Refractory Sideroblastic Anemia Research Articles

MDS-516 A Rare Case of X-Linked Recessive Sideroblastic Anemia (XLSA) Masquerading as Myelodysplastic Syndrome-Refractory Anemia With Ringed Sideroblasts (MDS - RARS)

XLSA may be confused clinically with MDS-RARS, which can have patient management implications. Sideroblastic anemia is categorized as a rare type of anemia by National Organization for Rare Disorders. Fewer than 200 cases with less than 100 unrelated probands have been described for X-linked recessive sideroblastic anemia (XLSA). XLSA is the most common type of non-syndromic congenital sideroblastic anemias (CSA), with almost 40% of all CSA cases involving mutations in the ALAS2 (δ- aminolaevulinic acid synthase) gene. Male patients (two-thirds of known cases) usually present in childhood or adolescence with symptoms of anemia, while female patients present in middle age. We present a case of XLSA in a male patient with symptom-onset in middle age. He initially presented with symptoms of anemia and received multiple blood transfusions over a period of 10 years. Subsequent bone marrow biopsy showed a hypercellular bone marrow with erythroid hyperplasia, increased iron and ringed sideroblasts consistent with refractory anemia with ringed sideroblasts, no abnormal karyotype in cytogenetics, and normal flow cytometry results. A liver biopsy showed hemosiderotic changes, and he was initially considered to have myelodysplastic syndrome-refractory anemia with ringed sideroblasts (MDS-RARS). Genetic testing, including SF3B1 gene mutation, revealed no findings suggestive of MDS. The patient was then started on iron chelating agents and pyridoxine with improvement in anemia and did not require any further transfusions with significant improvement in his symptoms. A hereditary anemia NGS gene sequencing and deletion/duplication panel was then done which showed pathogenic X-linked recessive hemizygous mutation involving ALAS2 gene-OMIM 301300. Response to the pyridoxine treatment, absence of SF3B1 gene mutation, and presence of ALAS2 gene mutation helped confirm the diagnosis of XLSA in our patient. This case report highlights the necessity for extensive workup in patients with sideroblastic anemia, given the rarity of XLSA and similarity in its clinical symptoms to MDS-RARS, and the need for its early diagnosis. In our patient, iron overload and subsequent liver cirrhosis developed due to multiple transfusions for refractory sideroblastic anemia which was treated as MDS-RARS and could have been avoided if XLSA had been suspected earlier in the course of the disease.

Development and characterization of cell models harbouring mtDNA deletions for in vitro study of Pearson syndrome.

ABSTRACTPearson syndrome is a rare multisystem disease caused by single large-scale mitochondrial DNA deletions (SLSMDs). The syndrome presents early in infancy and is mainly characterised by refractory sideroblastic anaemia. Prognosis is poor and treatment is supportive, thus the development of new models for the study of Pearson syndrome and new therapy strategies is essential. In this work, we report three different cell models carrying an SLMSD: fibroblasts, transmitochondrial cybrids and induced pluripotent stem cells (iPSCs). All studied models exhibited an aberrant mitochondrial ultrastructure and defective oxidative phosphorylation system function, showing a decrease in different parameters, such as mitochondrial ATP, respiratory complex IV activity and quantity or oxygen consumption. Despite this, iPSCs harbouring ‘common deletion’ were able to differentiate into three germ layers. Additionally, cybrid clones only showed mitochondrial dysfunction when heteroplasmy level reached 70%. Some differences observed among models may depend on their metabolic profile; therefore, we consider that these three models are useful for the in vitro study of Pearson syndrome, as well as for testing new specific therapies. This article has an associated First Person interview with the first author of the paper.

