Apheresis is a medical procedure that allows healthcare providers to separate blood into its individual components using a specialized machine, collecting or removing specific elements before returning the rest to the body. This versatile technique serves two main purposes: collecting blood components from healthy donors to help patients in need, or treating medical conditions by removing harmful substances from a patient’s bloodstream.

Understanding How Apheresis Works

When you undergo apheresis, a machine draws blood from your body through a needle inserted into a vein, usually in your arm. Some patients may have blood collected through a central line, which is a tube inserted into a large vein in the upper shoulder or near the collarbone. The blood then enters a device called a centrifuge, which spins the blood at specific speeds to separate it based on the density of its components.^[1]

Blood naturally consists of four main parts: red blood cells, white blood cells, platelets, and plasma. Red blood cells are the heaviest, so they settle at the bottom during spinning. White blood cells and platelets come next in order of weight, with plasma being the lightest component that rises to the top. The machine is programmed to collect whichever component is needed, while the remaining parts are returned to your body through the same needle or through a second needle in your other arm.^[2]

The entire process uses sterile, single-use equipment to ensure safety. To prevent blood from clotting during the procedure, an anticoagulant solution containing citrate is automatically mixed with your blood as it flows through the machine. This medication keeps the blood flowing smoothly throughout the collection process.^[1]

Different Types of Apheresis Procedures

Healthcare providers use several different types of apheresis depending on what needs to be collected or removed. Leukapheresis focuses on removing white blood cells from the bloodstream. This treatment helps ease symptoms in patients whose white blood cells are multiplying uncontrollably, which can cause serious complications like bleeding in the brain or difficulty breathing.^[1]

Plasmapheresis, also called plasma exchange, removes the liquid portion of blood that contains proteins. During this procedure, abnormal proteins that may be attacking healthy organs are filtered out, and the removed plasma is replaced with a solution of 5 percent human albumin prepared from healthy donors, or sometimes with donated plasma from other people. This exchange removes approximately 65 percent of harmful components during a single treatment session.^[2]

Photopheresis is a specialized treatment that modifies white blood cells called lymphocytes. The machine removes these cells and treats them with a medication called methoxsalen, which makes them sensitive to ultraviolet light. The cells are then exposed to UVA light inside the machine before being returned to the patient. This process changes how the immune system works and can help decrease symptoms in certain conditions.^[1]

Red blood cell exchange transfusion removes damaged or unhealthy red blood cells and replaces them with healthy ones donated by others. This is particularly helpful for patients with sickle cell disease, where abnormally shaped red blood cells cause problems throughout the body.^[1]

Platelet depletion removes excess platelets from the blood. Platelets help blood form clots, but having too many can cause dangerous complications like abnormal clotting or bleeding. Removing the extra platelets before returning the blood helps prevent these problems.^[1]

Peripheral blood stem cell collection gathers immature stem cells from the bloodstream for use in stem cell transplants. Before this procedure, patients take medication for several days to move stem cells from their bone marrow into their bloodstream, making them easier to collect.^[1]

Medical Conditions Treated with Apheresis

Apheresis plays an important role in treating blood cancers. Healthcare providers may use it for acute myeloid leukemia, certain types of lymphoma including cutaneous T-cell lymphoma, multiple myeloma, and Waldenstrom macroglobulinemia. For people going through intense chemotherapy, apheresis can preserve healthy stem cells that will be returned to them after treatment is complete.^[1]

Many common blood disorders benefit from apheresis treatment. Patients with sickle cell anemia, where abnormally shaped red blood cells cause pain and organ damage, often receive red blood cell exchange transfusions. The procedure is also used for cryoglobulinemia, a condition where abnormal proteins in the blood thicken in cold temperatures, and thrombotic thrombocytopenic purpura, a rare disorder that causes dangerous blood clots throughout the body.^[1]

Several neurological conditions respond to plasma exchange therapy. These include Guillain-Barré syndrome, where the immune system damages nerves causing weakness and paralysis; multiple sclerosis, a disease affecting the brain and spinal cord; and myasthenia gravis, which causes muscle weakness. Apheresis removes harmful antibodies that attack the nervous system while other medications work to stop the body from making more of them.^[1]

Beyond these main categories, apheresis can treat complications from organ transplants, including graft versus host disease where transplanted cells attack the recipient’s body, and transplant rejection where the immune system tries to destroy the transplanted organ.^[1]

Blood Donation Through Apheresis

Healthy people can donate specific blood components through apheresis to help patients in hospitals. This type of donation is different from regular whole blood donation because it collects only the needed component. For example, a platelet apheresis donation can provide as many platelets as would come from four to six whole blood donations, making it a highly efficient way to help patients.^[2]

During a double red cell apheresis donation, the machine collects twice as many red blood cells as a regular whole blood donation would provide. The donor receives back their plasma and platelets, meaning they are only giving the red cells. Because more red cells are collected, donors must wait up to 16 weeks before donating again, compared to the standard eight weeks for whole blood. However, this means donors can help twice as much while visiting the donation center half as often.^[2]

