Luspatercept for the treatment of congenital sideroblastic anemia: Two case reports

Congenital sideroblastic anemia (CSA) is a group of disorders caused by different genetic mutations that result in low iron utilization and ineffective erythropoiesis. Current treatments are limited, and some patients do not respond to vitamin B6 therapy. Luspatercept is a novel erythropoietic maturation agent approved for adult β-thalassemia and Myelodysplastic syndromes with ring sideroblasts (MDS-RS) associated with ineffective erythropoiesis. Here we report 2 patients with CSA due to mutations in ALAS2 and SLC25A38 genes who became unresponsive after a period of treatment with vitamin B6 and iron chelators but achieved transfusion independence and a markedly reduced spleen after combination with luspatercept.

Thalidomide as an Effective Treatment in Sideroblastic Anemia, Immunodeficiency, Periodic Fevers, and Developmental Delay (SIFD)

PURPOSE

Sideroblastic anemia, immunodeficiency, periodic fevers, and developmental delay (SIFD) is an autosomal recessive syndrome caused by biallelic loss-of-function variant of tRNA nucleotidyl transferase 1 (TRNT1). Efficacious methods to treat SIFD are lacking. We identified two novel mutations in TRNT1 and an efficacious and novel therapy for SIFD.

METHODS

We retrospectively summarized the clinical records of two patients with SIFD from different families and reviewed all published cases of SIFD.

RESULTS

Both patients had periodic fever, developmental delay, rash, microcytic anemia, and B cell lymphopenia with infections. Whole-exome sequencing of patient 1 identified a previously unreported homozygous mutation of TRNT1 (c.706G > A/p.Glu236Lys). He received intravenous immunoglobulin (IVIG) replacement and antibiotics, but died at 1 year of age. Gene testing in patient 2 revealed compound heterozygous mutations (c.907C > G/p.Gln303Glu and c.88A > G/p.Met30Val) in TRNT1, the former of which is a novel mutation. Periodic fever was controlled in the first month after adalimumab therapy and IVIG replacement, but recurred in the second month. Adalimumab was discontinued and replaced with thalidomide, which controlled the periodic fever and normalized inflammatory markers effectively. A retrospective analysis of reported cases revealed 69 patients with SIFD carrying 46 mutations. The male: female ratio was 1: 1, and the mean age of onset was 3.0 months. The most common clinical manifestations in patients with SIFD were microcytic anemia (82.6%), hypogammaglobulinemia/B cell lymphopenia (75.4%), periodic fever (66.7%), and developmental delay (60.0%). In addition to the typical tetralogy, SIFD features several heterogeneous symptoms involving multiple systems. Corticosteroids, immunosuppressants, and anakinra have low efficacy, whereas etanercept suppressed fever and improved anemia in reports. Bone-marrow transplantation can be used to treat severe SIFD, but carries a high risk. In total, 28.2% (20/71) of reported patients died, mainly because of multi-organ failure. Biallelic mutations located in exon1-intron5 lead to more severe phenotypes and higher mortality. Furthermore, 15.5% (11/71) patients survived to adulthood. The symptoms could be resolved spontaneously in five patients.

CONCLUSIONS

Thalidomide can control the inflammation of SIFD and represents a new treatment for SIFD.

A Rare Autoinflammatory Disorder in a Pediatric Patient with Favorable Response to Etanercept: Sideroblastic Anemia with B Cell Immunodeficiency, Periodic Fevers, and Developmental Delay Syndrome

Introduction: Sideroblastic anemia with B cell immunodeficiency, periodic fevers, and developmental delay (SIFD) syndrome is caused by biallelic TRNT1 mutations. TRNT1 gene encodes a CCA-adding tRNA nucleotidyl transferase enzyme. Mutant TRNT1 results in immunodeficiency and anemia in various degrees, accompanied by several organ involvement. Case Presentation: We present here a 15-month old male, demonstrated brittle hair, growth hormone deficiency, recurrent fever, arthritis, recurrent infections, mild anemia, and hypogammaglobulinemia. The patient did not respond to colchicine treatment, and after establishing SIFD diagnosis with the presence of homozygote c.948-949delAAinsGG (p.Lys317Glu) mutation in TRNT1 gene, we commenced monthly intravenous immunoglobulin replacement and weekly subcutaneous etanercept. A rapid resolution of fever episodes and infections occurred after initiation of this treatment regimen. Afterward, both anemia and growth parameters have improved during follow-up. Conclusion: SIFD syndrome should be considered in patients with recurrent fever, arthritis, and growth retardation even in the absence of severe anemia and prominent hypogammaglobulinemia.

PROGNOSIS OF ACUTE LEUKEMIA DEPENDING ON THE IRON METABOLISM PARAMETERS IN CHILDREN AFTER CHORNOBYL NUCLEAR POWER PLANT ACCIDENT

OBJECTIVE

To determine the influence of iron metabolism on the prognosis of acute lymphoblastic (ALL) and (AML)myeloblastic leukemia at the different phases of chemotherapy in children after Chоrnobyl accident.

MATERIALS AND METHODS

333 children (295 - ALL, 38 - AML) were examined at the stages of chemotherapy. Thecomparison group included 93 children without leukemia. Acute leukemia variants, patients survival, relapses, thenature of disease (live child or died), iron methabolism (morphometric parameters of erythrocytes, SI, SF, STf, TS),manifestations of dyserythropoiesis, bone marrow sideroblast and patients radiation dose were taken into account.

RESULTS

In 295 patients with ALL the following variants of leukemia were established: pro-B-ALL in 23, «common»type of ALL in 224, pre-B-ALL in 29, T-ALL in 19. Thirty eight patients were diagnosed with AML (11 - M1, 19 - M2,8 - M4). Doses of radiation in patients with AL were (2.78 ± 0.10) mSv and they did not correlate with clinical andhematological parameters, disease variant. Relapse rates and shorter survival were in patients with T-ALL, pro-B-ALLand AML with SF levels > 500 ng/ml (p < 0.05). The amount of children with normochromic-normocytic anemias andmanifestations of dysplasia of erythroid lineage elements was greater in the AML than in ALL. SF content in patientswas elevated during chemotherapy and was lower than the initial one only in the remission period. Transferrin wasreliably overloaded with iron: TS (70.2 ± 2.3) % compared with the control group (32.7 ± 2.1) %. Correlationbetween TS and survival of patients was detected (rs = -0.45). Direct correlation between the number of iron granules in erythrocariocytes and SF level (rs = 0.43) was established, indicating the phenomena of ineffective erythropoiesis.

