Take a deep breath….

March 21, 2008 at 5:25 am

Hi, I would like to offer a few comments.
First and foremost, people consider not only the absolute CD4 count, but also the relative numbers and function when thinking about immunodeficiency. The absolute numbers can go down if the number of white blood cells are reduced. This definitely happens after rituxan and can happen after IV IgG. I have seen a lowered white blood cell count after almost every cycle of rituxan given in children in our clinic including given for autoimmune diseases. Please let us know what his WBC count is. He could have an appropriate CD4 percentage, but a low WBC and the absolute number of CD4 cells will be low. For example, if someone has a WBC of 5000, the calculated number for absolute CD4 might be very different than if the WBC was 1000, but the percentage could be appropriate.
T cells are the generals or directors of the immune response and help make sure than B cells act appropriately. As compactdisc states, often people look at T cell dependent immune responses to see if the rest of the immune system “works” specifically against challenges in order to figure out if the problem is just with T cells, just with B cells, or with both. Often people look at specific antibody titers to tetanus and pneumococcus–which is why he asked about immunizations.
The fact that Dell is almost 4 years old and has not had lots of significant infections is a very strong argument that he does not have a severe combined immunodeficiency with both B and T cells not working.
The most important point of this point is that people have to look at the whole immune system to figure out what is wrong and that a low CD4 count does not always mean that the problem is with the T cell system.

2. Whatever the reason for a lowered CD4 count, it is definitely worth being safe to take bactrim (as I think you meant) or septra (as Dawn meant). this is the same medicine, but two different brand names. It helps prevent “opportunistic infections” particularly a kind of pneumonia for which T cells are important fighters. At our institution, we often put children who are getting high doses of steroids on bactrim (septra) as a precaution.

3. My third point is that it is REALLY unusual for a tiny baby like Dell to get an autoimmune disease. It happens, but people should always think about if the immune system is able to regulate and balance itself correctly when this happens meaning if there is a primary immunodeficiency problem that leads to dysregulation. Your immunologist is good to think about it. It does not mean that it is there, but you want to know because if it is…
a. All of you can know other ways to help keep Dell safe in life.
b. It might give some insights into other ways to treat the CIDP.
The biggest point of this is that knowledge is not always bad and that if he has a primary immunodeficiency, it does not mean it is a completely separate disease–they are likely related and knowing this might be a good thing because it might help change the approach to them and might even result in better control of the CIDP, but definitely in better safety with treatment.

4. If the WBC number and the absolute B cell number were okay before the rituxan, it might be a good thing to have the whole picture looked over by someone that specializes in primary immunodeficiencies in children. Many major medical centers with children’s hospitals (typically associated with medical schools) have such departments. We have a really good immunodeficiency clinic here at this very large children’s hospital in Indiana, but I know there are also good ones in New Orleans (through LSU or Tulane) and University of Alabama in Birmingham. I cannot at this late hour think of people in Mississippi, but I could ask around if you would like. I do not know where you live in Mississippi. If you live in northwest Mississippi, St Jude’s probably has primary immunodeficiency experts.

WithHope for cure of these diseases.