PMC9911860_01
Biopsy of neck mass showing extramedullary disease (EMD). On the left is hematoxylin and eosin (H&E) staining of neck mass (original magnification 200x), and on the right is immunohistochemical (IHC) staining for CD138 (original magnification 200x).
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Unfortunately, a bulky subcutaneous mass appeared on the right side of her neck 3 months after initial diagnosis, and fine-needle aspiration biopsy suggested extramedullary disease (EMD) ( Figure 1 ). In addition, the pathological examination by percutaneous image-guided biopsy revealed the necrosis of neck mass 1 month after CAR-T cell therapy ( Supplementary Figure S1 ), and flow cytometry showed that MM cells in bone marrow was decreased ( Figure 2H ).
(A) Timeline of patient preparation and CAR-T therapy for patient 1 from peripheral blood collection to 1 month after anti-BCMA CAR-T cell infusion, including bridging cryoablation, lymphodepleting chemotherapy, and CAR-T infusion. (B) Changes in body temperature after CAR-T cell infusion. (C) The levels of IL-6, TNF-alpha, C-reactive protein and D-dimer in serum at different time points after CAR-T cell infusion. (D, E) The percentage of anti-BCMA CAR-T cells in peripheral blood mononuclear cells (PBMCs) at different time points. The plot was gated on PBMCs. (F) CT-guided percutaneous cryoablation rapidly induced liquefaction necrosis of the neck mass. PET/CT showed that the neck mass was eliminated 1 month after combination therapy with cryoablation and CAR-T therapy, and it remained in remission 80 days after CAR-T cell infusion. (G) The neck mass showed a marked reduction in size 1 month after CAR-T cell infusion. (H) Flow cytometry analyses showed that MM cells was remarkably decreased in bone marrow 1 month after CAR-T cell infusion. The plot was gated on CD19 negative, CD45 dim or negative and/or CD56 positive cells.
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Thus, she received CT-guided percutaneous cryoablation 1 week before anti-BCMA CAR-T cell infusion ( Figure 2A ). In order to prevent severe CRS, the patient was administrated with anti-BCMA CAR-T cells in a dose-escalation scheme with an initial dose of 0.5 x 106 cells/kg, followed by 0.5  x 106 cells/kg and 1 x 106 cells/kg, respectively ( Figure 2A ).The next day after the first dose of CAR-T cells, the patient vomited and had a fever with a temperature of 38.8 C ( Figure 2B ), which suggested grade 1 CRS. The peak of CAR-T cell levels in peripheral blood mononuclear cells (PBMCs) reached 26.3% on day 12 ( Figure 2D, E ). Serum IL-6 reached peak levels of 298.7 pg/mL 13 days after CAR-T cell infusion ( Figure 2C ). One month after anti-BCMA CAR-T cell therapy, the neck mass was significantly decreased in size ( Figure 2G ) and PET/CT showed the elimination of EMD ( Figure 2F ). In addition, the pathological examination by percutaneous image-guided biopsy revealed the necrosis of neck mass 1 month after CAR-T cell therapy ( Supplementary Figure S1 ), and flow cytometry showed that MM cells in bone marrow was decreased ( Figure 2H ). EMD remained in remission 80 days after CAR-T cell infusion ( Figure 2F ).
PMC9911860_02
Biopsy of right thigh mass showing primary cutaneous diffuse large B cell lymphoma, leg type (PCLBCL-LT) with c-MYC/BCL2 double-expressor. The first image is H&E staining of thigh mass (original magnification 200x), and the other images are IHC staining for CD19, CD20, BCL6, BCL2, C-MYC, CD10, MUM1, PAX5, Ki-67, CD5, and CD3 (original magnification: 200x).
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Immunohistochemistry analysis showed CD19 (+), CD20 (+), BCL2 (+), C-MYC (+), BCL6 (+), MUM1 (+), PAX5 (+), Ki-67 (+, 80%), CD10 (-), CD3 (-), and CD5 (-) ( Figure 3 ).
(A) Timeline of patient preparation and CAR-T therapy for patient 2 from peripheral blood collection to 1 month after anti-CD19 CAR-T cell infusion, including bridging cryoablation, lymphodepleting chemotherapy, and CAR-T cell infusion. (B) Changes in body temperature after CAR-T cell infusion. (C) The levels of IL-6, C-reactive protein and D-dimer in serum at different time points after CAR-T cell infusion. (D, E) The percentage of anti-CD19 CAR-T cells in peripheral T cells at different time points. The plot was gated on CD3+ cells (T cells). (F) CT-guided percutaneous cryoablation rapidly induced liquefaction necrosis of the bulky thigh mass, PET/CT showed that the right thigh mass remained in remission 8 months after CAR-T cell infusion. (G) MRI revealed that the thigh mass was remarkably decreased 1 month after the combination of cryoablation and CAR-T therapy and it was completely eliminated 6 months after CAR-T cell infusion. (H) Combination therapy induced the remission of newly emerging distant metastases 15 days after CAR-T cell infusion.
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MRI showed the right thigh mass was about 8.5 x 7.3 x 9.3 cm in size 21 days before anti-CD19 CAR-T cell infusion ( Figure 4G ), which suggested tumor progression. Therefore, he immediately received CT-guided percutaneous cryoablation to control disease progression and reduce tumor burden after an evaluation by a multidisciplinary team ( Figure 4A ). Within 4 days after CAR-T cell infusion, he presented with hypotension and recurrent fever ( Figure 4B ), and serum IL-6 reached its peak level of 2235.78 pg/mL 4 days after CAR-T cell infusion, which suggested severe CRS ( Figure 4C ). CAR-T cell expansion in peripheral T cells reached peak levels of 50.59 % on day 6 ( Figure 4D, E ), which was gradually decreased during the subsequent 2 weeks. MRI showed that the thigh mass was remarkably decreased 30 days after CAR-T cell infusion ( Figure 4G ). Intriguingly, a newly emerging mass on the dorsum of the right foot during CAR-T cell manufacturing was completely eliminated 15 days after CAR-T cell infusion ( Figure 4H ). Interestingly, the bulky disease was completely eliminated six months after CAR-T cell infusion ( Figure 4G ). To date, the patient still remained in remission ( Figure 4F ).