Outcomes of allogeneic stem cell transplantation in patients with paroxysmal nocturnal hemoglobinuria with or without aplastic anemia

Clinical observation of low-dose combination chemotherapy in refractory/recurrent paroxysmal nocturnal hemoglobinuria patients: A single-center retrospective analysis

BACKGROUND

We performed a retrospective analysis to investigate the clinical characteristics and therapeutic strategies of 20 refractory/recurrent PNH patients, including the clinical efficacy of chemotherapy treatment, safety, and survival.

METHODS

The clinical data of 20 classic PNH patients who were refractory/recurrent or had glucocorticoid dependence in our hospital were analyzed, including clinical manifestations, laboratory examinations, treatment efficacy, and survival.

RESULTS

Seventeen patients had a marked improvement in anemia after chemotherapy, 14 patients acquired blood transfusion independence, and the Hb of 3 patients increased to normal levels. Although 6 patients still needed blood transfusion, the transfusion interval was significantly prolonged. The percentages of LDH, TBIL, and RET, which are indicators of hemolysis, were significantly lower than those before chemotherapy. The dosage of adrenal glucocorticoids was reduced by more than half compared with that before chemotherapy.

CONCLUSIONS

Chemotherapy can reduce PNH clones, promote normal hematopoiesis, and control hemolytic attack. It is a promising and widely used therapeutic method.

Unmanipulated haploidentical donor and matched unrelated donor hematopoietic stem cell transplantation in patients with paroxysmal nocturnal hemoglobinuria: a single-center study

We analyzed the outcomes of 32 patients with paroxysmal nocturnal hemoglobinuria (PNH) who underwent either a haploidentical donor (HID) or a matched unrelated donor (MUD) hematopoietic stem cell transplantation (HSCT). Seventeen patients received an HSCT from an HID and 15 patients received an HSCT from an MUD. The median follow-up time of the surviving patients was 36 months (range: 12-96 months). No significant differences were observed in the 3-year overall survival (OS) between the HID and MUD cohorts (74.1%±11.4% vs. 93.3%±6.4%, respectively, p=.222) or in the 3-year failure-free survival (68.8%±11.8% vs. 86.7%±8.8%, respectively, p=.307). Treatment-related mortality occurred in five patients. A univariate analysis of risk factors revealed platelet engraftment failure negatively impacted OS and FFS. We conclude that HID and MUD-HSCT are feasible and can be effective options for those PNH patients with concomitant bone marrow failure, recurrent life-threatening thrombosis, and uncontrollable hemolysis.

Different clinical courses with the same findings: two cases of paroxysmal nocturnal hemoglobinuria presenting with thrombocytopenia

Paroxysmal nocturnal hemoglobinuria (PNH) is a clonal stem cell disease that manifests with chronic intravascular hemolysis, thrombosis, and bone marrow failure. Various degrees of cytopenias accompany the disease. Although laboratory and clinical findings are similar, the disease may show different courses and require different treatments. Herein, we report two different courses of PNH with similar clinical and laboratory findings.

Hematopoietic Stem Cell Transplantation for Patients with Paroxysmal Nocturnal Hemoglobinuria with or without Aplastic Anemia: A Multicenter Turkish Experience

Objective:

Although inhibition of the complement system at different steps is a promising therapy modality in patients with paroxysmal nocturnal hemoglobinuria (PNH), allogeneic hematopoietic stem cell transplantation (HCT) is still the only curative therapy, especially for patients with intractable hemolysis or bone marrow failure. The aim of this study is to evaluate the outcomes of allogeneic HCT in PNH patients with aplastic anemia (PNH-AA) or without.

Materials and Methods:

Thirty-five PNH/PNH-AA patients who were treated with allogeneic HCT in 10 transplantation centers in Turkey were retrospectively analyzed.

Results:

Sixteen (45.7%) and 19 (54.3%) patients were diagnosed with classical PNH and PNH-AA, respectively. The median age of the patients was 32 (18-51) years. The 2-year overall survival (OS) rate and rate of graft-versus-host disease-free, failure-free survival (GFFS) was 81.2% and 78.1%, respectively. The 2-year OS in cases of classical PNH and PNH-AA was 81.3% and 79.9%, respectively (p=0.87), and 2-year GFFS in cases of PNH and PNH-AA was 79% and 76% (p=0.977), without statistical significance. The OS and GFFS rates also did not differ between transplantations with matched sibling donors (MSDs) and matched unrelated donors (MUDs).

Conclusion:

Allogeneic HCT with MSDs or MUDs is a good option for selected patients with classical PNH and PNH-AA. In particular, patients with debilitating and refractory hemolysis and patients with bone marrow failure might form an excellent group of candidates for allogeneic HCT.

