anti-cw antibody?

[pndg]

forgive me if i put this in the wrong section! i am currently 11w3d pregnant, and my routine 8w blood work came back fine except on test found antibodies present in my blood. called me in for more blood. they asked if i have ever had a transfusion, which i have not. issued blood work for the baby's father, he is A+ and i am B+ so we are compatible. doc says it is the anti-cw antibody, and he would discuss more in depth at my next appointment, and i have heard nothing since. i can't find anything reliable or consistent on this, looking for any advice on what to expect? a nurse said im most likely going to be categorized as high risk and monitored but shouldnt worry too much. any insight is welcomed-thanks!

[Mabel Adams]

Clliff, do you think it is time we created a section for "patients with antibody questions" or some such? It might make it easier for them to find a place to post and read related posts. Just a thought.

[Mabel Adams]

First some background that I hope will help with understanding your test results. Your immune system can make antibodies to foreign substances when it is exposed to them (like the chickenpox virus or the killed virus or bacteria particles in a vaccine). The part of these foreign substances that your immune system recognizes and makes antibodies against are called "antigens." Red blood cells have lots of different kinds of antigens on their surfaces--the ones most people have heard of are those of the ABO system and Rh antigens. These are what give you your blood type of A positive or B negative. The positive and negative part refers to the Rh antigen "D." There are actually quite a few additional antigens in the Rh system (and many others) that most people have never heard of. One of these is Cw. Red cell antigen variations are inherited from your parents and you and your husband will pass red blood cell antigens on to your baby. The genes on your DNA that you pass on for these antigens come on pairs of chromosomes--you get one of each pair from one parent and the other chromosome of each pair from the other parent. Because you have never been transfused, you probably were exposed to the Cw antigen during a previous pregnancy through a small amount of blood leaking across the placenta (usually at delivery) from the baby's blood system into your blood stream. That baby must have had red blood cells with the Cw antigen on them that he or she inherited from his/her father (since you must lack the Cw antigen yourself in order to be able to make the antibody against it). Still with me? Now that they have found this antibody they will try to predict if the baby you are now carrying will have that antigen on his/her red cells and also how strong the antibody is. The Cw antigen is pretty rare so the first question would be if the father of this baby is the same as that of all previous pregnancies you have had. If you have remarried, the chance of both fathers being Cw positive is pretty small. Even if previous pregnancies had the same father, due to its low frequency, he is not likely to carry Cw on both of that pair of chromosomes so he would probably have only a 50% chance of passing the Cw antigen on to this baby. If this baby does not have the Cw antigen on its red cells, there is absolutely no risk to it from your Anti-Cw antibody. So, they are probably testing the father's blood for the Cw antigen. This is not a test that every lab can perform so it may take a week or more to get results back from the lab they sent it to. If his blood is Cw negative (lacks the antigen) then the baby can't inherit it (unless the baby came from a donor egg or some such) so then you have nothing to worry about. If his blood is Cw positive then the baby probably has a 50% chance of inheriting it. They will probably do an antibody titer on your blood to see how strong the antibody is in your blood. If it stays weak throughout the pregnancy, the baby will probably be fine. If it is strong now or gets strong later they may choose to do other tests to monitor how the baby is doing. A special ultrasound test is common. If those look fine throughout the pregnancy then the baby will probably be fine or maybe jaundiced after birth (skin turns yellow from too much bilirubin in his blood). If the baby is too jaundiced, they will put him under special lights that help his body break down the bilirubin. If they see signs of problems on the ultrasounds they may choose to deliver a few weeks early or some other intervention. The antibody is crossing the placenta into the baby just like all those good antibodies to everything you are immune to, but, if he has the Cw antigen on his red cells, the antibody will attach to it and his immune system will destroy those red blood cells. Bilirubin is a breakdown product of this process. If there is too much antibody (and he is Cw positive) it could even make him anemic but they will find that on the ultrasound tests and know to intervene before it does him any lasting damage. Odds are that this baby will be Cw negative and you don't have to worry about anything. If you have more questions, please post again. I know that pregnancy can be a great time for worrying.

This antibody does not mean you are sick. The only other thing it means for you beyond pregnancy is that if you were ever to need a blood transfusion, it might take a bit longer to find you compatible blood. It would be a good idea for you to let the Lab/Blood Bank department of any hospital you go to know that you have this antibody because it will make preparing blood for transfusion easier, faster and safer for you. If you live in a place where you are likely to go to only one hospital, I would suggest phoning the hospital and asking to speak to the Lab, then someone in the Blood Banking dept. Tell them what antibody you have and they will either record it in their system for the future or ask you for a copy of the report (which your doctor can send). When you change hospitals, you can have the Lab at the new hospital phone the old hospital for this information (you might have to sign a release form). Blood bankers understand all of this well, but not many others do so it is easier to let them speak to each other. Again, please post again if you have more questions. I hope this answer hasn't totally befuddled you.