Platelet donations are particularly important because platelets only last five days before they expire, unlike red blood cells which can be stored much longer. Hospitals constantly need fresh platelets for cancer patients and others whose platelet counts are low. Healthy donors can give platelets as often as every seven days, making it possible to help patients regularly.^[2]

Donor apheresis takes longer than a whole blood donation, typically lasting anywhere from 90 minutes to two hours for most procedures. Despite the longer time commitment, the process is easy and painless, and many donors find it rewarding to know their donation is going directly to patients who need that specific blood component.^[2]

What to Expect During an Apheresis Procedure

Before your apheresis appointment, your healthcare provider will give you specific instructions on how to prepare. In general, drinking plenty of fluids in the days before your procedure is helpful. If you are donating peripheral blood stem cells, you will need to take medication for several days beforehand to move the stem cells from your bone marrow into your bloodstream where they can be collected.^[1]

For patients undergoing platelet donation, it is important to avoid taking aspirin for at least two days before the procedure, and non-steroidal anti-inflammatory drugs should not be taken within 24 hours of donation. These medications affect how platelets function and could make the collected platelets less effective for patients who receive them.^[2]

On the day of your procedure, you will sit in a comfortable chair, similar to a recliner. A healthcare professional will clean the needle site with an iodine preparation to prevent infection, then insert a sterile needle into a vein in your arm. If you have had successful blood draws from a particular vein in the past, let the staff know so they can use that site.^[1]

During the procedure, you can relax, read, watch movies, listen to music, or talk with other donors or staff members. The length of time varies depending on what type of apheresis you are having. Most procedures take between one and a half to four hours to complete. Some people feel cold during the procedure because the anticoagulant solution is at room temperature. Staff can provide heating pads and blankets to keep you comfortable.^[1]

Some people experience tingling around their lips or in their fingers during apheresis. This happens because the citrate anticoagulant temporarily lowers calcium levels in the blood. If this occurs, the staff can pause the procedure and give you calcium tablets to relieve the symptoms. Most side effects are minor and go away quickly.^[2]

Safety and Potential Complications

Apheresis is generally safe and well tolerated by both healthy donors and patients receiving treatment. The procedure has been used successfully since the early 1970s, and the technology has improved significantly over the decades. However, as with any medical procedure that involves inserting needles into veins, some risks exist.^[2]

The most common side effects include feeling tired, nauseous, dizzy, or cold during the procedure. The tingling sensations around the mouth and in the fingers that some people experience are caused by the citrate anticoagulant temporarily affecting calcium levels. A temporary increase in itching or a low-grade fever may occur after photopheresis. Blood pressure may decrease during the procedure, which is why patients remain seated or lying down and are monitored throughout.^[1]

Inserting the large needles or catheters necessary for apheresis can sometimes cause complications at the insertion site. These may include bruising, bleeding, or infection. If a central line is placed in the upper chest or shoulder area, there is a small risk of puncturing the lung, which could cause a collapsed lung called pneumothorax. However, healthcare providers take precautions to minimize these risks.^[5]

Because plasma exchange involves removing large volumes of plasma and replacing it with albumin or donated plasma, this process does not replace all the proteins normally found in plasma. Immunoglobulin proteins and certain clotting factors are not fully replaced, which means patients may temporarily have lower levels of these important substances. For patients with thrombotic thrombocytopenic purpura, fresh frozen plasma is used as the replacement fluid instead of albumin because it contains necessary proteins.^[5]

Serious complications such as abnormal heart rhythms, seizures, electrolyte imbalances, and unexplained bleeding are very rare. Healthcare providers monitor patients closely throughout the procedure and can quickly address any problems that arise. Despite these potential risks, the benefits of apheresis for treating serious medical conditions generally far outweigh the possible complications.^[12]

How Apheresis Helps Save Lives

The impact of apheresis on patient care is substantial. More than 1,000 patients receive apheresis treatments each year at major medical centers, and many more benefit from receiving blood components collected through donor apheresis. The procedure is particularly crucial for cancer patients, who make up 95 percent of platelet recipients at some hospitals.^[2]

One major advantage of apheresis-collected blood components is that they expose the recipient to fewer different donors. When platelets are collected from whole blood donations, it takes six to eight different donors to create enough platelets for one patient transfusion. With apheresis, all those platelets come from a single donor, greatly reducing the patient’s exposure to different blood types and decreasing the chance of reactions.^[2]

For therapeutic apheresis, the ability to remove specific harmful substances from the blood while preserving healthy components gives doctors a powerful tool. In rapidly progressive autoimmune diseases, plasma exchange can remove existing harmful antibodies while other medications work to prevent the body from making more. This combination approach can save lives when medications alone are not enough.^[5]

The procedure also allows for selective removal based on specific medical needs. In lipid apheresis, for example, low-density lipoprotein cholesterol can be selectively removed from plasma for patients with familial hypercholesterolemia, an inherited condition causing dangerous accumulation of cholesterol. This targeted approach provides treatment options for patients whose conditions cannot be managed through diet and medication alone.^[5]