CONCLUSIONS

The negative influence of iron excess in the patients body on the hemopoiesis function, manifestations of ineffective erythropoiesis and the course of acute leukemia in children have been established. Changes inferrokinetic processes in children can be the basis of leukemоgenesis development.

Luspatercept in Patients with Lower-Risk Myelodysplastic Syndromes

BACKGROUND

Patients with anemia and lower-risk myelodysplastic syndromes in whom erythropoiesis-stimulating agent therapy is not effective generally become dependent on red-cell transfusions. Luspatercept, a recombinant fusion protein that binds transforming growth factor β superfamily ligands to reduce SMAD2 and SMAD3 signaling, showed promising results in a phase 2 study.

METHODS

In a double-blind, placebo-controlled, phase 3 trial, we randomly assigned patients with very-low-risk, low-risk, or intermediate-risk myelodysplastic syndromes (defined according to the Revised International Prognostic Scoring System) with ring sideroblasts who had been receiving regular red-cell transfusions to receive either luspatercept (at a dose of 1.0 up to 1.75 mg per kilogram of body weight) or placebo, administered subcutaneously every 3 weeks. The primary end point was transfusion independence for 8 weeks or longer during weeks 1 through 24, and the key secondary end point was transfusion independence for 12 weeks or longer, assessed during both weeks 1 through 24 and weeks 1 through 48.

RESULTS

Of the 229 patients enrolled, 153 were randomly assigned to receive luspatercept and 76 to receive placebo; the baseline characteristics of the patients were balanced. Transfusion independence for 8 weeks or longer was observed in 38% of the patients in the luspatercept group, as compared with 13% of those in the placebo group (P<0.001). A higher percentage of patients in the luspatercept group than in the placebo group met the key secondary end point (28% vs. 8% for weeks 1 through 24, and 33% vs. 12% for weeks 1 through 48; P<0.001 for both comparisons). The most common luspatercept-associated adverse events (of any grade) included fatigue, diarrhea, asthenia, nausea, and dizziness. The incidence of adverse events decreased over time.

CONCLUSIONS

Luspatercept reduced the severity of anemia in patients with lower-risk myelodysplastic syndromes with ring sideroblasts who had been receiving regular red-cell transfusions and who had disease that was refractory to or unlikely to respond to erythropoiesis-stimulating agents or who had discontinued such agents owing to an adverse event. (Funded by Celgene and Acceleron Pharma; MEDALIST ClinicalTrials.gov number, NCT02631070; EudraCT number, 2015-003454-41.).

[A microcytic sideroblastic anemia successfully treated with B6 vitamin]

INTRODUCTION

Sideroblastic anemia is a rare cause of microcytic anemia, which is characterized by ring sideroblasts on bone marrow aspirate. This anemia can be congenital or acquired.

CASE REPORT

We report the case of an alcoholic 49-year-old man who presented with a severe microcytic sideroblastic anemia related to pyridoxine (B6 vitamin) deficiency. Acid folic deficiency was associated. The blood count normalized within one month after vitamin supplementation.

CONCLUSION

Pyridoxine deficiency must be sought in sideroblastic anemia in patients at risk.

A Novel ALAS2 Mutation Resulting in Variable Phenotypes and Pyridoxine Response in a Family with X-linked Sideroblastic Anemia

We report a novel ALAS2 gene mutation c.1315A>G (p.Lys439Glu) identified in a family, which caused evidently different hematologic phenotypes. The proband was a 17-year-old man with severe microcytic hypochromic anemia, excessive ring sideroblasts in the bone marrow, and iron overload. A hemizygous ALAS2 mutation in exon 9, c.1315A>G (p.Lys439Glu), was identified through sequence analysis. We assume that this amino acid substitution affects the enzymatic activity of ALAS2 by affecting its interaction with the cofactor pyridoxal 5'-phosphate, since the patient was responsive to pyridoxine treatment. This novel mutation likely accounts for variable hematologic phenotypes in the family of this patient: his 15-year-old hemizygous brother was asymptomatic, while his heterozygous mother was mildly anemic.

Effect of 5-aminolevulinic acid on erythropoiesis: a preclinical in vitro characterization for the treatment of congenital sideroblastic anemia

Congenital sideroblastic anemia (CSA) is a hereditary disorder characterized by microcytic anemia and bone marrow sideroblasts. The most common form of CSA is attributed to mutations in the X-linked gene 5-aminolevulinic acid synthase 2 (ALAS2). ALAS2 is a mitochondrial enzyme, which utilizes glycine and succinyl-CoA to form 5-aminolevulinic acid (ALA), a crucial precursor in heme synthesis. Therefore, ALA supplementation could be an effective therapeutic strategy to restore heme synthesis in CSA caused by ALAS2 defects. In a preclinical study, we examined the effects of ALA in human erythroid cells, including K562 cells and human induced pluripotent stem cell-derived erythroid progenitor (HiDEP) cells. ALA treatment resulted in significant dose-dependent accumulation of heme in the K562 cell line. Concomitantly, the treatment substantially induced erythroid differentiation as assessed using benzidine staining. Quantitative reverse transcription polymerase chain reaction (RT-PCR) analysis confirmed significant upregulation of heme-regulated genes, such as the globin genes [hemoglobin alpha (HBA) and hemoglobin gamma (HBG)] and the heme oxygenase 1 (HMOX1) gene, in K562 cells. Next, to investigate the mechanism by which ALA is transported into erythroid cells, quantitative RT-PCR analysis was performed on previously identified ALA transporters, including solute carrier family 15 (oligopeptide transporter), member (SLC15A) 1, SLC15A2, solute carrier family 36 (proton/amino acid symporter), member (SLC36A1), and solute carrier family 6 (neurotransmitter transporter), member 13 (SLC6A13). Our analysis revealed that SLC36A1 was abundantly expressed in erythroid cells. Thus, gamma-aminobutyric acid (GABA) was added to K562 cells to competitively inhibit SLC36A1-mediated transport. GABA treatment significantly impeded the ALA-mediated increase in the number of hemoglobinized cells as well as the induction of HBG, HBA, and HMOX1. Finally, small-interfering RNA-mediated knockdown of ALAS2 in HiDEP cells considerably decreased the expression of HBA, HBG, and HMOX1, and these expression levels were rescued with ALA treatment. In summary, ALA appears to be transported into erythroid cells mainly by SLC36A1 and is utilized to generate heme. ALA may represent a novel therapeutic option for CSA treatment, particularly for cases harboring ALAS2 mutations.

