Red cell aplasia and chronic granulocytic leukaemia

Pure red cell aplasia

Pure red cell aplasia (PRCA) is a syndrome defined by a normocytic normochromic anemia with severe reticulocytopenia and marked reduction or absence of erythroid precursors from the bone marrow. Diamond-Blackfan anemia is a congenital form of PRCA. Acquired PRCA may be either a primary disorder or secondary to some other disorder or agent. Primary acquired PRCA is an autoimmune disorder that is frequently antibody-mediated. Myelodysplastic syndromes may also present with the morphologic appearance of PRCA. Secondary acquired PRCA may be associated with collagen vascular/autoimmune disorders such as systemic lupus erythematosus; lymphoproliferative disorders such as chronic lymphocytic leukemia or large granular lymphocyte leukemia; infections, particularly B19 parvovirus; thymoma and other solid tumors; or a variety of other disorders, drugs, or toxic agents. The therapeutic approach to PRCA typically involves immunosuppression, but specific pathogenic subtypes are associated with specific therapeutic approaches. Cyclosporine A, with or without concurrent corticosteroids, appears to be the single most effective immunosuppressive agent.

Pure red cell aplasia

Pure red cell aplasia (PRCA) is a syndrome defined by a normocytic normochromic anemia with severe reticulocytopenia and marked reduction or absence of erythroid precursors from the bone marrow. Diamond-Blackfan anemia is a congenital form of PRCA. Acquired PRCA may be either a primary disorder or secondary to some other disorder or agent. Primary acquired PRCA is an autoimmune disorder that is frequently antibody-mediated. Myelodysplastic syndromes may also present with the morphologic appearance of PRCA. Secondary acquired PRCA may be associated with collagen vascular/autoimmune disorders such as systemic lupus erythematosus; lymphoproliferative disorders such as chronic lymphocytic leukemia or large granular lymphocyte leukemia; infections, particularly B19 parvovirus; thymoma and other solid tumors; or a variety of other disorders, drugs, or toxic agents. The therapeutic approach to PRCA typically involves immunosuppression, but specific pathogenic subtypes are associated with specific therapeutic approaches. Cyclosporine A, with or without concurrent corticosteroids, appears to be the single most effective immunosuppressive agent.

[A case of systemic lupus erythematosus accompanied with pure red cell aplasia]

Pure red cell aplasia (PRCA) is a rare cause of anemia associated with SLE. We herein report a case presenting with SLE and PRCA. A 33-year-old woman, who had been suffering from photosensitivity, proteinuria, and pancytopenia, was diagnosed to have SLE. She showed normochromatic normocytic anemia. The serum level of haptoglobin was <10 mg/dl, and Direct Coombs' test was negative. Her reticulocyte count was 0.8%. Her clinical and laboratory features, except for anemia, had recovered in response to 50 mg/day of prednisolone. The serum level of haptoglobin had normalized, but the reticulocyte count remained low. The bone marrow findings revealed erythroid hypoplasia, and she was diagnosed to have PRCA complicated with SLE. No viral DNA of human parvovirus B19 in her bone marrow was detected. The anemia gradually improved following the further use of 50 mg/day prednisolone. In order to disclose the mechanism of PRCA in this patient, we examined the effects of her peripheral T lymphocytes on erythrogenesis, using erythroid colony-forming cells (ECFC) in her peripheral blood. When we co-cultured peripheral T cells and ECFC, her T cells inhibited erythroid colony formation in a dose dependent manner. Several reports have shown the presence of inhibitory factors in SLE patients' serum such as antibodies against erythroid progenitors or erythropoietin, while other reports have shown abnormal T cells that inhibit the growth of erythroid progenitors. Our study suggests that these inhibitory T cells may therefore have played an important role in the pathogenesis of this patient.

Erythropoietin-induced, antibody-mediated pure red cell aplasia

Pure red cell aplasia (PRCA) is a rare haematological condition that is characterized by severe aregenerative anaemia due to an almost complete cessation of red blood cell production. While antibody-mediated PRCA was extremely rare before 1998, the incidence of this disorder increased sharply after 1998 in patients receiving subcutaneous epoetin alfa produced by Ortho-Biotech and marketed outside the USA. The diagnosis of antibody-mediated PRCA relies mostly on the results of bone marrow biopsy or aspirate, which shows an absence of erythroid precursors and/or red cell maturation arrest while counts of white cell and platelet precursors are normal, and on the identification of circulating anti-erythropoietin antibodies. Retrospective analysis of PRCA cases has shown that immunosuppressive therapy can induce a disappearance of anti-erythropoietin antibodies in most patients. Eur J Clin Invest 2005; 35 (Suppl. 3): 95-99.

