Hematopoietic Cell Transplantation for Aplastic Anemia and other Bone Marrow Failure Syndromes

Number: 0627

Table Of Contents

Policy
Applicable CPT / HCPCS / ICD-10 Codes
Background
References

---

Policy

Scope of Policy

This Clinical Policy Bulletin addresses hematopoietic cell transplantation for aplastic anemia and other bone marrow failure syndromes.

1. Medical Necessity

   1. Aetna considers allogeneic hematopoietic cell transplantation medically necessary for the treatment of severe aplastic anemia, Diamond-Blackfan anemia, Fanconi's anemia, paroxysmal nocturnal hemoglobinuria, and pure red cell aplasia when members meet the transplanting institution's selection criteria. 
   2. In the absence of a institution's selection criteria, Aetna considers allogeneic hematopoietic cell transplantation medically necessary for treatment of the following:
      
      
      1. Severe aplastic anemia when the member has at least 3 of the 4 following features:
         
         
         • Bone marrow cellularity less than 25 % (markedly hypocellular)
         • Neutrophil count less than 0.5 x 10⁹/L
         • Reticulocyte count less than 1 % or less than 20 x 10⁹/L (corrected for hematocrit)
         • Un-transfused platelet count less than 20 x 10⁹/L
      2. Pure red cell aplasia when the member has the following features:
         
         
         • Bone marrow cellularity less than 25 % (markedly hypocellular); and
         • Reticulocyte count less than 1 % or less than 20 x 10⁹/L (corrected for hematocrit).
      3. Diamond-Blackfan anemia in persons who are refractory to corticosteroids.
      4. Fanconi's anemia in persons with severe bone marrow failure, myelodysplastic syndrome, or acute myelogenous leukemia. 
      5. Paroxysmal nocturnal hemoglobinuria with ongoing transfusion requirements and a suitable human leukocyte antigen (HLA)-matched donor.
      6. Congenital dyserythropoietic anemia when member is transfusion-dependent and has failed interferon alfa, and splenectomy.
      7. Aetna considers repeat allogeneic stem cell transplantation medically necessary for primary graft failure, failure to engraft or rejection in severe aplastic anemia, Diamond-Blackfan anemia, Fanconi's anemia, paroxysmal nocturnal hemoglobinuria, and pure red cell aplasia.

2. Experimental, Investigational, or Unproven

   Aetna considers autologous hematopoietic cell transplantation experimental, investigational, or unproven for the treatment of severe aplastic anemia, Diamond-Blackfan anemia, Fanconi's anemia, paroxysmal nocturnal hemoglobinuria, and pure red cell aplasia because its effectiveness for these indications has not been established.

---

Table:

CPT Codes / HCPCS Codes / ICD-10 Codes

Code	Code Description
Information in the [brackets] below has been added for clarification purposes.   Codes requiring a 7th character are represented by "+":
Transplantation - Allogeneic:
CPT codes covered if selection criteria are met:
38230	Bone marrow harvesting for transplantation; allogeneic
38240	Hematopoietic progenitor cell (HPC); allogeneic transplantation per donor
86813	HLA typing; A, B or C multiple antigens
86817	DR/DQ, multiple antigens
86821	lymphocyte culture, mixed (MCL)
Other CPT codes related to the CPB:
38100	Splenectomy; total (separate procedure)
38101	partial (separate procedure)
38102	total, en bloc for extensive disease, in conjunction with other procedure (List in addition to code for primary procedure)
38120	Laparoscopy, surgical, splenectomy
38204 - 38215	Bone marrow or stem cell services/procedures
85004 - 85049	Blood count
85055	Reticulated platelet assay
85060	Blood smear, peripheral, interpretation by physician with written report
85097	Bone marrow, smear interpretation
86920 - 86923	Compatibility test each unit
HCPCS codes covered if selection criteria are met:
S2150	Bone marrow or blood-derived stem-cells (peripheral or umbilical), allogeneic or autologous, harvesting, transplantation, and related complications; including: pheresis and cell preparation/storage; marrow ablative therapy; drugs, supplies, hospitalization with outpatient follow-up; medical/surgical, diagnostic, emergency, and rehabilitative services; and the number of days of pre- and post-transplant care in the global definition
Other HCPCS codes related to the CPB:
J9212	Injection, interferon alfacon-1, recombinant, 1 microgram
J9213	Injection, interferon, alfa-2a, recombinant, 3 million units
J9214	Injection, interferon, alfa-2b, recombinant, 1 million units
J9215	Injection, interferon, alfa-n3, (human leukocyte derived), 250,000 iu
S0145	Injection, pegylated interferon alfa-2a, 180 mcg per ml
S0148	Injection, pegylated interferon alfa-2b, 10 mcg
ICD-10 codes covered if selection criteria are met:
D59.5	Paroxysmal nocturnal hemoglobinuria [Marchiafava-Micheli]
D60.0 - D61.9	Aplastic anemia [severe]
D64.4	Congenital dyserythropoietic anemia
T86.5	Complications of stem cell transplant
Z94.84	Stem cells transplant status
Transplantation - Autologous:
CPT codes not covered for indications listed in the CPB:
38232	Bone marrow harvesting for transplantation; autologous
38241	Hematopoietic progenitor cell (HPC); autologous transplantation

