Pure red cell aplasia: review of treatment and proposal for a treatment strategy

Recommendations for Pregnancy in Rare Inherited Anemias

Rare inherited anemias are a subset of anemias caused by a genetic defect along one of the several stages of erythropoiesis or in different cellular components that affect red blood cell integrity, and thus its lifespan. Due to their low prevalence, several complications on growth and development, and multi-organ system damage are not yet well defined. Moreover, during the last decade there has been a lack of proper understanding of the impact of rare anemias on maternal and fetal outcomes. In addition, there are no clear-cut guidelines outlining the pathophysiological trends and management options unique to this special population. Here, we present on behalf of the European Hematology Association, evidence- and consensus-based guidelines, established by an international group of experts in different fields, including hematologists, gynecologists, general practitioners, medical geneticists, and experts in rare inherited anemias from various European countries for standardized and appropriate choice of therapeutic interventions for the management of pregnancy in rare inherited anemias, including Diamond-Blackfan Anemia, Congenital Dyserythropoietic Anemias, Thalassemia, Sickle Cell Disease, Enzyme deficiency and Red cell membrane disorders.

Anemias excluding cobalamin and folate deficiencies

Anemias are one of the commonest maladies affecting humans. They result from either a failure of production by the bone marrow (hypoproliferative), or from premature destruction or loss (hyperproliferative) of red cells. Hypoproliferative anemias typically result from deficiencies of essential nutrients, stem cell abnormalities or deficiency, and infiltrative processes of the bone marrow. In the hyperproliferative forms, the bone marrow function is normal and anemia results from bleeding or shortened erythrocyte lifespan due to hemoglobinopathies, red cell enzyme disorders, membrane defects, or external factors such as antibodies, trauma, or heat injury. The etiology of anemia is frequently obvious, but when obscure, a systematic diagnostic approach frequently yields the answer. It is important to realize that anemias are usually a consequence of another disease process, which must be identified. Without correction of the underlying disease process, the treatment is likely to fail.

Clinical use of cyclosporine as an adjunctive therapy in the management of feline idiopathic pure red cell aplasia

The clinical use of cyclosporine is described in a group of client-owned cats diagnosed with idiopathic pure red cell aplasia (PRCA). All 10 cats were treated with combinations of glucocorticoids and cyclosporine. Of the 10 cats, the eight for which follow-up data was available achieved and maintained remission for a median of 31 and 406 days, respectively. Therapy was reduced or discontinued in 7/8 cats; 2/7 maintained remission off therapy and 5/7 cats relapsed. Remission was reinduced in four cats, with 3/4 cats maintained long-term on low dose therapy. Adverse effects associated with cyclosporine therapy were responsive to dose reduction or drug withdrawal. Feline idiopathic PRCA was responsive to combination immunosuppressive therapy with glucocorticoids and cyclosporine. Relapse was common, particularly after drug discontinuation; therefore, most cats required maintenance long-term low dose therapy.

Pure red cell aplasia caused by acute hepatitis a

Pure red cell aplasia is characterized as a normocytic anemia associated with reticulocytopenia and the absence of erythroblasts in the bone marrow. Pure red cell aplasia can be induced by various causes such as thymoma, connective tissue disease, viral infection, lymphoma, and adverse drug reactions. There have been only a few reports of pure red cell aplasia associated with acute viral hepatitis A. In Korea, no case of pure red cell aplasia caused by acute hepatitis A has yet been reported. We recently experienced a case of acute viral hepatitis A complicated by pure red cell aplasia. The patient was successfully treated with corticosteroids. Here we report this case and review the literature.

