Korean J Lab Med.  2010 Dec;30(6):575-579. 10.3343/kjlm.2010.30.6.575.

Late-onset Neutropenia Following Rituximab Therapy as a Treatment of Diffuse Large B-cell Lymphoma: A Single Institution Study

• Kim M
• Lee JK
• Hong YJ
• Hong SI
• Kang HJ
• Chang YH

• KMID: 1781661
• DOI: http://doi.org/10.3343/kjlm.2010.30.6.575

Abstract

BACKGROUND
Late-onset neutropenia (LON) following rituximab therapy has been reported in recent years. However, its incidence has not been reported in Korea. The aim of this study is to investigate the incidence of LON after rituximab therapy in Korean patients with diffuse large B-cell lymphoma (DLBCL).
METHODS
Ninety-eight cases of DLBCL treated with rituximab between 2004 and 2008 were evaluated. We identified LON as defined by the neutrophil count of <1.5x10(9)/L without apparent cause after the recovery of neutrophil count following rituximab therapy. Bone marrow aspiration and biopsy specimens at the time of neutropenia were available for retrospective review in only 5 of the patients.
RESULTS
LON was observed in 15 (15.3%) of the 98 patients. In the bone marrow specimens of the 5 patients, promyelocytes were relatively increased and the maturation index of the granulopoiesis was 2:1-3:1, which reflects maturation arrest.
CONCLUSIONS
The incidence of LON following rituximab therapy was 15.3% in Korean patients with DLBCL. Although there are several hypotheses about the causative mechanisms of LON, we suggest that maturation arrest at the promyelocyte stage of granulopoiesis may be one of the mechanisms involved in the development of LON.

Keyword

Rituximab; Late-onset neutropenia; Maturation arrest

MeSH Terms

Adult
Aged
Antibodies, Monoclonal, Murine-Derived/adverse effects/*therapeutic use
Antineoplastic Agents/adverse effects/*therapeutic use
Bone Marrow Cells/pathology
Cell Differentiation
Female
Humans
Lymphoma, Large B-Cell, Diffuse/*drug therapy
Male
Middle Aged
Neutropenia/diagnosis/*epidemiology
Retrospective Studies