[Copper deficiency anemia morphologically mimicking myelodysplastic syndrome]

A 64-year-old man underwent kidney transplantation for progressive chronic renal failure which had developed 8 years after allogeneic bone marrow transplantation for acute myeloid leukemia. Because of post-operative complications, he had been placed on intravenous hyperalimentation. Three months after the transplantation, anemia rapidly progressed (hemoglobin, 7.9 g/dl). The proportion of reticulocytes was 0.2%, but white blood cell and platelet counts remained within normal ranges. Serum iron, vitamin B12, and folate levels were normal. Bone marrow examination showed the presence of ringed sideroblasts and cytoplasmic vacuoles in a fraction of erythroid cells. Megakaryocytes were adequate in number with normal morphology. Although the findings were consistent with refractory anemia with ringed sideroblasts according to the WHO classification, cytoplasmic vacuolations were also observed in myeloid cells, suggesting copper deficiency. Indeed, serum copper and ceruloplasmin levels were found to be low (33 μg/dl and 11 mg/dl, respectively), and oral copper supplementation at a daily dose of 1 mg was initiated. There was a prompt increase in reticulocytes, and the hemoglobin level was normalized within one month, in response to this regimen. In progressive anemia cases with ringed sideroblasts in the bone marrow, copper deficiency should be considered in the differential diagnosis.

New mutation in erythroid-specific delta-aminolevulinate synthase as the cause of X-linked sideroblastic anemia responsive to pyridoxine

BACKGROUND/AIMS

Congenital sideroblastic anemias (SA) are characterized by the presence of ringed sideroblasts in the bone marrow. The most common form is X-linked SA, which results from mutations in erythroid-specific δ-aminolevulinate synthase (ALAS2), the first enzyme in heme biosynthesis. In addition, autosomal recessive mutations in the erythroid-specific mitochondrial transporter SLC25A38 and glutaredoxin 5 (GLRX5) have recently been identified in SA patients with isolated erythroid phenotype.

MATERIALS AND METHODS

We studied 5 young males with congenital SA from the Czech Republic. Mutation analysis was performed on the complete coding regions of 3 candidate genes (ALAS2, SLC25A38 and GLRX5), and the enzyme activity of ALAS2 was measured by a continuous spectrophotometric assay.

RESULTS

We found the previously published R452H and R452C ALAS2 mutations in 3 patients. A novel K156E substitution in ALAS2 was discovered in 1 pyridoxine-responsive patient. The functional study showed that this substitution severely decreases ALAS2 enzyme activity. In 1 pyridoxine-refractory patient, no mutations were detected in ALAS2, SLC25A38 or GLRX5.

CONCLUSION

Our report extends the list of known ALAS2 mutations, with the addition of a novel K156E substitution that is responsive to pyridoxine treatment and contributes to the general knowledge of congenital SA cases characterized worldwide.

Refractory anaemia with ringed sideroblasts associated with marked thrombocytosis (RARS-T) with superimposed 5q-syndrome

Refractory anaemia with ringed sideroblasts associated with marked thrombocytosis (RARS-T) is a rare entity belonging to myeloproliferative/myelodysplastic syndromes. Myelodysplastic syndrome (MDS) with isolated del(5q) is a category of MDS characterized by better prognosis and specific morphology. Herein we describe a 69-year-old male with anaemia and thrombocytosis presenting with coexisting features of both these rare diseases. After the description of the clinical data, we summarize the histopathologic, cytogenetic and molecular findings, as well as introduced treatment. Next, we discuss possible diagnostic options with reference to the relevant literature.

Treatment of myelodysplastic syndrome with cyclosporin A

A multicenter prospective study was carried out to evaluate the efficacy of cyclosporin A (CsA) in 32 patients with myelodysplastic syndromes. The FAB subtypes of the patients included refractory anemia, refractory anemia with ringed sideroblasts, and refractory anemia with excess blasts. The dosage of CsA was 3 to 6 mg/kg per day and was adjusted according to the blood concentration of CsA and the responses of patients. The drug was administered twice a day for more than 3 months. After 3 months of treatment, hematological improvement was observed in 18 of 32 patients (56.3%) by the criteria of the International Working Group. At the end of the follow-up (median time, 14 months), 4 patients showed alteration of disease progression, including 1 complete remission and 3 partial remissions, and 16 patients showed hematological improvement. There were a total of 20 responders. The response rate was 62.5% (20/32). It was shown that the CsA therapy was effective in patients with refractory anemia or refractory anemia with excess blasts and both hypo- and hyperplastic bone marrows might respond to the therapy. The survival time was significantly longer in responders than in nonresponders. The study shows that CsA therapy is potentially the most effective therapy for myelodysplastic syndromes.

Risk-based management of myelodysplastic syndrome

Most adult patients with hematopoietic failure due to myelodysplastic syndrome (MDS) are treated with supportive care measures, including hematopoietic growth factors (epoetin alfa, darbepoetin alfa, filgrastim, pegfilgrastim, sargramostim), red blood cell or platelet transfusions, and antimicrobial agents. Allogeneic stem cell transplantation can be curative, but only a small subset of patients are eligible for transplantation, and until recently there were few options other than supportive care for transplant-ineligible patients. Since 2004, the US Food and Drug Administration (FDA) has approved three new therapies specifically for the indication of MDS: two DNA methyltransferase inhibitors (azacitidine and decitabine) and an immunomodulatory agent (lenalidomide). Several other drugs are used by clinicians for treatment of patients with MDS, but are not specifically FDA-approved for this indication. With several therapeutic options available, yet none of them effective in the majority of cases, it can be challenging for clinicians to choose the most appropriate treatment for an individual patient. Here we discuss a risk-based management approach to MDS that incorporates recent data regarding these new therapies. While many questions remain about the optimal use of newer agents, the long-standing perception of MDS as a syndrome where therapeutic nihilism is the only realistic approach is slowly beginning to change.