Interferon-alpha-induced pure red cell aplasia following chronic myelogenous leukemia

We report a case of pure red cell aplasia (PRCA) that resulted from interferon (IFN)-alpha therapy for chronic myelogenous leukemia. PRCA improved within 1 month after IFN-alpha was discontinued. This case indicates the involvement of IFN-alpha in the pathogenesis of PRCA.

Pure red cell aplasia in a patient with chronic granulocytic leukaemia treated with interferon-alpha

Interferon-alpha has been shown to improve survival in patients with chronic granulocytic leukaemia, therefore it is increasingly becoming part of the standard treatment of this condition. Interferon has a wide variety of side-effects. Pure red cell aplasia has been reported in a few cases of chronic granulocytic leukaemia but this usually heralds the onset of the transformation to the acute phase. This paper reports a possible, and not previously reported, side-effect of interferon-alpha in a patient with chronic granulocytic leukaemia.

Pure red cell aplasia in a case of Ph negative BCR/ABL rearranged CML with t(12;14)(q23;p11)

A patient with chronic myelogenous leukemia (CML) associated with pure red cell aplasia (PRCA) is reported. The occurrence of PRCA has been described previously in sporadic cases of Philadelphia chromosome (Ph) positive CML. In this patient, however, the Ph-chromosome was not detected; cytogenetic analysis revealed a t(12;14)(q23;p11) as the sole abnormality. Molecular studies by Southern and PCR analyses showed the rearrangement of the BCR and ABL sequences and expression of the chimeric bcr/abl mRNA, thus confirming the diagnosis of CML. To our knowledge, this is the first report on a case of PRCA associated with Ph negative CML at diagnosis. The possible connection between CML and PRCA is discussed.

Red cell aplasia in myelodysplastic syndrome

Six cases of red cell aplasia occurring in patients with myelodysplastic syndromes (MDS) showed a diversity of clinical course and prognosis. In some patients red cell aplasia may have represented an evolution of MDS while in others autoimmune destruction of erythoblasts may have been the mechanism. A proliferative phase is seen in many of these patients, the clinical importance of which is uncertain.

Detection of erythroid hypoplasia in myelofibrosis using erythrokinetic studies

The iron kinetic model described by Ricketts et al was used to study haemopoiesis in chronic myelofibrosis. The clearance of 59Fe-labelled transferrin from the plasma was analysed to quantify total, effective, and ineffective erythropoiesis, denoted by the terms marrow iron turnover (MIT), red cell iron turnover (RCIT), and per cent ineffective iron turnover (IIT%), respectively, in 12 cases of this disease. The patterns obtained were variable: values for MIT ranged from 24.4 to 510 mumol/l blood/day; those for RCIT from 0.4 to 119 mumol/l blood/day; and those for IIT% from 67 to 98%. One noteworthy feature was the presence in two cases of functional erythroid hypoplasia; these were characterised by severely reduced values for MIT (24.4 and 28 mumol/l blood/day) and RCIT (0.4 and 8 mumol/l blood/day.) A systematic study of the erythrokinetic features of myelofibrosis may indicate that erythroid hypoplasia is a more common cause of anaemia in this disease than has been previously recognised.

Chronic myeloid leukemia associated with pure red cell aplasia and terminating in promyelocytic transformation

After intermittent treatment with busulphan over a 7-year period for chronic myeloid leukemia (CML) in chronic phase, a 39-year-old female developed leukocytosis in association with pure red cell aplasia (PRCA). Bone marrow examination confirmed erythroid aplasia, and culture revealed a total absence of erythroid progenitor cells. The patient then was treated with azathioprine, corticosteroids, cyclophosphamide, plasma exchange, and cyclosporin A, but she remained erythroblastopenic and transfusion dependent for more than a year, at which time a promyelocytic transformation supervened. The authors propose that this sequence of events, hitherto unreported, is a manifestation of the multistep progression of CML.