---

Background

Aplastic anemia (AA) is characterized by peripheral blood pancytopenia, resulting from a failure of the bone marrow to produce blood cells.  In the United States, it has an age-adjusted incidence of 2.2 per million populations per year.  Pathogenic mechanisms for AA vary and include intrinsic defects of hematopoietic stem cells, defects in the marrow micro-environment, and abnormal humoral or cellular immune control of hematopoiesis.  In most patients, AA is of unknown etiology (idiopathic), whereas in some, the disease can be secondary to infections, drugs or toxin exposure, and hereditary causes (e.g., Fanconi's anemia or Diamond-Blackfan syndrome).  Severe AA is defined by the presence of neutrophils less than 0.5 x 10⁹/L, platelets less than 20 x 10⁹/L, reticulocytes less than 1 %, and bone marrow cellularity less than 20 %.  When 3 of 4 of these symptoms are present, the median survival without therapy is about 3 months, with only 20 % of patients surviving for 12 months.  Currently, 2 definitive treatments are available for patients with severe AA:

1. immuno-suppressive therapy (IST) that includes the use of anti-thymocyte globulin, cyclosporine, and cyclophosphamide; and
2. allogeneic bone marrow transplantation (ABMT). 

The benefits of each are comparable.  However, certain subsets of patients derive superior benefit from one or the other.

Allogeneic bone marrow transplantation from human leukocyte antigen (HLA)-matched, related donors is generally accepted as the initial treatment of choice for young patients (less than 20 years old).  It results in the complete reconstitution of hematopoiesis, whereas autologous hematopoietic remissions after IST are more susceptible to relapse.  The literature indicates that survival rates after ABMT, in patients between the ages of 20 and 40, are comparable to those reported for IST.  Better survival rates after ABMT have been attained with improved conditioning regimens and graft-versus-host disease (GVHD) prophylaxis.  Best current results demonstrate long-term, event-free survivals with successful allografts on the order of 90 %.  Long-term complications after ABMT include GVHD and secondary neoplasms.  The role of ABMT from an unrelated donor is being investigated.

For patients older than 40, the generally accepted treatment of choice is IST, which entails the combination of anti-thymocyte globulin and cyclosporin A.  A variable proportion of patients (ranging from 20 to 80 %) respond to IST.  However, although responses may be frequent, long-term outcome is guarded because some patients may relapse and others may develop a clonal disorder, including myelodysplasia, leukemia, or paroxysmal nocturnal hemoglobinuria.  Long-term complications of IST include recurrence and development of clonal myeloid disorders.

In a review on ABMT for the treatment of AA, Horowitz (2000) stated that long-term survival rates ranged from less than 40 to more than 90 % in reported series.  These rates have improved over the past 20 years due to significant reductions in GVHD, interstitial pneumonitis, and early transplant-related mortality.  Most long-term survivors have excellent performance status.  Late complications such as cataracts, thyroid disorders, joint problems, and therapy-related cancers are observed, especially in patients who received radiation for pre-transplant conditioning.  Results are best in young patients transplanted with bone marrow from a HLA-identical sibling; early transplantation is appropriate in this group.  For older patients or those without an HLA-identical related donor, transplants are better reserved for those who fail to respond to IST.

