In a long-term prospective study of leukocyte alkaline phosphatase (LAP) activity in patients with advanced Hodgkin's disease, there was an excellent correlation between LAP activity and "active" disease in the absence of known corticosteroid therapy and major infection. Most patients with 'inactive" disease had normal LAP activity. Serial measurements of LAP activity appear to be a useful adjunct in evaluating not only the clinical state of patients with Hodgkin's disease but also their response to therapy.
Bennett JM, Nathanson L, Rutenburg AM. Significance of Leukocyte Alkaline Phosphatase in Hodgkin's Disease. Arch Intern Med. 1968;121(4):338-341. doi:10.1001/archinte.1968.03640040032006