We talked in a previous article about blood donation, what you should know about donating blood, and the special cases in which you should better not to donate blood. We provided some information about the donation process and how it is possible for a healthy person to donate at least 3 times per year in order to provide what patients require for treatment. What we covered in the last article was the traditional perspective of whole blood donation.
Are there other types of blood donation that are non-traditional?
The answer is "YES". Apheresis blood donation or single cell blood donation. The simple Latin meaning of the word is (taking away). It means that you can donate only one fraction of the regular blood bag. You can either donate only red blood cells or you can only donate platelets. It goes by the same principles as donating blood as regards the selection criteria, but there are some differences on some technical aspects.
What are the differences?
First, you don't get a nurse to stick a needle in your arm, and then you fill a plastic bag and it's over. Second, It doesn't end in 10 minutes as usual. It's about sticking a needle or two into one or both of your arms, and through those needles you're connected through sterile tubes to a device that slowly draws a small amount of blood ( usually 100-150 ml at a time ), this small portion of your blood enters into the device through the tubes, is spun under high speed to separate the cells form the blood, and then return blood back to you to draw another amount.
Does it take a lot of time?
I don't want you to feel as if you're connected to a blood sucking monster or something. Everything is pretty much regulated. Most of these procedures are done to let you donate a specific number of platelets, for example. So, before you donate your platelets this way, a staff member will record your weight and height, enter those into the computer of the device to calculate how much platelets you can donate. If a patient needs 10 units of platelets, I just enter that amount and the device will calculate how much time it will take you to give that amount. Usually it takes no more than an hour.
Are there any side effects recorded to apheresis donation?
When you go through an apheresis donation, and in order that your blood doesn't get clotted inside the tubes, they usually contain an anticoagulant called citrate. One of the very rare side effects of citrate especially when it is returned back to your body is that it lowers your free calcium, which would make you feel a tingling sensation that starts around the lips.
What should you do if that happens?
Nothing, the blood transfusion center where you're in will provide you with either milk or calcium tablets for you to take either before or during platelet donation.
Apheresis donations are very important for some patients that need blood components on a regular basis, because such patients develop antibodies to the given blood that they usually take, so with time, their blood just sort of rejects future blood donations. Usually blood banks solve that problem though assigning certain well known regular blood donors for these patients. The blood bank matches their blood groups down to the smallest subgroup and chooses the most compatible blood donor for the right patient. That way, we can protect the patients from facing difficulty in finding the right blood, and also we can ease the pain that they might suffer if they had a reaction with blood that is not perfectly right.
Are there other uses for the apheresis machine?
Of course. We have a machine that extracts some cellular components from the blood and collects them into separate blood bags for patients. Using the same principles, the apheresis machine can extract some harmful particles out of the blood of sick people in order to make them better. The best example of illnesses that are treated in that way wound be auto-immune diseases like Systemic Lupus Erythematosus, a disease in which the blood contains antibodies that react against the patient's body parts, and Multiple Myeloma, a blood disease in which some blood cells produce some protein particles in excess. These protein particles deposit in different body part making patients suffer pain and other symptoms.
The usual treatment for auto-immune patients is corticosteroids, drugs that lower production of antibodies and proteins by cells, but the success rate is really low, that extraction of these antibodies and proteins through "plasma-pheresis" becomes inevitable. Here the Latin meaning is (taking away plasma harmful components).
Second, we can also remove excess platelets from the blood of patients with abnormal production of platelets by their bone marrow. It is well known that if you have more platelets than normal, your blood may start making blood clots. Normally, with the average platelet counts of 150,000 to 400,000 cells/ cubic milliliters, these blood clots are lysed by the body, but with outrageously high platelet counts, these minute blood clots may lead to stroke.
Third, plasmapheresis also can remove harmful cholesterol from patients with increased cholesterol in blood. It has been discovered long time ago that there are different parts of cholesterol inside the body, each serves a specific function inside the body. It was found that the most harmful fraction to blood vessels is LDL (Low Density Lipoproteins).
What's the bottom line about apheresis blood donation?
If you're giving that part of your blood to a patient, then we can call that apheresis blood donation, and your blood will be used for treatment of others. If you are the patient and you're (taking away) part of your blood for your own treatment, it is not actually blood donation, because no patient will be using your blood or plasma. It will be discarded after the apheresis session. Apheresis has been a turning point that transformed some of the traditional blood bank procedures into therapeutic means to treat a lot of diseases.
Next time... Red Blood Cell Transfusions...