Kojima and co-workers (2000a) compared the long-term outcome of acquired AA in children treated with IST or ABMT.  They recommended ABMT as first-line therapy in pediatric severe AA patients with an HLA-matched family donor.  Alternative donor ABMT was recommended as salvage therapy in patients who relapsed or did not respond to initial IST.  In a Consensus Conference on the Treatment of Aplastic Anemia, the participants recommended that the number of courses of IST for non-responders before unrelated ABMT consideration to be 1 for children and 2 for adults (Kojima et al, 2000b).

Bone marrow failure (BMF) syndromes entail a broad group of diseases of varying etiologies, in which hematopoieisis is abnormal or completely arrested in one or more cell lines.  Bone marrow failure syndromes can be an acquired AA or can be congenital, as part of such syndromes as Fanconi anemia (FA), Diamond Blackfan anemia (DBA), and Schwachman Diamond syndrome.  Hematopoietic bone marrow/stem cell transplantation is a therapeutic option for patients with BMF syndromes (Steele et al, 2006, Myers and Davies, 2009, Mehta et al, 2010).

In a report from the Aplastic Anemia Committee of the Japanese Society of Pediatric Hematology on hematopoietic stem cell transplantation (HSCT) for DBA, Mugishima et al (2007) stated that transfusion-dependent DBA patients opt for allogeneic HSCT as curative therapy.  These investigators analyzed clinical outcomes of 19 transplanted Japanese patients.  Prior to HSCT, 10 patients (53 %) suffered hemosiderosis with organ dysfunction, and all 8 with short stature (42 %) had adverse effects of prednisolone.  Median age at the time of HSCT was 56 months.  Transplantation sources were 13 bone marrow (6 HLA-matched siblings, and 6 HLA-matched and 1 HLA-mismatched unrelated donors), 5 cord blood (2 HLA-matched siblings and 3 HLA-mismatched unrelated donors), and 1 peripheral blood from haploidentical mother.  All 13 patients with BMT and 2 with sibling cord blood transplantation (CBT) had successful engraftment.  Of 3 patients who underwent unrelated CBT, 1 died after engraftment, and the other 2 had graft failure but succeeded in a second BMT from an HLA-disparate father and unrelated donor, respectively.  One died shortly after haploidentical peripheral blood stem cell transplantation (PBSCT).  The 5-year failure-free survival rate after BMT was higher than CBT (100 %: 40 %, p = 0.002).  Platelet recovery was slower in 7 unrelated BMT than in 6 sibling BMT (p = 0.030).  No other factors were associated with engraftment and survival.  These results suggested that allogeneic BMT, but not unrelated CBT, is an effective HSCT for refractory DBA.

In a report from the Italian pediatric group, Locatelli and colleagues (2007) noted that HSCT represents the only treatment potentially able to prevent/rescue the development of marrow failure and myeloid malignancies in patients with FA.  While in the past HSCT from an HLA-identical sibling was proven to cure many patients, a higher incidence of treatment failure has been reported in recipients of an unrelated donor (UD) or HLA-partially matched related allograft.  These researchers analyzed the outcome of 64 FA patients (age range of 2 to 20 years) who underwent HSCT between January 1989 and December 2005.  Patients were transplanted from either an HLA-identical sibling (n = 31), an UD (n = 26), or an HLA-partially matched relative (n = 7).  T-cell depletion of the graft was performed in patients transplanted from an HLA-disparate relative.  The 8-year estimate of overall survival (OS) for the whole cohort was 67 %; it was 87 %, 40 % and 69 % when the donor was an HLA-identical sibling, an UD, and a mismatched relative, respectively (p < 0.01).  The outcome of recipients of grafts from an UD improved over time, the probability of survival being 10 % and 72 % for patients transplanted before and after 1998, respectively (p < 0.05).  The OS probability of children who did or did not receive fludarabine in preparation for the allograft was 86 % and 59 %, respectively (p < 0.05).  These data provided support to the concept that a relevant proportion of FA patients undergoing HSCT can now be successfully cured, even in the absence of an HLA-identical sibling, especially if the conditioning regimen includes fludarabine.