Mucormycosis in a patient with low risk myelodysplasia treated with anti-TNF-alpha

Accelerated programmed cell death or apoptosis appears to play an important role in the pathogenesis of myelodysplasia. As overexpression of TNF-alpha has been described to induce cell death in myelodysplasia, treatment with anti-TNF-alpha is currently being explored. Caution is needed because of an increased risk of opportunistic infection during anti-TNF-alpha treatment. We here describe a patient who was treated with anti-TNF-alpha for low risk myelodysplasia and died of invasive mucormycosis.

Pregnancy-induced pancytopenia with cellular bone marrow: distinctive hematologic features

Three patients with pregnancy-induced pancytopenia also exhibited variable features of sideroblastic anemia and amegakaryocytic thrombocytopenia. Treatment with anti-thymocyte globulin proved highly effective in two cases and a spontaneous remission occurred in the third. This illness is distinct from the more commonly reported incidental association of pregnancy with classic aplastic anemia. Its differentiation from myelodysplasia is also emphasized.

Antiapoptotic Role of Growth Factors in the Myelodysplastic Syndromes: Concordance BetweenIn vitroandIn vivoObservations

PURPOSE

Erythroid apoptosis in low-risk myelodysplastic syndrome (MDS) maybe mediated via mitochondrial release of cytochrome c and subsequent caspase activation. In the present study, we compared the in vitro and in vivo effects of proerythroid treatment with erythropoietin + granulocyte colony-stimulating factor (G-CSF) on myelodysplastic erythropoiesis regarding apoptosis and preferential growth of clones with cytogenetic abnormalities.

EXPERIMENTAL DESIGN

We enrolled 15 refractory anemia (RA) and 11 refractory anemia with ringed sideroblasts (RARS), including 5q- aberration, monosomy 7, and trisomy 8, before initiation of treatment and followed nine patients after successful treatment. The effects of G-CSF and erythropoietin were assessed. The expression of G-CSF receptor (G-CSFR) was explored during erythroid maturation. The relative growth of erythroid progenitors with cytogenetic aberrations in presence of erythropoietin was investigated.

RESULTS

Significant redistribution of cytochrome c was seen before treatment at all stages of erythroid differentiation. This release was blocked by G-CSF during the whole culture period and by erythropoietin during the latter phase. Both freshly isolated glycophorin A+ bone marrow cells and intermediate erythroblasts during cultivation retained their expression of G-CSFR. Cytochrome c release and caspase activation were significantly less pronounced in progenitors obtained from successfully treated nonanemic patients and showed no further response to G-CSF in vitro. Moreover, erythropoietin significantly promoted growth of cytogenetically normal cells from 5q- patients, whereas no such effect was observed on erythroblasts from monosomy 7 or trisomy 8 patients.

CONCLUSION

We conclude that growth factors such as erythropoietin and G-CSF can act both via inhibition of apoptosis of myelodysplastic erythroid precursors and via selection of cytogenetically normal progenitors.

Cyclosporin A in myelodysplastic syndrome: a preliminary report

Therapeutic approaches are not well established in patients with myelodysplastic syndrome (MDS). We evaluated response to cyclosporin A (CyA) in 19 cases with MDS who were enrolled for the study [13 refractory anemia (RA), 5 refractory anemia with excess of blasts (RAEB), and 1 refractory anemia with ringed sideroblasts (RARS)]. Bone marrow was normocellular in ten, hypercellular in five, and hypocellular in four cases. Fifteen patients were transfusion dependent and the rest were not transfusion dependent but with a hemoglobin range of 6.4-8.8 g% with a mean of 7.4 g%. CyA was given at a dose of 3-5 mg/kg per day. A major response was observed in seven patients with RA, which was sustained on follow-up. Four cases of RA showed minor response and two cases of RA did not respond to CyA therapy. A minor response was also seen in one RAEB and one RARS case, while one RAEB case that initially showed a major response relapsed on therapy. The first effect of therapy was evident after a mean period of 2.5 months. A rise in platelets and leukocyte count was seen in three and two cases, respectively. One case developed renal failure on therapy and later died of septicemia. Response to CyA was independent of bone marrow cellularity. CyA could be an effective mode of therapy in patients with MDS especially those having RA.

Hypochromic red blood cells in low-risk myelodysplastic syndromes: effects of treatment with hemopoietic growth factors

BACKGROUND AND OBJECTIVES

The anemia of low-risk myelodysplastic syndromes (MDS), refractory anemia (RA) and RA with ringed sideroblasts (RARS), may respond to treatment with hematopoietic growth factors (GF)); erythropoietin (Epo) +/- granulocyte colony-stimulating factor (G-CSF). The present study was designed to assess whether functional iron deficiency may develop in MDS patients receiving these treatments.

DESIGN AND METHODS

Erythrocyte scattergrams from 34 patients with RA and RARS (untreated, transfused, or GF-treated with partial or complete erythroid response) were analyzed with Bayer-Advia equipment.

RESULTS

In untreated RARS, the proportion of hypochromic erythrocytes (Hypo-e, median 6.2%, range 1.1-8%) and hypochromic reticulocytes (Hypo-r, median 45%, range 22-48%), as well as mean corpuscular volume (MCV, median 101 fL) were significantly elevated compared to corresponding values in controls. These values increased further after GF-treatment (median 11%, 57%, and 105 fL, respectively), in spite of improved hemoglobin values and adequate body iron stores. The values observed in untreated RA patients largely fell within the normal range, and there was no significant influence of GF treatment. Notably, the hemoglobin content of reticulocytes (MCHr) did not differ between MDS and controls, and was not influenced by GF treatment.

INTERPRETATION AND CONCLUSIONS

The red cell population in RARS shows morphological abnormalities in terms of varying but overall increased size, and reduced hemoglobin concentration. The proportion of abnormal cells increases after successful pro-erythroid GF treatment, indicating that GF promote erythroblast survival, and maturation into erythrocytes. Hence, the finding of hypochromic red cells should not routinely be interpreted as a marker for Epo-induced functional iron deficiency in MDS.

Vitamin-B6-sensible hereditäre sideroblastische Anämie

HISTORY

A 30-year-old patient was admitted for investigation of microcytotic, hypochromic anemia (hemoglobin 8.3 g/dl) with splenomegaly.

