Unusual complications after bone marrow transplantation for dyskeratosis congenita

Dyskeratosis congenita (DC) is a rare inherited disorder often associated with aplastic anaemia. We report the cases of five boys transplanted with an HLA-identical related donor for severe aplastic anaemia (SAA) associated to DC; in all cases successful engraftment was observed. Three patients died 2–8 years after bone marrow transplantation (BMT) with signs of endothelial cell damage syndrome (kidney microangiopathy and liver veno-occlusive disease). Another boy died 1 year after BMT from Evans syndrome and invasive aspergillosis. One boy currently presents anaemia, polyarthritis of unknown origin, pulmonary fibrosis and gut malabsorption 7.5 years after BMT. SAA associated with DC can be successfully treated by allogeneic BMT. However, these early and late complications observed are very unusual after BMT and probably reflect the association of transplanted-related factors, evolution of the underlying disease, and increased sensitivity of endothelial cells. Modified conditioning approaches, advances in supportive care and surveillance of these unusual complications offer the possibility of improved outcome for these patients.     

Allogeneic bone marrow transplantation for severe aplastic anaemia-the London experience

Using the Seattle protocol with minor modifications, 23 patients with severe aplastic anaemia received allogeneic bone marrow transplants from HLA/ mixed leucocyte culture matched sibs in three London centres between 1973 and 1977. Ten patients (43.5%) are alive 6 months to 5 years after transplantation, and are well with full haemopoietic reconstitution, two with autologous bone marrow recovery following the graft procedure. A failure of the marrow graft to take, or take followed by rejection occurred in 12 patients (52%). Failure of marrow recovery was associated with a high early mortality from bacterial or fungal infection. The only survivors amongst those who rejected the first graft were four patients in whom a subsequent graft from the same donor was successful, and two in whom autologous recovery occurred. Graft versus host disease (GVHD) occurred in seven patients, and was fatal in one case. The most frequent complication after successful engraftment was varicella-zoster infection which occurred in five patients and was fatal in one patient. The overall results compare favourably with those from other transplant centres, but the high rate of graft rejection and low incidence of GVHD differ from other series. The results should encourage further referral of patients with severe AA for bone marrow transplantation.     

Identification of DKC1 gene mutations in Japanese patients with X-linked dyskeratosis congenita

Dyskeratosis congenita (DC) is a rare inherited multisystem disorder characterized by the triad of abnormal skin pigmentation, nail dystrophy and mucosal leucoplakia. X-linked recessive inheritances are recognized in approximately 40% of the patients. DKC1 has been identified as the gene responsible for X-linked DC, and genetic analyses have been performed in a worldwide study. Here, we performed genetic analysis of five Japanese patients with presumed X-linked DC, and identified four mutations in the DKC1 gene, including two novel missense mutations (Q31K and T357A). Such genetic analysis is useful for the definite diagnosis and genetic counselling of patients.     

Success of allogeneic marrow transplantation for children with severe aplastic anaemia

Allogeneic marrow transplantation offers curative therapy for children with severe aplastic anaemia (SAA). We report the outcomes of 148 children with SAA who received human leucocyte antigen (HLA)-matched related marrow grafts between 1971 and 2010. Patients were divided into three groups, reflecting changes in conditioning and graft-versus-host disease (GVHD) prophylaxis regimens that occurred over time. Patients in Group 1 were conditioned with cyclophosphamide (CY; 200 mg/kg) followed by 'long' (102 d) methotrexate (MTX). Patients in Groups 2 and 3 received CY alone (Group 2) or combined with anti-thymocyte globulin (Group 3) followed by 'short' (days 1, 3, 6, and 11) MTX and ciclosporin (until day 180). With a median follow-up of 25 years, the 5-year survivals were 66%, 95%, and 100% for Groups 1, 2, and 3, respectively (overall P < 0·0001). The 3-year estimates of graft rejection were 22%, 32%, and 7%, respectively. The probabilities of grades III-IV acute and 2-year chronic GVHD were 15%, 0%, and 3%, and 21%, 21%, and 10%, respectively. Advances in preparative and GVHD prophylaxis regimens, and supportive care during the past 40 years have led to improved outcomes for children with SAA. These results confirm the use of allogeneic marrow transplantation for children with SAA who have HLA-matched related donors.     

