Polyneuropathy improvement following autologous stem cell transplantation for POEMS syndrome

To study the evolution of the neuropathy and long-term disability in a large cohort of patients with POEMS (polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes) syndrome following autologous stem cell transplantation (ASCT).

Retrospective chart review documenting the clinical, electrophysiologic, and laboratory characteristics of patients with POEMS syndrome undergoing ASCT at Mayo Clinic, Rochester.

Sixty patients with a median follow-up time of 61 months were studied. All patients had peripheral polyneuropathy and demonstrated neurologic improvement after ASCT (apart from one patient who died early). Before ASCT, 27 patients (45%) required a wheelchair and 17 (29%) required a walker or foot brace. At the end of the follow-up period, no patient was using a wheelchair and 23 patients (38%) were using a foot brace. The median Neuropathy Impairment Score improved from 66 to 48 points at 12 months and to 30 points at most recent follow-up (p < 0.0001). Median Rankin Scale score improved from 3 to 1.5 (p < 0.0001). Vascular endothelial growth factor levels decreased from a median of 452 to 63.5 pg/mL (p < 0.0001). The ulnar compound motor action potential amplitude (median) improved from 4.3 to 7.6 mV (p < 0.0001) and ulnar compound motor action potential conduction velocity (median) improved from 34 to 51 m/s (p < 0.0001). Predicted forced vital capacity improved from 81% to 88% (p < 0.0001). Periengraftment syndrome occurred in 24 patients. Fourteen patients required additional chemotherapy and/or radiation following ASCT, but there was no clinical deterioration in the neuropathy in any of these patients. Six patients died: 1 due to POEMS, 1 due to failed engraftment, and 4 due to other malignancies (2 myelodysplastic syndrome, 1 lymphoma, 1 metastatic lung cancer).

Patients with POEMS syndrome who undergo ASCT have a significant and meaningful improvement of their neuropathy by multiple measurements during both short and long-term follow-up, which corresponds to reduction in morbidity and disability (none are in wheelchair long-term). Periengraftment syndrome was common but manageable. Fatal complications, although rare, did occur, usually in association with other malignancies.

This study provides Class IV evidence that for patients with POEMS syndrome, ASCT improves neuropathy-related function.