The Apheresis Process

Overview

Apheresis collects your stem cells as an outpatient procedure. You sit in a comfortable chair while a machine takes blood from one arm and returns it to the other. The machine separates your stem cells from the rest of your blood. The process takes 2-4 hours total. Most donors finish in one session.

This is usually the easiest part of donation. You may feel needle sticks at the start, coolness as your blood returns, or mild tugging sensations. Some donors feel lightheaded when the machine starts, but staff watch you constantly. Mild tingling around the lips can happen from the anticoagulant in the machine. Calcium supplements fix this quickly.

How does apheresis work?

Peripheral blood stem cell (PBSC) collection happens through apheresis. You'll lie or sit in a comfortable chair while a machine gently separates your stem cells from your blood, collecting the cells and returning everything else. It's not surgery; there's no anesthesia. It's the gentlest collection method, though it requires a few hours of your time.

During the procedure, the following occurs:

• Non-surgical procedure with no anesthesia required
• Sitting in a comfortable chair for 2-4 hours
• Machine separates stem cells from your blood
• Returns red blood cells and plasma to your body
• Usually requires only one collection session

What is PBSC collection?

PBSC collection uses a specialized machine to separate your blood into components. Your whole blood enters, where a centrifuge isolates the stem cells and white blood cells you're donating. Red cells, platelets, and plasma are returned to you.

For blood access, doctors typically use two arm vein needle sticks. One needle takes blood out, while one returns it. Occasionally, if you have difficult veins, they'll use a central venous catheter in your chest or neck instead.

Vascular access. Two main approaches are used for PBSC collection:

• Two arm vein needle sticks (standard)
• One needle draws blood out
• One needle returns blood to body
• Central catheter if veins are difficult
• Choice depends on your vein quality

The apheresis machine itself is specialized and portable. The entire procedure is non-surgical and takes 2-4 hours per session. Most donors complete collection in just one session, though rarely a second session is needed if the first collection yields slightly lower cell counts.

The apheresis process

How the machine works

The apheresis machine takes in whole blood at a steady rate. Inside the machine, the blood is separated by density (using a centrifuge) or by electrical or physical characteristics. The stem cell and white blood cell layer is directed into a collection bag. The remaining blood (red cells, platelets, plasma) is returned to your bloodstream.

What happens. The machine operates through a continuous process:

• Blood flows in a continuous circuit from your arm through the machine and back
• Machine automatically regulates flow rates and collection volume
• Monitors your blood pressure and oxygen levels continuously
• Alerts staff immediately if anything abnormal is detected
• Entire system is sterile and single-use

You won't be exposed to another person's blood. The process is carefully controlled to ensure your safety and optimal cell collection.

What it feels like

During apheresis, you feel the needle sticks (like a blood draw), then usually nothing much. Some donors describe the return of blood as feeling cool or slightly cold. Some feel occasional tugging as blood flows.

Common sensations. Most donors experience:

• Usually painless needle insertion
• Blood flow feels cool/cold
• Occasional tugging sensation
• Mostly boring and uneventful
• Some mild tingling possible (harmless)

Most donors sit quietly, watching television, reading, or talking with staff. You might feel lightheaded or dizzy, especially as the machine drains blood initially. This is normal and usually improves with slow breathing. Staff monitors you continuously and can pause collection if you feel unwell.

Physical sensations. Some donors notice:

• Pressure at needle insertion sites
• Mild bruising developing at needle sites
• Citrate-related tingling (lips or fingers)
• All sensations are harmless and manageable
• Calcium supplements resolve citrate effects quickly

The experience is boring more than painful. Most donors describe it as the easiest part of donation.

How long does collection take?

Duration varies. Collection time depends on these factors:

• Most commonly 2-4 hours
• Can range from 1.5-5 hours
• Usually only one session
• Occasional second session if needed
• Speed depends on CD34+ count

Collection times vary based on your CD34+ count, blood flow rate, and target collection volume. Donors with very high CD34+ counts mobilize faster and finish quickly (as little as 1.5-2 hours), while donors with adequate but lower counts take 3-4 hours.

You'll be positioned comfortably in a reclining chair with blankets available. You can use the bathroom if needed—staff temporarily pauses collection and unconnects the collection lines. You can eat snacks or drink beverages, and many collection centers provide entertainment, wifi, and a comfortable environment.

If collection is taking longer than expected, staff explains why. Sometimes the machine needs adjustment. Sometimes your flow rate is lower than anticipated. These adjustments are normal and don't mean anything is wrong.

What if not enough cells?

The collection team monitors how many cells are being collected in real-time. If after the anticipated collection time you haven't reached the target number, they discuss options: continue collection longer today, or schedule a second apheresis session tomorrow.

A second collection session means returning to the center the next day and repeating the process. This is fairly common and doesn't mean anything went wrong. Sometimes blood flow is slower than anticipated. Sometimes the donor's mobilization was slightly lower than expected. Having two collection sessions just means the goal is reached with two procedures instead of one.

Rarely (1-2% of collections), the target cell count isn't reached even after multiple sessions. This might happen if the patient is in such urgent condition that the team decides to proceed with partially collected cells, or if mobilization was inadequate. Your team would discuss all options with you and the patient's transplant center.

• Usually reach target in one session
• Second session sometimes needed
• Not a failure; part of normal variation
• Rarely, don't reach target
• Team discusses options if needed

After collection is complete

Once collection is finished, the needles are removed and a small bandage is placed at each site. You can eat and drink normally. You're encouraged to drink fluids and eat a light meal—some centers provide snacks. You'll rest for 10-15 minutes, and then you're usually free to go.

After collection. You can expect:

• No anesthesia restrictions, so you can drive safely
• Can return to normal activities when you feel ready
• Mild fatigue is common (from mobilization and apheresis)
• Some donors rest at home, others return to work
• Listen to your body and rest as needed

Your arm might be bruised at the needle sites, and that's normal. Bruises resolve in days to weeks. You might notice mild arm swelling if the bruising is significant—elevate your arm above your heart if this happens.

You'll have follow-up appointments to monitor your recovery, typically a blood draw 1 week post-collection and a phone check-in around day 14. Your team calls or emails you with results and next steps.