Long-term marrow culture in patients with aplastic anemia compared with marrow transplant recipients and normal controls.
Patients with severe aplastic anemia (SAA; n = 46) were studied in long-term bone marrow culture (LTBMC) systems and compared with allogeneic marrow transplant (BMT) recipients (n = 16) (within 30 days following BMT) and normal control patients (n = 12). SAA patients were divided in two groups: transfusion-dependent (Tx-D) SAA patients (group A; n = 15) and transfusion-independent (Tx-I) patients after treatment with antilymphocyte globulin (group B; n = 31). Cultures were analyzed at three levels: stromal layer (SL) formation (score: 0, no SL; 1, half confluent SL; and 2, confluent SL), number of nucleated cells in suspension, and growth of CFU-GM colonies. SL formation was rapid and complete in SAA patients, groups A and B (mean score on day 14: 1.3 and 1.4), similar to controls (mean score on day 14: 1.3), whereas an impairment of SL formation was seen in BMT recipients (mean score on day 14: 1.0). The number of nucleated cells in suspension increased significantly on day 7 of culture in controls (7.6-fold), significantly more than in BMT and SAA patients, and declined thereafter. Colony formation was also significantly increased on day 7 in Tx-I SAA patients, BMT recipients, and normal controls (4-, 5-, and 16-fold, respectively), lasting respectively 2, 3, and 4 weeks. Increments of colony formation were also obtained in Tx-D SAA patients, but in the first week of culture only.


CONCLUSIONS
1) a significant impairment of SL formation was seen in BMT recipients, but not in SAA patients; 2) a significant increment of granulocyte-macrophage colony-forming units (CFU-GM) growth can be obtained in patients with marrow failure early after starting long-term culture; 3) the number of CFU-GM grown in these culture conditions from Tx-I SAA patients parallels the number of progenitors from early post-BMT recipients; and 4) progenitor cells from Tx-D SAA patients are not only reduced in numbers, but also exhibit a poor ability to survive in LTBMC.
Bacigalupo
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A
Divisione Ematologia II, Ospedale S. Martino, Genova, Italia.
Figari
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Tong
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Piaggio
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Miceli
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Frassoni
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Caciagli
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Badolati
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Marmont
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D000741:Anemia, Aplastic / Q000473:pathology* / Q000601:surgery; D001854:Bone Marrow Cells; D016026:Bone Marrow Transplantation / Q000473:pathology*; D002478:Cells, Cultured; D006410:Hematopoiesis; D006801:Humans; D066298:In Vitro Techniques; D013997:Time Factors