Roth and colleagues (2009) stated that paroxysmal nocturnal hemoglobinuria (PNH) is characterized by the clinical triad of corpuscular hemolytic anemia, thrombophilia, and cytopenia.  This is caused by an acquired mutation of the PIG (phosphatidylinositol glycan)-A gene of the pluripotent hematopoietic stem cell.  This results in a deficiency of GPI (glycosylphosphatidylinositol)-anchors and GPI-anchored proteins on the surface of affected blood cells.  Flow cytometry is the standard for diagnosis and measurement of type and size of the PNH clone.  Treatment of PNH is mainly symptomatic.  Allogeneic BMT is the only curative option in case of severe complications during the course of the diseases.

Li and colleagues (2013) noted that although high-dose cyclophosphamide seems to achieve durable complete remission, there are still concerns about its too much early toxicity.  Thus, these researchers designed a clinical study to examine the effects of high-dose cyclophosphamide/anti-thymocyte globulin (ATG) combined with cord blood infusion as first-line therapy for patients with severe AA.  Between January 2003 and September 2007, these investigators treated 16 treatment-naive patients with severe AA with cord blood infusion after high-dose cyclophosphamide (50 mg/kg/day × 2) and rabbit ATG (3 mg/kg/day × 5) therapy.  Although only 1 patient had durable full donor engraftment, 14 of the enrolled 16 patients had rapid autologous hematopoietic recovery.  The median recovery time for neutrophils and platelets was only 23 and 37 days after infusion of cord blood.  Of the 15 responding patients, all patients achieved treatment-free remission: 9 patients met the criteria for a complete remission; 6 patients achieved a partial remission.  The authors concluded that infusion of cord blood after high-dose cyclophosphamide/ATG resulted in a rapid autologous hematologic recovery and a high response rate in patients with treatment-naive patients with severe AA.  They stated that these promising results merit further investigation and confirmation on a larger number of patients.

An UpToDate review on "Aplastic anemia: Prognosis and treatment" (Schrier, 2013) states that "Only a fraction of patients with severe aplastic anemia in first or second complete remission are able to mobilize sufficient stem cells to undergo autologous hematopoietic cell transplantation (HCT).  Accordingly, patients with relapsing or resistant disease, who have even fewer mobilizable stem cells than those in remission, are not candidates for autologous HCT".  Furthermore, an UpToDate review on "Hematopoietic cell transplantation in aplastic anemia" (Negrin, 2013) recommends the use of allogeneic HCT; it does not mention the use of autologous HCT as a therapeutic option.

UpToDate reviews on "Hematopoietic cell transplantation for Diamond-Blackfan anemia and the myelodysplastic syndromes in children" (Khan, 2013) and "Hematopoietic cell transplantation for idiopathic severe aplastic anemia and Fanconi anemia in children" (Khan and Negrin, 2013) do not mention the use of autologous HCT as a therapeutic option.

An UpToDate review on "Diagnosis and treatment of paroxysmal nocturnal hemoglobinuria" (Rosse, 2013) states that "autologous transplantation is unlikely to be successful because of the difficulty in obtaining sufficient numbers of normal stem cells".

In a Cochrane review, Peinemann and associates (2013) evaluated the effectiveness and adverse events of first-line allogeneic HSCT of HLA-matched sibling donors compared to first-line immunosuppressive therapy including cyclosporine and/or anti-thymocyte or anti-lymphocyte globulin in patients with acquired severe AA.  The authors concluded that there are insufficient and biased data that do not allow any conclusions to be made about the comparative effectiveness of first-line allogeneic HSCT of an HLA-matched sibling donor and first-line treatment with cyclosporine and/or anti-thymocyte or anti-lymphocyte globulin (as first-line immunosuppressive therapy).  These investigators stated that they were unable to make firm recommendations regarding the choice of intervention for treatment of acquired severe AA.

