Successful Treatment of Pediatric Refractory Burkitt Lymphoma PTLD after Liver Transplantation using Anti-CD19 Chimeric Antigen Receptor T-Cell Therapy

Abstract

In the immunocompromised setting, recipients of solid-organ or hematopoietic stem-cell transplants carry an increased risk of post-transplant lymphoproliferative disorder (PTLD). Burkitt lymphoma (BL) PTLD is a rare form of monomorphic B-cell PTLD, which lacks a standard best treatment. Here, we report the successful treatment of refractory BL-PTLD with autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy. A male patient was diagnosed with BL-PTLD, with an increasing Epstein-Barr virus (EBV) viral load, at 21 months after undergoing living liver transplantation from his mother due to neonatal biliary atresia. After 10 cycles rituximab +/- intensive chemotherapy and surgical tumor resection, the tumors significantly advanced. Next-generation sequencing (NGS) was performed on formalin-fixed paraffin-embedded tumor tissue, revealing one mutation in exon 5, TP53: p.A159 V, which may be associated with chemo-resistance. Thus, treatment was started with autologous anti-CD19 CAR T-cell therapy. We administered 9.0 × 10⁶/kg autologous anti-CD19 CAR T-cells, after conditioning with cyclophosphamide and fludarabine. Unexpectedly, the patient experienced only mild (Grade II) cytokine release syndrome (CRS) without neurotoxicity. Finally, he went into complete remission (CR), and has achieved 16-month event-free survival to date. In addition, liver function has remained stably within the normal range without any immunosuppressive therapy. The literature includes only five previously reported BL cases treated with CAR T-cell therapy. In conclusion, the present case suggests that autologous anti-CD19 CAR T-cell therapy may represent a new therapeutic option for some cases of refractory BL-PTLD.Clinical trial number: ChiCTR2000032211.

Keywords: Burkitt lymphoma; CAR T-cells; CD19; PTLD.

Figure 1.

Patient’s clinical features before chimeric antigen receptor (CAR) T-cell therapy. (A) The trend of EBV DNA load before CAR T-cell therapy. Red arrows indicate diagnosis of Burkitt lymphoma post-transplant lymphoproliferative disorder (BL-PTLD). (B) Upon diagnosis, positron emission tomography-computed tomography (PET-CT) revealed multiple nodules in the abdomen and pelvis, multiple enlarged lymph nodes in the left axilla and both sides of the neck, and multiple skeletal lesions exhibiting hypermetabolism. (C) After four rounds of chemotherapy, PET-CT showed that the tumor had increased in size. (D) At 55 days after CAR T-cell infusion, PET-CT revealed no typical malignant tumor-like hypermetabolic lesions anywhere in the patient’s body. (E) Next-generation sequencing (NGS) was performed on a tumor tissue samples, revealing one mutation in exon 5, TP53: p.A159 V, which may be associated with chemo-resistance. (F) The specific treatment process used in this case. The red five-pointed star indicates surgical tumor resection, and the red triangles indicate radiotherapy (total 25 Gy) and tomotherapy (total 16 Gy).

Figure 2.

Pathological analysis of the lymph-node mass led to diagnosis of Burkitt lymphoma post-transplant lymphoproliferative disorder (BL-PTLD). (a) Pathological morphology (HE staining; 10 × 20) showed tumor cells diffusely spread out and densely proliferated, exhibiting medium cell volume, small cytoplasm, and large nuclei, with a quasi-circular shape. Obvious apoptosis and starry-sky appearance were observed. (b) Immunohistochemistry (10 × 20) indicated strong uniform membrane expression of CD19 on tumor cells. (c) EBV-encoded small RNA (EBER) in situ hybridization (10 × 20) revealed strong uniform nuclear expression of EBER in tumor cells. (d) C-myc gene fluorescence in situ hybridization (FISH; 10 × 100). Red arrows indicate abnormal C-myc gene fracture.

Figure 3.

Chimeric antigen receptor (CAR) T-cell therapy efficiency and clinical response. (A) Schematic of CAR T-cell treatment. (B) Flow cytometric analysis of CAR T-cell expression. Transduced live singlet cells were stained with primary anti biotin–F(ab)′2, followed by streptavidin-PE (light blue). Nontransduced cells (pink) served as negative controls. (C) Anti-CD19 CAR T-cells from the patient, CAR T-cells from a healthy donor, or untransduced T-cells were incubated with GFP-overexpressing ALL cell lines (GFP⁺ Reh) for 24 h at an effector-to-target ratio of 1:4. Cytotoxic effects were measured by flow cytometry. (D) Trends of changes in maximum body temperature, and white blood cell (WBC) and lymphocyte counts after CAR T-cell treatment. (E) Trends of changes in C-reactive protein (CRP), interleukin-6 (IL-6), and serum lactate dehydrogenase (LDH) after CAR T-cell treatment. (F) Changes in the approximate tumor volume according to B ultrasound.