Hemophagocytic syndrome after allogeneic hematopoietic cell transplantation: more a graft rejection than an infectious process?

Diagnosis and Management of Secondary HLH/MAS Following HSCT and CAR-T Cell Therapy in Adults; A Review of the Literature and a Survey of Practice Within EBMT Centres on Behalf of the Autoimmune Diseases Working Party (ADWP) and Transplant Complications Working Party (TCWP)

“…We report an estimated rate following allogeneic HSCT of 1.09% and much lower estimate of 0.15% following autologous HSCT. This is slightly higher than an EBMT study including 15 centres from 2005 to 2009, which identified sHLH/MAS in 0.3% of patients (5/1,423) undergoing allogeneic HSCT (47). The estimated rate from our survey and the EBMT study are lower than incidence reports in other studies, at ∼3-4% (2, 6, 8).…”

Treatment of rare co‐occurrence of Epstein–Barr virus‐driven post‐transplant lymphoproliferative disorder and hemophagocytic lymphohistiocytosis after allogeneic stem cell transplantation

“…HLH is uncommon after alloSCT, with a reported prevalence of 0.3%, and is mostly associated with infections, such as EBV in our case . Infections might trigger HLH in patients with active malignancy because of treatment‐ or malignancy‐related immunosuppression.…”

“…However, as B-cell depletion was sufficient to eradicate EBV and treat HLH, we assume no significant role of EBVinfected CTL in the present case. Redjoul et al (7) reported a patient with HLH after alloSCT without evidence of malignancy or infection as trigger but activated macrophages of recipient origin, raising the question of other mechanisms for HLH after alloSCT. This possibility is supported by a higher incidence of HLH after umbilical cord blood transplantation and reduced-intensity conditioning, where a higher proportion of surviving recipient macrophages can be assumed (10).…”

Post‐hematopoietic stem cell transplant hemophagocytic lymphohistiocytosis or an impostor: Case report and review of literature

“…There seems to be a disproportionately higher incidence of HLH after allogeneic as compared to autologous HSCT as shown by Abdelkefi et al (8.8% in allogeneic vs 0.9% in autologous HSCT group). Kobayashi et al showed a similar trend but a large multicenter study from Europe by Redjoul et al reported a much lower incidence of 0.3%. Furthermore, patients receiving UCB graft (especially those with a higher degree of HLA mismatch; 4/6) or those undergoing haploidentical PBSC transplantation with post‐transplant Cy have a significantly higher risk for post‐HSCT HLH .…”