Dear Ange,

Most people are familiar with Rh disease in babies - this is where an Rh negative mom is carrying an Rh positive baby and produces antibodies against the Rh antigen, a protein which is carried on the baby's red cells. Cells which are coated with antibody are quickly destroyed.  This condition was a major cause of fetal and newborn death until the introduction of Rhogam which is now given to Rh negative mothers during pregnancy and just after birth (or miscarriage) in order to prevent the development of these antibodies.  What many people do not know is that the red cells carry many other antigens besides ABO and Rh.  Several of the steps involved in testing done during pregnancy or before anyone receives a blood transfusion are aimed at detecting the presence of antibodies to any of these many antigens and making sure that if the antibodies are present, the patient receives blood that does not carry those antigens.

Since a baby's genetic makeup comes from both mother and father, it is very possible that the baby's red cells may contain antigens different from the mother's and in some cases, may trigger the production of antibodies during pregnancy or after birth due to the leakage of small amounts of fetal blood into the mother's system.  After the Rh system, the Kell antigen is the one most likely to cause antibody production in the general population.  In your mom's case, her cells are Kell negative and her baby's are Kell positive and she is making antibodies against the Kell antigen found on her baby's red blood cells.  There is not as much known about Hemolytic Disease of the Newborn or HDN (the official medical term for Rh and other diseases of this type) caused by antibodies outside of the Rh system. However, there is some research that suggests that Kell may cause problems not just through the destruction of red blood cells but also by blocking the production of new blood cells in the bone marrow, thus causing an even more severe anemia than would be expected just from red cell destruction.

As far as I know, there is no substance like Rhogam which can be given to moms producing antibodies to other antigens, such as Kell.  So for now, the doctors will probably monitor the baby's condition, perhaps induce labor or take the baby early through a c-section and then perhaps, if the condition is very severe, use exchange transfusions right after birth (or perhaps even before birth - don't know if they are doing that for this condition) in order to remove the offending antibodies from the baby's system.  If there is a lot of damage going on prenatally, then the fetus may indeed not survive, but hopefully this will not be the case for this mom.

The good news is that these antibodies (of the IgG type)  will not hurt the baby.  The amount found in mother's milk is very small, if at all, and what is there will not be transported into the baby's bloodstream where it can be harmful.  In humans, the transfer of IgG and IgM antibodies takes place mainly through the placenta where there are special receptors which allow this to take place (in contrast, in many other animals, horses for example, the receptors for antibody transfer are not found in the placenta but rather in the newborn gut tissue - the receptor activity in the gut is very short-lived, so if these animals do not receive colostrum during the first 24 hours or so after birth, they are very likely to die of infection soon afterwards).  It is mainly IgA antibodies which are responsible for part of the immune protection provided by breastmilk and which are capable of moving from mothers' milk into babys' systems.

Anyways, this has gotten very long, but I hope not too confusing.  If mom has a live birth, then breastfeeding can commence as for any other newborn.  Love, good medical care and maybe a little luck will hopefully be enough to bring this pregnancy to a positive conclusion.

Warmly,
Sharon Knorr, BSMT, ASCP, IBCLC
Newark, NY (near Rochester on Lake Ontario)
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