Advances in the understanding of dyskeratosis congenita

Dyskeratosis congenita (DC) is a rare inherited syndrome exhibiting marked clinical and genetic heterogeneity. It is characterised by mucocutaneous abnormalities, bone marrow failure and a predisposition to cancer. Bone marrow failure is the principal cause of premature mortality. Studies over the last 10 years have demonstrated that DC is principally a disease of defective telomere maintenance. All DC patients have very short telomeres and the genetically characterised cases of DC have mutations in six genes which either encode components of the telomerase complex ( DKC1 , TERC , TERT , NOP10 , NHP2 ) or shelterin ( TINF2 ); these are important in the elongation and protection of the telomeric end, respectively. These advances have led to the recognition of cryptic forms of DC, such as presentations with aplastic anaemia and myelodysplasia. They have also increased our understanding of normal haematopoiesis and provided new insights to the aetiology of some cases of aplastic anaemia and related haematological disorders.     

Correction of stromal cell defect after bone marrow transplantation in aplastic anaemia

Defects in stromal cell function have been demonstrated in a number of aplastic anaemia (AA) patients. Here we have studied a patient with severe AA and abnormal stromal cell function who underwent bone marrow transplantation (BMT). The objective of this study was to investigate the timing and the mechanism of correction of the stromal defect after transplantation. The patient, a 25-year-old woman with severe AA, underwent BMT from her brother. BM was obtained from the patient on five occasions: 2 weeks pre BMT, and 3, 8, 16 and 21 months post BMT. Stromal cells were grown to confluence and recharged with purified CD34+ cells from normal donors. The support of such cells, as assessed by weekly colony-forming assay (CFU) of non-adherent cells, was compared with that of stromal layers grown from normal BM. A novel technique of combined fluorescence in situ hybridization (FISH) and immunocytochemistry was used to determine the origin of specific stromal cell types on cytospins of stroma post BMT. Stromal function was defective at 2 weeks pre BMT and at 3 months post BMT, but returned to normal at 8 and 16 months post BMT. At 21 months post BMT, stromal fibroblasts and endothelial cells were shown to be of recipient origin, and macrophages and T cells were of donor origin. We present here evidence in a case of severe AA for defective stromal function before BMT and delayed normalization of function after BMT. This correlated with engraftment of donor macrophages and T cells, but not fibroblasts and endothelial cells.     

Treatment of dyskeratosis congenita with Granulocyte Colony-Stimulating Factor and Erythropoietin

Aplastic anaemia is both frequent and difficult to manage in patients with dyskeratosis congenita (DC). We recently treated a 23-year-old male for a year with granulocyte colony-stimulating factor (G-CSF) and erythropoietin (Ep), with an excellent neutrophil response, and a transient effect on haemoglobin levels. G-CSF alone or combined with other cytokines may provide at least a partial effect in pancytopenic patients with DC.     

Immunological recovery after bone marrow transplantation for severe aplastic anaemia: A Brazilian experience

Abstract: Twenty-nine patients with severe aplastic anaemia (SAA) were submitted to bone marrow transplantation (BMT) and their immunological recovery analysed. Total lymphocyte counts, estimation of B lymphocytes, T lymphocytes and their subsets, natural-killer (NK) activity were performed. Cells with the CD8 + phenotype and NK activity were the first signs of immunological recovery, whereas the CD4 + subset recovered later in patients who suffered from acute graft versus host disease (GvHD) and infections. Acute and chronic GvHD, cirrhosis, rejection and HIV viral infection contributed to the persistence of the profound immunodeficiency status observed after BMT. Our results did not differ greatly from the others and confirmed that BMT may be performed in underdeveloped countries despite the difficulties it might pose.     

Bone marrow transplantation for severe aplastic anaemia a review of the Westminster experience of 24 cases

Summary Twenty-four patients have received bone marrow transplantation for severe aplastic anaemia at the Westminster Hospitals since 1974. Twelve patients are long term survivors. Infectious complications in association with graft rejection, graft versus host disease or prolonged neutropenia were the major cause of death. In the last 18 months the introduction of more effective conditioning regimes and Cyclosporin A as graft versus host disease prophylaxis has improved the survival rate to 85%. One patient has required regrafting for late graft failure without evidence of graft rejection.     

Unexplained aplastic anaemia, immunodeficiency, and cerebellar hypoplasia (Hoyeraal-Hreidarsson syndrome) due to mutations in the dyskeratosis congenita gene, DKC1

Hoyeraal-Hreidarsson (HH) syndrome is a multisystem disorder affecting boys characterized by aplastic anaemia (AA), immunodeficiency, microcephaly, cerebellar-hypoplasia and growth retardation. Its pathogenesis is unknown. X-linked dyskeratosis congenita (DC) is an inherited bone-marrow-failure syndrome characterized by skin pigmentation, nail dystrophy and leucoplakia which usually develop towards the end of the first decade of life. AA occurs in >90% of cases of DC. We speculated that mutations in the gene responsible for X-linked DC (DKC1) may account for the HH syndrome, due to the phenotypic similarities between the disease in respect of AA and gender bias. We therefore analysed the DKC1 gene in two HH families. In one family a nucleotide change at position 361(A --> G) in exon 5 was found in both affected brothers; in the other family a nucleotide change at position 146(C --> T) in exon 3 was found in the affected boys. The finding of these two novel missense DKC1 mutations demonstrates that HH is a severe variant of DC. They also show that mutations in DKC1 can give rise to a very wide clinical spectrum of manifestations. Boys with unexplained AA or immunodeficiency should be tested for mutations in DKC1 even though they may lack diagnostic features of DC.     