A Rare Case of Pearson's Syndrome with Predominant Hematological Manifestations and Novel Mitochondrial Deletion

Summary- Pearson's syndrome is a very rare cause of transfusion dependent anemia in infants with presence of pancreatic exocrine deficiency and other systemic abnormalities. We present a case of Pearson syndrome in an infant with primary hematological manifestations and a novel mitochondrial deletion.Introduction- Pearson syndrome is a very rare cause of refractory transfusion dependent childhood anemia caused by mitochondrial DNA defects resulting in refractory sideroblastic anaemia, vacuolization of bone marrow precursors, exocrine pancreatic dysfunction and other metabolic defectsMaterial and Methods- A 6 month old infant presented with complaints of progressive pallor since one month, failure to thrive and fast breathing for 2 days. On examination he had severe anaemia with signs of congestive cardiac failure and hepatomegaly.Results- Peripheral smear findings revealed macrocytic anaemia with mild thrombocytopenia. Bone marrow aspirate revealed a cellular marrow with mild erythroid hyperplasia and characteristic cytoplasmic vacuolations in myeloid and occasional erythroid precursors. There were about 30% ring sideroblasts observed on perl's stain. In view of suspicion of Pearson's syndrome, baby was further investigated which revealed high serum lactate levels (35mg/dl). However, fecal fat excretion was normal. Mitochondrial DNA analysis revealed a point mutation in NADH dehydrogenase 3 (ND3 region) of mt DNA as opposed to large mtDNA deletions observed in previously reported cases of Pearson's syndrome.Discussion- Sideroblastic anemia presenting in infancy is an uncommon cause of anemia often requiring multiple transfusions. Pearson's syndrome is a rare cause of sideroblastic anaemia, it presents in infancy, carrying a grave prognosis and requires high index of suspicion. Clinical picture is highly variable due to Mitochondrial DNA heteroplasmia. Mitochondrial DNA deletion/duplication studies carry a confirmative value. Pyridoxine was not very effective and child required repeated transfusions. This case is presented for its rarity, hematological features and associated novel mitochondrial mutation. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Index of Suspicion

The reader is encouraged to write possible diagnoses for each case before turning to the discussion. We invite readers to contribute case presentations and discussions. Please inquire first by contacting Dr. Deepak Kamat at DKamat@med.wayne.edu. An 18-year-old male with a 3-year history of alcohol abuse is referred from a rehabilitation center for fever, nausea, and nonbloody diarrhea for 3 days. Six weeks ago, he enrolled in an alcohol rehabilitation program and stopped drinking alcohol. Three weeks later, he noticed yellowing of his eyes and skin, difficulty sleeping, and dyspnea. On examination, his temperature is 100.6°F (38.1°C), blood pressure is 99/62 mm Hg, pulse is 124 beats per minute, and respiratory rate is 24 breaths per minute. He is slow to answer questions. There is no asterixis. He appears thin and jaundiced with enlarged parotid glands. Decreased breath sounds are noted on the right. A tender, enlarged liver and mild abdominal distension are noted. Trace bilateral lower-extremity edema is present. No stigmata of chronic liver disease are found. Laboratory findings reveal the following: white blood cell count, 25,600/μL (25.6 × 109/L) (87% neutrophils); hemoglobin, 8.2 g/dL (82 g/L); mean corpuscular volume, 106 fL; platelets, 40 × 103/μL (40 × 109/L); sodium, 135 mEq/L (135 mmol/L); potassium, 3.5 mEq/L (3.5 mmol/L); chloride, 106 mEq/L (106 mmol/L); bicarbonate, 15 mEq/L (15 mmol/L); blood urea nitrogen, 24 mg/dL (8.6 mmol/L); creatinine, 1.01 mg/dL (89 μmol/L); glucose, 118 mg/dL (6.6 mmol/L); alkaline phosphatase, 182 U/L; aspartate aminotransferase (AST), 194 U/L; alanine aminotransferase (ALT), 71 U/L; total bilirubin, 11.8 mg/dL (201.8 μmol/L); direct bilirubin, 7.3 mg/dL (124.9 μmol/L); albumin, 2.7 g/dL (27 g/L); prothrombin time, 19.2 seconds; and international normalized ratio, 1.4. Ethanol and acetaminophen were not detected in the serum. A chest radiograph reveals a right pleural effusion …

