Intravenous immunoglobulins in patients with clinically suspected chronic immune-mediated neuropathy

Intravenous immunoglobulins (IVIg) are an efficacious treatment for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy (MMN). IVIg is considered in patients who have a high suspicion of an inflammatory neuropathy, but do not meet diagnostic criteria. The objective of this retrospective study was to assess which diagnostic results led to the decision to administer IVIg and to determine the rate of improvement. We included consecutive patients suspected of CIDP or MMN who did not meet the electrophysiological EFNS/PNS criteria and received IVIg treatment. Patients were included in a tertiary referral center for inflammatory neuropathies and motor neuron diseases. Thirty-five patients were included; 19 patients suspected of CIDP and 16 suspected of MMN. Nerve hypertrophy on ultrasound (80% of patients suspected of CIDP and 67% of patients suspected of MMN) and/or elevated cerebrospinal fluid (CSF) protein (53% of patients suspected of CIDP and 45% of patients suspected of MMN) were the most frequent findings that supported the diagnosis. Thirteen patients suspected of CIDP (68%) and five patients suspected of MMN (31%) responded to treatment. There was no association between the presence of the EFNS/PNS supportive criteria, including nerve hypertrophy on ultrasound, and treatment response. In conclusion, enlarged nerves on ultrasound and elevated CSF protein were the main reasons to start IVIg treatment in our study, although findings did not correlate with treatment response. In tertiary referral clinics, IVIg treatment could be considered in selected patients with a high suspicion of an inflammatory neuropathy, especially in those suspected of CIDP.