3 Bovine Blood Groups

Transcript

Greetings dear veterinarians

In the last presentation we saw the basics of large animal transfusion with those clinical facts now we move into the next stage where we need to know about the bovine blood groups and how to collect blood from the donor cause.

Now blood types are basically representing certain specific antigens. These are present on the surface of the erythrocytes. In human we have the ABO system but the same is not used in animals, in bovines we have a different system a species specific antigen presentation is there. The number of blood groups in cattle are bovines it varies between species many times in the bovines or cattle it exceeds 80 whereas in case of Camelidae it’s only one in the new world Camelidae and then there are certain kind of antibodies to blood group antigens we need to know about. So there could be a naturally occurring antibody or the antibodies that may get acquired after an exposure to the particular blood antigen. Now what happens the naturally occurring antibodies occur in the most species and they vary in their pathological significance, some even may not even produce a transfusion reaction.

The acquired antibodies what happens they get developed or acquired after exposure to an incompatible blood group or any blood product that contains a particular antigen. Now when such antigen exposure is happen these acquired antibodies are produced and this causes some sort of reactions sometimes it may even induce a hemolytic reaction or agglutination or hemolysis of the cells.

So to avoid these sort of transfusion reactions we need to go for the blood typing. Bovine blood typing is not available in common conditions or in the field scenario which is available only in the referral centers, IR institutions and not much companies are available who manufacture the kits only very few diagnostic labs are available. Now compatibility testing, right so we use cross matching to test the compatibility generally we send the sample to the laboratory and we can do that or if you have a point of care lab at your own practice we can do that. Many times the administration of typed negative blood will not prevent a transfusion reaction so don’t expect that even after typing the reaction may not happen it can happen, varied antigens are there that may cause such a consequence.

Now from the clinician’s standpoint these antigens are sometimes the practices should be able to familiarize with that. But due to the lack of commercially available kits practices are finding it difficult to know the antigen systems in the in their respective practice area. Now many times these antigens gets coupled with platelets leukocytes and plasma proteins and induce immune mediated reactions. So we need to be careful whenever incompatible blood is used and erythrocyte antigens themselves can produce antibodies in the recipient. So many many disadvantages occurs whenever there is a incompatible antigen usage.

Now these are the common blood groups in the cattle so they are named with different alphabets like A, B, C then F, J, L then there is M, O, R, S T and Z these are the ones until now has been identified and in some of the referral labs the kits are available for typing these 11 groups. Now out of these 11 groups, group B and J are the most important one and clinically relevant. But what happens is even in within the B itself there are more than 60 antigens. So, we can’t perfectly do and identify a blood that is very safe for the recipient because 60 antigens can be varying. We can’t basically do any very close matching for such cases.

And J antigen now this is a lipid found in the body fluids and gets absorbed into the erythrocytes. So basically it is not a true antigen but still it can produce some interferences. Newborn calves may not have this antigen but it gets acquired in the first six months of life. Even sometimes the J negative animals can develop antibodies. so, we need to be very very careful when we are using uh such cases.

And in case of younger animals Neonatal Isoerythrolysis (NI) is a possibility. It’s not a naturally occurring phenomena but Bouts of neonatal isolation can happen after a blood dried vaccine is being used for example some of the vaccines they use for anaplasmosis, babesiosis. These can bring in Isoerythrolysis and most common antigens that cattle get sensitized is the A and F systems.

Now in the next part we will see how to do donor blood collection from the bovines. For small volume blood collection we can use donors at the hospital setup. In some of the countries where the big slaughter houses are there people go and collect blood from the slaughter houses also. But in our small practices we use donor cows, a healthy donor cow about four and five year old and possibly it should be a dry animal or at least one month after calving, these are the preferred animal. A larger sized cows with a body condition score of 5 that will be good enough and most importantly we need to contain their excitement we provide allowing care for them so that it cooperates for your collection. Basically, we don’t need to have any specific treatment for the blood donors. After donation you can just send them home and always calculate the PCV for both donor and recipient. For donors sometimes PCV may go less than 15 but animal may look like not even a sick, so you need to take into account.

Now we look at the use of Anticoagulants for the Bovine blood collection. For bovine donations either you can use a sodium citrate normally 12 grams of sodium citrate dissolved in 300 ml of saline will be enough to collect 5 liters of blood, and basically about 9 liters of blood will be more than sufficient to keep a cow alive and sometimes even as low as 3 liters can be enough but you need to aim for a collection of 5 liters so that this will improve the PCVand the relieve the Anemia significantly. You can even store the blood and you can use it but whenever you are using with stored blood preferably do it within the 24 hours, and for this reason we always collect fresh blood whenever there is a immediate requirement, we don’t collect and store them. A cow with PCV of 8 may even stand and walk around, so we think it is a good but suddenly it may deteriorate. So pcv alone will not be good guidance you need to decide based on each case.

Now collecting at the clinical setup now how to collect for example if it is in your farm you can use the human blood bag like this, and put it put the you can either use a jugular catheter, or the collection set available with the standard blood bags, put the needle into the jugular vein and start collecting and the bag has to be keep agitated, if it is in the hospital you can do it with a blood collection monitor that keep on agitating the blood bag. The most important thing is maintain the donor in a quite calm situation if required you can even use mild sedation and do a very perfect aseptic preparation of the jugular vein and then put the needle into the jugular vein and then collect. Probably it will take less than few minutes for getting the end tablet collected, and what is the needle size or catheter size 14 gauge will be useful even with the 16 gauge needle you can do that and normally 400 ml of 3.8 percent sodium citrate can be used, add it to a four litre collection bag if it is a bigger volume collection a four litre collection bag or even a bucket where you can add this uh three point eight percent sodium citrate and you can collect the blood and start transfusing to the max and use that. The other formula is to use about 38 gram of sodium state into one litre of Hartmanns solution and then that will support for two cows.

Now what are the basic limitations is that the limitation here is no more than 20 % of the blood should be collected from the donor so that is the most important point you need to keep in mind never collect more than twenty percent of the bonus blood volume. And all the collection storage as well as transfusion should be done in a very very aseptic manner because you are going and dealing with the jugular vein, it’s a central vein we can’t take risk even a small change can bring in infection or massive bleedings. So, we need to be very cautious in that, so now we need to know how to collect from the donors and there are additional reading materials available about the care of the donor cows and what are the things to be done for a donor, if you have any doubt kindly let us know will be there to clarify.

Thank you