Clinical and Biological Characterization of Patients with Low/Intermediate-1 Risk Myelodysplastic Syndrome and Iron Overload

AbstractAbstract 4956 Introduction.Patients with Myelodysplastic Syndrome (MDS) are susceptible to developing iron overload as a response to the red blood cell (RBC) transfusions and ineffective hematopoiesis. This iron overload (IOL) is characterized by an increase in oxygen-reactive species accompanied by a decrease in antioxidants, and results in hepatic, cardiac and endocrine disorders, as well as an increased risk of infection. Ineffective hematopoiesis promotes iron absorption at intestinal level. This process is enhanced by the presence of mutations in the hereditary hemochromatosis gene (HFE). This study aims to define the features that accompany patients with iron overload, comparing them to a MDS population at diagnosis. Patients and methods.34 low/int-1 MDS patients (International Prognostic Score System, IPSS) were assessed, 22 of them at diagnosis and 12 patients when IOL was developed. Peripheral blood samples were drawn after informed consent was obtained from the patient or the patient′s guardians in accordance with the Declaration of Helsinki. The analyzed parameters were: WHO classification, sex, age, blood count, number of RBC units received, iron metabolism, and mutations of the HFE gene. Liver damage was estimated by measuring Alanine transaminase (ALT) levels, and liver iron concentration (LIC) detected by Magnetic Resonance (MR). Likewise, levels of labile plasmatic iron (LPI) (eLPI Assay Kit, Aferrix) were quantified by spectrofluorimetric determination. Oxidative damage was assessed by quantifying the modified base 8-oxo-2-hydroxi-deoxiguanosine (8-oxo-dG) by means of High-Performance Liquid Chromatography (HPLC) and the O2− anion levels by flow cytometry. Results.According to the WHO classification, 72. 2% of cases with MDS and IOL assessed belonged to Refractory Sideroblastic Anemia (RSA) group, unlike 27. 3% of patients at diagnosis (p=0. 0265). In comparison to diagnosis patients, IOL subjects presented lower mean age (76 vs. 81 years; p=0. 0172), hemoglobin levels (7. 5 ± 0. 4 vs. 10. 3 ± 0. 3 g/dl; p<0. 0001), and red blood cell count (2. 3 ± 0. 1 vs. 3. 0 ± 0. 1×109/l; p<0. 0001). Moreover, higher levels of ferritin (median 1147 vs. 219 μg/dl; p<0. 0001), Transferrin Saturation Index (TSI) (median 89. 4 vs. 31. 5%; p<0. 0001) and ALT (median 14. 9 vs. 11. 0 U/l; p=0. 0263) were observed when compared to the diagnosis patients. On the other hand, among IOL patients the average levels for LIC were 13. 8 ± 2. 0 mg Fe/g (normal levels <4. 0 mg Fe/g), and higher LPI concentrations were detected (median 1. 2 vs. 0. 1 U; p<0. 0001). These patients received an average of 28 ± 9 RBC units. Interestingly, two of the patients developed IOL without previously having received any transfusions; both of whom were diagnosed with RSA, having the H63D mutation of the HFE gene. Regarding the oxidative damage, in patients with IOL a significant increase of 8-oxo-dG (p=0. 0040) and O2− anions (p=0. 0157) was observed. Conclusions.1.Patients with IOL show alterations in their hematological and iron metabolism parameters, liver damage and high LPI levels.2.IOL is associated with increased oxidative damage at DNA level and production of superoxide radicals.3.There are cases of IOL patients who are not transfusion dependent, where the presence of RSA and HFE gene mutations plays a determining role.4.Patients with IOL can benefit from effective chelation therapy that reduces the harmful effects of iron. Disclosures:Carbonell:Novartis Farmacéutica, S. A.: Research Funding; Universitat de València: Research Funding.

