Lymph Node Flow Cytometry as a Prompt Recognition of Ultra Early Onset PTLD: A Successful Case of Rituximab Treatment

Ultra early posttransplantation lymphoproliferative disorder (PTLD) is a rare and fatal complication after hematopoietic stem cell transplantation (HSCT). Here we report, by lymph node (LN) flowcytometry, that we early recognized ultra early PTLD after an HLA-matched sibling allo-HSCT followed by a successful treatment with anti-CD20 antibody (rituximab) in a patient in progress disease for angioimmunoblastic T-cell lymphoma (AITL). The patient was conditioned with a reduced intensity conditioning (RIC) regimen. One week after transplantation, the patient developed high fever, generalized fatigue, high Epstein-Barr virus (EBV) load, and LN enlargement. An LN lymphocyte suspension and peripheral blood flowcytometry was performed to find majority of LN lymphocytes highly expressed CD20. By highly suspicious PTLD, 4 doses of rituximab (375 mg/m(2) qw) were given immediately followed by reducing and withdrawing immunosuppressant reagent. PTLD was later confirmed by pathology. The patient had good response to rituximab, showing absence of fever, reduction in LN size, and no detectable EBV-DNA. Twenty months after HSCT, the patient remains well without evidence of AITL and PTLD. The current report is one of the earliest cases of PTLD after HSCT. Taken together, by LN flowcytometry as a prompt recognition, rituximab can be an effective preemptive therapy for ultra early developed PTLD.