Williams and colleagues (2014) noted that randomized clinical trials in pediatric AA are rare and data to guide standards of care are scarce.  Eighteen pediatric institutions formed the North American Pediatric Aplastic Anemia Consortium (NAPAAC) to foster collaborative studies in AA.  The initial goal of NAPAAC was to survey the diagnostic studies and therapies utilized in AA.  The survey indicated considerable variability among institutions in the diagnosis and treatment of AA.  There were areas of general consensus, including the need for a bone marrow evaluation, cytogenetic and specific fluorescent in-situ hybridization assays to establish diagnosis and exclude genetic etiologies with many institutions requiring results prior to initiation of IST; uniform referral for HSCT as first line therapy if an HLA-identical sibling is identified; the use of first-line IST containing horse anti-thymocyte globulin and cyclosporine A (CSA) if an HLA-identical sibling donor is not identified; supportive care measures; and slow taper of CSA after response.  Areas of controversy included the need for telomere length results prior to IST, the time after IST initiation defining a treatment failure; use of hematopoietic growth factors; the preferred rescue therapy after failure of IST; the use of specific hemoglobin and platelet levels as triggers for transfusion support; the use of prophylactic antibiotics; and follow-up monitoring after completion of treatment.  The authors concluded that these initial survey results reflected heterogeneity in diagnosis and care amongst pediatric centers and emphasized the need to develop evidence-based diagnosis and treatment approaches in this rare disease.

Aplastic anemia is a disorder characterized by the presence of pancytopenia and a hypo-cellular bone marrow.  Acquired pure red cell aplasia (PRCA), a part of a unique form of AA, is a rare condition of profound anemia characterized by the absence of reticulocytes and the virtual absence of erythroid precursors in the bone marrow.

An UpToDate review on "Determining eligibility for allogeneic hematopoietic cell transplantation" (Deeg and Sandmaier, 2014) states that "In general, allo-HCT may be considered in the following settings …. Nonmalignant inherited and acquired marrow disorders – Treatment of sickle cell anemia, beta-thalassemia major, refractory Diamond-Blackfan anemia, myelodysplastic syndrome, idiopathic severe aplastic anemia, paroxysmal nocturnal hemoglobinuria, pure red cell aplasia, Fanconi anemia, amega-karyocytosis, or congenital thrombocytopenia".

Second Hematopoietic Stem Cell Transplantation for Graft Failure in Adult Patients with Severe Aplastic Anemia

Yahng and colleagues (2018) stated that data regarding the optimal approach for 2nd allogeneic HSCT (allo-HSCT) after graft failure (GF) in acquired severe AA (SAA) are still limited and heterogeneous.  These researchers examined 24 patients who underwent 2nd HLA-matched sibling donor (MSD) peripheral blood HSCT for GF.  The re-conditioning regimen (TNI-750/ATG) consisted of a single-dose of total nodal irradiation (TNI, 750 cGy) and anti-thymocyte globulin (ATG; Thymoglobulin, 1.25 mg/kg/day for 3 days).  All but 1 patient achieved successful engraftment of neutrophils (median of 12 days, range of 5 to 21) and platelets (median of 15 days, range of 9 to 316); 2 patients with subsequent secondary GF achieved successful engraftment after a 3rd HSCT from the same MSD.  After a median follow-up of 57.4 months (range of 11.2 to 155.2), the 5-year OS and failure-free survival were 95.7 % (95 % confidence interval [CI]: 87.7 % to 100 %) and 87.5 % (95 % CI: 75.2 % to 100 %), respectively; 1 patient developed grade II acute GVHD, and the 2-year cumulative incidence of chronic GVHD was 23.5 % (95 % CI: 8.1 % to 43.5 %).  The authors concluded that the findings of this study demonstrated successful outcomes following a 2nd MSD HSCT in SAA after GF, and the results suggested TNI-750/ATG is a feasible re-conditioning option.

Haploidentical Hematopoietic Cell Transplantation for the Treatment of Aplastic Anemia