[Mabel Adams]

It looks like there is a previous thread with more info on anti-Cw here:

http://www.pathlabtalk.com/forum/showthread.php?1694-Advise-With-Anti-cw-Antibodie-Detection-In-Pregnancy-Screening-Please!!

[pndg]

thank you Mabel Adams for your thorough information! The baby's father's blood work came back with no antibodies found, however i am a little confused as to how i have this antibody seeing as how i have never been pregnant before? could it be something i was born with inherited from one of my parents? though my mom does not have the anti-cw, and my father gives blood (i know this because he is that rare blood type that is compatible with everyone). again, thank you VERY much!

[pndg]

after further searching i found this:

http://www.api-pt.com/Reference/SpecialTopics/11A_EDU-01_BBank.pdf

it states that it is "often naturally occuring" which i'm taking to mean i am just one of the lucky "2% of caucasians" to have this. first described in 1946, so not lot of testing for it routinely other than donating blood/pregnancy. i still find it odd that there aren't many documented cases on this haha

[Mabel Adams]

Antibodies in the father's blood would really be of no concern in this case. Whether or not he has the Cw antigen on his cells so that he can pass that trait onto the baby would be what matters most in testing him. The 2% of Caucasians are those with the antigen, not the antibody which you have.

Since you have never been transfused or pregnant before that removes the most common ways your immune system could have been stimulated to make the antibody. It is not impossible that the baby you are carrying now has caused you to make the antibody but it is unusual so early in the pregnancy. There are also some obscure ways listed in the literature that people have been exposed to other people's red blood cells. Your history does increase the likelihood that the antibody is "naturally occurring" which usually means that your immune system was exposed to some similar antigen and made an antibody that cross-reacts with the Cw antigen on Red cells. Blood donors would not routinely be tested for the presence of the Cw antigen. You would not be expected to inherit an antibody--only the antigen on your red cells. Unfortunately, in the world of medicine, not everything is straightforward, black and white. We often remark that the antibodies forgot to read our text books to know how they are supposed to behave. Doctors don't often deal with these unusual antibodies much and even they sometimes get antigens and antibodies turned around in trying to explain your lab results. They have even been known to occasionally order the wrong blood test.

Congratulations and many blessings upon you and your baby.

[Cliff]

Clliff, do you think it is time we created a section for "patients with antibody questions" or some such? It might make it easier for them to find a place to post and read related posts. Just a thought.

Done and moved.

Thanks for the suggestion.

[pndg]

the hospital seemed to be under the impression that i was born with this based on my medical history. small town though, they may not be too familiar with this particular antibody (I'm assuming the reason I was called in a day after my initial appointment where they drew blood for routine tests & claimed they "didn't draw enough blood for all tests" was because the one panel came back abnormal detecting antibodies and they needed more blood to send out for further testing) my doctor has been out of the office for the last two weeks, so i take it that's why i haven't heard anything. its frustrating that there isn't much consistent information about this online, especially considering this is my first pregnancy. not quite sure how this antibody constitutes calling me "high-risk", I'm thinking that would be for insurance purposes so that the extra appointments & ultrasounds they may do can be considered "medically nescessary" as opposed to the initial sonogram & 20 week ultrasound being the only two that count as "medically nescessary" at this hospital?

[Mabel Adams]

I think everyone you have spoken to is maybe just giving you their best guess and trying to be reassuring. I am not sure what "high risk" really will mean for you if the doctor chooses to apply that at all. They may have more precise information later. Don't lie awake nights worrying about this. If there are things to keep an eye on they will do that--maybe extra blood draws and ultrasounds. If there is found to be any reason to intervene then they can explain that. Feel free to ask the doctor your questions until you are satisfied with the answers. He can always put you in touch with someone in the reference lab that did the actual testing if he doesn't feel expert enough. Or maybe he will send you to a perinatologist. You can look online for Hemolytic Disease of the Newborn but even at high quality medical sites you will probably find only the common ABO and Rh (D antigen, not Cw antigen) forms. You will also probably find the descriptions of the ailment scary, but they can do things to avoid the worst of those effects so I suggest you read them with that in mind if at all. I think there is not much online because this is complicated to explain and only Medical Lab Scientists (like most of us on this site) and doctors in only a few medical specialties are likely to know much about red cell antibodies.