Marrow aplasia developing 3 years after treatment with busulphan for chronic myeloid leukaemia

A 31-year-old woman with Philadelphia chromosome-positive chronic myeloid leukaemia (CML) was treated intermittently with high-dose busulphan over a 6-yr period (total dose 1320 mg). 3 yr later (after receiving no further cytotoxic drugs) she developed pancytopenia and marrow aplasia of relatively abrupt onset. Transfusion of reconstituted blood-derived stem cells (collected 7 yr previously) re-established chronic phase CML. These events are more consistent with 'stem cell exhaustion' than with an acquired marrow microenvironmental defect occurring in the course of CML. The contribution of busulphan is uncertain.

Cyclosporin-A therapy of pure red cell aplasia in a patient with B-cell chronic lymphocytic leukemia

A 65-year-old woman with B-cell chronic lymphocytic leukemia (CLL) and pure red cell aplasia (PRCA) is described. After initial chemotherapy with three different regimens over 3 months (prednisone, chlorambucil/vincristine, cyclophosphamide, bleomycin/cyclophosphamide, etoposide, prednisone), normalization of the blood lymphocyte count was observed, but lymphocyte infiltration of the bone marrow persisted and erythropoiesis remained virtually absent. Monotherapy with cyclosporin-A (CyA) was begun. After 35 days, a marked increase in the reticulocyte count was observed, and with continuing therapy, there was a rapid increase in the hemoglobin level. Follow-up after 13 months of uninterrupted treatment with CyA revealed remission of both CLL and PRCA. CyA should be investigated further as a therapeutic modality for PRCA in patients with CLL, and such trials might provide further clues to the pathogenesis of this peculiar association.

Red cell hypoplasia, thrombocytosis, and leucocytosis: myelodysplastic and proliferative syndrome

Three patients with chronic red cell aplasia also showed thrombocytosis or granulocytosis, or both. All had morphological evidence of myelodysplasia on examination of bone marrow aspirate but none had a detectable chromosomal abnormality. These patients seem to provide evidence of a separate entity within the spectrum of myelodysplastic and myeloproliferative disease.

The role of antilymphocyte globulin in the treatment of chronic acquired bone marrow failure

Antilymphocyte globulin is an immunoglobulin preparation prepared from heterologous serum after the animal (horse or rabbit) has been immunised with human lymphocytes, obtained from the thymus (antithymocyte globulin, ATG) or thoracic duct (antilymphocyte globulin, ALG). The rationale for the use of ALG in the treatment of chronic acquired marrow failure is based on its immunosuppressive activity and the fact that a proportion of cases of bone marrow failure, whether affecting single or multiple haemopoietic cell lines are due to immune-mediated suppression of haemopoiesis. In addition, in vitro studies have shown that ALG also has an immunostimulatory effect on lymphokine and haemopoietic growth factor production, and may therefore directly stimulate haemopoietic progenitor cells. ALG has been used for the treatment of aplastic anaemia and acquired chronic marrow failure affecting single cell lines namely pure red cell aplasia (PRCA), amegakaryocytic thrombocytopenia and chronic neutropenia due to immune inhibition of granulopoiesis ('acquired white cell aplasia'). ALG is used for treatment of non-severe aplastic anaemia (NSAA) and in those cases of severe aplastic anaemia (SAA) where allogeneic transplantation is not possible or is not indicated. Treatment with ALG results in 75% long term survival for NSAA and 40-50% for SAA although there is a very severe subgroup of SAA defined by peripheral blood neutrophils of less than 0.2 x 10(9)/l who rarely benefit from ALG therapy. For those patients who do not respond a second course of ALG can be given later using ALG from a different animal source.(ABSTRACT TRUNCATED AT 250 WORDS)

Pure red cell aplasia as possible early manifestation of chronic myeloid leukemia

Cytogenetic studies as well as erythroid and myeloid progenitor cell assays were performed in a 29-yr-old epileptic man with pure red cell aplasia (PRCA) who had been treated with primidone for several years. Despite clinical evidence of preleukemia, our studies indicated an underlying atypical Philadelphia chromosome-positive myeloproliferative disorder. These laboratory findings were confirmed by the subsequent development of chronic myeloid leukemia (CML) which terminated in a CALLA-positive lymphoblastic crisis 32 months later. The rare concurrent occurrence of PRCA and CML and the possible inducing role of the preceding antiepileptic treatment are discussed.