Immunohistochemistry of affected tissue may guide cGVHD treatment decisions

Towards a Better Understanding of the Atypical Features of Chronic Graft-Versus-Host Disease: A Report from the 2020 National Institutes of Health Consensus Project Task Force

Alloreactive and autoimmune responses after allogeneic hematopoietic cell transplantation can occur in non-classical chronic graft-versus-host disease (chronic GVHD) tissues and organ systems or manifest in atypical ways in classical organs commonly affected by chronic GVHD. The National Institutes of Health (NIH) consensus projects were developed to improve understanding and classification of the clinical features and diagnostic criteria for chronic GVHD. While still speculative whether atypical manifestations are entirely due to chronic GVHD, these manifestations remain poorly captured by the current NIH consensus project criteria. Examples include chronic GVHD impacting the hematopoietic system as immune mediated cytopenias, endothelial dysfunction, or as atypical features in the musculoskeletal system, central and peripheral nervous system, kidneys, and serous membranes. These purported chronic GVHD features may contribute significantly to patient morbidity and mortality. Most of the atypical chronic GVHD features have received little study, particularly within multi-institutional and prospective studies, limiting our understanding of their frequency, pathogenesis, and relation to chronic GVHD. This NIH consensus project task force report provides an update on what is known and not known about the atypical manifestations of chronic GVHD, while outlining a research framework for future studies to be undertaken within the next three to seven years. We also provide provisional diagnostic criteria for each atypical manifestation, along with practical investigation strategies for clinicians managing patients with atypical chronic GVHD features.

Chronic graft-versus-host disease presenting as acute polymyositis: A case series and systematic review

Chronic graft-versus-host disease (cGvHD) remains a significant complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Commonly targeted organs are skin, eyes, mouth, gastrointestinal tract, and liver. Muscular involvement and presentation as acute polymyositis (APM) remain a rare manifestation of cGvHD. We present a case series of three patients who presented with APM as a sole presentation of cGvHD and were treated successfully with corticosteroids and ruxolitinib. We also conducted a systematic review including 72 patients to summarize current literature regarding APM associated with cGvHD after allo-HSCT. The estimated incidence of cGvHD-associated APM is up to 3.4%, with a median time to onset of 1.6 years post-allo-HSCT. Most cases (85%) presented with myalgia and progressive bilateral proximal muscle weakness with elevated creatine kinase and/or aldolase. Over half of the patients had a prior history of acute GvHD. Isolated APM presenting without other clinical manifestations of cGvHD was rare. Biopsy of affected muscles usually shows characteristic myonecrosis, which remains the gold standard for diagnosis. Most cases respond to systemic steroids and immunosuppressive therapy. However, refractory cases remain challenging to treat and can cause significant morbidity and mortality. Ruxolitinib appears to be an effective therapy in this setting.

Chronic Graft-Versus-Host-Disease-Related Polymyositis: a 17-Months-Old Child with a Rare and Late Complication of Haematopoietic Stem Cell Transplantation

Background

Chronic graft versus host disease (cGVHD) occurs in 20–30% of paediatric patients receiving haemopoietic stem cell transplantation (HSCT). Neuromuscular disorders such as polymyositis are considered a rare and distinctive but non-diagnostic manifestation of cGVHD and, in the absence of other characteristic signs and symptoms, biopsy is highly recommended to exclude other causes.

Case report

We report a case of a 17-months-old child affected by hemophagocytic lymphohistiocytosis who underwent a matched unrelated donor haematopoietic stem cell transplantation (HSCT). She developed severe cGVHD-related polymyositis that was successfully treated with high-dose steroid therapy, rituximab and sirolimus.

Conclusions

This is the first case of cGVHD-related-polymyositis described in a pediatric patient which was successfully treated with rituximab.

Up-to-date tools for risk assessment before allogeneic hematopoietic cell transplantation

Cure of malignant and non-malignant hematological diseases is potentially possible after allogeneic hematopoietic stem cell transplantation (HCT). Accurate evaluation of the risk-benefit ratio for an individual patient could improve the decision-making process about transplant, which ultimately would increase the likelihood of success. Several transplant-related models were designed in an effort to optimize decision-making about suitable candidates for allogeneic HCT. In 1998, The European Society for Blood and Marrow Transplantation (EBMT) developed a five-component pretransplantation risk scoring system for patients with CML. The EBMT score was later tested in patients with various hematological disorders, and it was shown to stratify risks of mortality after allogeneic HCT. More recent research efforts focused on models that assess health status before HCT. A HCT-specific comorbidity index was designed to assign weights to 17 relevant comorbidities that were shown to independently predict non-relapse mortality. Performance status scales and comprehensive geriatric assessment tools might uncover additional overall health limitations that affect long-term survival among older recipients of allogeneic HCT. Other models include the pretransplantation assessment of mortality score that summarizes the impacts of eight different pretransplantation patient- and disease-specific variables into a 50-point model that predicts survival. The disease-risk index captures the impact of primary diagnoses and disease status on relapse and survival following allogeneic HCT. The values and limitations of each model are discussed herein. We also provide insight on how to use these models in the clinic to decide about offering allogeneic HCT with the most suitable conditioning regimen intensity.