Le syndrome de Pearson : à propos de 2 observations à révélation néonatale

Among the etiologies of anemia in the newborn, those related to mitochondrial cytopathies are rare. Pearson syndrome is mostly diagnosed during infancy and characterized by refractory sideroblastic anemia with vacuolization of marrow progenitor cells and exocrine pancreatic dysfunction. We describe two diagnosed cases of Pearson syndrome in the early neonatal period caused by severe macrocytic aregenerative anemia. Bone marrow aspiration revealed sideroblastic anemia and vacuolization of erythroblastic precursors. The diagnosis was confirmed by genetic analysis revealing a deletion in the mitochondrial DNA. These two newborns received monthly transfusions. Five other newborns suffering from Pearson syndrome with various clinical symptoms were found in literature. Pearson syndrome, rarely diagnosed in newborns, should be suspected in the presence of macrocytic aregenerative anemia and requires a bone marrow aspirate followed by a genetic analysis from a blood sample.

Results of a phase 2 study of valproic acid alone or in combination with all-trans retinoic acid in 75 patients with myelodysplastic syndrome and relapsed or refractory acute myeloid leukemia

Valproic acid (VPA) inhibits histone deacetylase activity and induces differentiation of acute myeloid leukemia (AML) blasts in vitro. We observed clinical responses to VPA in patients with myelodysplastic syndrome (MDS) and AML. Here, we report follow-up data on 75 patients. Of these, 66 were started on VPA monotherapy, with later addition of all-trans retinoic acid (ATRA) in patients who did not respond or relapsed. Nine patients were treated with VPA + ATRA from the start. Median treatment duration was 4 months for VPA and 2 months for ATRA. Hematological improvement, according to international working group criteria for MDS, was observed in 18 patients (24%). Median response duration was 4 months. ATRA exerted no additional effect in patients receiving the combination from the start or benefited primary VPA nonresponders. However, of ten VPA responders who relapsed, four achieved a second response after addition of ATRA. Response rates were strongly dependent on disease type according to WHO classification. We found a response rate of 52% in MDS patients with a normal blast count (refractory sideroblastic anemia, refractory cytopenia with multilineage dysplasia, and refractory sideroblastic cytopenia with multilineage dysplasia). The response rate was 6% in refractory anemia with excess blasts (I + II), 16% in AML, and 0% in chronic myelomonocytic leukemia. Bone marrow blast count was the only variable that predicted responses. We conclude that VPA is clinically useful in low-risk MDS. For patients with high-risk MDS, VPA may be combined with chemotherapy or demethylating drugs. If patients relapse after an initial response to VPA, ATRA has the potential to induce a prolonged second response.

Prenatal manifestation of pancytopenia in Pearson Marrow-Pancreas Syndrome

Pearson marrow-pancreas syndrome is a fatal disease characterized by refractory sideroblastic anemia with vacuolization of marrow precursors, dysfunction of the exocrine pancreas and severe lactic acidosis, caused by mitochondrial DNA (mtDNA) deletions and duplications. We report on a male neonate in whom pancytopenia was already diagnosed prenatally by ultrasound (cerebral blood flow). He exhibited severe metabolic acidosis and anemia at birth and in the clinical course his condition progressively worsened with severe pancytopenia and metabolic acidosis resulting in death after 12 weeks. DNA was extracted from peripheral leukocytes of the patient and his parents and examined using long polymerase chain reaction and southern blot hybridization. Sequence analysis revealed a 4381-base pair deletion of mtDNA in the patients but not in his parents leukocytes. Although seldom, in prenatal pancytopenia Pearson syndrome should be considered.

