Authors: Levine TD, Kafaie J, Zeidman LA, Saperstein DS, Bland RJ

PMID: 31650561 DOI: 10.1002/mus.26748


Introduction: Causes of small-fiber peripheral neuropathies (SFN) are often undefined. In this study we investigated associations of serum autoantibodies, immunoglobulin G (IgG) vs fibroblast growth factor receptor-3 (FGFR-3), and immunoglobulin M (IgM) vs trisulfated heparan disaccharide (TS-HDS) in cryptogenic SFN.

Methods: One hundred fifty-five patients with biopsy-proven SFN and no identified cause for their neuropathy were blindly tested for serum IgM vs TS-HDS and IgG vs FGFR-3.

Results: Forty-eight percent of SFN patients had serum antibodies, 37% with IgM vs TS-HDS and 15% with IgG vs FGFR-3. TS-HDS antibodies were more frequent in SFN patients than in controls (P = .0012). Both antibodies were more common in females, and with non-length-dependent nerve pathology. Nintey-two percent of patients with acute-onset SFN had serum IgM vs TS-HDS.

Discussion: Autoantibodies directed against TS-HDS and FGFR-3 suggest an immune disorder in otherwise idiopathic SFN. Serum IgM vs TS-HDS may be a marker for SFN with an acute onset.

Keywords: FGFR-3; TS-HDS; autoantibodies; pathogenesis; small-fiber neuropathy.