subtle at first, but they increase as the deficiency worsens.

 

Causes

Vitamin deficiency anemia occurs when your body doesn't have enough of the vitamins needed to produce adequate numbers of healthy red blood cells. Red blood cells carry oxygen from your lungs throughout your body. If your diet is lacking in certain vitamins, vitamin deficiency anemia can develop. Or vitamin deficiency anemia may develop because your body can't properly absorb the nutrients from the foods you eat.

Causes of vitamin deficiency anemias, also known as megaloblastic anemias, include:

• Folate deficiency anemia. Folate, also known as vitamin B-9, is a nutrient found mainly in fruits and leafy green vegetables. A diet consistently lacking in these foods can lead to a deficiency.

  An inability to absorb folate from food can also lead to a deficiency. Most nutrients from food are absorbed in your small intestine. People with diseases of the small intestine, such celiac disease, or those who have had a large part of the small intestine surgically removed or bypassed may have difficulty absorbing folate or its synthetic form, folic acid. Alcohol decreases absorption of folate, so drinking alcohol to excess may lead to a deficiency. Certain prescription drugs, such as some anti-seizure medications, can interfere with absorption of this nutrient.

  Pregnant women and women who are breast-feeding have an increased demand for folate, as do people undergoing hemodialysis for kidney disease. Failure to meet this increased demand can result in a deficiency.

• Vitamin B-12 deficiency anemia (pernicious anemia). Vitamin B-12 deficiency can result from a diet lacking in vitamin B-12, which is found mainly in meat, eggs and milk. Vitamin B-12 deficiency anemia can also occur if your small intestine can't absorb vitamin B-12. This may be due to surgery to your stomach or small intestine (such as gastric bypass surgery), abnormal bacterial growth in your small intestine, or an intestinal disease, such as Crohn's disease or celiac disease, that interferes with absorption of the vitamin. Vitamin B-12 deficiency can also be caused by a tapeworm ingested from contaminated fish because the tapeworm saps nutrients from your body. However, a vitamin B-12 deficiency is most often due to a lack of a substance called intrinsic factor.

  Intrinsic factor is a protein secreted by the stomach that joins vitamin B-12 in the stomach and escorts it through the small intestine to be absorbed by your bloodstream. Without intrinsic factor, vitamin B-12 can't be absorbed and leaves your body as waste. Lack of intrinsic factor may be due to an autoimmune reaction in which your immune system mistakenly attacks the stomach cells that produce it. Vitamin B-12 deficiency anemia caused by a lack of intrinsic factor is called pernicious anemia.

• Vitamin C deficiency anemia. Vitamin C deficiency can develop if you don't get enough vitamin C from the foods you eat. Vitamin C deficiency is also possible if something impairs your ability to absorb vitamin C from food. For instance, smoking impairs your body's ability to absorb vitamin C.

 

Risk factors for vitamin deficiency anemia vary by type of vitamin deficiency.

Folate deficiency anemia

Your risk of folate deficiency anemia may be increased if:

• You're pregnant, and you aren't taking a multivitamin containing folic acid.
• You have intestinal problems that interfere with absorption of folate.
• You abuse alcohol because alcohol interferes with the absorption of folate.
• You take certain prescription medications, such as some anti-seizure drugs, that can block absorption of folate.
• You're undergoing hemodialysis for kidney failure. Ask your doctor whether you need supplemental folic acid to prevent a deficiency.
• You're undergoing cancer treatment. Some drugs used to treat cancer can interfere with the metabolism of folate.
• You don't eat many fruits and vegetables. If your diet is greatly lacking in fresh fruits and vegetables, or you consistently overcook your food, you may be at risk of folate deficiency anemia.

Vitamin B-12 deficiency anemia (pernicious anemia)

Your risk of vitamin B-12 deficiency anemia may be increased if:

• You don't eat meat and dairy products, foods that contain a lot of vitamin B-12. Vegetarians who don't eat dairy products and vegans, who don't eat any foods from animals, may fall into this category.
• You have an intestinal disease or abnormal bacterial growth in your stomach or have had surgery to your intestines or stomach that interferes with the absorption of vitamin B-12.
• You lack intrinsic factor. Most people with a vitamin B-12 deficiency anemia lack intrinsic factor — a protein secreted by the stomach that is necessary for absorption of vitamin B-12. Lack of intrinsic factor may be due to an autoimmune reaction, or it may be inherited.
• You take certain medications. Antacids and some drugs used to treat type 2 diabetes may interfere with B-12 absorption.
• You have another autoimmune disorder. People with endocrine-related autoimmune disorders, such as diabetes or thyroid disease, may have an increased risk of developing a specific type of vitamin B-12 deficiency anemia called pernicious anemia.

Vitamin C deficiency anemia

Your risk of vitamin C deficiency anemia may be increased if:

• You're malnourished and you're not getting the nutrients and vitamins you need.
• You smoke. Smoking can lead to vitamin C deficiency because it decreases the absorption of this vitamin.
• You abuse alcohol. People who drink heavily don't absorb vitamin C as effectively, putting them at risk of vitamin C deficiency anemia.
• You have a chronic illness. Certain chronic illnesses, such as cancer or chronic kidney disease, increase your risk of vitamin D deficiency anemia by affecting the absorption of vitamin C.

   

  Complications

  Being deficient in vitamins increases your risk of many health problems:

  • Pregnancy complications. Pregnant women with folate deficiency may be more likely to experience complications, such as premature birth. A developing fetus that doesn't get enough folate from its mother can develop birth defects of the brain and spinal cord. If you're thinking of becoming pregnant, ask your doctor whether you should consider taking folic acid supplements so that your body's stores of folate will be enough to support your baby.
  • Nervous system disorders. While vitamin B-12 is important for the production of red blood cells, it's also important for a healthy nervous system. Untreated, vitamin B-12 deficiency can lead to neurological problems, such as persistent tingling in your hands and feet or problems with balance. It can lead to mental confusion and forgetfulness because vitamin B-12 is necessary for healthy brain function. Without treatment for vitamin B-12 deficiency, neurological complications can become permanent. Vitamin B-12 deficiency can cause these and other health problems before it leads to anemia.
  • Scurvy. Vitamin C deficiency can lead to scurvy. Signs and symptoms of this rare disease include bleeding under the skin and around the gums.