A patient with paroxysmal nocturnal hemoglobinuria (PNH) received a syngeneic peripheral blood stem cell transplant (PBSCT) with high-dose cyclophosphamide (CY) conditioning. He had a reasonable engraftment and complete hematologic recovery. However, at 12 months after PBSCT, he became symptomatic and peripheral blood cells were almost entirely composed of glycosylphosphatidylinositol-anchored proteins deficient cells. This case suggests that high-dose CY may not exert a significant effect on PNH clones in the long term, although it had been effective in allogeneic BMT. In view of the possible autoimmune basis, it seems to be necessary to include other immunosuppressive therapy including ALG in addition to CY. Bone Marrow Transplantation (2001) 28, 987–988.
Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal disorder of hematopoietic stem cells characterized by recurrent intravascular hemolysis, pancytopenia, and a predisposition to venous thrombosis. PNH results from a somatic mutation of the PIG-A gene, that is responsible for glycosylphosphatidylinositol (GPI) anchor deficiency. Although the natural course of PNH is highly variable, patients with PNH finally die due to deep venous thrombosis, bone marrow failure-related complications, myelodysplastic syndrome, and leukemic progression. Among variable managements of PNH patients, bone marrow transplantation (BMT) has been considered to be the only potential curative treatment. In very rare circumstances in which the patient has a syngeneic donor, syngeneic BMT will be preferable to allogeneic BMT, because of the absence of GVHD. Among five reported cases of syngeneic BMT without a conditioning regimen, only one case achieved long-term survival1 and four cases showed a return to pathologic hematopoiesis.2,3,4,5 These data suggest that simple BM infusion without conditioning in PNH may not be an effective therapeutic option as noted in aplastic anemia. In this case, therefore, we have performed syngeneic transplantation by using the same conditioning regimen that has been used in allogeneic BMT.1
We have performed syngeneic transplantation in a 31-year-old man with high-dose cyclophosphamide conditioning and G-CSF-mobilized peripheral blood stem cells (PBSCs). He had received a syngeneic bone marrow infusion without conditioning 10 years ago. Two years later, he started to have frequent episodes of hemolysis and was maintained with steroids, iron replacement and transfusion. At the time of peripheral blood stem cell transplantation (PBSCT), Hb was 9.5 g/dl, WBC count 3.4 × 109/l and platelet count 79 × 109/l. Bone marrow aspiration revealed about 30–40% cellularity in the tissue section particles. Chromosome analysis showed no abnormality. For the stem cell source and conditioning regimen we used G-CSF-mobilized PBSCs harvested from the same syngeneic donor following cyclophosphamide at a dose of 50 mg/kg i.v. on each of 4 consecutive days. Harvested PBSCs were 25.38 × 108 MNCs/kg and 8.05 × 106 CD34+ cells/kg of the recipient. He was treated in a HEPA-filtered room and received antimicrobial prophylaxis and G-CSF (subcutaneous injection, 5 μg/kg) until neutrophils reached values above 0.5 × 109/μl. His WBC count reached 0.8 × 109/μl on day 9 and 2.2 × 109/μl on day 10 after PBSCT. His platelet count was increased to 53 × 109/μl without transfusion on day 16. He was discharged without any complications on day 19. Flow cytometric analysis of GPI-AP (CD66b (polymorphonuclear neutrophils, PMNs), CD59 (red blood cells, RBCs)) in the peripheral blood was performed by a direct immunofluorescent method before and after the PBSCT. The peripheral blood of the syngeneic donor was also analyzed as a control. Most of the patient's PMNs (98%) and RBCs (85%) were GPI-AP deficient cell population before PBSCT, but the GPI-AP expressed by normal cell populations were successively increased after PBSCT. At 9 months after PBSCT, the majority of the patient's PMNs (92%) and RBCs (90%) expressed GPI-AP. However 12 months after PBSCT, he again became symptomatic and his peripheral blood PMNs (98%) and RBCs (82%) were almost entirely composed of GPI-AP deficient cells. He remains alive with frequent hemolytic episodes and transfusion support (Table 1).