Flow Cytometric Analysis of the Expression of Fas/Fasl in Bone Marrow CD34+ Cells in Myelodysplastic Syndromes: Relation to Disease Progression

The role of apoptosis in the pathobiology of myelodysplastic syndromes (MDS) remains controversial. We studied the expression of CD95 and CD95L in CD34+ cells of patients with newly diagnosed MDS by flow cytometry, and examined the relation between this expression and FAB and WHO types, total number of CD34+ bone marrow (BM) cells and the degree of peripheral cytopenias. The patients with refractory anemia (RA) and sideroblastic anemia showed CD34+ cells in numbers comparable to normal donors, but had a higher percentage of CD95/CD34 and CD95L/CD34 positive cells. An inverse correlation was found between these cells and the total CD34+ cells. This was also observed when only patients with RA were analyzed. In RAEB, however, CD95/CD95L expression correlated with CD34+ cells but not with the percentage of BM blasts. After classification by the WHO proposal, the patients with refractory cytopenias with multilineage dysplasia showed features intermediary between RA and RAEB. No significant correlation was seen between the expression of CD95/CD95L and the peripheral blood counts. These results are in keeping with the hypothesis that, as the number of MDS precursors increases during disease progression they become less succeptible to apoptosis.

Severe autoimmune cytopenias in treatment-naive hepatitis C virus infection: clinical description of 35 cases.

To determine the clinical characteristics and outcome of patients with chronic hepatitis C virus (HCV) infection presenting severe autoimmune cytopenia unrelated to interferon alpha therapy, we analyzed characteristics and outcomes of 35 patients with HCV (16 from our departments and 19 from the literature). We considered active autoimmune hemolytic anemia (AHA) as a decrease of at least 2 g/dL in hemoglobin levels, an increase of at least 0.6 mg/dL in the serum unconjugated bilirubin level, a reticulocyte count >5%, and a positive direct Coombs test. Severe neutropenia was defined as a neutrophil count <0.5 x 10(9)/L, and severe thrombocytopenia as a platelet count <30 x 10(9)/L. We identified the following cytopenias: AHA (17 cases), severe thrombocytopenia (16 cases), aplastic anemia (2 cases), severe neutropenia (1 case), refractory sideroblastic anemia (1 case), and pure red cell aplasia (1 case). Three patients simultaneously presented 2 types of severe cytopenias. Twenty-seven patients (77%) were female and 8 (23%) male, with a mean age at diagnosis of cytopenia of 51.7 years (range, 18-84 yr). Immunologic markers were detected in 19 (68%) of 28 patients, the most frequent being hypocomplementemia in 16 (57%), cryoglobulins in 15 (54%), antinuclear antibodies in 12 (43%), and rheumatoid factor in 5 (18%). Other associated processes were autoimmune diseases in 14 (50%) of 28 and human immunodeficiency virus (HIV) coinfection in 3 (9%) of 32. We found clinical and immunologic differences between HCV patients with AHA and those with severe thrombocytopenia. Patients with HCV-related AHA showed a higher prevalence of associated autoimmune diseases (71%), cryoglobulins (67%), and cirrhosis (59%). All had a good response to corticosteroids, but a poor prognosis (47% mortality). In contrast, patients with HCV-related severe thrombocytopenia had a lower prevalence of associated autoimmune diseases (11%), a poorer response to corticosteroids (55%), and lower mortality (6%), with HIV/HBV coinfections in some patients. The 35 cases presented demonstrate that different types of immune-mediated cytopenias may be severe and clinically significant in patients with HCV infection. Hemolytic anemia and severe thrombocytopenia were the most frequent cytopenias observed. Most patients responded well to corticosteroids, although a higher rate of mortality was observed in those with liver cirrhosis.

Microvesicular steatosis, hemosiderosis and rapid development of liver cirrhosis in a patient with Pearson's syndrome

