Rituximab-induced thrombocytopenia: a cohort study

Area of Science:

• Pharmacovigilance
• Hematology
• Clinical Pharmacology

Background:

• Drug safety data from clinical practice is crucial for understanding adverse events.
• Thrombocytopenia is a known adverse drug reaction of rituximab, but its incidence and risk factors in real-world settings require further investigation.

Purpose of the Study:

• To estimate the incidence of rituximab-induced thrombocytopenia (platelet count <100 × 10(9)/L) in clinical practice.
• To identify risk factors associated with the development of thrombocytopenia following rituximab administration.

Main Methods:

• A cohort of 90 patients receiving rituximab was analyzed.
• Patients were monitored for thrombocytopenia development within 30 days of treatment.
• Risk factors were explored by comparing patients with and without thrombocytopenia.

Main Results:

• The cumulative incidence of thrombocytopenia was 30% (27/90), with 20% (18/90) experiencing grade 3/4 severity.
• A lower pre-administration platelet count (217 vs. 324 × 10(9)/L) was a significant risk factor (P=0.011).
• Treatment in an oncology setting (OR 4.7) and high platelet distribution width (PDW) were associated with increased risk.

Conclusions:

• The incidence of rituximab-induced thrombocytopenia in clinical practice is higher than previously reported in clinical trials.
• Healthcare professionals should consider thrombocytopenia a relevant adverse reaction to rituximab.
• Increased platelet count monitoring is recommended for patients in oncology, with low baseline platelet counts, or high PDW.