Tolerability and Efficacy of s.c. IgG Self-Treatment in ME/CFS Patients with IgG/IgG Subclass Deficiency: A Proof-of-Concept Study.
Scheibenbogen, Carmen, Sotzny, Franziska, Hartwig, Jelka et al. · Journal of clinical medicine · 2021 · DOI
Quick Summary
This study tested whether injecting immunoglobulin G (IgG), a type of protective protein from the immune system, could help ME/CFS patients who have low levels of this protein and get frequent infections. Seventeen patients received monthly injections under the skin for 12 months. About half the patients who completed the treatment felt noticeably better, with less fatigue and improved ability to function in daily life, though some patients had to stop due to side effects.
Why It Matters
For ME/CFS patients with immune deficiencies and recurrent infections, this study provides preliminary evidence that IgG replacement may be a tolerable treatment option that benefits a subset of patients. Identifying potential biomarkers (LDH and soluble IL-2 receptor) could help future research determine which patients are most likely to respond to this therapy.
Observed Findings
5 of 12 patients completing per-protocol treatment (42%) met primary endpoints for fatigue and physical functioning improvement at month 12
Adverse events led to treatment discontinuation in 4 patients, indicating tolerability concerns for some individuals
Two additional patients showed clinical improvement at earlier timepoints (months 6 and 9) despite not meeting criteria at month 12
Elevated baseline LDH and soluble IL-2 receptor levels were associated with treatment response
Initial dose escalation over 2 months (0.2 g/kg/month then 0.4 g/kg/month) appeared tolerable before reaching maintenance dose
Inferred Conclusions
Self-administered subcutaneous IgG therapy is feasible and potentially tolerable for ME/CFS patients with IgG deficiency
Clinical improvement in fatigue and physical functioning occurred in a meaningful subset of treated patients, suggesting potential therapeutic benefit for carefully selected individuals
Biomarkers such as LDH and soluble IL-2 receptor may help identify patients most likely to benefit from IgG replacement therapy
Remaining Questions
Which specific patient characteristics or biomarkers best predict who will respond to s.c. IgG therapy and who will experience adverse effects?
What This Study Does Not Prove
This study does not prove that IgG therapy works for all ME/CFS patients or even for all patients with IgG deficiency, as it was a small open-label trial without a control group. The 42% response rate does not establish cause-and-effect; improvement could be due to placebo effect, natural disease variation, or other concurrent factors. The findings cannot be generalized beyond the specific patient population studied (those with mild IgG deficiency and recurrent infections).