ElGohary and associates (2020) noted that AA is a serious hematological disorder, which is solely cured by HSCT.  Haploidentical HSCT is an emerging modality with encouraging outcomes in several blood conditions.  These investigators examined the feasibility and safety of haploidentical HSCT in patients with severe and very severe AA.  This was a systematic review and meta-analysis of studies related to haploidentical stem cell transplantation in idiopathic AA investigating rates of successful engraftment, acute GVHD (aGVHD), chronic GVHD (cGVHD), transplant-related mortality (TRM), and post-transplantation viral infections (including cytomegalovirus [CMV]) in patients with AA.  The effects of reduced-intensity conditioning (RIC) and non-myeloablative conditioning (NMA), as well as various GVHD prophylaxis regimens on these outcomes were evaluated.  A total of 15 studies were identified (577 patients, 58.9 % males); successful engraftment was observed in 97.3 % of patients (95 % CI: 95.9 to 98.7) while grades II to IV aGVHD and cGVHD were reported in 26.6 % and 25.0 %, respectively.  The pooled incidence of TRM was 6.7 % per year (95 % CI: 4.0 to 9.4).  RIC regimens were associated with higher proportions of successful engraftment (97.7 % versus 91.7 %, p = 0.03) and aGVHD (29.5 % versus 18.7 %, p = 0.008) when compared with NMA regimens with no differences in cGVHD or mortality incidence.  When compared with methotrexate (MTX)-containing regimens and other regimens, post-transplant cyclophosphamide-containing regimens reduced the rates of aGVHD (28.6 %, 27.8 %, and 12.8 %, respectively, p = 0.02), CMV viremia (55.7 %, 38.6 %, and 10.4 %, respectively, p < 0.001), and CMV disease in initially viremic patients (2.1 %, 33.0 %, and 0 %, respectively, p < 0.001).  The authors concluded that haploidentical HSCT was associated with promising outcomes in terms of successful engraftment and reduced complications.  Moreover, these researchers stated that future prospective trials are needed to identify the preferred conditioning regimen, GVHD prophylaxis, and graft source in the setting of haploidentical transplant for AA.

Prata and colleagues (2020) stated that in the absence of an HLA-matched donor, the best treatment for acquired AA patients refractory to immunosuppression is unclear.  These researchers collected and analyzed data from all acquired AA patients who underwent a haploidentical transplantation with post-transplant cyclophosphamide in Europe from 2011 to 2017 (n = 33).  The cumulative incidence of neutrophil engraftment was 67 % (95 % CI: 51 to 83 %) at D +28 and was unaffected by age group, stem cell source, ATG use, or Baltimore conditioning regimen.  The cumulative incidence of grades II to III acute GVHD was 23 % at D +100, and limited chronic GVHD was 10 % (0 to 20) at 2 years, without cases of grade IV acute or extensive chronic GVHD.  Two-year OS was 78 % (64 to 93 %), and 2-year GVHD-free survival was 63 % (46 to 81 %).  In univariate analysis, the 2-year OS was higher among patients who received the Baltimore conditioning regimen (93 % (81 to 100 %) versus 64 % (41 to 87 %), p = 0.03), whereas age group, stem cell source, and ATG use had no effect.  The authors concluded that these findings using unmanipulated haploidentical transplantation and post-transplant cyclophosphamide for treating refractory AA patients are encouraging, but warrant confirmation in a prospective study with a larger number of patients and longer follow-up.

Furthermore, an UpToDate review on "Hematopoietic cell transplantation for aplastic anemia in adults" (2020) states that "Haploidentical related donor – Evidence is more limited regarding the use of haploidentical related donors in AA (related donors who share one HLA haplotype with the recipient, such as a full or half sibling, parent, or child). However, use of haploidentical donors is increasing and may be appropriate for a patient for whom HCT is indicated and an HLA-matched donor is not available".

Allogeneic Hematopoietic Cell Transplantation for Congenital Dyserythropoietic Anemia