Telomere length is associated with disease severity and declines with age in dyskeratosis congenita

Background

Dyskeratosis congenita is a cancer-prone bone marrow failure syndrome caused by aberrations in telomere biology.

Design and Methods

We studied 65 patients with dyskeratosis congenita and 127 unaffected relatives. Telomere length was measured by automated multicolor flow fluorescence in situ hybridization in peripheral blood leukocyte subsets. We age-adjusted telomere length using Z-scores (standard deviations from the mean for age).

Results

We confirmed that telomere lengths below the first percentile for age are very sensitive and specific for the diagnosis of dyskeratosis congenita. We provide evidence that lymphocytes alone and not granulocytes may suffice for clinical screening, while lymphocyte subsets may be required for challenging cases, including identification of silent carriers. We show for the first time using flow fluorescence in situ hybridization that the shortest telomeres are associated with severe variants (Hoyeraal-Hreidarsson and Revesz syndromes), mutations in DKC1, TINF2, or unknown genes, and moderate or severe aplastic anemia. In the first longitudinal follow up of dyskeratosis congenita patients, we demonstrate that telomere lengths decline with age, in contrast to the apparent stable telomere length observed in cross-sectional data.

Conclusions

Telomere length by flow fluorescence in situ hybridization is an important diagnostic test for dyskeratosis congenita; age-adjusted values provide a quantitative measure of disease severity (clinical subset, mutated gene, and degree of bone marrow failure). Patients with dyskeratosis congenita have accelerated telomere shortening. This study is registered at www.clinicaltrials.gov (identifier: {"type":"clinical-trial","attrs":{"text":"NCT00027274","term_id":"NCT00027274"}}NCT00027274).     

Dyskeratosis congenita: its link to telomerase and aplastic anaemia

Dyskeratosis congenita (DC) is an inherited bone marrow failure syndrome exhibiting considerable clinical and genetic heterogeneity. X-linked recessive, autosomal dominant and autosomal recessive forms are recognised. The gene mutated in X-linked DC (DKC1) encodes a highly conserved nucleolar protein called dyskerin. Dyskerin associates with the H/ACA class of small nucleolar RNAs which are important in guiding the conversion of uracil to pseudouracil in ribosomal RNA. Dyskerin also associates with the RNA component of telomerase (hTR) which is important in the maintenance of telomeres. Mutations in hTR were recently demonstrated in patients with autosomal dominant DC and in a subset of patients with aplastic anaemia (AA) but without other diagnostic features of DC. This discovery demonstrates that both DC and a subset of AA are due to a defect in telomerase. The link between DC and AA and in turn to defective telomerase suggests that treatments directed at correction of telomerase activity might benefit DC/AA patients who do not respond to conventional therapy.     

Unrelated donor bone marrow transplantation for children and adolescents with aplastic anaemia or myelodysplasia

Allogeneic transplantation from an HLA-matched family member has been shown to be effective in reconstituting normal haemopoiesis in young people with severe cytopenias, classified as myelodysplastic syndrome (MDS) or severe aplastic anaemia (SAA). Unrelated donor transplant is a therapeutic choice for patients without a suitable family member donor. We report the outcome of seven patients < 20 years old with SAA and 10 with MDS treated with BMT from an HLA A,B DRB1 matched ( n  =8) or A or B locus mismatched ( n  =9) unrelated donor at the University of Minnesota between March 1988 and August 1995. Primary graft failure occurred in two patients and secondary graft failure in one, who was subsequently successfully engrafted with a second donor marrow infusion. Grades II–IV GVHD occurred in 10/16 (63%), and grades III–IV in 6/16 (37%) evaluable patients. Nine of the 17 patients (six with MDS and three with SAA) survive with full donor chimaerism, a median of 1.2 years post-BMT (range 3 months to 7 years). We recommend early referral for consideration of unrelated donor BMT for young patients with MDS, and patients with SAA without response to immunosuppression.     

A patient with X‐linked dyskeratosis congenita presenting with bronchiolitis obliterans requiring lung transplantation and immunodeficiency

Dyskeratosis congenita (DKC) is a syndrome characterized by immunodeficiency, bone marrow (BM) failure, somatic abnormalities, and predisposition to malignancy, resulting from mutations in proteins involved in maintenance of telomeres. Pulmonary fibrosis resulting in respiratory failure is a serious complication affecting approximately 20% of DKC patients. Pediatric pulmonologists should consider this diagnosis in patients with lung fibrosis and concurrent immunodeficiency or BM failure. Pediatr Pulmonol. 2013; 48:91–93. © 2012 Wiley Periodicals, Inc.     

