Congenital Spherocytosis Can Cause Severe Anaemia And Jaundice In Newborns
Question: My sister’s two children have congenital spherocytosis diagnosed right after they were born. There are quite a few relatives on my side of the family who have had their spleens removed, most likely due to the same medical condition. My wife is now pregnant with our first child. I am really scared that our baby may develop the same condition. Is there anything that we can do?
You need to tell your doctors about the family history of congenital spherocytosis (CS). Because this is a fairly common medical problem, let me explain in more detail so that you and other readers can understand it a little better.
CS is a genetic condition that affects the covering of red blood cells in our blood. Normal red blood cells have a donut shape when examined under the microscope: they have a thick rim and a very thin center.
In individuals with CS, some of the proteins that make up the covering of red blood cells are either deformed or absent altogether. As a result, the covering of these red cells is defective and cannot maintain this donut shape. Instead, they become spherical in shape, like a ball, hence the name spherocytosis.
There is an important reason why red blood cells are shaped like donuts. Blood goes through all parts of the body, bringing oxygen to, and removing carbon dioxide from organs and tissues. In order to pass through very small blood vessels, red blood cells have to be able to change their shape to squeeze through these tiny passages. It is a whole lot easier if the cells are shaped like donuts.
The problem occurs when these cells try to go through the spleen. The very small channels there make it almost impossible for them to pass through. As a result, these abnormal cells are trapped inside the spleen. Over time, the spleen becomes enlarged and very firm. Some ‘scavenger’ cells called macrophages in the spleen will break down defective red blood cells, converting the red haemoglobin into a yellow pigment called bilirubin. The iron in the cells is recycled to make new cells.
Since red blood cells are broken down faster, people with CS have lower haemoglobin than normal, a condition that is called anaemia. The severity of CS is very variable; some have mild disease where haemoglobin is only slightly below normal. Their condition cannot be diagnosed without sophisticated tests. Others have moderate to severe anaemia that may require transfusions.
Because red blood cells are broken down faster, the bone marrow has to produce them at a much faster pace. Haemoglobin in the blood will strike a balance at some point, when production and removal of red blood cells are equal. However, this balance can be tipped off by virus infections, which suppress the bone marrow and reduce production of new red blood cells. That is why CS patients should receive influenza vaccine (commonly known as flu shot) once a year to prevent this infection.
The most serious virus of all is the Human Parvovirus B19, which causes ‘slapped cheek disease’ in children. This virus can completely stop the bone marrow’s ability to produce red blood cells for a short period of time. When this happens, the haemoglobin drops rapidly, and the patient can get desperately ill, unless transfusion can be given quickly. Unfortunately there is no vaccine for this virus as yet.
Patients with moderately severe CS often have signs of jaundice. The white part of their eyes, called the sclera, turns yellow in colour due to the pigment bilirubin. This pigment is normally broken down and excreted by the liver. However, when too much bilirubin is produced, it accumulates in the body, and leads to jaundice. Gall stone may also develop in CS patients for the same reason.
The most serious form of CS happens in some newborn infants. A large proportion of their red blood cells can disintegrate shortly after birth. As a result, the haemoglobin drops rapidly, and the baby can go into heart failure. In addition, large amount of bilirubin can be produced in a very short time. High bilirubin in a newborn can lead to brain damage.
Therefore families with CS should alert their physicians so that their babies can be monitored carefully after birth, to make sure these serious problems do not occur. If they do, a procedure called ‘exchange transfusion’ can be done to replace the baby’s blood with donated adult’s blood. This will solve the problem of low haemoglobin as well as high bilirubin.
If the baby has no problem after birth, close follow up is still necessary, because red blood cells can break down slowly, and anaemia can occur after a few months.
Believe it or not, the best treatment that can ‘cure’ CS is to remove the spleen (a procedure called splenectomy). The spleen is actually quite normal except being enlarged because of trapped red blood cells. However, by removing the spleen, even defective spherical red blood cells can survive longer, like normal cells. Haemoglobin rises after surgery, and bilirubin drops to normal.
There is a serious downside to splenectomy. The spleen is a very important organ that manufactures antibodies to fight infections, especially against bacteria. Without the spleen, serious and sometimes fatal infections can occur.
Because of this danger, children with severe CS require vaccination as early as possible to protect them against most dangerous bacterial infections. When they reach 5 or 6 years of age, decision has to be made about the spleen. After splenectomy, penicillin is needed for many years (may be for life) to prevent an especially dangerous bacteria called Pneumococcus.
I should mention a little more about the genetics of CS. It is the most common medical condition that affects the covering of red blood cells. In North America, it is estimated that 1 in every 5000 individuals with North European background has CS. Other ethnic groups are much less affected.
CS affects males and females equally. Most of the time, an abnormal gene is being passed on from one parent, while the other parent has the normal gene. Sometimes the child receives an abnormal gene from each parent, in this case both parents are called ‘carriers’ and they are not affected by the disease.
Finally, CS can also occur without any family history. There can be ‘mutation’ of the gene (spontaneous change of the genetic code) during the development of the foetus.
Because of your family history, you may want to have tests done to determine whether you have a mild form of CS. Regardless, your baby needs to be monitored carefully after birth to make sure that he/she does not carry the disease, because it can be very serious in young children.