We used high-dose CY as a conditioning regimen because it has been reported to be an effective immunosuppressive agent that could be beneficial to patients with severe aplastic anemia and PNH with aplastic anemia in BMT and has never shown secondary clonal disorder.6,7 The patient had reasonable engraftment and complete hematologic recovery but rapidly relapsed between 9 months and 12 months after syngeneic PBSCT. When we considered that clinically, development of PNH needs an abnormal PNH clone resulting from somatic mutation in PIG-A and an environment injurious to other hematopoietic stem cells through GPI-mediated mechanism, we could draw some inferences from this relapsed PNH case.8 First, CY alone may be not sufficient to eradicate the PNH clone and also in view of the possible autoimmune basis of aplastic anemia and of bone marrow aplasia with PNH, could not provide sufficient immune suppression. In the setting of a mixed chimeric state, it might be possible to imagine a scenario where the original disease process could attack the normal donor marrow and the minimized PNH clone could expand again. Unfortunately, we could not determine the characteristics of relapsed PNH clone because we did not evaluate the underlying PIG-A mutation.5,9 Second, allogeneic transplantation following non-myeloablative conditioning regimens has cured PNH regularly1,6,10 whereas relapse is common after syngeneic transplantation.2,3,4,5 This suggest that an allo-reactive mechanism might contribute to the success of BMT for PNH, either by helping to eradicate autoreactive T cells, or the PNH clone, or both.
Syngeneic transplantation in PNH could also provide useful insights into the pathophysiology of the disease as it has in aplastic anemia. We thought that in this case, PNH relapse might result from persistence of the autoimmune process, with emergence of a new PNH clone or re-growth of the original PNH clone. This case might support the hypothesis that an autoimmune process might be closely related to pathological environment for the clonal selection of PNH clone through a GPI-mediated mechanism.5,8 We suggest that it might be helpful to include other immunosuppressive agents such as anti-lymphocyte globulin (ALG) in transplant conditioning in patients with PNH in addition to CY.
Kawahara K, Witherspoon RP, Storb R . Marrow transplantation for paroxysmal nocturnal hemoglobinuria Am J Hematol 1992 39: 283–288
Kolb HJ, Holler E, Bender-Götze C et al. Myeloablative conditioning for marrow transplantation in myelodysplastic syndromes and paroxysmal nocturnal hemoglobinuria Bone Marrow Transplant 1989 4: 29–34
Hershko C, Ho WG, Gale RP, Cline MJ . Cure of aplastic anemia in paroxysmal nocturnal hemoglobinuria by bone marrow infusion from identical twin: failure of peripheral-leukocyte transfusion to correct marrow aplasia Lancet 1979 1: 945–947
Champlin RE, Feig SA, Sparkes RS, Gale RP . Bone marrow transplantation from identical twins in the treatment of aplastic anemia implications for the pathogenesis of the disease Br J Haematol 1984 56: 455–463
Endo M, Beatty PG, Vreeke TM et al. Syngeneic bone marrow transplantation without conditioning in a patient with paroxysmal nocturnal hemoglobinuria: in vivo evidence that the mutant stem cells have a survival advantage Blood 1996 88: 742–750
Szer J, Deeg HJ, Witherspoon RP et al. Long-term survival after marrow transplantation for paroxysmal nocturnal hemoglobinuria with aplastic anemia Ann Intern Med 1984 101: 193–195
Brodsky RA, Sensenbrenner LL, Jones RJ . Complete remission in severe aplastic anemia after high-dose cyclophosphamide without bone marrow transplantation Blood 1996 87: 491–494
Luzzatto L, Bessler M, Rotoli B . Somatic mutations in paroxysmal nocturnal hemoglobinuria: a blessing in disguise? Cell 1997 88: 1–4
Nafa K, Bessler M, Deeg HJ, Luzzatto L . New somatic mutation in the PIG-A gene emerges at relapse of paroxysmal nocturnal hemoglobinuria Blood 1998 92: 3422–3427
Antin JH, Ginsburg D, Smith BR et al. Bone marrow transplantation for paroxysmal nocturnal hemoglobinuria: eradication of the PNH clone and documentation of complete lymphohematopoietic engraftment Blood 1985 66: 1247–1250
About this article
Cite this article
Cho, S., Lim, J., Kim, Y. et al. Conditioning with high-dose cyclophosphamide may not be sufficient to provide a long-term remission of paroxysmal nocturnal hemoglobinuria following syngeneic peripheral blood stem cell transplantation. Bone Marrow Transplant 28, 987–988 (2001) doi:10.1038/sj.bmt.1703259
- paroxysmal nocturnal hemoglobinuria
- high-dose cyclophosphamide
- syngeneic peripheral blood stem cell transplantation
How we treat paroxysmal nocturnal hemoglobinuria: A consensus statement of the Canadian PNH Network and review of the national registry
European Journal of Haematology (2019)
Development of hemolytic paroxysmal nocturnal hemoglobinuria without graft loss following hematopoietic stem cell transplantation for acquired aplastic anemia
Pediatric Transplantation (2019)
Biology of Blood and Marrow Transplantation (2019)
Successful reduced-intensity conditioning hematopoietic stem cell transplantation for paroxysmal nocturnal hemoglobinuria with aplastic anemia in two children
Pediatric Blood & Cancer (2018)