Marrow transplantation for pancytopenia in dyskeratosis congenita

Summary A 33-year-old man with dyskeratosis congenita received a marrow transplant to treat severe pancytopenia. The graft was successful, but the patient developed severe acute graft-versus-host-disease grade IV and died 51 days post-grafting. — The outcome of transplantation in dyskeratosis congenita is compared to that in Fanconi's anaemia due to the resemblance of both diseases in some aspects.     

A successful pregnancy after bone marrow transplantation for severe aplastic anaemia with pre-transplant conditioning of total lymph-node irradiation and cyclophosphamide

Summary. Pregnancy after bone marrow transplantation (BMT) for severe aplastic anaemia (SAA) is now an encouraging reality. We present a successful pregnancy, 4 years after BMT for SAA, in a woman being immunosuppressed before transplantation with cyclophosphamide and total lymphnode irradiation (TLI). No fetal complication was diagnosed.     

Long-term outcome of acquired aplastic anaemia in children: comparison between immunosuppressive therapy and bone marrow transplantation

A total of 100 children under the age of 17 years with acquired aplastic anaemia (AA) were initially treated with immunosuppressive therapy (IST) (n = 63) or bone marrow transplantation (BMT) (n = 37) from an HLA-matched family donor. The projected 10-year survival rates were 55 +/- 8% and 97 +/- 3% respectively (P = 0.004). Because the IST group included 11 non-responders who were salvaged by BMT from an HLA-matched unrelated donor, we compared failure-free survival (FFS) between the groups. The probability of FFS at 10 years was 97 +/- 3% for the BMT group, compared with 40 +/- 8% for the IST group (P = 0.0001). Seven patients evolved to myelodysplastic syndrome (MDS) with monosomy 7 and the estimated cumulative incidence of MDS 10 years after diagnosis was 20 +/- 7% in the IST group. We compared the outcome of children treated with IST during the two consecutive periods of 1983-91 (group A, n = 40) and 1991-8 (group B, n = 23) to assess the impact of combined therapy with antithymocyte globulin and cyclosporin. The probability of FFS at 7 years follow-up was the same in the two groups (50 +/- 8% vs. 40 +/- 15%, P = 0.40). We recommend BMT as first-line therapy in paediatric severe AA patients with an HLA-matched family donor. Alternative donor BMT is recommended as salvage therapy in patients who relapse or do not respond to initial IST.     

Recombinant human erythropoietin for the treatment of the anaemia associated with autologous bone marrow transplantation

Summary. Patients with solid tumours undergoing highdose chemotherapy with autologous bone marrow transplantation use an average of 10 units of packed red blood cells (PRBC) while awaiting haemopoietic reconstitution. They are also known to have inappropriately low endogenous erythropoietin levels for their degree of anaemia. This pilot study was designed to determine the effects of recombinant human erythropoietin (rHuEPO) on erythroid recovery and PRBC transfusion requirements. Ten patients received high-dose chemotherapy (days - 7 to -3), bone marrow reinfusion (day 0), and then rHuEPO (day 1 onward). RHuEPO (200 units/kg intravenous bolus daily), along with iron supplementation, was administered for 28 d or until a haematocrit (Hct) of 35% (independent of transfusions) was reached, whichever occurred first. PRBCs were routinely given for Hct 25% and platelets for counts < 20000/μl. Eight (80%) patients developed a brisk reticulocytosis (median peak reticulocyte count 0.32 × 10⁹/l) and a haematocrit 30% independent of red blood cell transfusions within 32 d of receiving marrow, as compared to 20/37 (54%) similarly treated controls. An unexpected finding was the more rapid engraftment in myeloid and platelet lineages in a subset of rHuEPO-treated patients. Quick return of red blood cells (17 v 33d) (P = 0.0001), platelets (14 v 19d) (P = 0.04), and neutrophils (13 v 25d) (P = 0.01) (with circulating myeloblasts and early myeloid forms) characterized recovery from an ifosfamide-based intensification with rHuEPO support. Similar trilineage enhancement of haemopoiesis did not occur with the possibly more myeloablative cyclophosphamide-based regimens. Despite the enhancement by rHuEPO on reticulocytosis, there was no significant decrease in PRBC transfusion requirements. RHuEPO proved to be a well-tolerated agent in enhancing reticulocytosis following high-dose chemotherapy. further study to elucidate the activity of erythropoietin on both erythroid and non-erythroid growth and maturation appears warranted.