Proposed diagnostic scoring system for PNSM-cGvHD

A proposed diagnostic scoring system for manifestations of chronic graft-versus-host disease (cGvHD) affecting the peripheral nervous system and muscles (PNSM) was published in Transplantation and Cellular Therapy by Steinberg et al. The scoring system was retrospectively applied to a single-centre cohort of 770 patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) between 2007 and 2022 and presented with suspected cGvHD involving the PNSM. Using the scoring system, PNSM-cGvHD was categorised as unlikely, possible, or probable across four distinct forms: immune-mediated inflammatory polyneuropathy, small-fiber polyneuropathy, neuromuscular junction disorder, and myositis. 

Key data: The scoring system integrated data spanning clinical symptoms, electrophysiology, cerebrospinal fluid (CSF) findings, concurrent cGvHD in National Institutes of Health (NIH)-defined organs, timing of onset (after immunosuppresion [IST] taper or following donor lymphocyte infusion [DLI] / stem cell backup, ≥3 months post-allo-HSCT), response to IST, histopathology, and other diagnostic measures. Of 770 patients screened, 15 (1.9%) presented with PNSM-cGvHD, classified as possible (n = 6) or probable (n = 9) using the proposed scoring system; the most common subtype was immune-mediated inflammatory polyneuropathy (n = 11). Long-term neurologic symptoms were observed in 9/15 patients, and 3/15 patients died in association with PNSM-cGvHD.

Key learning: The proposed scoring system provides a framework for consistent diagnosis and classification of atypical presentations of cGvHD in the PNSM. Further evaluation in larger cohorts is warranted to validate its clinical utility.