INVESTIGATIONS

Bone marrow smear showed a normocellular marrow with augmented severely dysplastic erythropoesis. Prussian-blue staining revealed an increased number of ring sideroblasts, thus myelodysplastic syndrome (refractory anemia with ringsideroblasts) was suspected.

DIAGNOSIS AND TREATMENT

Review of former laboratory values and investigations of the patient's family revealed the correct diagnosis of x-linked sideroblastic anemia (XLSA). The patient was treated with oral pyridoxine. Hemoglobin levels steadily increased, so the diagnosis of pyridoxine-responsive sideroblastic anemia was made. Liver biopsy showed secondary fibrosis with beginning cirrhosis due to iron overload. Therapy with deferoxamine and phlebotomies was initiated.

CONCLUSION

XLSA is a rare differential diagnosis of acquired forms of sideroblastic anemias. A high degree of clinical suspicion is necessary for diagnosis because morphological studies such as histology and cytology may not yield conclusive results. A correct diagnosis is especially important because of the uncomplicated therapeutic options.

A promoter mutation in the erythroid-specific 5-aminolevulinate synthase (ALAS2) gene causes X-linked sideroblastic anemia

X-linked sideroblastic anemia (XLSA) is caused by mutations in the erythroid-specific 5-aminolevulinate synthase gene (ALAS2). XLSA was diagnosed in a 32-year-old woman with a mild phenotype and moderately late onset. Pyridoxine therapy had no effect in the proband, but in her affected son engendered a modest increase in hemoglobin concentration and a 4-fold reduction in ferritin iron. Molecular analysis identified a C to G transversion at nucleotide -206 from the transcription start site, as defined by primer extension, in the proximal promoter region of ALAS2. No other mutations were found in the promoter region, the flanking intronic sequences, the exons, or the 3' genomic region. The same mutation was found in her affected son but not in any other of her unaffected relatives. The mutation resulted in a 94% loss of activity relative to the wild-type sequence for a luciferase reporter construct containing the proximal 293 nucleotides (nt's) of the ALAS2 promoter when transfected into human erythroid K562 cells. Confirming the mutation's deleterious effect, the ALAS2 mRNA level in the proband's erythroid precursors was reduced 87%. The mutation occurred in or near 3 different putative transcription factor binding sites of unknown erythroid importance. The dramatic decreases in reporter activity and mRNA level suggest that the region of the mutation may bind a novel and important erythroid regulatory element.

Late-onset X-linked sideroblastic anemia following hemodialysis

X-linked sideroblastic anemia (XLSA) is due to deficient activity of erythroid-specific 5-aminolevulinate synthase (ALAS2). We report here a patient who developed sideroblastic anemia at the age of 81 years while undergoing hemodialysis. The diagnosis of sideroblastic anemia was established by the presence of ringed sideroblasts in the bone marrow, and treatment with oral pyridoxine completely eliminated the ringed sideroblasts. We identified a novel point mutation in the fifth exon of this patient's ALAS2 gene, which resulted in an amino acid change at residue 159 from aspartic acid to asparagine (Asp159Asn). In vitro analyses of recombinant Asp159Asn ALAS2 revealed that this mutation accounted for the pyridoxine-responsiveness of this disease. The very late onset in this case of XLSA emphasizes that nutritional deficiencies caused either by dietary irregularities in the elderly or, as in this case, by maintenance hemodialysis therapy, may uncover occult inherited enzymatic deficiencies in the heme biosynthetic pathway.

[An older female patient with refractory anemia and hemochromatosis]

CASE HISTORY AND CLINICAL FINDINGS

A 69-year-old woman was admitted because of a normocytic anemia. One year before an acute B19 parvovirus infection had been diagnosed, but the anemia was attributed to intestinal bleeding caused by a dysplastic colonic polyp. However, anemia persisted despite polypectomy. There was an excessive elevation of serum ferritin.

ADDITIONAL EXAMINATIONS

A bone marrow biopsy and aspirate led to the diagnosis of a myelodysplastic syndrome (pure sideroblastic anemia). Ultrasound demonstrated advanced fibrosis of the liver. Fibrosis in association with severe parenchymatous siderosis was also demonstrated by histology. Analysis of the hemochromatosis gene (B-HFE, nt 845, G/A) was negative.

DIAGNOSIS, THERAPY AND CLINICAL COURSE

The patient had secondary hemochromatosis due to a myelodysplastic syndrome. An acute infection with parvovirus B19 had been noted at the time of the first admission, one year before MDS was diagnosed. At that time, hemochromatosis had already caused fibrosis of the liver. However, complete regression of organ siderosis was achieved by deferoxamine administration. The myelodysplastic syndrome itself did not show any progression even 7 years after the diagnosis was established.

CONCLUSION

Our case demonstrates the uncommon association between sideroblastic anemia and secondary hemochromatosis. Acute parvovirus infection may induce severe anemia in myelodysplastic syndromes. In acute B19 parvovirus infections an underlying hematologic disease should be excluded.

Prolonged administration of erythropoietin increases erythroid response rate in myelodysplastic syndromes: a phase II trial in 281 patients

Treatment with recombinant human erythropoietin (rHuEpo) improves anaemia in approximately 20% of patients with myelodysplastic syndromes (MDS). We investigated the potential advantage of a prolonged administration of rHuEpo to achieve higher erythroid response rates (RR) in 281 MDS patients: 118 with refractory anaemia (RA), 77 with refractory anaemia and ringed sideroblasts (RARS), 59 with refractory anaemia with excess of blasts and blast count < 10% (RAEB-I), and 27 with RAEB and blast count between 11-20% (RAEB-II). rHuEpo was given subcutaneously at a dose of 150 U/kg thrice weekly, for a minimum of 26 weeks. Response to treatment was evaluated after 12 and 26 weeks of therapy. The overall RR was 45.1%; the RR for RA, RARS, RAEB-I and RAEB-II were 48.3%, 58.4%, 33.8% and 13% respectively. A significant increase in RR was observed at week 26 in RA, RARS and RAEB-I patients, as the response probability increased with treatment duration. The RR was higher in the good cytogenetic prognostic group and serum Epo level of > 150 U/l at baseline predicted for non-response. The median duration of response was 68 weeks and the overall risk of leukaemic transformation was 21.7%. These results suggest that prolonged administration of rHuEpo produces high and long-lasting erythroid RR in MDS patients with low blast counts, particularly in those with pretreatment serum Epo levels of < 150 U/l and good cytogenetic prognosis.