Rangarajan et al (2022) stated that HCT is the sole curative option for congenital dyserythropoietic anemia (CDA), a rare type of hemolytic anemia characterized by anemia, ineffective erythropoiesis, and secondary hemochromatosis.  In a retrospective, multi-center study, these investigators reported the outcomes of children with CDA who underwent HCT at participating Pediatric Transplantation and Cellular Therapy Consortium centers.  Clinical information on HCT and associated outcomes was collected retrospectively using a common questionnaire.  Data were analyzed using descriptive statistics and appropriate analysis.  A total of 18 patients with CDA who underwent allogeneic HCT between 2002 and 2020 were identified.  The majority of patients (n = 13) had CDA type II, and the remainder had either CDA type I (n = 2) or CDA of unknown type (n = 3).  Mutations were identified in 7 patients (39 %), including SEC23B in 5, GATA1 in 1, and abnormality of chromosome 20 in 1; 13 patients had evidence of iron overload pre-HCT and received chelation therapy for a median duration of 10 months (range of 2 months to 17 years) pre-HCT.  The median age at the time of HCT was 5.5 years (range of 0.7 to 26 years).  Donors were HLA-matched (sibling, 4; unrelated, 10) and mismatched (haploidentical, 1; unrelated, 3).  Graft sources were bone marrow in 15 patients, umbilical cord blood in 2 patients, or both in 1 patient.  Conditioning included busulfan-based myeloablative (67 %), fludarabine-based reduced-intensity (27 %), or non-myeloablative (6 %) regimens; 5 patients developed veno-occlusive disease, and 4 had viral reactivation.  The cumulative incidence of acute GVHD was 33 %, and that of chronic GVHD was 22 %; 4 patients (22 %) experienced graft failure; all engrafted following either a 2nd HCT (n = 2) or 3rd HCT (n = 2) but sustained considerable morbidities (3 GVHD, 1 death, 2 viral reactivation).  With a median follow-up of 3.2 years (range of 0.6 to 14 years)), the 2-year OS, event-free survival (EFS), and GVHD-free EFS were 88 % (95 % CI: 73 % to 100 %), 65 % (95 % CI: 45 % to 92 %), and 60 % (95 % CI: 40 % to 88 %), respectively.  Univariate analysis did not identify any patient- or transplantation-related variables impacting outcomes.  The authors concluded that the findings of this study indicated that HCT could be curative for patients with CDA.  Strategies such as aggressive chelation, use of pre-conditioning therapy, and early HCT in the presence of a suitable donor before co-morbidities occur are needed to improve engraftment without increasing the risk for toxicity and mortality.

Furthermore, an UpToDate review on “Overview of causes of anemia in children due to decreased red blood cell production” (Narla and Sandoval, 2022) states that “The congenital dyserythropoietic anemias (CDA) are a rare group of disorders that result in anemia caused by ineffective erythropoiesis and multinuclear erythroblasts.  Treatment may include splenectomy, interferon alfa, and transfusion in symptomatic patients … Hematopoietic cell transplantation (HCT) is a curative therapy for many malignant and nonmalignant hematologic/immunologic disorders.  HCT has been described in 7 patients with CDA.  Four had CDA I, two had CDA II, and, in one case, the CDA type was unknown.  These 7 patients received hematopoietic stem cells from matched sibling donors, and all successfully engrafted and became transfusion-independent”.

Peripheral Blood Stem Cell Transplantation versus Bone Marrow Transplantation for Aplastic Anemia

Zhang et al (2023) noted that HSCT is an effective treatment for AA.  Recently, PBSCT has gradually replaced traditional BMT; however, which graft source exhibits a better therapeutic effect and prognosis for AA remains unclear.  In a systematic review and meta-analysis, these investigators compared PBSCT versus BMT for the treatment of AA   They searched PubMed, Embase, and the Cochrane Library without language limitations for studies using PBSCT or BMT for AA.  Data were analyzed using the Open Meta-Analyst.  These researchers identified 17 of 18,749 studies, including 7 comparative reports and 9 single-arm reports, with a total of 3,516 patients receiving HSCT (1,328 and 2,188 patients received PBSCT and BMT, respectively).  The outcomes of the comparative studies showed similar 5-year OS (relative risk [RR] = 0.867; 95 % CI: 0.747 to 1.006), similar transplant-related mortality (RR = 1.300; 95 % CI: 0.790 to 2.138), graft failure rate (RR = 0.972; 95 % CI: 0.689 to 1.372) between the PBSCT group and the BMT group, while the PBSCT group had a significantly higher incidence of chronic GVHD (RR = 1.796; 95 % CI: 1.571 to 2.053) and a higher incidence of grade-IV acute GVHD (RR = 1.560; 95 % CI: 1.341 to 1.816) compared to the BMT group.  The outcomes of single-arm reports showed similar 3-year OS and incidences of chronic GVHD, acute II to IV GVHD, III to IV GVHD, transplant-related mortality, and graft failure rate between PBSCT and BMT.  The authors concluded that before 2010, PBSCT was not superior to BMT in terms of 5-year OS, transplant-related mortality and graft failure rate; however, it exhibited a higher risk of both chronic and acute GVHD.  After 2010, PBSCT and BMT showed similar 3-year OS, GVHD risks, transplant-related mortality and graft failure rate.  These investigator noted that PB grafts were more suitable for HSCT of the AA for convenience and pain relief.

---

References