First case report of acquired pure red cell aplasia associated with micafungin

A 70-year-old Japanese man with chronic kidney disease under treatment with oral prednisolone for organizing pneumonia developed pulmonary aspergilloma. The patient was started on micafungin (MCFG), with no addition of any other new drug. About 5 weeks later, aggravation of his normocytic anemia associated with a low reticulocyte count was observed. Bone marrow puncture and biopsy revealed intense hypoplasia of the erythroblasts. As there was no evidence of malignancy, human parvovirus B19 infection, autoimmune diseases or hemorrhage, the patient was diagnosed as having acquired pure red cell aplasia (PRCA). The anemia improved along with an increase of the reticulocyte count to the normal level within 12 weeks of discontinuation of the MCFG therapy. The patient showed no evidence subsequently of any recurrence of the normocytic normochromic anemia or relapse of the PRCA. This is the first reported case of PRCA associated with MCFG.

Delayed spontaneous remission in a child with primary acquired chronic pure red cell aplasia

The acquired form of pure red cell aplasia (PRCA) presents either as an acute self-limited disease, predominantly seen in children, or as a chronic illness more frequently seen in adults with rare spontaneous remissions. A 14-year-old boy presented with pallor, without hepatosplenomegaly, jaundice, lymphadenopathy, petechiae, or any other apparent abnormalities. Isolated anemia in the presence of normal white cell and platelet counts with a marrow of normal cellularity and absence of erythroblasts but normal myeloid cells and megakaryocytes revealed the diagnosis of PRCA. All possible investigations excluded secondary causes of PRCA. The patient required packed red cell transfusions every 2 to 3 weeks. He failed therapy with intravenous immunoglobulin, corticosteroids, cyclosporine A plus corticosteroids, antithymocyte globulin, anti-CD 20 (rituximab), and erythropoietin (EPO). He showed a severe, resistant, and transfusion-dependent PRCA. Spontaneous remission with normal hemoglobin and reticulocyte levels was dramatic 6.5 years after the diagnosis of PRCA and 3.6 years after his last treatment.

Diagnosis and management of acquired pure red cell aplasia

Pure red cell aplasia is a syndrome characterized by a severe normocytic anemia, reticulocytopenia, and absence of erythroblasts from an otherwise normal bone marrow. Although the causes and natural course of this syndrome are variable and although the anemia in some patients can be managed by treatment of an underlying inflammatory or neoplastic disease, the pathogenesis of a large number of cases is autoimmune, including those associated with thymoma, and are best managed with immunosuppressive therapy.

Acquired pure red cell aplasia: updated review of treatment

Pure red cell aplasia (PRCA) is a syndrome characterized by a severe normocytic anaemia, reticulocytopenia, and absence of erythroblasts from an otherwise normal bone marrow. Primary PRCA, or secondary PRCA which has not responded to treatment of the underlying disease, is treated as an immunologically-mediated disease. Although vigorous immunosuppressive treatments induce and maintain remissions in a majority of patients, they carry an increased risk of serious complications. Corticosteroids were used in the treatment of PRCA and this has been considered the treatment of first choice although relapse is not uncommon. Cyclosporine A (CsA) has become established as one of the leading drugs for treatment of PRCA. However, common concerns have been the number of patients treated with CsA who achieve sustained remissions and the number that relapse. This article reviews the current status of CsA therapy and compares it to other treatments for diverse PRCAs.

Protection of Mammalian Cells from Severe Acute Respiratory Syndrome Coronavirus Infection by Equine Neutralizing Antibody

The aetiological agent for severe acute respiratory syndrome (SARS) has been determined to be a new type of coronavirus (SARS-CoV) that infects a wide range of mammalian hosts. Up to now, there have been no specific drugs to protect against SARS-CoV infection, thus developing effective strategies against this newly emerged viral infection warrants urgent efforts. Adoptive immune therapy with pathogen-specific heterologous immunoglobulin has been successfully used to control the dissemination of many viral infections. To investigate whether a neutralizing antibody against SARS-CoV raised in an artiodactylous host can have a protective role on primate cells, we prepared serum IgGs and their pepsin-digested F(ab’)2 fragments from horses inoculated with purified SARS-CoV (BJ-01 strain). The protective effect of the F(ab’)2 fragments against SARS-CoV infection was determined in cultured Vero E6 cells by cytopathic effect (CPE), MTT and plaque-forming assays and in a Balb/c mouse model by CPE and quantitative RT-PCR. The results showed the neutralization titres of F(ab’)2 from three horses all reached at least 1:1600, and 50 μg of the F(ab’)2 fragments could completely neutralize 1x104 TCID50 SARS-CoV in vivo. Additionally, we observed that F(ab’)2 against BJ-01 strain could also protect cells from infection by the variant GZ-01 strain in vitro and in vivo. Our work has provided experimental support for testing the protective equine immunoglobulin in future large primate or human trials.