Background/Aims: Pearson's marrow-pancreas syndrome consists of refractory sideroblastic anemia with vacuolization of marrow precursors and exocrine pancreas dysfunction. Patients with this disease usually have large deletions of the mitochondrial genome. We report a patient with Pearson's syndrome who had predominantly hepatic manifestations such as microvesicular steatosis, hemosiderosis and rapidly developing cirrhosis. Methods: Analysis of the mitochondrial and nuclear genomes, determination of enzyme activities and of the hepatic iron content were performed using standard techniques of molecular biology and biochemistry. Results: The patient had typical ringed sideroblasts in a bone marrow smear and a 7436-bp deletion of the mitochondrial genome in all tissues investigated, compatible with Pearson's syndrome. He died within 3 months after birth due to liver failure. Histopathological analysis of the liver revealed complete cirrhosis with signs of chronic cholestasis, microvesicular steatosis and massive hemosiderosis. In addition, the patient was heterozygous for the C282Y and H63D mutations of the hemochromatosis gene. Conclusions: Pearson's syndrome should be added to the list of neonatal diseases which can cause microvesicular steatosis, hepatic accumulation of iron and liver cirrhosis.

Schwachman or Pearson syndrome

American Journal of HematologyVolume 57, Issue 3 p. 262-262 Free Access Schwachman or Pearson syndrome Şinasi Özsoylu, Corresponding Author Şinasi Özsoylu Fatih University Medical Faculty, Emek, Ankara, TurkeyFatih University Medical Faculty, Emek, Ankara, TurkeySearch for more papers by this author Şinasi Özsoylu, Corresponding Author Şinasi Özsoylu Fatih University Medical Faculty, Emek, Ankara, TurkeyFatih University Medical Faculty, Emek, Ankara, TurkeySearch for more papers by this author First published: 06 December 1998 https://doi.org/10.1002/(SICI)1096-8652(199803)57:3<262::AID-AJH20>3.0.CO;2-BAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat References 1 Pearson HA, Lobel JS, Kocvshis SA, et al: A new syndrome of refractory sideroblastic anemia with vaculization of marrow precursors and exocrine pancreatic dysfunction. J Pediatr 95: 976– 984, 1979. 2 Cormier V, Rötig A, Rasore A, et al: Widespread multi-tissue deletions of mitochondrial genome in the Pearson marrow-pancreas syndrome. J Pediatr 117: 599– 602, 1990. 3 Schussherni A, Choi SJ, Silverberg M: Exocrine pancreatic insufficiency with congenital anomalies. J Pediatr 89: 782, 1976. 4 Aytemiz GU Argey A, Rötig A, Gümrük F, et al: Pearson's marrow pancreas syndrome in two Turkish Children. Acta Haematol 87: 206– 920, 1992. Volume57, Issue3March 1998Pages 262-262 ReferencesRelatedInformation

The effects of thrombopoietin on the growth of acute myeloblastic leukemia cells.

Thrombopoietin (TPO) is a novel hematopoietic growth factor that was cloned as a ligand for c-mpl proto-oncogene. The c-mpl proto-oncogene is expressed on various types of human leukemia cell lines derived from erythroid, megakaryocytic, and stem-cell leukemia cells. Also, c-mpl mRNA is detectable on blast cells in about half of acute myeloblastic leukemia (AML) cases regardless of French-American-British (FAB) classification. In the cases with myelodysplastic syndrome, c-mpl is expressed in a substantial fraction of refractory anemia with excess of blast (RAEB), RAEB in transformation, and chronic myelomonocytic leukemia cells, but not in refractory anemia or sideroblastic anemia. Little or no expression of c-mpl mRNA is observed in human lymphoid cell lines and blast cells of acute lymphoblastic leukemia cases. The in vitro treatment of AML cells with TPO resulted in proliferation in about 70% of c-mpl-positive AML cases. The proliferative responses of AML cells to TPO were observed not only in M7-type, but also in the other subtypes of AML cases. Furthermore, the TPO-induced proliferation of AML cells was augmented by the addition of the other hematopoietic growth factors such as interleukin-3 (IL-3), IL-6, stem cell factor, or granulocyte-macrophage colony-stimulating factor. In addition to proliferation, TPO appeared to induce megakaryocytic differentiation in a small part of AML cells. These results suggested that TPO/c-mpl system might contribute, at least in part, to abnormal growth and differentiation of AML cells.