Erythropoietin-dependent transformation of myelodysplastic syndrome to acute monoblastic leukemia

Acute monoblastic leukemia (acute myeloid leukemia [AML], French-American-British type M5a) with leukemia cutis developed in a patient 6 weeks after the initiation of erythropoietin (EPO) therapy for refractory anemia with ringed sideroblasts. AML disappeared from both marrow and skin after the discontinuation of EPO. Multiparameter flow cytometric analysis of bone marrow cells demonstrated coexpression of the EPO receptor with CD45 and CD13 on the surface of blasts. The incubation of marrow cells with EPO, compared to without, resulted in 1.3- and 1.6-fold increases, respectively, in tritiated thymidine incorporation and bromodeoxyuridine incorporation into CD13(+) cells. Clinical and laboratory findings were consistent with the EPO-dependent transformation of myelodysplastic syndrome (MDS) to AML. It is concluded that leukemic transformation in patients with MDS treated with EPO may be EPO-dependent and that management should consist of the discontinuation of EPO followed by observation, if clinically feasible.

Cytogenetic responses in high-risk myelodysplastic syndrome following low-dose treatment with the DNA methylation inhibitor 5-aza-2'-deoxycytidine

Decitabine (5-aza-2'-deoxycytidine) acts as a powerful demethylating agent in vitro. Clinically, low-dose decitabine ameliorates cytopenias including induction of trilineage responses in approximately 50% of patients with high-risk myelodysplastic syndrome (MDS). We examined the incidence and kinetics of cytogenetic responses to decitabine in these patients. Of 115 successfully karyotyped patients, 61 (53%) had clonal chromosomal abnormalities prior to treatment. Major cytogenetic responses were observed in 19 patients (31% of those with abnormal cytogenetics, 17% of all patients by intention-to-treat) after a median of three courses (range, 2-6) until best cytogenetic response. Progressive decrease of the abnormal clone over time was also determined using fluorescence in situ hybridization (FISH) analysis in two patients. Median duration of cytogenetic responses was 7.5 months (range, 3-15). Analysis of response by the International Prognostic Scoring System (IPSS) cytogenetic risk groups revealed three out of five cytogenetic responses (60%) in the IPSS 'low-risk' group, 6 out of 30 with 'intermediate risk' (20%) and 10 out of 26 in the 'high-risk' group (38%). Median survival in these cytogenetic subgroups was 30, 8 and 13 months respectively. The relative risk of death in patients achieving a major cytogenetic response was 0.38 (95% confidence interval 0.17-0.88) compared with patients in whom the cytogenetically abnormal clone persisted (P = 0.0213). In conclusion, repeated courses of low-dose decitabine induce cytogenetic remissions in a substantial number of elderly MDS patients with pre-existing chromosomal abnormalties; these are associated with improved survival compared with patients in whom the cytogenetically abnormal clone persists. Patients with 'high-risk' chromosomal abnormalities may particularly benefit from this treatment.

Serum leptin levels in patients with sideropenic and pernicious anemia: the influence of anemia treatment

Leptin is a 16 kDa protein hormone involved in food intake, energy expenditure regulation and numerous other physiological processes. Recently, leptin has been demonstrated to stimulate hematopoietic stem cells in vitro. The aim of our study was to measure serum leptin and erythropoietin levels in patients with sideropenic (n = 18) and pernicious anemia (n=7) before and during anemia treatment. Blood samples for the blood count, leptin and erythropoietin determinations were obtained by venepunction at the time of the diagnosis of anemia and after partial and complete anemia recovery. The relationships of serum leptin levels to erythropoietin levels and blood count parameters were also studied. No significant differences in serum leptin levels between the groups studied were found. The serum leptin levels in none of groups were modified by treatment of anemia (basal levels, the levels during treatment and after anemia recovery were 13.1+/-14.5 vs 12.8+/-15.6 vs 12.0+/-14.8 ng/ml in patients with sideropenic anemia and 7.8+/-8.5 vs 9.5+/-10.0 vs 8.9+/-6.6 ng/ml in patients with pernicious anemia). The erythropoietin levels were higher at the time of anemia in both groups and decreased significantly after partial or complete recovery. Serum leptin levels in both groups correlated positively with the body mass index. No significant relationships were found between serum leptin levels and erythropoietin values or various parameters of the peripheral blood count. We conclude that serum leptin levels in patients with sideropenic and pernicious anemia positively correlate with the body mass index but are not influenced by the treatment of anemia.

Granulocyte colony-stimulating factor inhibits Fas-triggered apoptosis in bone marrow cells isolated from patients with refractory anemia with ringed sideroblasts

Treatment with granulocyte colony-stimulating factor (G-CSF) plus erythropoietin may synergistically improve hemoglobin levels and reduce bone marrow apoptosis in patients with refractory anemia with ringed sideroblasts (RARS). Fas-induced caspase activity is increased in RARS bone marrow cells. We showed that G-CSF significantly reduced Fas-mediated caspase-8 and caspase-3-like activity and the degree of nuclear apoptotic changes in bone marrow from nine RARS patients. A decrease in mitochondrial membrane potential and an increase in intracellular reactive oxygen species occurred in Fas-treated cells, but became significant only 24 h after changes in caspase activity and decrease in proliferation. G-CSF also reduced the magnitude of these late apoptotic changes. In CD34-selected normal cells, G-CSF induced myeloid colony growth, and an overall small decrease in the number of erythroid colonies. By contrast, G-CSF induced a 33-263% increase of erythroid colony formation in CD34+ cells from four of five RARS patients with severely reduced erythroid growth, while the normal or slightly reduced erythroid growth of three other patients was not influenced by G-CSF. This study suggests that G-CSF may reduce the pathologically increased caspase activity and concomitant apoptotic changes, and promote erythroid growth and differentiation of stem cells from RARS patients. Our data support the clinical benefit of G-CSF in this subgroup of myelodysplastic syndromes.

