IVIG in the Treatment of Autoimmune Small Fiber Neuropathy with TS-HDS, FGFR-3, or Plexin D1 Antibodies

Eligibility Criteria

• 1. Patients ≥ age 18
• 2. Patient with clinical and biopsy evidence of pure small fiber neuropathy (with or without dysautonomia) as evidenced by reduced IENFD on skin biopsy using PGP 9.5 as the immunostain. Biopsy must have been performed within 12 months of study enrollment, and using Corinthian Reference Laboratory (Benbrook, TX).
• 3. Patients must have elevated and/or abnormal titers of autoantibodies to TS-HDS-IgM or FGFR3-IgG or Plexin-D1, measured by the Washington University Neuromuscular Laboratory (St Louis) within 12 months of study enrollment.
• 4. Patients must have a baseline pain score on a visual analogue scale (VAS) of Greater or equal to 4/10
• 5. Patients must have a baseline Utah Early Neuropathy Scale (UENS) score of Greater or equal to 4/10
• 6. Small Fiber Neuropathy Screening List (SFNSL) score of 11/84 or greater
• 7. Non-pregnant, non-lactating female
• 8. Patients must be able to travel to Detroit, MI (USA) for the infusions, follow-up biopsy, and other clinical activities; these will not be performed elsewhere
• 1. Any other known cause for small fiber neuropathy other than the presence of the elevated titers of the novel auto-antibodies.
• 2. Patients with generalized, severe musculoskeletal conditions other than SFN that prevent a sufficient assessment of the patient by the physician.
• 3. Electromyography/nerve conduction study (EMG/NCS) evidence of large fiber polyneuropathy, to be confirmed by study PI
• 4. Underlying severe heart, kidney, liver disease, or HIV infection, (Note: If there is no previous HIV test result documented, a test may be performed in order to confirm eligibility)
• 5. Patients with a history of deep vein thrombosis within the last year prior to baseline visit or pulmonary embolism ever; patients with susceptibility to embolism or deep vein thrombosis.
• 6. Known significant IgA deficiency with antibodies to IgA.
• 7. History of hypersensitivity, anaphylaxis or severe systemic response to immuno-globulin, blood or plasma derived products, or any component of IVIG 10%,
• 8. Known blood hyperviscosity, or other hypercoagulable states,
• 9. Use of IgG products within six months prior to enrollment,
• 10. Patients with a history of drug or alcohol abuse within the past five years prior to enrollment,
• 11. Patients unable or unwilling to understand or comply with the study protocol