[Malcolm Needs ☆]

Mabel, as ever, your posts are well-written, absolutely correct and will, I hope, serve to allay any fears that this good lady has about her pregnancy.

[Mabel Adams]

Thanks Malcolm. I rather thought I rambled all over the place but it is a hard topic to explain in a straightforward way to a lay person. I think we maybe should put together a response for patients on their Frequently asked questions. Of course, wikipedia is getting half-way decent on antibodies. Maybe we should put our efforts there to provide information.

[Malcolm Needs ☆]

I agree with the first bit. I am more worried about the second bit, because, as I understand it, anything on Wikipedia can be altered by a third party, and that could land us in trouble.

[Mabel Adams]

Yes, Wikipedia can be updated by anyone that has signed up but no one but us nerds is likely to make changes to the antibody sections. If someone did, you can go change it back!

[Malcolm Needs ☆]

Yes, Wikipedia can be updated by anyone that has signed up but no one but us nerds is likely to make changes to the antibody sections. If someone did, you can go change it back!

But that is exactly what worries me Mabel. How would we know unless we went onto the site at regular intervals to see if there have been any changes?

[Mabel Adams]

There is a site somehow associated with immunohematology on which you do not lurk?

[Malcolm Needs ☆]

There is a site somehow associated with immunohematology on which you do not lurk?

Several, I suspect!!!!!!!!!!!

:haha::haha:

[rmblack]

Mabel, as ever, your posts are well-written, absolutely correct and will, I hope, serve to allay any fears that this good lady has about her pregnancy.

I was thinking the exact same thing. Very well done.

I hope her pregnancy goes well.

[ElinF]

I was thinking the exact same thing. Very well done.

I hope her pregnancy goes well.

I am totally printing out her response and letting students read it. Very well written.

[EDibble]

May I just add how much I *love* being in this group! :D

[Lady of the House]

I have a question for you learned folk: how would having a positive anti-Cw screen affect someone who is transfusion dependent?As a nurse consultant, I am dealing with a patient with low counts and a history of multiple transfusions with packed cells and platelets, how would a positive screen for anti-Cw affect him? He is now refractory to treatment. I need your help, please! Thanks in advanced.

[Malcolm Needs ☆]

I have a question for you learned folk: how would having a positive anti-Cw screen affect someone who is transfusion dependent?As a nurse consultant, I am dealing with a patient with low counts and a history of multiple transfusions with packed cells and platelets, how would a positive screen for anti-Cw affect him? He is now refractory to treatment. I need your help, please! Thanks in advanced.

As far as I know, an anti-Cw has never, convincingly been reported in the literature to cause a delayed haemolytic transfusion reaction. There is the suggestion that it may cause Cw+ red cells not to last as long in the recipient's circulation as would be expected, but even the evidence for this is not convincing. In the UK, as long as the blood is cross-match compatible by the indirect antiglobulin test (THE gold standard test in blood transfusion), the units would be considered suitable for transfusion.

Although there are cases published implicating this antibody in mild forms of haemolytic disease of the foetus and newborn, again, as far as I am aware, there has only ever been one case report of anti-Cw causing hydrops foetalis, and that case was particularly unconvincing, because the paper was written by Obstetricians, with no input from the hospital's own blood bank (or, at least, none of the authors were from the hospital's own blood bank) and the case most certainly was never referred to the Regional Reference Laboratory for confirmation (my own).

There is overwhelming evidence that anti-Cw, therefore, is largely a clinically benign antibody in terms of blood transfusion, and very little real evidence that it can be clinically significant in pregnancy.

I hope that helps, but others in the USA and elsewhere may like to comment, or even argue with my opinion.

[Mabel Adams]

Only 2-3% of donor units will carry the Cw antigen so finding compatible blood won't be difficult. The AHG (indirect antiglobulin) crossmatch that Malcolm mentioned takes about a half hour longer to do than the more common methods. If your hospital does not do its own antibody identification testing and they choose to send the specimen out to a reference lab for testing (which I don't think would usually be necessary) that could add significantly to the time between the specimen being drawn and compatible blood being available. A quick chat with your blood bank people should give you an estimate of any extra time they need. Sometimes we ask that OP transfusions of patients with known antibodies have a day's delay between specimen collection and transfusion in case we run into new problems that take a long time to work up. That keeps the patient from having to be sent home or from waiting around at the hospital.

