Scientists at the Baylor College of Medicine in Houston and theMedizinische Biochemie, Universitat des Saarlandes, inHamburg, Germany, have identified unique serum antibodies inpatients with amyotrophic lateral sclerosis (ALS) which couldlead to the first serum diagnostic for the disease, as well as ameans to monitor the efficacy of potential therapeutic agents.
R. Glenn Smith and collaborators reported in Thursday's issueof The New England Journal of Medicine that patients with ALS,or Lou Gehrig's disease, have antibodies to specific componentsof the L-type calcium channel, whereas the majority of patientssuffering from other neurodegenerative disorders H as well ascontrol subjects H do not. Cephalon Inc. supported this researchin part, and has exclusive rights to the technology.
Serum from 75 percent of the patients with ALS contained IgGantibodies that reacted with protein purified from L-type,voltage-gated calcium channels from rabbit skeletal muscle.This reaction is not specific to patients with ALS, theresearchers noted: they also saw positive reactions with serumfrom patients with Lambert-Eaton syndrome and Guillain-Barre syndrome. (The IgGs differ functionally, however, in theway they affect calcium channel activity.)
In contrast, only 4 percent of the normal subjects and about 3percent of patients with no motor neuron disease had reactiveserum. Moreover, the researchers found that serum reactivity,as measured by enzyme-linked immunoassays, correlated withdisease progression.
Stanley Appel, chairman of the department of neurology at theBaylor College of Medicine and a co-author on the paper, said,"For the first time we have some insight into what initiatesALS. The positive correlation between the levels of antibodyand the progression of disease suggests that autoimmunity maybe a primary event in ALS."
ALS is a fatal disease affecting about 25,000 to 30,000individuals in the U.S. Cephalon of West Chester, Pa. isdeveloping a recombinant form of human insulin-like growthfactor-1, or Myotrophin, to treat this disease. Phase I clinicaltrials in the U.S. using Myotrophin began in August.
Another compound with potential therapeutic application forALS is ciliary neurotrophic factor (CNTF). Both RegeneronPharmaceuticals Inc. (NASDAQ:REGN) of Tarrytown, N.Y. and ajoint venture between Synergen Inc. (NASDAQ:SYGN) ofBoulder, Colo., and Syntex Corp. (NYSE:SYN) of Palo Alto, Calif.,started CNTF trials this year. Cephalon (NASDAQ:CEPH) closedThursday at $12, down 25 cents a share.
-- Jennifer Van Brunt Senior Editor
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