case_images: PMC11379505_01
case_images: Histologic images of the patient's bone marrow sample. (A) Pretransplant bone marrow H&E stained histologic image shows a cellular bone marrow with maturing trilineage hematopoiesis. (B) CD71 immunohistochemical stain highlights an appropriate number and proportion of erythroid precursors. (C) E-cadherin immunohistochemical stain weakly stains early erythroid precursors (red boxes). (D) Day 66 post-transplant bone marrow H&E shows a hypocellular bone marrow with markedly reduced erythroid elements. (E) CD71 shows very rare erythroid elements. (F) E-cadherin is essentially negative. (G) Bone marrow H&E stained histologic image after last dose of bortezomib shows a persistently hypocellular marrow. (H, I) CD71 and E-cadherin immunohistochemical stains show that erythroid precursors are essentially absent. (J) H&E image of bone marrow after multiple doses of isatuximab shows a normocellular bone marrow with maturing trilineage hematopoiesis. (K) CD71 highlights erythroid precursors which are once again seen in normal proportion and numbers. (L) E-cadherin shows early erythroid precursors. All images shown at 400x magnification.
case_images: CRIHEM2024-5790011.001.jpg
case_images: PMC11379505_01_CRIHEM2024-5790011.001.jpg
case_images: fig1
case_images: Immunohistochemical staining for CD71 and E-cadherin confirmed absence of erythroid precursors (Figure 1).
case_images: Treatment outcomes of therapies for pure red cell aplasia. Shown are the hemoglobin and reticulocyte count after therapy with rituximab, bortezomib, darbepoetin alfa, prednisone, and isatuximab.
case_images: CRIHEM2024-5790011.002.jpg
case_images: PMC11379505_01_CRIHEM2024-5790011.002.jpg
case_images: fig2
case_images: Subsequently, the patient received bortezomib, darbepoetin, and low-dose prednisone, yet no response was observed (Figure 2).