Molecular and Genetic Analyses of Two Patients with Pearson's Marrow-Pancreas Syndrome

Pearson's syndrome, a rare and fatal disorder characterized by refractory sideroblastic anemia and pancreatic insufficiency in infancy, is classified into mitochondrial cytopathies. To understand the molecular and genetic bases of this disorder, we have investigated the mitochondrial respiratory chain enzymes and the mitochondrial DNA (mtDNA) in two Japanese patients with Pearson's syndrome. Immunoblot analysis from various tissues showed the different grades of defects in the subunits of respiratory enzyme complexes. The analyses of mtDNA showed that the deletion in patient 1 spanned 4977 bp from the ATPase 8 gene to the NADH dehydrogenase 5 gene between 13-bp direct repeats, whereas the deletion in patient 2 spanned 3151 bp from the transfer RNA(His) gene to the cytochrome b gene unrelated to any repeated sequences. The deleted mtDNA was heteroplasmic in all the analyzed tissues, but the proportions of deleted mtDNA were quite different. We observed a tendency for the tissue with low percentages of normal-sized mtDNA to show low contents of complex I subunits. Analysis of the entire sequence of both patient's mtDNA showed several nucleotide substitutions including alteration of the initiation codon of the NADH dehydrogenase 5 gene. Some of these nucleotide substitutions might contribute to the phenotypic expression of Pearson's syndrome synergistically with the deletion.

Iron overload complicating sideroblastic anemia—Is the gene for hemochromatosis responsible?

Idiopathic hemochromatosis is a hereditary disease that is associated with human leucocytic antigens A3, B7, and B14. A genetic association between human leucocytic antigen-linked hemochromatosis and idiopathic refractory sideroblastic anemia has been suggested that may predispose some patients with idiopathic refractory sideroblastic anemia to develop gross iron overload. Study of the family of a patient with idiopathic refractory sideroblastic anemia and hemochromatosis revealed that 2 of 5 first-degree relatives had significant elevations of serum ferritin, and a shared human leucocytic antigen haplotype, supporting the concept that patients with idiopathic refractory sideroblastic anemia and significant iron overload have at least one allele for hemochromatosis.

Natural History of Idiopathic Refractory Sideroblastic Anemia

We analyzed the natural history of idiopathic refractory sideroblastic anemia (IRSA) in 37 patients studied between 1969 and 1986. Although erythroid abnormalities were prominent in all, 12 patients also showed involvement of the granulocytic and/or megakaryocytic cell lines, and nonrandom chromosomal aberrations were observed in five of 23 patients studied for such defects. Measurements of erythroid marrow function showed in most cases erythroid expansion with ineffective erythropoiesis. In seven patients, however, the erythroid activity was found to be inappropriately low for the degree of anemia. Transfusion dependence occurred in 26 of 37 cases. Iron overload was a common feature at presentation but produced clinical manifestations of hemochromatosis only in those patients who subsequently had a regular need for blood transfusions. Five patients progressed to bone marrow failure, and another five patients (two of whom had monosomy 7) evolved into acute nonlymphocytic leukemia (ANLL). The median survival was 72 months, with a high transfusion requirement, multilineage defects, and inappropriately low erythroid proliferation being associated with a poor prognosis. The most common causes of death were complications of iron overload and evolution into ANLL. We conclude that (a) the natural history of IRSA is characterized by an initial phase of erythroid hyperplasia and ineffective erythropoiesis, which is usually stable for many years but in a subset of patients may be followed by a phase of marrow failure with or without the later emergence of leukemic blasts; (b) peripheral blood counts, measurement of erythroid marrow function, and chromosomal analysis are useful for identifying subjects at risk of evolution into marrow failure or ANLL; and (c) IRSA patients with no need for blood transfusions are very likely to be long survivors, whereas those who become transfusion dependent are at risk of death from the complications of secondary hemochromatosis.

