Retroviral synthetic peptide serum antibodies in human sporadic amyotrophic lateral sclerosis.

We examined 101 sera from 32 adult sporadic amyotrophic lateral sclerosis (ALS) patients, including nine with positive enzyme-linked immunosorbent assay (ELISA) serum antibodies against human spuma retrovirus (HSRV) [human foamy virus (HFV)] envelope (env) and/or capsid (gag) proteins, for peptide seroreactivity. Synthetic peptides 10 to 14 amino acids in length were selected from HSRV (3), maedi-visna virus (1), human nerve growth factor-beta (1), and human amyloid-beta sequences (1). Eighteen of 101 ALS sera compared with six of 144 control sera reacted to any of the sequences (p < 0.01) (i.e., 8/32 ALS patients and 2/93 control patients bound to a synthetic peptide, p < 0.01). Peptide VLA- [NGF beta(1-14)] was reproducibly recognized by one of the 93 neurologic controls, and one of the 32 ALS patients reproducibly reacted to synthetic peptides [EET-, HSRVenv/NGF beta(55-61)] and [GSN-, beta-amyloid(25-35)] simultaneously. This amyloid-A(25-35) peptide corresponds to the neurotoxic and neurotrophic tachykinin homology sequence described by Yanker. Only ALS patients (no controls) reacted with the visna/CNTF peptide SMC- and HSRVbcl-1/amyloid(740-751) peptide EGP-. Testing a total of 245 sera from 125 patients, three reproducible reactivities (two ALS, one OND) were observed both with and without glutaraldehyde linkage. Of the four peptides recognized either by more than one serum from the same patient with ALS or by sera from ALS patients only (EET-, GSN-, SMC-, EGP-), two share a circumscript homology with maedi-visna virus envelope glycoprotein (Table 1).(ABSTRACT TRUNCATED AT 250 WORDS)