Intravenous immunoglobulins in autoimmune- or parvovirus B19-mediated pure red-cell aplasia

Pure red-cell aplasia (PRCA) is defined as the absence of mature erythroid precursors in a bone marrow that otherwise exhibit normal cellularity. Acquired PRCA may occur in association with neoplasms (such as lymphoproliferative disorders), thymoma, autoimmune disorders, pregnancy, or as a consequence of chronic human parvovirus B19 (B19) infection in an immunologically incompetent host. PRCA may also develop after exposure to drugs (erythropoietin or tacrolimus). PRCA of autoimmune origin was first treated successfully with intravenous immunoglobulins (IVIg) more than 20 years ago. Since then, B19-associated PRCA in solid-organ transplant recipients and in human immunodeficiency virus (HIV)-infected patients has also been successfully treated with IVIg. Routine maintenance therapy is probably not indicated in HIV-infected patients with CD4+ counts above 300/microL, whereas repeated infusions might be necessary if CD4+ count is below 80.

A sustained response to low dose interferon-α in a case of refractory pure red cell aplasia

Acquired pure red cell aplasia (PRCA) may be the result of a cellular or humoral autoimmune process. One proposed mechanism is the destruction of erythroid progenitors by self-reactive, cytotoxic T cells or natural killer (NK) cells. These cells normally express MHC class I receptors (KIR) which inhibit cytotoxicity when the target cell expresses the HLA class I antigen(s) they bind. Therefore, loss of these antigens on maturing erythroid progenitors may render them susceptible to destruction by the pathogenic cells. Interferon-alpha (INF-alpha) increases HLA class I expression on hematopoietic precursor cells. Therefore, we initiated a trial of INF-alpha in a patient with refractory PRCA. Following treatment, he developed transfusion independence, and a sustained normal hematocrit. Analysis of bone marrow erythroid cells revealed an increase in expression of HLA class I molecules. INF-alpha should be used in a controlled trial in patients with PRCA to determine its activity and mechanism of action.

Very severe aplastic anemia appearing after thymectomy

Aplastic anemia is a rare complication of thymoma and is extremely infrequent after thymectomy. We present a case of a 60-year-old woman with very severe aplastic anemia appearing sixteen months after thymectomy for a thymoma. She underwent thymectomy for a thymoma in April 2000. Preoperative examination revealed no hematologic abnormality. About sixteen months after the operation, she was readmitted because of pancytopenia with cough and fever. Bone marrow aspiration revealed a very severe hypoplasia in all the three cell lines with over 80% fatty tissue, and chest CT revealed no recurrence of thymoma. Her aplastic anemia had responded to cyclosporine A and granulocyte-colony stimulating factor (G-CSF).

CAMPATH-1H in the treatment of autoimmune cytopenias

BACKGROUND

The autoimmune cytopenias encompass the disorders of immune thrombocytopenia purpura (ITP), pure red-cell aplasia (PRCA), autoimmune hemolytic anemia (AIHA), autoimmune neutropenia and various combinations of these conditions. T lymphocytes are thought to play an important role in the pathogenesis of autoimmune cytopenias, and the presence of autoantibody may represent an epiphenomenon, rather than the primary pathogenetic mechanism. The majority of patients usually respond to standard immunosuppressive therapy and can mostly be treated as out-patients. A small proportion, however, have severe, resistant and life-threatening disease, or may experience major morbidity from side effects of drugs given to treat their disease.

