Is R-CHOP Therapy a Lymphoma Growth Factor?

Area of Science:

• Hematology
• Oncology
• Immunology

Background:

• Indolent lymphomas, such as marginal zone lymphoma, are often treated with chemoimmunotherapy.
• R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) is a standard regimen for various lymphomas.
• Bone marrow infiltration is a common characteristic of lymphoma, impacting treatment response and monitoring.

Observation:

• A patient with marginal zone lymphoma and significant bone marrow infiltration presented with a dramatic lymphocytosis flare.
• Following the initiation of R-CHOP therapy, the patient's lymphocyte count rapidly increased from 329 to 707 × 10⁹/L within 7 days.
• The lymphocytosis flare was not associated with other clinical signs like lymphadenopathy, despite a grade III infusion-related side effect during rituximab administration.

Findings:

• The observed lymphocytosis flare is hypothesized to result from lymphocyte release from heavily infiltrated bone marrow.
• Lymphocyte demargination may also contribute to the sudden increase in peripheral blood lymphocyte counts.
• This phenomenon highlights a potential, albeit rare, response to R-CHOP therapy in the context of bone marrow involvement.

Implications:

• Clinicians should be aware of the possibility of lymphocytosis flares when initiating R-CHOP therapy in lymphoma patients with extensive bone marrow infiltration.
• Close monitoring of lymphocyte counts is crucial in such cases, especially when bone marrow aspirates reveal packed infiltration.
• This case underscores the importance of integrating peripheral blood counts with bone marrow pathology findings for comprehensive patient management.