Risk for complications in patients with hemophagocytic lymphohistiocytosis who undergo hematopoietic stem cell transplantation: myeloablative versus reduced-intensity conditioning regimens

Abstract

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative option for patients with primary hemophagocytic lymphohistiocytosis (HLH) and for patients with secondary HLH who fail to respond to therapy. Advances in HSCT and supportive care measures have resulted in improved patient outcomes and decreased treatment-related mortality. Despite the overall improvement in outcome, HLH patients who undergo HSCT using myeloablative conditioning regimens are still at significant risk for complications. The HLH-94 study conducted by the Histiocyte Society reported a 30% TRM with increased pulmonary and hepatic complications. Recently, the use of reduced-intensity conditioning (RIC) regimens has shown favorable outcomes when compared to conventional HSCT and lower rate of acute complications. In this review we compare the potential complications of myeloablative and RIC regimens for HSCT in HLH patients.

Keywords::

• BMT
• children
• complications
• hemophagocytic lymphohistiocytosis

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• The use of myeloablative conditioning regimens in pediatric hemophagocytic lymphohistiocytosis patients carries a high risk for treatment-related mortality.

• Nearly, 50% of the patients who underwent myeloablative hematopoietic stem cell transplantation will require intensive care unit admission.

• Nonmyleoablative conditioning regimens reduced treatment-related mortality but are associated with mixed donor chimerism and risk for graft failure.

• Future studies should focus on late outcomes and graft failure in large cohort of patients undergoing nonmyeloablative conditioning hematopoietic stem cell transplantation for hemophagocytic lymphohistiocytosis.