METHODS

We have treated 21 patients with autoimmune cytopenias with the MAb Campath-1H, and for later patients in this series, in combination with low dose CYA.

RESULTS

Responses were seen in 14 of 20 evaluable patients, although relapse occurred in seven patients. In many patients corticosteroid therapy could be discontinued or greatly reduced.

DISCUSSION

We conclude that Campath-1H can induce remissions in autoimmune cytopenias and we critically review its role in the treatment of these disorders.

Study of 22 Egyptian patients with Diamond-Blackfan anemia, corticosteroids, and cyclosporin therapy results

OBJECTIVE

Diamond-Blackfan anemia is a rare congenital hypoproliferative anemia of infancy and early childhood. Treatment with corticosteroids is commonly used, but with limited success. Trials with cyclosporin-A (CSA) are not frequently reported. Therefore, in this study we analyzed our results in the management of this rare disease by different medical treatments.

DESIGN

The results of 22 patients diagnosed at our Hematology Center in the New Cairo University Children's Hospital during the period 1991-2001 were retrospectively analyzed. Our patients first received prednisolone (2 mg/kg/d) for different courses according to their response. Since the year 2000, the steroid nonresponders received CSA (3-12 mg/kg/d) for 6 months unless treatment complications developed.

RESULTS

The age at the onset of the disease ranged from 1 to 24 months (median: 2.5 months). The mean values of the hemoglobin, the reticulocyte count, and the myeloid/erythroid ratio at the onset of the disease were 4.75 +/- 1.79 g/dL, 0.14 +/- 0.16, and 39.4 +/- 27.08, respectively. Patients received prednisolone from 0.25 to 10 years (median: 2 years). Ten patients were nonresponders (45.5%), and 5 patients (22.7%) responded to corticosteroid therapy. Two of 5 responders are off treatment with a hemoglobin level of >9 g/dL, and 3 of 5 are currently corticosteroid-dependent. Of 10 patients not responding to steroids, 8 received CSA for 6 months. Four patients (50%) responded to CSA therapy. A significant positive association was found between CSA dose and response.

CONCLUSION

CSA therapy should be tried in steroid-resistant Diamond-Blackfan anemia patients before blood transfusion or corticosteroid therapy complications are instituted.

High-dose methylprednisolone therapy in pure red cell aplasia

OBJECTIVE

To report our experience using high-dose methylprednisolone (HDMP) treatment in a patient with primary acquired pure red cell aplasia (PRCA) who failed to respond to conventional prednisone therapy.

CASE SUMMARY

A 29-year-old woman reported weakness, was easily fatigued, and had developed palpitations. On physical examination, pallor and splenomegaly were detected. On blood smear, mild macrocytic anemia was seen. Bone marrow aspiration and biopsy revealed normocellularity, erythroid hypoplasia (E/M: 1/10), reduction in erythroid precursors, and normal megakaryocytes and myeloid series. No disease associated with secondary PRCA was detected. Oral prednisone 1 mg/kg (total 60 mg/d) was started as conventional treatment. However, the patient's status deteriorated and the hemoglobin concentration fell from 6.5 to 5.5 g/dL within the first week of hospitalization. HDMP was then begun. Treatment protocol consisted of methylprednisolone 30 mg/kg for 4 days, 20 mg/kg for 3 days, 10 mg/kg for 3 days, 5 mg/kg for 4 days, and 1 mg/kg for 2 weeks. The patient's hemoglobin concentration increased from 5.5 to 14.2 g/dL over a period of 9 weeks. Transient hyperglycemia and cushingoid appearance were seen during prednisone treatment.

DISCUSSION

Exactly how steroids enhance erythropoiesis in PRCA is unknown. It seems likely that steroids render abnormal erythroid progenitors more sensitive to marrow growth factors, thereby permitting them to differentiate to functional precursors. HDMP treatment had been rarely used in patients with primary acquired PRCA. Limited studies using HDMP have shown variable results.

