Beautiful questions sir @lemouth , I will pick them one after the other.

Firstly this:

As we know that issues could show up with cold agglutinins, can’t they be simply removed from donated blood before getting into the fridge in the blood banks? Or at least, can’t we make sure that the levels of cold agglutinins are low enough to make any transfusion safe? Is there any practical showstopper to proceed as (naively) suggested above?

In clinical practice, one of the guiding principle employed is empathy. most of the patient's relative have hard time getting people to donate blood for their ward in cases where they are not eligible to donate. Blood here is now commercialized to the point that this patients pay heavily as much as $31 for a pint of blood. If we decide to bill them for virtually all assays, they will end up incurring more debts to pay. Since the case is rare like I mentioned in the article, the test is often omitted. Though removing cold agglutinins from blood is a near impossibility task (To my best of knowledge, it's not possible) even though it is, by the time the blood has undergone such a supposed Process which definitely would be rigorous, the likelihood of the blood being sterile becomes questionable. We wouldn't want to give a patient an infected the blood (will result to septicemia)

Antibodies are proteins, if they were cells, then we might then be think of using irradiation to wipe them out or reduce their level. Though one area I feel that would also align with your idea is the production of anti Agglutinins antibodies that are antagonistic and specific in nature. They can bind to the cold agglutinins and inactive them. Still, the condition is not so common, probably reason for less research into it.

can’t the blood be warmed up a little before being transfused?

Regarding this question sir, I also agree with you. The issue here is that, cold agglutinin disease as we saw in the article is an auto immune disease. Meaning that human cells attack itself through the antibody production.

The standard thing for any blood that is removed from the refrigerator is to allow the blood attain and acclamatize room temperature before transfusion to patients. For cold agglutinins disease patient, Even if this is done, cold agglutinin will still react because some also react at room temperature 25-27 degrees Celsius. If we decide to incubate the blood to warm it up, the chances of the blood lysing is high and this infact will be the worst case scenario (will be fatal). In order not to complicate issues, we just totally avoid blood bank refrigerated blood and give them freshly donated blood which will even be warm.

Do we need to check compatibility factor with all of them when a transfusion is in order?

Not at all sir, the major ones that pose grave threat are the ABO and Rh blood groups. Their efforts are fatal if left unchecked.

Pheeew, what a question and definitely not naive.. haha. They created room for further explanation and understanding.

More attention and considerations are given to clinically significant blood groups.