PMC5173507_01
Bone marrow biopsy and peripheral blood smear at the time of diagnosis.The bone marrow is hypoplastic (A: Hematoxylin and Eosin staining). Diffuse reticulin (B: silver impregnation technique) and collagen fibrosis (C: Azan staining) with atypical megakaryocytes (D: Factor VIII immunohistochemistry staining) are seen. The marrow was classified as MF-2 by the European Consensus on grading bone marrow fibrosis. May-Giemsa staining of the peripheral blood smear shows agranular neutrophils (E top), pseudo Pelger-Huet anomaly (E middle), and erythrocyte anisocytosis (E bottom).
1349-7235-55-3351-g001.jpg
PMC5173507_01_1349-7235-55-3351-g001.jpg
g001
There were no nucleated red blood cells or tear-drop cells in the peripheral blood smear, but agranular neutrophils, pseudo Pelger-Huet anomaly, and erythrocyte anisocytosis were seen (Fig. 1E). There were diffuse fibrotic changes (Fig. 1A) mainly consisting of reticulin fibers that were positively stained by a silver impregnation technique (Fig. 1B). Azan staining and factor VIII immunohistochemistry staining showed a relative increase in the numbers of collagen fibers and megakaryocytes, respectively (Fig. 1C and D).
PMC5173507_02
Clinical course of hematopoietic stem cell transplantation (HSCT). The second HSCT was performed after graft failure of the first HSCT. BIPM: biapenem, BKV: BK virus, BT: body temperature, BU: busulfan, CMV: cytomegalovirus, CY: cyclophosphamide, FISH: fluorescent in situ hybridization, FLU: fludarabine, G-CSF: granulocyte colony stimulating factor, MEL: melphalan, MMF: mycophenolate mofetil, PBSCT: peripheral blood stem cell transplantation, Plt: platelet count, STR: short tandem repeats, TAC: tacrolimus
1349-7235-55-3351-g002.jpg
PMC5173507_02_1349-7235-55-3351-g002.jpg
g002
HSCT, the patient's neutrophil count was greater than 0.5x109 cells/L, and there was complete donor chimerism of the nucleated cells on Day 32 (recipient white blood cells <5% by a short tandem repeat analysis). However, his neutrophil count rapidly decreased from 4.55x109/L on Day 31 to less than 0.1x109/L on Day 38 of the first HSCT (Fig. 2).
Change in degree of marrow fibrosis and hematopoietic cell recovery. At the first engraftment, the marrow fibrosis remained but was moderately decreased, especially the reticulin fibrosis. Both the collagen and reticular fibrosis decreased further on days 22, 57 and 83 of the second HSCT and hematopoietic cells gradually recovered. HE: Hematoxylin and Eosin staining, AG: silver impregnation technique, Azan: Azan staining
1349-7235-55-3351-g003.jpg
PMC5173507_02_1349-7235-55-3351-g003.jpg
g003
Because a BM biopsy (Day 35 of the first HSCT as Day -20 of the second HSCT in Fig. 3) revealed that the degree of marrow fibrosis had decreased, no hemophagocytosis had been seen, and the numbers of hematopoietic cells had slightly recovered, we thought that the findings indicated secondary graft failure. After the second HSCT, both types of marrow fibers gradually disappeared, while there was gradual recovery of the hematopoietic cells on biopsies performed on Days 57 and 83 (Fig. 3).