CONCLUSIONS

HDMP treatment may be considered safe and effective in patients with primary acquired PRCA who do not respond to conventional steroid therapy.

Concomitant thymectomy and cardiac operation in a patient with pure red cell aplasia

Pure red cell aplasia is a rare condition resulting in severe anemia. Medical therapy is indicated, unless a thymoma is present. In patients with concurrent cardiac pathology requiring operation, simultaneous operation should be contemplated to avoid risky resternotomy. We describe an exceptionally rare case of a patient with pure red cell aplasia secondary to a thymoma who underwent concomitant thymectomy and coronary artery grafting with a successful surgical outcome.

Diamond-blackfan anemia and cyclosporine therapy revisited

A girl with Diamond-Blackfan anemia diagnosed in infancy started cyclosporine A (CSA) therapy at 9 years and 8 months of age after experiencing unacceptable side effects while receiving prednisone. Since then, she has been followed-up for more than 4 years. She exhibited a dramatic response to CSA, with weaning and then cessation of steroid therapy after 5 months. She has remained transfusion-independent. Attempts to discontinue CSA therapy have been unsuccessful. Relapse of the anemia has occurred in the context of viral infections with missed CSA doses. The major clinical problem during treatment has been recurrent oral aphthous ulceration, which responds to topical therapy. She is currently maintained on CSA 100 mg twice daily with a hemoglobin of 10.2 g/dL and a reticulocyte count of 1.6%. A trial of CSA therapy should be considered in patients with Diamond-Blackfan anemia in whom steroid therapy has failed before a transfusion program is instituted or alternative donor stem cell transplantation is entertained.

New Insights into the Pathophysiology of Acquired Cytopenias

This review addresses three related bone marrow failure diseases, the study of which has generated important insights in hematopoiesis, red cell biology, and immune-mediated blood cell injury. In Section I, Dr. Young summarizes the current knowledge of acquired aplastic anemia. In most patients, an autoimmune mechanism has been inferred from positive responses to nontransplant therapies and laboratory data. Cytotoxic T cell attack, with production of type I cytokines, leads to hematopoietic stem cell destruction and ultimately pancytopenia; this underlying mechanism is similar to other human disorders of lymphocyte-mediated, tissue-specific organ destruction (diabetes, multiple sclerosis, uveitis, colitis, etc.). The antigen that incites disease is unknown in aplastic anemia as in other autoimmune diseases; post-hepatitis aplasia is an obvious target for virus discovery. Aplastic anemia can be effectively treated by either stem cell transplantation or immunosuppression. Results of recent trials with antilymphocyte globulins and high dose cyclophosphamide are reviewed.

Dr. Abkowitz discusses the diagnosis and clinical approach to patients with acquired pure red cell aplasia, both secondary and idiopathic, in Section II. The pathophysiology of various PRCA syndromes including immunologic inhibition of red cell differentiation, viral infection (especially human parvovirus B19), and myelodysplasia are discussed. An animal model of PRCA (secondary to infection with feline leukemia virus [FeLV], subgroup C) is presented. Understanding the mechanisms by which erythropoiesis is impaired provides for insights into the process of normal red cell differentiation, as well as a rational strategy for patient management.

Among the acquired cytopenias paroxysmal nocturnal hemoglobinuria (PNH) is relatively rare; however, it can pose formidable management problems. Since its first recognition as a disease, PNH has been correctly classified as a hemolytic anemia; however, the frequent co-existence of other cytopenias has hinted strongly at a more complex pathogenesis. In Section III, Dr. Luzzatto examines recent progress in this area, with special emphasis on the somatic mutations in the PIG-A gene and resulting phenotypes. Animal models of PNH and the association of PNH with bone marrow failure are also reviewed. Expansion of PNH clones must reflect somatic cell selection, probably as part of an autoimmune process. Outstanding issues in treatment are illustrated through clinical cases of PNH. Biologic inferences from PNH may be relevant to our understanding of more common marrow failure syndromes like myelodysplasia.

