I know most has been cover over and over, but I found the following, and it seems to cover most points regarding Campath's method of action, in a clear and concise mannor. Its not for MS specifically, but its the same compound being used.
Pharmacology and use:
Campath is used to treat leukemia by exploiting antibody mediated lysis of CD52 presenting cells. The CD52 antigen is a cell surface protein found on essentially all B and T lymphocytes, a majority of monocytes, macrophages and most granulocytes. The CD52 antigen is not present on erythrocytes or hematopoetic stem cells. In leukemia there is an excess of B and T cells, so Campath permits selective reduction of lymphocyte populations. For treatment of B-cell chronic lymphocytic leukemia
Mechanism Of Action:
Campath binds to the CD52 antigen present on most B and T lymphocytes. This binding leads to antibody-dependent lysis of leukemic cells.
I haven't checked the validity of the above information, but I was surprised by the part that says "CD52 antigen present on most
B and T lymphocytes" and before that it says "found on essentially all
B and T lymphocytes". I would be interested to know a number here?
Now, the other question which wasn't covered by the above, or explicitly in anything I can remember, is how long after treatment, Campath continues to kill these lymphocytes? Is it a life long effect?