Tolerability and Efficacy of s.c. IgG Self-Treatment in ME/CFS Patients with IgG/IgG Subclass Deficiency: A Proof-of-Concept Study

Abstract

BACKGROUND: Chronic fatigue syndrome (ME/CFS) is a complex disease frequently triggered by infections. IgG substitution may have therapeutic effect both by  ameliorating susceptibility to infections and due to immunomodulatory effects.  METHODS: We conducted a proof of concept open trial with s.c. IgG in 17 ME/CFS  patients suffering from recurrent infections and mild IgG or IgG subclass  deficiency to assess tolerability and efficacy. Patients received s.c. IgG  therapy of 0.8 g/kg/month for 12 months with an initial 2 months dose escalation  phase of 0.2 g and 0.4 g/kg/month. RESULTS: Primary outcome was improvement of  fatigue assessed by Chalder Fatigue Scale (CFQ; decrease ≥ 6 points) and of  physical functioning assessed by SF-36 (increase ≥ 25 points) at month 12. Of 12  patients receiving treatment per protocol 5 had a clinical response at month 12.  Two additional patients had an improvement according to this definition at months  6 and 9. In four patients treatment was ceased due to adverse events and in one  patient due to disease worsening. We identified LDH and soluble IL-2 receptor as  potential biomarker for response. CONCLUSION: Our data indicate that  self-administered s.c. IgG treatment is feasible and led to clinical improvement  in a subset of ME/CFS patients.