New Insights into the Pathophysiology of Acquired Cytopenias

This review addresses three related bone marrow failure diseases, the study of which has generated important insights in hematopoiesis, red cell biology, and immune-mediated blood cell injury. In Section I, Dr. Young summarizes the current knowledge of acquired aplastic anemia. In most patients, an autoimmune mechanism has been inferred from positive responses to nontransplant therapies and laboratory data. Cytotoxic T cell attack, with production of type I cytokines, leads to hematopoietic stem cell destruction and ultimately pancytopenia; this underlying mechanism is similar to other human disorders of lymphocyte-mediated, tissue-specific organ destruction (diabetes, multiple sclerosis, uveitis, colitis, etc.). The antigen that incites disease is unknown in aplastic anemia as in other autoimmune diseases; post-hepatitis aplasia is an obvious target for virus discovery. Aplastic anemia can be effectively treated by either stem cell transplantation or immunosuppression. Results of recent trials with antilymphocyte globulins and high dose cyclophosphamide are reviewed.

Dr. Abkowitz discusses the diagnosis and clinical approach to patients with acquired pure red cell aplasia, both secondary and idiopathic, in Section II. The pathophysiology of various PRCA syndromes including immunologic inhibition of red cell differentiation, viral infection (especially human parvovirus B19), and myelodysplasia are discussed. An animal model of PRCA (secondary to infection with feline leukemia virus [FeLV], subgroup C) is presented. Understanding the mechanisms by which erythropoiesis is impaired provides for insights into the process of normal red cell differentiation, as well as a rational strategy for patient management.

Among the acquired cytopenias paroxysmal nocturnal hemoglobinuria (PNH) is relatively rare; however, it can pose formidable management problems. Since its first recognition as a disease, PNH has been correctly classified as a hemolytic anemia; however, the frequent co-existence of other cytopenias has hinted strongly at a more complex pathogenesis. In Section III, Dr. Luzzatto examines recent progress in this area, with special emphasis on the somatic mutations in the PIG-A gene and resulting phenotypes. Animal models of PNH and the association of PNH with bone marrow failure are also reviewed. Expansion of PNH clones must reflect somatic cell selection, probably as part of an autoimmune process. Outstanding issues in treatment are illustrated through clinical cases of PNH. Biologic inferences from PNH may be relevant to our understanding of more common marrow failure syndromes like myelodysplasia.

Intravenous immunoglobulin treatment in hematological diseases

In the last decade large amounts of intravenous immunoglobulin (i.v.Ig) have been used worldwide. Doubts exist as to whether this increased use is paralleled by a comparable growth of reliable data on the therapeutic effectiveness of i.v.Ig. We performed a literature search using MEDLINE from January 1981 to January 1997 and analysed articles on the use of i.v.Ig in hematological disorders and searched for published guidelines. For most hematological disorders, evidence to use i.v.Ig as first line therapy is not very strong. For many disorders no controlled trials have been performed. In published guidelines, i.v.Ig is only recommended, with a few exceptions, when other treatments have failed or are contraindicated. Therefore the increase of consumption of i.v.Ig can not be explained by an increase in established indications in hematology.

Large granular lymphocyte leukemia with pure red cell aplasia in a renal transplant recipient

