Case Report: Qizhi Yishen Capsule-induced bone marrow granulomas and severe myelosuppression.

Background: Drug-induced bone marrow injury is an under-recognised adverse drug reaction (ADR) that can present with fever, cytopenias, and eosinophilia. Drug-induced bone marrow granuloma formation remains exceedingly rare among ADRs, and to our knowledge, no such cases associated with traditional Chinese medicine (TCM) formulations have been previously reported.

Case presentation: A 79-year-old woman with chronic kidney disease (CKD) developed fever and marked eosinophilia after six weeks of treatment with Qizhi Yishen Capsule, a sinomenine-containing TCM formulation. She rapidly progressed to agranulocytosis and pancytopenia. Bone marrow biopsy revealed non-caseating granulomas with severe myelosuppression and grade 3 fibrosis. Immunohistochemistry showed CD3⁺ T-cell predominance within granulomas with CD20⁺ B cells absent. The Naranjo score was 7 (probable ADR). Treatment with glucocorticoids and granulocyte colony-stimulating factor (G-CSF) resulted in complete hematologic recovery.

Conclusion: This case documents bone marrow granulomas and severe myelosuppression following Qizhi Yishen Capsule administration, a sinomenine-containing TCM formulation. A Naranjo score of 7 (probable) and immunohistochemical evidence of CD3⁺ T-cell infiltration within the granulomata support a drug-related, cell-mediated pathogenesis. Clinicians should consider drug-induced bone marrow toxicity in patients receiving this formulation, particularly those with CKD.