Incidence and characteristics of engraftment syndrome after autologous hematopoietic cell transplantation in light chain amyloidosis

Successful Treatment of Severe Steroid-Resistant Engraftment Syndrome Following Haploidentical Allogeneic Hematopoietic Stem Cell Transplantation for Acute Myeloid Leukemia with Emapalumab: A Case Report

Engraftment syndrome (ES) is an early complication of hematopoietic stem cell transplantation (HSCT) characterized by fever and additional clinical manifestations including rash, diarrhea, lung infiltrates, weight gain, and neurological symptoms. Steroid-resistant ES following HSCT significantly affects the efficacy of transplantation and may even result in patient mortality. As ES essentially represents a cytokine storm induced by engrafted donor cells with interferon-gamma (IFN-γ) playing a central role, we hypothesized that emapalumab (an anti-IFN-γ monoclonal antibody) may be an effective approach to treat steroid-resistant ES. Here, we present a case report of a 14-year-old female patient who received a second haploidentical HSCT due to a relapse of acute myeloid leukemia. Nine days after the transplantation, the patient developed a fever and exhibited a poor response to antimicrobials (ceftazidime/avibactam). A few days later, the patient presented with a new-onset rash, weight gain, and impaired liver function, leading to a diagnosis of ES. Initial immunosuppressive (tacrolimus and mycophenolate mofetil) treatment failed to control the disease. On day 16 post-transplantation, the patient received two infusions of 50 mg of emapalumab. Following the initiation of emapalumab treatment, the patient's fever returned to normal and ES was effectively controlled. This case report demonstrated that emapalumab had a possible efficacy for steroid-resistant ES and provided a novel therapeutic strategy to treat this clinical complication.

Characteristics of Engraftment Syndrome following Autologous Stem Cell Transplantation in Light Chain Amyloidosis with Renal Involvement

Engraftment syndrome (ES) is a clinical complication that occurs during the neutrophil recovery phase following hematopoietic stem cell transplantation. The clinical features of ES in light chain (AL) amyloidosis remains to be thoroughly investigated. This study was conducted to better understand the characteristics of ES following autologous stem cell transplantation (ASCT) in AL amyloidosis with renal involvement. We conducted this single-center retrospective study in 302 patients with AL amyloidosis who underwent ASCT between July 2010 and December 2021. Sixty-seven of the 302 patients (22.2%) developed ES, with a median time to the occurrence of ES after stem cell reinfusion of 11 days (range, 7 to 17 days). Among the outcome measures in this study, estimated glomerular filtration rate (eGFR) at baseline and C-reactive protein (CRP) level on the day of granulocyte engraftment were statistically different between the ES patients and non-ES patients. We observed no significant difference between the 2 groups in transplantation-related adverse events (grade ≥ 2), hematologic and organ responses, overall survival, and progression-free survival. Furthermore, CRP level at granulocyte engraftment (odds ratio [OR], 1.012; 95% confidence interval [CI], 1.004 to 1.020; P = .002) and the absence of induction chemotherapy before ASCT (OR, 1.977; 95% CI, 1.047 to 3.731; P = .036) were identified as risk factors for the development of ES, whereas a higher eGFR at baseline (OR, .981; 95% CI, .969 to .993; P = .002) was identified as a protective factor against ES. Our data show a 22.2% incidence of ES in AL amyloidosis patients with renal involvement after ASCT and identify associated risk and protective factors, which can improve the understanding of this clinical complication.

Guidelines for high dose chemotherapy and stem cell transplantation for systemic AL amyloidosis: EHA-ISA working group guidelines

AL amyloidosis is a systemic amyloidosis and is associated with an underlying plasma cell dyscrasia. High dose intravenous melphalan and autologous stem cell transplantation was developed for the treatment of AL amyloidosis in the early 1990s and was prompted by its success in multiple myeloma. This application has evolved significantly over the past three decades. These guidelines provide a comprehensive assessment of eligibility criteria, stem cell collection and mobilisation strategies and regimens, risk-adapted melphalan dosing, role for induction and consolidation therapies, specific supportive care management, long-term outcome with respect to survival, haematologic response and relapse and organ responses following stem cell transplantation. These guidelines are developed by the experts in the field on behalf of the stem cell transplant working group of the International Society of Amyloidosis (ISA) and European Haematology Association (EHA).