Apoptosis in refractory anaemia with ringed sideroblasts is initiated at the stem cell level and associated with increased activation of caspases

Treatment with granulocyte colony-stimulating factor plus erythropoietin may improve haemoglobin levels in patients with ringsideroblastic anaemia (RARS) and reduce bone marrow apoptosis. We studied bone marrow from 10 RARS patients, two of whom were also investigated after successful treatment. Mononuclear, erythroid and CD34+ cells were analysed with regard to proliferation, apoptosis, clonogenic capacity and oncoprotein expression, in the presence or absence of Fas-agonist, Fas-blocking antibody 2 and caspase-3 inhibitor. During culture, RARS bone marrow cells showed higher spontaneous apoptosis (P < 0.05) and caspase activity (P < 0.05)) than bone marrow cells from healthy donors. Eight out of nine patients had reduced growth of erythroid colony-forming units (CFU-E) (< 10% of control) and granulocyte-macrophage CFU (CFU-GM) (< 50% of control) from CD34+ cells. Fas ligation increased apoptosis and decreased colony growth equally in RARS and controls, but caused significantly more caspase activation in RARS (P < 0.01). Fas-blocking antibody showed no significant inhibitory effect on spontaneous apoptosis or ineffective haematopoiesis, as measured using phosphatidylserine exposure, the terminal deoxynucleotide transferase-mediated dUTP-biotin nick-end labelling technique, caspase activity or clonogenic growth. Caspase inhibition reduced apoptosis, increased proliferation and enhanced erythroid colony growth from CD34+ cells in RARS, but showed no effect on normal cells. CFU-E improved > 1000% after successful treatment. Thus, erythroid apoptosis in RARS is initiated at the CD34+ level and growth factor treatment may improve stem cell function. Enhanced caspase activation at the stem cell level, albeit not mediated through endogenous activation of the Fas receptor, contributes to the erythroid apoptosis in RARS.

Familial-skewed X-chromosome inactivation as a predisposing factor for late-onset X-linked sideroblastic anemia in carrier females

X-linked sideroblastic anemia (XLSA) is caused by mutations in the erythroid-specific 5-aminolevulinic acid synthase (ALAS2) gene. An elderly woman who presented with an acquired sideroblastic anemia is studied. Molecular analysis revealed that she was heterozygous for a missense mutation in the ALAS2 gene, but she expressed only the mutated gene in reticulocytes. Her 2 daughters and a granddaughter were heterozygous for this mutation, had normal hemoglobin levels, and expressed the normal ALAS2 gene in reticulocytes. A grandson with a previous diagnosis of thalassemia intermedia was found to be hemizygous for the ALAS2 mutation. Treatment with pyridoxine completely corrected the anemia both in the proband and her grandson. All women who were analyzed in this family showed skewed X-chromosome inactivation in leukocytes, which indicated a hereditary condition associated with unbalanced lyonization. Because the preferentially active X chromosome carried the mutant ALAS2 allele, acquired skewing in the elderly likely worsened the genetic condition and abolished the normal ALAS2 allele expression in the proband. (Blood. 2000;96:4363-4365)

A novel mutation of the erythroid-specific gamma-Aminolevulinate synthase gene in a patient with non-inherited pyridoxine-responsive sideroblastic anemia

A novel missense mutation, G663A, in exon 5 of the erythroid-specific delta-aminolevulinate synthase gene (ALAS2) was identified in a Japanese male with pyridoxine-responsive sideroblastic anemia. Activity of the mutant delta-aminolevulinate synthase protein expressed in vitro was 15.1% compared with the normal control, but was increased up to 34.5% by the addition of pyridoxal 5'-phosphate, consistent with the clinical response of the patient to pyridoxine treatment. The same mutation was also detected in genomic DNa from the oral mucosal membrane of the patiet; however, it was not detected in other family member. These findings suggest that this G663A mutation is responsible for sideroblastic anemia in the proband, and may be an index mutation in this pedigree.

[An infant case of sideroblastic anemia that responded to oral pyridoxine]

An 8-month-old boy was admitted because of paleness. Laboratory studies disclosed microcytic and hypochromic anemia: red blood cell count 156 x 10(4)/microliter, hemoglobin 3.5 g/dl, mean cell volume 66 fl, and reticulocytes 0.5/1000. Serum iron was 433 micrograms/dl and exocrine pancreatic dysfunction was not observed. Examination of bone marrow revealed prominent erythroid hyperplasia; 18% of the erythroblasts were distinct ringed sideroblasts. Electron microscopic studies found intramitochondrial iron deposits in the erythroblasts. The patient was given a diagnosis of sideroblastic anemia and responded to oral pyridoxine (50 mg/day) with an immediate increase of reticulocytes to 97/1000, resulting in an improved hemoglobin concentration. He has maintained remission for more than 1 year following discontinuation of pyridoxine, which was administered for 2 months. Congenital sideroblastic anemia is relatively rare and mostly occurs in males, suggesting an X-linked recessive mode of inheritance. Recently, X-linked sideroblastic anemia has been shown to be caused by missense mutations in the delta-aminolevulinic acid synthase (ALAS) gene. A point mutation in exon 5 of the ALAS gene was found in this patient. Iron-deficiency anemia is the most common hematologic disease of infancy and childhood, resulting from lack of sufficient iron for synthesis of hemoglobin. It is therefore mandatory to differentiate sideroblastic anemia from iron-deficiency anemia and other common anemias.

Dyserythropoietic changes and sideroblastic anemia in patients with hairy cell leukemia before and after therapy with 2-chlorodeoxyadenosine

Active hairy cell leukemia is associated with an increase of RDW (Red Cell Distribution Width) which normalizes after successful therapy with 2-chlorodeoxyadenosine (2-CdA). To clarify this phenomenon, bone marrow films performed before therapy with 2-CdA and after its successful completion were subjected to careful evaluation. Dyserythropoietic changes were present in 5 out of 17 patients before the therapy with 2-CdA. In 2 patients the changes were only slight, characterized by irregularities of the shape of nucleus and nuclear contour, in the remaining 3 patients the changes were marked, represented by nuclear lobulation, karyorrhexis and binuclearity, with the presence of ringed sideroblasts in one of them. After therapy with 2-CdA complete hematologic remission was achieved in 4 patients with disappearance of dyserythropoietic changes and normalization of RDW values. In the last patient with ringed sideroblasts despite complete remission with disappearance of tumoral cells in the bone marrow as demonstrated by immunohistochemical analysis of trephine bone marrow biopsy with monoclonal antibody DBA 44 the condition deteriorated, RDW remained unchanged, the sideroblastic anemia progressed.