Natural history of idiopathic refractory sideroblastic anemia

We analyzed the natural history of idiopathic refractory sideroblastic anemia (IRSA) in 37 patients studied between 1969 and 1986. Although erythroid abnormalities were prominent in all, 12 patients also showed involvement of the granulocytic and/or megakaryocytic cell lines, and nonrandom chromosomal aberrations were observed in five of 23 patients studied for such defects. Measurements of erythroid marrow function showed in most cases erythroid expansion with ineffective erythropoiesis. In seven patients, however, the erythroid activity was found to be inappropriately low for the degree of anemia. Transfusion dependence occurred in 26 of 37 cases. Iron overload was a common feature at presentation but produced clinical manifestations of hemochromatosis only in those patients who subsequently had a regular need for blood transfusions. Five patients progressed to bone marrow failure, and another five patients (two of whom had monosomy 7) evolved into acute nonlymphocytic leukemia (ANLL). The median survival was 72 months, with a high transfusion requirement, multilineage defects, and inappropriately low erythroid proliferation being associated with a poor prognosis. The most common causes of death were complications of iron overload and evolution into ANLL. We conclude that (a) the natural history of IRSA is characterized by an initial phase of erythroid hyperplasia and ineffective erythropoiesis, which is usually stable for many years but in a subset of patients may be followed by a phase of marrow failure with or without the later emergence of leukemic blasts; (b) peripheral blood counts, measurement of erythroid marrow function, and chromosomal analysis are useful for identifying subjects at risk of evolution into marrow failure or ANLL; and (c) IRSA patients with no need for blood transfusions are very likely to be long survivors, whereas those who become transfusion dependent are at risk of death from the complications of secondary hemochromatosis.

Is the HLA‐linked haemochromatosis allele implicated in idiopathic refractory sideroblastic anaemia?

In order to assess the previously reported association of HLA-linked idiopathic haemochromatosis with idiopathic refractory sideroblastic anaemia (IRSA), the prevalence of HLA-A3 antigen in a group of 22 patients with IRSA was compared to that observed in healthy controls and in patients with homozygous idiopathic haemochromatosis and to that calculated for a population heterozygous for idiopathic haemochromatosis. The prevalence of A3 in patients with IRSA (0.23) was quite similar to that observed in controls (0.29) and significantly different from that observed in homozygous (0.73; P less than 10(-5] and heterozygous (0.57; P less than 10(-3] haemochromatosis. Serum iron, transferrin saturation, serum ferritin and liver iron concentration showed no difference in IRSA patients with or without A3. It is concluded that there is neither systematic association between the haemochromatosis allele and IRSA nor systematic implication of such an allele in the development of iron overload observed in IRSA.

A study of a female with congenital sideroblastic anemia

A female infant with congenital refractory sideroblastic anemia is described. A marked reduction of delta-aminolevulinic acid (ALA) synthetase activity of erythroblasts was noticed with and without treatment of pyridoxal phosphate. Mitochondrial neutral protease activity of erythroblasts, which inactivates specifically the apo form of ALA synthetase, was normal and the sensitivity of apo form of ALA synthetase to the neutral protease was also normal. It was speculated that the reduction of ALA synthetase activity is not due to the high speed of destruction, but rather due to the impairment in production of ALA synthetase, which could explain the unresponsiveness to pyridoxine therapy in this case.

Syndrome of refractory sideroblastic anemia with vacuolization of marrow precursors and exocrine pancreatic dysfunction presenting in the neonate

RECENTLY, Pearson et aP repor ted a new syndrome of refractory sideroblastic anemia with vacuol izat ion of marrow precursors and exocrine pancrea t ic dysfunction. Their four pat ients had a severe aregenera t ive anemia and normal cellularity of the mar row in contrast to the p redominan t neu t ropen ia and hypocel lu lar mar row seen in Schwachman-Bodian s y n d r o m e ? 3 W e recently cared for a newborn infant whose findings fit the syndrome described by Pearson. Her case was unusua l in tha t she presented with severe pancy topen ia m u c h earlier in life and was found to have fibrosis of the thyroid gland at autopsy, a f inding previously undescr ibed.