Late-onset neutropenia following rituximab therapy: incidence, clinical features and possible mechanisms

Abstract

Late-onset neutropenia (LON) is emerging as a common adverse effect to rituximab therapy owing to widespread use of this drug in the treatment of B-cell lymphomas and autoimmune diseases. However, the true incidence and mechanisms are not fully understood. LON has been reported in 5–27% of rituximab-treated lymphoma patients. Similar figures apply for autoimmune patients but they appear to have more infections during the neutropenic period. Recent reports imply that host factors may play an intriguing role for development of LON, for example, polymorphisms in FCGR3. Pronounced B-lymphocyte depletion and lower serum IgM, as reported in LON patients during the period of neutropenia compared with matched controls, may play a role for understanding the mechanisms and risk stratification for emergence of LON.

Keywords::

• autoimmune diseases
• B-lymphocyte depletion
• late adverse event
• late-onset neutropenia
• lymphoma
• rituximab

Acknowledgements

The authors acknowledge Associate Professor Hans Hägglund and Professor Bengt Fadeel for valuable discussions.

Financial & competing interests disclosure

The study was supported by grants from the Regional Agreement on Medical Training and Clinical Research (ALF) between Stockholm County Council and Karolinska Institutet. The study was also supported by grants for PhD studies from Karolinska Institutet. The authors have no other 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 apart from those disclosed.

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