R411C mutation of the ALAS2 gene encodes a pyridoxine-responsive enzyme with low activity

A R411C missense mutation of the erythroid-specific delta-aminolaevulinate synthase (ALAS2) gene was identified in a pedigree with X-linked pyridoxine-responsive sideroblastic anaemia (XLSA). The normal and the mutant cDNAs were expressed in E. coli, and the enzyme protein was purified. ALAS activity of the mutant enzyme was 12% and 25%, when incubated in the absence and the presence of pyridoxal 5'-phosphate, respectively, compared with that of the wild-type enzyme. These findings suggest that the R411C mutation accounts for low ALAS activity and a partial pyridoxine-responsiveness of the disease in the patient.

Long-term disappearance of previous chromosomal abnormalities in myelodysplastic syndromes treated with low dose cytosine arabinoside and granulocyte/macrophage-colony stimulating factor

Most therapies for elderly patients with myelodysplastic syndromes offer few short responses and little improvement in survival. We describe two patients who, after several cycles of low dose cytosine arabinoside and GM-CSF, achieved and maintained complete remission and became transfusion independent. Previous chromosomal abnormalities also disappeared and karyotype remains normal.

The molecular biology and pyridoxine responsiveness of X-linked sideroblastic anaemia

Pyridoxine-responsive, X-linked sideroblastic anaemia (XLSA) has been shown to be caused by missense mutations in the erythroid-specific ALA synthase gene, ALAS2. These are scattered widely across the part of the gene encoding the catalytic domain and in half the cases affect residues conserved throughout evolution. Only a loose correlation has been found between the in vitro kinetics and stability of the catalytic activity of the recombinant variant enzymes and the in vivo severity and pyridoxine-responsiveness of the anaemia. Enhanced instability in the absence of pyridoxal phosphate (PLP) or decreased PLP and substrate binding have been noted. A detailed explanation of the anaemia and its response to pyridoxine, however, requires greater insight into the structure-function relationships of this protein than we have at present. Knowledge of its tertiary structure and further knowledge of intracellular factors which impinge on the ability of normal and variant ALAS2 to contribute to haemoglobin production are also required. Mutations in the same gene which affect mitochondrial processing, terminate translation prematurely, or are thought to abolish function altogether cause an XLSA that is refractory to treatment with pyridoxine. A major complication of this disorder is its accompanying increased iron absorption and iron overload which occurs in patients and female heterozygotes. Mutation detection enables the early diagnosis of those affected, targeted education of families, early treatment with pyridoxine and prevention of iron overload. It also allows for a distinction to be made between late-onset variants of this condition and the more insidious refractory anaemia with ring sideroblasts. The next few years of investigation should be illuminating as tools now exist to study all aspects of this protein from the gene to the mitochondrial matrix.

Vitamin B6 responsive sideroblastic anaemia in a patient with tuberculosis

A 39-year-old woman was admitted with fatigue, weight loss, and fever. Nothing, except skin pallor could be found on physical examination. Her haemoglobin (Hb) was 6.3 g/dl. The blood picture showed dimorphic red cell changes and there were dyserythropoiesis and ring sideroblasts in the bone marrow. After detailed investigations, she was diagnosed with tuberculosis, and anaemia was assigned to chronic disease. With anti-tuberculosis therapy (including isoniazid), her Hb and bone marrow findings returned to normal. After cessation of therapy, Hb fell to 8.9 g/dl. Bone marrow examination again showed dyserythropoietic morphologic abnormalities and ring sideroblasts. No reason could be identified to explain the recurrence of anaemia. When we realised that preparations of isoniazid included vitamin B6 to prevent the development of sideroblastic anaemia, we challenged with pyridoxin 200 mg daily. Her Hb rose to 14.6 g/dl. We suggest that in any cases with sideroblastic anaemia, if no cause can be identified, or anaemia persists or recurs despite therapy, pyridoxine therapy should be instituted.

Familial sideroblastic anemia with emergence of monosomy 5 and myelodysplastic syndrome

The case history of two sisters with pyridoxine-refractory familial sideroblastic anemia (FSA) is presented in which one developed a myelodysplastic syndrome (MDS) with monosomy for chromosome 5. Bone marrow examination of both patients at diagnosis showed erythroid hyperplasia with more than 50% ring sideroblasts. Karyotypic analysis initially showed a normal 46, XX karyotype in both of the children. Therapeutic trials with pyridoxine, prednisone, and erythropoietin were unsuccessful. The first patient required regular transfusions and developed a significant hemosiderosis. At the age of 9 years, 7.5 years after the diagnosis of FSA, refractory anemia with excess of blasts (RAEB) was diagnosed. Bone marrow cytogenetic analysis revealed a clone with monosomy for chromosome 5. Her sister's illness was detected at the age of 12 years. She has a more benign course of disease, remains largely transfusion independent and until now shows no signs of myelodysplasia. To our knowledge this is the first observation of a transition of FSA to MDS accompanied by the appearance of a chromosomal abnormality. FSA might be another type of bone marrow failure syndrome, therefore close follow-up of these patients may be necessary.

Growth hormone deficiency and empty sella in DIDMOAD syndrome: an endocrine study

Two girls with DIDMOAD syndrome are presented. One also had severe megaloblastic-sideroblastic anaemia and the other several neurological manifestations. Both were short with defective growth hormone secretion. Computed tomography revealed empty sella in both girls; one had widespread atrophic cortical and cerebellar changes. High doses of thiamine improved the anaemia in the first case, increased C peptide secretion in both, but had no effect on the neurological abnormalities.

[Yersinia enterocolitica septicemia, iron overload and deferoxamine]

Infections due to Yersinia enterocolitica are usually limited to the bowel. When infection is generalized, the role of iron overload and iron chelation has been discussed. We report the case of a 55 year-old patient with sideroblastic anemia who received repetitive transfusions and deferoxamine for 4 years and heme arginate for 2 months, and who was admitted in our institution for Yersinia enterocolitica sepsis. Treatment by third-generation cephalosporins and aminoglycosides has allowed favorable outcome.