Poikilocytosis

What is poikilocytosis?

Poikilocytosis (pronounced “poy-kuh-low-sai-TOW-suhs”) is a term healthcare providers use to describe abnormally shaped red blood cells. With poikilocytosis, more than 10% of red blood cells in a blood sample aren’t shaped like normal red blood cells.

Your red blood cells carry oxygen to tissues and organs throughout your body. Think of oxygen as the energy supply your body’s cells need to function. Normal red blood cells are about the same size and shape. They’re round with an indentation in the center, like a disk.

Red blood cells of abnormal sizes (anisocytosis) or shapes (poikilocytosis) may signal that your red blood cells can’t carry oxygen efficiently. When this happens, you have anemia.

Abnormal red blood cell shapes (poikilocytes)

Providers categorize abnormal red blood cell shapes based on their features. With poikilocytosis, you may have one or more of the following abnormal cells, or poikilocytes:

• Acanthocytes (spur cells): Cells with spikes of different lengths and widths jutting outside the cell membrane.
• Codocytes (target cells): Cells with a dark center in the middle, resembling a bullseye.
• Dacrocytes (teardrop cells): Cells that narrow or come to a point at one side, like a teardrop.
• Drepanocytes (sickle cells): Curved and thin cells that resemble a sickle or crescent.
• Echinocytes: Cells covered in evenly spaced thorny projections, like a sea urchin.
• Elliptocytes (ovalocytes or cigar cells): Oval and abnormally long cells, with shapes ranging from an egg to a cigar.
• Schistocytes: Red cell fragments that are usually jagged but may be any shape.
• Spherocytes: Spherical cells that resemble a ball or a globe.

What are the symptoms of poikilocytosis?

Symptoms depend on what’s causing poikilocytosis. The most common symptoms are the same as those you get with anemia.

Anemia symptoms include:

• Weakness or fatigue.
• Shortness of breath (dyspnea).
• Fast or irregular heartbeat (arrhythmia).
• Occasional “whooshing” sound in your ear (pulsatile tinnitus).
• Headache.
• Dizziness.
• Pale skin.
• Chest pain.

What causes poikilocytosis?

Causes include inherited or acquired conditions. Some conditions that may be either inherited or acquired, like myelodysplastic syndrome, can cause poikilocytosis.

Inherited conditions

Most inherited conditions that cause poikilocytosis involve problems with DNA, or the genetic code that a red blood cell needs to develop, function and survive. Red blood cells with abnormal structures often break down prematurely, before your body can replace them with new red blood cells. This is called hemolytic anemia.

Inherited conditions that cause poikilocytosis include:

• Hereditary elliptocytosis.
• Hereditary spherocytosis.
• McLeod syndrome.
• Pyruvate kinase deficiency.
• Sickle cell disease.
• Thalassemia.

Acquired conditions

Several conditions that develop over time can cause abnormally shaped red blood cells. For example, you can develop various forms of anemia if you don’t get enough of the nutrients your body needs to make healthy red blood cells, like Vitamin B12, folate and iron. Poikilocytosis is a common sign of these deficiencies. Diseases that interfere with red blood cell production, like some forms of cancer, can also cause poikilocytosis.

Acquired conditions that cause poikilocytosis include:

• Autoimmune hemolytic anemia.
• Burns.
• Celiac disease.
• Infections.
• Iron-deficiency anemia.
• Kidney disease.
• Leukemia.
• Liver disease.
• Megaloblastic anemia.
• Myelofibrosis.
• Poisoning.
• Reaction to a blood transfusion.
• Reaction to a splenectomy.
• Snakebite.

What are the complications of poikilocytosis?

Most causes of poikilocytosis are manageable or even reversible with treatment. Without treatment, some causes can be debilitating or even potentially life-threatening. For example, if you have anemia, you may feel so drained that you can’t carry out your daily routine. Over time, the lack of healthy red blood cells can cause organ failure.

Untreated anemia in children can slow their growth and development.

Once your healthcare provider diagnoses what’s causing poikilocytosis, they can prescribe treatments to prevent complications.

How is poikilocytosis diagnosed?

A healthcare provider can perform a peripheral blood smear (PBS) to diagnose poikilocytosis. During this test, a lab technologist looks at a blood sample underneath a microscope. They’ll be able to tell how many oddly shaped cells you have and what kinds.

Some cell types are more common in certain conditions.

Still, shapes can vary in a single condition. For example, multiple abnormal cell types may be present in conditions like hemolytic anemia, megaloblastic anemia, myelofibrosis, thalassemia and others.

Your providers will likely perform additional tests to diagnose what’s causing your poikilocytosis.

Additional tests to determine what’s causing poikilocytosis

Providers commonly order a PBS along with a complete blood count (CBC). A CBC is a test that gathers information about your blood cells, including levels and size. Certain values on a CBC can provide additional information about your red blood cells that helps your provider diagnose what’s causing poikilocytosis, including:

• Mean corpuscular volume (MCV): The average size of your red blood cells.
• Mean corpuscular hemoglobin (MCH): The average amount of hemoglobin in your red blood cells.
• Mean corpuscular hemoglobin concentration (MCHC): The average amount of hemoglobin concentration in your red blood cells.
• Red cell distribution width (RDW): How varied in size your red blood cells are.

Your provider may also check your Vitamin B12, folate and iron levels. They may perform liver function tests, among others.

How is poikilocytosis treated?

Treatment depends on what’s causing poikilocytosis and how serious your symptoms are.

For example, if poikilocytosis results from a nutritional deficiency, taking supplements or changing your diet to include more vitamin B12 or folate often reverses poikilocytosis.

Many inherited conditions require careful monitoring. You may need regular blood transfusions to ensure you have enough healthy red blood cells. Or, you may only need treatment depending on whether you’re experiencing symptoms.

Can poikilocytosis be prevented?

You can’t prevent inherited causes of poikilocytosis, but you can reduce your risk of some acquired forms.

One of the best ways to care for your red blood cells is to consume the nutrients your body needs for red blood cell production. Ensuring you have enough Vitamin B, folate and iron can provide key ingredients your body needs to make healthy red blood cells. Limiting how much alcohol you drink can help, too. In excess, alcohol makes it harder for your body to absorb these nutrients.

What is the outlook?

Overall, the prognosis is good, especially if an acquired condition is causing poikilocytosis. The outlook for inherited causes varies, depending on the condition. For example, people with sickle cell disease have a reduced life expectancy. New treatments continue to improve the outlook, allowing people to live past their 50s with manageable symptoms.

When should I see my healthcare provider?

Schedule a visit with your healthcare provider if you’re experiencing symptoms of anemia.

Even if you’re feeling healthy, it’s important to schedule annual check-ups so that your provider can check on your blood cells. Simple blood tests, like a PBS or a CBC, can help your healthcare provider diagnose and treat health issues before they cause complications.

Is poikilocytosis serious?

Poikilocytosis isn’t serious, but it may signal an underlying condition that can lead to complications without treatment. It’s important to understand what’s causing poikilocytosis so you can get treatment if you need it.

A note from Cleveland Clinic

Poikilocytosis may sound like a serious medical issue, but it’s not. It’s just one feature of your red blood cells that healthcare providers can use to assess your health. Don’t hesitate to ask your provider questions if you learn that your red blood cells are abnormal. They can tell you whether it signals a potential issue with your health. If so, they can recommend treatments or lifestyle changes to reverse poikilocytosis or manage the condition causing it.