Rituximab Therapy in Immunocompromised Patients
Mechanism of Action and Cell Targeting
- Rituximab is a chimeric monoclonal antibody that targets CD20, a B cell-specific surface antigen, leading to selective B cell depletion for 6-12 months, as recommended by the British Association of Dermatologists 1, 2.
Critical Safety Concerns
- The British Association of Dermatologists guidelines report that among 8 pemphigus patients treated with rituximab, two died from nosocomial pneumonia and bacterial sepsis, and one child developed persistent hypogammaglobulinemia, highlighting the need for caution 1, 3.
- The 2024 EHA-ESMO guidelines explicitly state that rituximab should be used with caution in patients with CD4 count <50 cells/μL and may need to be delayed, due to the increased risk of opportunistic infections 4, 5.
Special Considerations
- Screening for hepatitis B is mandatory before rituximab, as reactivation can be fatal, and the same principle applies to tuberculosis in immunocompromised patients, as stated by the EHA-ESMO guidelines 4, 6.
- The European Hematology Association and European Society for Medical Oncology guidelines recommend considering PCP prophylaxis during and following rituximab treatment, particularly with triple immunosuppression or additional risk factors 4, 6.
Monitoring Requirements
- The British Journal of Dermatology recommends obtaining baseline immunoglobulin levels before initiating therapy and monitoring complete blood count at 2-4 month intervals during treatment for cytopenias 1, 2.