Advances in Hematopoietic Stem Cell Transplantation for Patients with Paroxysmal Nocturnal Hemoglobinuria

In the era of eculizumab, the number of patients with paroxysmal nocturnal hemoglobinuria (PNH) who undergo hematopoietic stem cell transplantation (HSCT) has decreased significantly. However, owing to the possibility of severe aplastic anemia (AA) or a suboptimal response to eculizumab, HSCT still plays an important role in the treatment of patients with PNH combined with AA or recurrent hemolysis-related symptoms despite its high level of risk. Here we review studies involving patients with PNH who underwent HSCT over the past 15 years and conclude that patients with refractory AA/PNH and patients with severe classical PNH are candidates for HSCT in countries where eculizumab is unavailable. The major causes of death from transplantation include graft-versus-host disease (GVHD), infection, and thrombotic microangiopathy. A haploidentical donor is a potential choice for patients without an HLA-matched donor. In addition, the use of eculizumab in combination with HSCT may help prevent GVHD.

Outcome of allogeneic hematopoietic stem cell transplantation in adult patients with paroxysmal nocturnal hemoglobinuria

The safety and efficacy of allogeneic hematopoietic stem cell transplantation (HSCT) for paroxysmal nocturnal hemoglobinuria (PNH) remain unclear. Therefore, we retrospectively analyzed the outcomes of 42 adult patients with PNH who underwent allogeneic HSCT using the registry database of the Japan Society for Hematopoietic Cell Transplantation. The median patient age was 32.5 years. The number of packed red cell (PRC) transfusions was < 20 times in 19 patients and ≥ 20 times in 16; 7 patients had missing data. Stem cell sources were bone marrow (N = 15) or peripheral blood (N = 13) from a related donor or bone marrow (N = 11) and cord blood (N = 3) from an unrelated donor. The cumulative incidence of neutrophil engraftment at day 40 was 81%. Six patients died before engraftment, and the 6-year overall survival (OS) was 74%. The OS of patients with < 20 pretransplant PRC transfusions was significantly higher than that of patients with ≥ 20 pretransplant PRC transfusions (95% vs. 63%; P < 0.05). Moreover, the OS of patients aged < 30 years was significantly higher than that of patients aged ≥ 30 years (90% vs. 59%; P < 0.05). Allogeneic HSCT for PNH could provide favorable survival; however, pretransplant transfusion burden and patient age should be considered when deciding the timing of allogeneic HSCT.

Allogeneic Hematopoietic Stem Cell Transplantation for Paroxysmal Nocturnal Hemoglobinuria: Multicenter Analysis by the Polish Adult Leukemia Group

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the sole potential cure for paroxysmal nocturnal hemoglobinuria (PNH); however, the data on its utility in PNH are limited. This retrospective analysis of patients with PNH who underwent allo-HSCT in 11 Polish centers between 2002 and 2016 comprised 78 patients with PHN, including 27 with classic PNH (cPNH) and 51 with bone marrow failure-associated PNH (BMF/PNH). The cohort was 59% male, with a median age of 29 years (range, 12 to 65 years). There was a history of thrombosis in 12% and a history of hemolysis in 81%, and 92% required erythrocyte transfusions before undergoing allo-HSCT. No patient received eculizumab, and 26% received immunosuppressive treatment. The median time from diagnosis to allo-HSCT was 12 months (range, 1 to 127 months). Almost all patients (94%) received reduced-toxicity conditioning, 66% with treosulfan. The stem cell source was peripheral blood in 72% and an identical sibling donor in 24%. Engraftment occurred in 96% of the patients. With a median follow-up of 5.1 years in patients with cPNH and 3.2 years in patients with BMF/PNH, 3-year overall survival (OS) was 88.9% in the former and 85.1% in the latter (P = not significant [NS]). The 3-year OS for patients with/without thrombosis was 50%/92% (P = NS) in the cPNH group and 83.3%/85.3% (P = NS) in the BMF/PNH group. The 3-year OS for in the BMF/PNH patients with/without hemolysis was 93.9%/62.9% (hazard ratio, .13; P = .016). No other factors impacted OS. After allo-HSCT, the frequency of the PNH clone was reduced to 0%, <1%, and <2.4% in 48%, 48%, and 4% of cPNH patients and in 84%, 11%, and 5% of BMF/PNH patients, respectively. The frequency of acute graft-versus-host disease (GVHD) grade II-IV was 23%, and the cumulative 1-year incidence of extensive chronic GVHD was 10.8% in the BMF/PNH group and 3.7% in the cPNH group. Allo-HSCT is a valid option for PNH patients, effectively eliminating the PNH clone with satisfactory overall survival and acceptable toxicity. Reduced-toxicity conditioning with treosulfan is effective and safe in patients with cPNH and BMF/PNH.