Neoplastic disorders sometimes accompany a renal transplant. Herein, we report a large granular lymphocyte (LGL) leukemia patient with pure red cell aplasia (PRCA) after renal transplantation. A 36-year-old female was presented to our department with anemia in February 1996. She had undergone hemodialysis because of pregnancy in December 1981. She received a renal transplantation from her mother in April 1986. After the transplantation, she received cyclosporin A (CyA) at 2 mg/kg/day, mizoribine at 1 mg/kg/day, and methylprednisolone at 0.1 mg/kg/day for 8 years. In July 1995, her hemoglobin level dropped to 9.3 g/dl, and anemia developed gradually. In January 1996, her hemoglobin was 5.8 g/dl, and she was given a red blood cell transfusion. Laboratory findings were as follows: RBC 1.46 x 10(12)/L; hemoglobin 5.8 g/dl; hematocrit 17.8%; leucocytes 5.2 x 10(9)/L with 62.4% neutrophils, 34.1% lymphocytes, 2.6% monocytes; platelets 50.8 x 10(10)/L; reticulocytes 0.4%. Bone marrow aspirate smears and biopsy sections revealed normal myeloid and megakaryocyte differentiation with few erythroid precursors. The lymphocytes were of medium size with granules in the cytoplasm. More than 90% of lymphocytes were of the LGL type. Surface markers of peripheral blood mononuclear cells demonstrated increases in the CD2+, CD3+, CD4-, and CD8+ populations. A monoclonal rearrangement of T-cell receptor (TCR)-beta chain gene was found by Southern blot analysis of the mononuclear cells in peripheral blood. A diagnosis of LGL leukemia with PRCA was made. During the next 4 months, she received six red blood cell transfusions, a total of 12 U. In March 1996, the patient was treated with cyclophosphamide (1 mg/kg/day). After 1 month of treatment, serum GPT levels increased to 60 IU/l. The dose of cyclophosphamide was reduced to 0.5 mg/kg/day. Two months after initiation of the therapy, the patient developed reticulocytosis and blood transfusion was not needed thereafter. During remission, the number of CD2+, CD3+, CD4-, and CD8+ lymphocytes decreased. Large granular lymphocytes decreased to less than 10% of peripheral blood. The monoclonal rearrangement of the TCR-beta chain gene in peripheral blood disappeared.

Acquired pure red cell aplasia in Japan

We reviewed the clinical features of 150 patients with acquired pure red cell aplasia (PRCA) in Japan. There were 35 patients with acute type and 115 with chronic type PRCA. Of the acute PRCA patients, 17 had human parvovirus B19 infection. Drug-induced PRCA was demonstrated in 7 patients. Of the 115 patients with chronic PRCA, 51 patients were classified as primary and 64 cases were associated with miscellaneous diseases such as thymoma, a variety of hematological disorders and collagen diseases. Among the hematological disorders, PRCA was most frequently seen in granular lymphocyte proliferative disorders (GLPD). The erythroid colony growth patterns from bone marrow were variable. The serum erythropoietin level was high in most patients. Various kinds of treatment were tried for the chronic PRCA cases. Cyclosporin A (CyA) was the most effective form of treatment and the response rate was 82% (31/38). Twenty-three of 37 patients (62%) responded to bolus methylprednisolone therapy. The largest number of patients were treated with oral prednisolone, and the therapy was effective in 27 of the 55 (49%). The response rate to cyclophosphamide was only 29% (5/17), but in combination with prednisolone, half of the patients (7/14) responded to the therapy. CyA is recommended as the first-line therapy for acquired chronic PRCA.

A case of pure red cell aplasia: follow-up on different immunosuppressive regimens

A 66-year-old patient was admitted to our hospital in January 1992 for further evaluation of severe normocytic anemia. Hemoglobin (Hb) was 3.5 g/dl, reticulocyte count 1%. Bone marrow showed a nearly complete lack of red cell precursors, thus favoring the diagnosis of acquired pure red cell aplasia (PRCA). Immunosuppressive therapy with prednisolone was started but had to be supplemented with azathioprine because of a further rapid decrease in Hb to 3.7 g/dl after an initial transfusion of 6 U red blood cells. However, with this regimen a renewed decrease in Hb to 6.6 g/dl was noted, and further transfusions were required. Therefore therapy was switched to cyclosporine A (CyA) while tapering off prednisolone. Four months after the initial diagnosis a positive parvovirus B19 IgM antibody was found. After the failure of hematological remission with three immunosuppressive regimens a course of high-dose intravenous immunoglobulins (IVIG) was administered in July 1992. Six weeks after IVIG therapy a peak hemoglobin concentration of 12.3 g/dl was noted, and further transfusion was not required. CyA was tapered off in October 1992. One month later CyA was reinstituted because of a relapse of PRCA but was unsuccessful until January 1993. At this time immunosuppressive CyA therapy was discontinued because of a periodontal abscess. In February 1993 a second IVIG infusion was given, and a second remission of PRCA was noted, showing an increase in hemoglobin up to 14.5 g/dl by November 1993. At the last follow-up visit in February 1994 our patient was still in complete hematological remission.

