Background/Purpose: To analyze the efficacy and tolerance of intravenous immunoglobulin (IVIG) therapy in 11 patients with primary Sjögren’s syndrome (pSS)-associated small-fiber neuropathy (SFN).

Methods: Retrospective, single-center study of the efficacy and safety of IVIG therapy for 6 months (0.4 g/kg/day monthly for 5 days) in 11 consecutive pSS-SFN patients. The primary endpoint was a decrease in pain intensity (scored on a 0-10 Numeric Rating Scale, NRS) ≥ 30% between the onset (M0) and the end of treatment (M6). The impact of treatment on quality of life (SF-36 scale) and small fiber neurophysiological tests was also evaluated.

Results: The median (95%CI) age at treatment onset was 52 (48-63) years with a median duration of SFN symptoms until treatment of 6.5 (3-11) years. Between M0 and M6, the median NRS score decreased from 7 (5.5-8) to 3 (1.8-5) (P <0.00001). The primary endpoint was achieved in 8 patients (72%). The median SF-36 physical component subscore also significantly improved from 23/100 to 48/100 (P = 0.003). Regarding neurophysiological tests, only the warm detection threshold improved from 5.5°C to 4.6°C (P = 0.01), others remaining stable. The most common side effect was transient headache during infusion (73%), while no major side effect was reported.

Conclusion: IVIG treatment appears to be effective and well tolerated in pSS-associated SFN, leading to a significant pain relief and improvement of quality of life and thermal sensory testing. These encouraging results need to be interpreted with caution and have to be confirmed in a randomized double-blinded placebo-controlled trial.