Revimmune kills off everything but your stem cells in the marrow. Campath just takes down the b-cells.
Are you sure you aren't thinking of rituximab/rituxan NHE?
You're right, Campath targets T-cells. http://www.mult-sclerosis.org/Campath1H.html
Campath-1H is something called a humanised anti-CD52 monoclonal antibody. I will try to explain what this means.
Because antibodies are so specific, researchers have looked at engineering antibodies to disable specific cells in the human body. These are known as monoclonal antibodies and have been called "magic bullets". Campath-1H is just such a monoclonal antibody. It is designed to latch onto cells expressing a protein called CD52 thereby killing them.
CD52 is a type of protein known as a leukocyte antigen. It is expressed on the surface of several types of white blood cells (leukocytes) including lymphocytes (which include T cells), macrophages, monocytes and thymocytes (immature lymphocytes). Campath-1H has been shown to be very effective at destroying T-cells, the cells responsible for initiating the damage in multiple sclerosis. CD52 is also expressed on the cells lining the male reproductive tract. I am unaware whether Campath-1H has any implications for male fertility.
After the initial infusion with Campath, the body's T cell population takes many years fully to regenerate. To make up for the lost immune function, reconstituted lymphocytes of a kind that weren't associated with the disease process in MS were given to the trial volunteers (Th2 cells).
It is thought that because the Campath-1H treatment moves the body's immune response away from a Th1 type of response, one third of the volunteers developed antibodies to a protein found in the thyroid organ (the thyrotropin receptor) and thus developed autoimmune thyroid disease.