Parvovirus B19 as a cause of acquired chronic pure red cell aplasia

Parvovirus B19 infection causes chronic anaemia in immunodeficient individuals by selective suppression of erythropoiesis. The bone marrow morphology is characteristic of pure red cell aplasia (PRCA). To determine the frequency of B19-induced PRCA we retrospectively analysed a series of 57 PRCA patients. B19 DNA was present in serum of eight patients (14%) and could be extracted from bone marrow aspirate slides from five of these patients. Recent exposure to the virus was confirmed by the presence of anti-B19 IgM in sera from four and by the finding of giant pronormoblasts in marrow aspirates from five of the B19 DNA-positive patients. The sensitivities of anti-B19 IgM and of giant pronormoblasts were only 50% and 63%, respectively; specificities were 90% and 92%. Unexpectedly, PRCA in two B19 DNA-positive patients remitted after antilymphocyte globulin or cyclosporin A therapy, suggesting that the clinical course of B19-induced PRCA may be indistinguishable from other forms of PRCA. As therapy with immunoglobulin is uniformly effective for treatment of B19-associated anaemia, our data suggest that all patients with acquired PRCA should be evaluated for evidence of B19 infection. B19 DNA analysis is the most reliable method to demonstrate infection.

Spontaneous IL-2 production in vitro in two patients with pure red cell aplasia

We investigated spontaneous cytokine production in two patients with pure red cell aplasia (PRCA). The peripheral blood mononuclear cells (PBMNC) from two patients produced IL-2. Cyclosporin A (CyA) suppressed in vitro IL-2 production in one patient, but not in the other. Spontaneous IL-2 production disappeared in one patient 10 months after the start of CyA therapy. The patient for whom CyA therapy was stopped after the disappearance of spontaneous IL-2 production has remained in continuous remission for 1 year. The present case suggests that spontaneous IL-2 production in PBMNC might be an indicator of disease activity.

Resolution of transfusion dependence by recombinant human erythropoietin (rHuEPO) in acquired pure red cell aplasia (PRCA) associated with myeloid metaplasia

A patient with acquired pure red cell aplasia and agnogenic myeloid metaplasia (AMM) was treated with rHuEPO. She became transfusion independent. Weekly injections of rHuEPO have maintained the response without side-effects or disease progression. In addition, marrow fibrosis and splenomegaly have decreased. Therefore, rHuEPO may be effective therapy for some patients with acquired PRCA and/or AMM.

Myelodysplastic syndromes in childhood: a population based study of nine cases

Nine cases of de novo myelodysplastic syndromes (MDS) in childhood from a population based study are presented. The annual incidence of MDS was 3.4/1,000,000 in children less than 15 years old, corresponding to 8.7% of all haematological malignancies in childhood. Two patients had Down's syndrome. None of the remaining patients had constitutional anomalies. All patients were classified according to the FAB classification. Five patients presented with refractory anaemia (RA), only one of these did not progress, one showed clonal evolution, and the remaining three patients all progressed to refractory anaemia with excess of blasts (RAEB). Three patients presented with RAEB. Two progressed to overt leukaemia. The last patient was classified as chronic myelomonocytic leukaemia (CMML). Clonal cytogenetic abnormalities were detected in five patients, in three of them as monosomy 7. Five patients have died; two of progressive disease, two of infections, and one of haemorrhage, two of the latter three patients died during therapy induced cytopenia. Of the four patients still alive, one patient showed a complete remission after cyclosporine and later immunoglobulin therapy, one patient is a long-term survivor after allogeneic bone marrow transplantation, and one patient apparently obtained a spontaneous remission several months after chemotherapy.