Autologous Hematopoietic Stem Cell Transplantation for Chronic Inflammatory Demyelinating Polyradiculoneuropathy.

BACKGROUND: Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) refractory to conventional therapy can lead to marked disability and represents a therapeutic challenge. OBJECTIVE: To report five cases of treatment-refractory disabling CIDP treated with autologous hematopoietic stem cell transplantation (AHSCT). METHODS: This was a retrospective cohort study from a tertiary care referral center for both neuromuscular disease and AHSCT. Patients with CIDP treated with AHSCT between 2008 and 2020 were included. All patients had major persistent and disabling neuropathic deficits despite combinations of intensive immunosuppressive therapy. The primary outcome measures were: Medical Research Council sum score, Overall Neuropathy Limitations Scale and requirement for ongoing CIDP immunotherapy after transplantation. We also analyzed safety outcomes by documenting all severe AHSCT-related complications. RESULTS: Five patients with refractory CIDP underwent AHSCT. Three were classified as manifesting a typical syndrome, two were classified as the multifocal Lewis Sumner variant. The mean age at time of CIDP diagnosis was 33.4 years (range 24-46 years), with a median delay of 46 months (range 21-135 months) between diagnosis and AHSCT. The median follow-up period was 41 months. All five patients were able to wean off CIDP-related immunotherapy. Marked improvements in Medical Research Council scale and overall Neuropathy Limitations Scale were noted in 4/5 patients. One patient with longstanding neurogenic atrophy showed no improvement in disability scales. There were no treatment-related deaths or critical illnesses. CONCLUSIONS: AHSCT can achieve marked sustained clinical improvement of refractory CIDP and may allow for weaning off long-term complex immunotherapies.

Temporal evolution of nerve conduction study abnormalities in anti-myelin-associated glycoprotein neuropathy.

BACKGROUND: A distal-predominant demyelinating symmetric pattern is most frequent in patients with neuropathy associated with anti-myelin-associated glycoprotein (MAG) antibodies. The literature however lacks longitudinal data to describe whether this is consistent over time. METHODS: From the Ottawa Neuromuscular Center database, we identified 23 patients with both immunoglobulin M gammopathy and anti-MAG antibodies. For median, ulnar and fibular motor conduction studies, we analyzed distal latency and amplitude, negative peak duration, terminal latency index (TLI), and conduction velocity. For median, ulnar, sural, and superficial fibular sensory conduction studies, we analyzed distal latency and amplitude. Results were compared for the earliest and the latest data sets. RESULTS: The mean time interval between the two assessment points was 6.5 years. Median and ulnar motor nerve conduction studies did not show a significant change for any of the parameters tested. There was disproportionate prolongation of median distal motor latency and reduction in TLI, compared to the ulnar nerve. Deep fibular motor conduction studies showed a marked reduction in amplitudes over time. Sensory potentials were recordable in the upper limb in less than 50% at the first study and less than 25% on the most recent study. There was an even larger attrition of recordable sural and superficial fibular sensory potentials. CONCLUSIONS: Our results highlight the stability of median and ulnar motor conduction study results over a mean observation period of 6.5 years. In contrast, lower limb motor and all sensory potentials show a marked trend toward becoming unrecordable.