[Alemtuzumab-based HLA-haploidentical transplantation for relapsed/refractory aggressive NK-cell leukemia]

Area of Science:

• Hematology
• Virology
• Immunology

Background:

• Chronic active Epstein-Barr virus (CAEBV) disease can progress to aggressive NK-cell leukemia (ANKL).
• Relapsed/refractory ANKL presents significant therapeutic challenges.

Purpose of the Study:

• To describe a challenging case of CAEBV progressing to relapsed/refractory ANKL.
• To evaluate the efficacy of sequential haploidentical peripheral blood stem cell transplantation (PBSCT) and the role of alemtuzumab in managing ANKL.

Main Methods:

• Diagnosis of CAEBV based on clinical presentation and EBV DNA levels in NK cells.
• Initial treatment with immunosuppressants and etoposide, followed by first HLA-haploidentical PBSCT with post-transplant cyclophosphamide.
• Second HLA-haploidentical PBSCT with alemtuzumab for relapsed/refractory ANKL.

Main Results:

• The patient initially diagnosed with CAEBV progressed to relapsed/refractory ANKL post-first PBSCT.
• The second PBSCT incorporating alemtuzumab achieved a remission of 264 days.
• Alemtuzumab demonstrated potential antitumor activity against ANKL.

Conclusions:

• Sequential haploidentical PBSCT can be considered for relapsed/refractory ANKL.
• Alemtuzumab may have a role in both GVHD prophylaxis and direct antitumor therapy for ANKL.
• Fusarium-related infective endocarditis was the cause of death, highlighting the risk of infections post-transplant.