High prevalence of small- and large-fiber neuropathy in a prospective cohort of patients with moderate to severe chronic GvHD

Increasing safety of allogeneic hematopoietic stem cell transplantation (allo-HSCT) has also increased the number of patients at risk for developing chronic GvHD (cGvHD). Peripheralnerve neurological manifestations and symptoms are being increasingly recognized in cGvHD, however, prospectively planned clinical studies have rarely been reported. There is a substantial lack of understanding of the mechanisms that lead to peripheral neuropathy (PN) in cGvHD and therapeutic options are profoundly limited and mostly symptomatic. Currently, myasthenia gravis, muscle cramps and PN are considered as ‘other’ complications related to cGvHD, whereas myositis and polymyositis are considered as ‘distinctive’ neurological manifestations of cGvHD. Consequently, the diagnosis of neurological cGvHD can only be established when additional ‘diagnostic’ manifestations of cGvHD are present and the neurological manifestations are still not incorporated into the scoring system.1, 2 This presents an important gap, because damage of the peripheral nervous system (PNS) in the context of cGvHD can produce severe disability, morbidity and mortality.2 In order to investigate the incidence and characteristics of PNS manifestations, with emphasis on small-fiber neuropathy (SFN), we have conducted a prospective cohort study on patients with cGvHD developed after allo-HSCT.