Epstein–Barr virus-associated haemophagocytic lympho-histiocytosis after stem cell transplantation

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

HLH occurring after HSCT is a relatively rare disease. Many conditions may mimic or trigger HLH in post-HSCT period (eg, cytokine release syndrome, engraftment syndrome, graft rejection/failure, acute graft-vs-host disease, infections systemic inflammatory response syndrome/sepsis, and thrombotic microangiopathy). Moreover, this period is usually marked by febrile illness, cytopenia, and a "cytokine storm" leading to elevation of inflammatory biomarkers like ferritin and sCD25. These parameters overlap with the diagnostic criteria for HLH. Such confounding factors make the management of post-HSCT HLH quite challenging. We illustrate this critical issue with case report of a patient who was diagnosed with HLH after allogeneic HSCT for tAML. He received MP and CsA for HLH but VP-16 was not administered due to fear of severe myelosuppression. Fortunately, he responded well to treatment and remains in remission to date. We recommend caution while using HLH-94/HLH-2004 guidelines for the diagnosis and management of post-HSCT HLH. In this article, we pinpoint these issues with a brief review of all the pediatric cases and clinical studies of post-HSCT HLH along with a critical evaluation of its various diagnostic criteria. Finally, based on the limitations of current diagnostic criteria, we suggest a need for formulating disease-specific diagnostic criteria for post-HSCT HLH.

Hemophagocytic lymphohistiocytosis (HLH): a review of literature

Hemophagocytic lymphohistiocytosis (HLH) is a rare disease in children and an exceptionally rare occurrence in adults. It is categorized broadly into primary (familial) or the secondary types; the latter being associated most commonly with an underlying malignancy. HLH carries a high rate of mortality, and the treatment itself is associated with significant morbidity and risk of mortality. A high degree of suspicion for the diagnosis, early treatment and aggressive supportive care is critical for management. We present a comprehensive review of literature describing the clinical features, diagnosis, management and outcome of HLH.

Etoposide-containing conditioning regimen reduces the occurrence of hemophagocytic lymphohistiocytosis after SCT

Hemophagocytic lymphohistiocytosis (HLH) is a rare life-threatening disease of severe hyperinflammation caused by uncontrolled proliferation of activated lymphocytes and macrophages that secrete high amounts of inflammatory cytokines. HLH occurring after SCT is difficult to diagnose. It is characterized by severe clinical manifestations and high mortality. Despite current therapeutic approaches, outcomes remain poor. We analyzed the incidence and risk factors of HLH after SCT and the response to treatment and prognosis of 554 patients with HLH after SCT. The cumulative incidence of HLH after SCT was 4.3% (24/554). Use of etoposide in the conditioning regimen was only factor that reduced HLH after SCT (P=0.027). All patients who received autologous transplantation were successfully treated. Patients with liver dysfunction (for example, high total bilirubin level, prolonged prothrombin time and high level of fibrinogen degradation products) had a poor response to treatment for HLH. Physicians should be cautious of HLH, while not using etoposide for conditioning regimen.

High incidence of haemophagocytic syndrome following umbilical cord blood transplantation for adults

Umbilical cord blood transplantation (CBT) is widely accepted, but one critical issue for adult patients is a low engraftment rate, of which one cause is haemophagocytic syndrome (HPS). We aimed to identify the contribution of HPS to engraftment failure after CBT, following preparative regimens containing fludarabine phosphate, in 119 patients (median age, 55 years; range; 17-69 years) with haematological diseases. Graft-versus-host disease prophylaxis comprised continuous infusion of a calcineurin inhibitor with or without mycophenolate mofetil. Of the 119 patients, 20 developed HPS within a median of 15 d (cumulative incidence; 16.8%) and 17 of them did so before engraftment. Donor-dominant chimaerism was confirmed in 16 of 18 evaluable patients with HPS. Despite aggressive interventions including corticosteroid, ciclosporin, high-dose immunoglobulin and/or etoposide, engraftment failed in 14 of 18 patients. Of these 14 patients, four received second rescue transplantation and all resulted in successful engraftment. Overall survival rates significantly differed between patients with and without HPS (15.0% vs. 35.4%; P < 0.01). Univariate and multivariate analysis identified having fewer infused CD34(+) cells as a significant risk factor for the development of HPS (P = 0.01 and 0.006, respectively). We concluded that engraftment failure closely correlated with HPS in our cohort, which negatively impacted overall survival after CBT.