[Outcomes of allogeneic hematopoietic stem cell transplantation in patients with paroxysmal nocturnal hemoglobinuria compared to paroxysmal nocturnal hemoglobinuria-aplastic anemia syndrome]

Objective: To compare the outcomes of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for paroxysmal nocturnal hemoglobinuria (PNH) with paroxysmal nocturnal hemoglobinuria-aplastic anemia (PNH-AA) syndrome. Methods: The outcomes of 46 patients who received allo-HSCT (16 PNH patients, 30 PNH-AA patients) from July 10, 2007 to June 2, 2018 were analyzed retrospectively. The conditioning regimen was busulfan, cyclophosphoramide, and ATG in haploidentical donors and unrelated donors. Patients with matched sibling donors were treated with the fludarabine, cyclophosphamide, and ATG regimen. Results: There were no differences of baseline data between the 2 groups except gender distribution and the numbers of haploidentical donor transplantation. The median values of absolute nucleated cell counts were 10.58 (3.83-13.83) ×10(8)/kg in the PNH group and 10.81 (3.96-33.40) ×10(8)/kg in the PNH-AA group (P=0.668) . The median doses of CD34(+) cells infused were 5.00 (3.14-8.42) ×10(6)/kg and 3.57 (1.97-6.17) ×10(6)/kg (P=0.002) , respectively. All patients obtained complete engraftment. The median time for myeloid engraftment were 11 (7-14) days in the PNH group and 12 (10-26) days in the PNH-AA group (P=0.003) . The median time for platelet engraftment were 13 (11-16) days and 18 (12-75) days (P=0.002) , respectively, after a median follow-up of 36 (4-132) months in the PNH group and 26 (4-75) months in the PNH-AA group (P=0.428) . There were no differences of incidence rates of acute graft-versus-host disease (aGVHD) , chronic GVHD and infection between PNH and PNH-AA groups (P>0.05) . No patient occurred early death and relapse. The estimated 3-year overall survival (OS) of PNH and PNH-AA groups were (100.0±0.0) % and (85.7± 6.6) % (P=0.141) , GVHD-free and failure-free survival (GFFS) were (100.0±0.0) %, (78.7±7.7) % (P=0.067) . Conclusions: allo-HSCT is effective for patients with PNH and PNH-AA syndrome. The preliminary results indicate that myeloid and platelet engraftment in PNH group were faster than PNH-AA group. There were no differences in OS and GFFS between PNH group and PNH-AA group.

Development of hemolytic paroxysmal nocturnal hemoglobinuria without graft loss following hematopoietic stem cell transplantation for acquired aplastic anemia

PNH is the most common clonal hematopoietic disorder arising in patients with aAA. PNH is caused by mutations in PIGA, a gene that encodes the catalytic subunit of an enzyme involved in the biosynthesis of GPI anchors, transmembrane glycolipids required for cell surface expression of many proteins. PNH clones likely arise as immune escape mechanisms in aAA by preventing CD1D-restricted T-cell recognition of GPI anchors and GPI-linked autoantigens. Though many patients with aAA treated with IST will develop subclinical PNH clones, only a subset will develop PNH disease, characterized by increased thrombosis, intravascular hemolysis, and potential for severe organ dysfunction. In contrast to IST, allogeneic HSCT for patients with aAA is thought to cure bone marrow aplasia and prevent hematopoietic clonal evolution to PNH. Herein, we present a phenomenon of host-derived PNH disease arising in a patient with aAA many years following MSD-BMT, highlighting the importance of monitoring for this clonal disease in aAA patients with stable mixed donor/recipient chimerism after HSCT. We also provide a literature review for similar occurrences of PNH arising after HSCT.

Post-Allogeneic Hematopoietic Stem Cell Transplantation Eculizumab as Prophylaxis Against Hemolysis and Thrombosis for Patients with Hematologic Disorders Associated with Paroxysmal Nocturnal Hemoglobinuria Clones

Paroxysmal nocturnal hemoglobinuria (PNH) is frequently seen in the context of other aplastic anemia and myelodysplastic syndromes and is associated with hemolysis and increased thromboembolic events. Allogeneic hematopoietic stem cell transplantation (alloHCT) is the sole curative treatment but is associated with significant morbidity. The terminal complement inhibitor eculizumab reduces hemolysis and thromboembolic events and is the sole Food and Drug Administration-approved therapy for PNH. Prophylactic administration of this agent in the early post-transplantation setting to prevent hemolysis and thrombosis has not been described in the literature. We describe our institutional experience of 8 patients with PNH who underwent alloHCT and who received at least 1 dose of eculizumab within 30 days of alloHCT for prevention of thrombosis and hemolysis. One patient with underlying aplastic anemia who received bone marrow stem cells failed to engraft. Another patient experienced steroid-refractory grade IV acute graft-versus-host disease and died of a fungal infection. The other patients engrafted well; no hemolysis, thrombotic events, or infections associated with encapsulated bacteria occurred in any of the 8 patients.