What sort of treatment is he refractory to now? If he has not been maintaining his Hgb between transfusions and the anti-Cw was recently identified, he may have had the bad luck to have recently received a Cw pos unit and those cells did not survive as expected. He may do better in future when they are able to make sure that he receives units that lack the Cw antigen (via AHG crossmatch). If he has been being transfused for a long time since this antibody was identified and still isn't getting a bump from the blood, then we can't really blame antibodies I don't think.

[jsherrie]

first some background that i hope will help with understanding your test results. Your immune system can make antibodies to foreign substances when it is exposed to them (like the chickenpox virus or the killed virus or bacteria particles in a vaccine). The part of these foreign substances that your immune system recognizes and makes antibodies against are called "antigens." red blood cells have lots of different kinds of antigens on their surfaces--the ones most people have heard of are those of the abo system and rh antigens. These are what give you your blood type of a positive or b negative. The positive and negative part refers to the rh antigen "d." there are actually quite a few additional antigens in the rh system (and many others) that most people have never heard of. One of these is cw. Red cell antigen variations are inherited from your parents and you and your husband will pass red blood cell antigens on to your baby. The genes on your dna that you pass on for these antigens come on pairs of chromosomes--you get one of each pair from one parent and the other chromosome of each pair from the other parent. Because you have never been transfused, you probably were exposed to the cw antigen during a previous pregnancy through a small amount of blood leaking across the placenta (usually at delivery) from the baby's blood system into your blood stream. That baby must have had red blood cells with the cw antigen on them that he or she inherited from his/her father (since you must lack the cw antigen yourself in order to be able to make the antibody against it). Still with me? Now that they have found this antibody they will try to predict if the baby you are now carrying will have that antigen on his/her red cells and also how strong the antibody is. The cw antigen is pretty rare so the first question would be if the father of this baby is the same as that of all previous pregnancies you have had. If you have remarried, the chance of both fathers being cw positive is pretty small. Even if previous pregnancies had the same father, due to its low frequency, he is not likely to carry cw on both of that pair of chromosomes so he would probably have only a 50% chance of passing the cw antigen on to this baby. If this baby does not have the cw antigen on its red cells, there is absolutely no risk to it from your anti-cw antibody. So, they are probably testing the father's blood for the cw antigen. This is not a test that every lab can perform so it may take a week or more to get results back from the lab they sent it to. If his blood is cw negative (lacks the antigen) then the baby can't inherit it (unless the baby came from a donor egg or some such) so then you have nothing to worry about. If his blood is cw positive then the baby probably has a 50% chance of inheriting it. They will probably do an antibody titer on your blood to see how strong the antibody is in your blood. If it stays weak throughout the pregnancy, the baby will probably be fine. If it is strong now or gets strong later they may choose to do other tests to monitor how the baby is doing. A special ultrasound test is common. If those look fine throughout the pregnancy then the baby will probably be fine or maybe jaundiced after birth (skin turns yellow from too much bilirubin in his blood). If the baby is too jaundiced, they will put him under special lights that help his body break down the bilirubin. If they see signs of problems on the ultrasounds they may choose to deliver a few weeks early or some other intervention. The antibody is crossing the placenta into the baby just like all those good antibodies to everything you are immune to, but, if he has the cw antigen on his red cells, the antibody will attach to it and his immune system will destroy those red blood cells. Bilirubin is a breakdown product of this process. If there is too much antibody (and he is cw positive) it could even make him anemic but they will find that on the ultrasound tests and know to intervene before it does him any lasting damage. Odds are that this baby will be cw negative and you don't have to worry about anything. If you have more questions, please post again. I know that pregnancy can be a great time for worrying.

This antibody does not mean you are sick. The only other thing it means for you beyond pregnancy is that if you were ever to need a blood transfusion, it might take a bit longer to find you compatible blood. It would be a good idea for you to let the lab/blood bank department of any hospital you go to know that you have this antibody because it will make preparing blood for transfusion easier, faster and safer for you. If you live in a place where you are likely to go to only one hospital, i would suggest phoning the hospital and asking to speak to the lab, then someone in the blood banking dept. Tell them what antibody you have and they will either record it in their system for the future or ask you for a copy of the report (which your doctor can send). When you change hospitals, you can have the lab at the new hospital phone the old hospital for this information (you might have to sign a release form). Blood bankers understand all of this well, but not many others do so it is easier to let them speak to each other. Again, please post again if you have more questions. I hope this answer hasn't totally befuddled you.

very well written!