Aplastic anemia (first of two parts): pathogenesis, diagnosis, treatment, and prognosis

Alteration in marrow stromal microenvironment and apoptosis mechanisms involved in aplastic anemia: an animal model to study the possible disease pathology

Aplastic anemia (AA) is a heterogeneous disorder of bone marrow failure syndrome. Suggested mechanisms include a primary stem cell deficiency or defect, a secondary stem cell defect due to abnormal regulation between cell death and differentiation, or a deficient microenvironment. In this study, we have tried to investigate the alterations in hematopoietic microenvironment and underlying mechanisms involved in such alterations in an animal model of drug induced AA. We presented the results of studying long term marrow culture, marrow ultra-structure, marrow adherent and hematopoietic progenitor cell colony formation, flowcytometric analysis of marrow stem and stromal progenitor populations and apoptosis mechanism involved in aplastic anemia. The AA marrow showed impairment in cellular proliferation and maturation and failed to generate a functional stromal microenvironment even after 19 days of culture. Ultra-structural analysis showed a degenerated and deformed marrow cellular association in AA. Colony forming units (CFUs) were also severely reduced in AA. Significantly decreased marrow stem and stromal progenitor population with subsequently increased expression levels of both the extracellular and intracellular apoptosis inducer markers in the AA marrow cells essentially pointed towards the defective hematopoiesis; moreover, a deficient and apoptotic microenvironment and the microenvironmental components might have played the important role in the possible pathogenesis of AA.

JAK2/STAT5 signaling pathway mediates Bojungbangdocktang enhanced hematopoiesis

Bojungbangdocktang (BJBDT) is a medicinal herbal cocktail that has been used for cancer prevention and treatment in traditional Korean medicine. In the current study, BJBDT was demonstrated to regulate hematopoiesis. BJBDT significantly increased the expression of hematopoietic cytokines interleukin (IL)-3, stem cell factor (SCF), granulocyte-macrophage-colony stimulating factor (GM-CSF), thrombopoietin (TPO) and erythropoietin (EPO) at the level of mRNA and secretion in hematopoietic stem cells (HSCs). Additionally, BJBDT enhanced the phosphorylation of Janus activated kinase 2 (JAK2) and signal transducer and activator of transcription 5 (STAT5) and STAT binding to gamma interferon activated sites (GAS) in HSCs. Furthermore, BJBDT significantly enhanced the growth rate of granulocyte erythrocyte monocyte macrophage colony-forming units (CFU-GEMM) and erythroid burst forming units (BFU-E) in vitro. Moreover, BJBDT increased the level of EPO at mRNA in kidney and plasma, and the numbers of erythroid-specific antigen Ter-119(+) erythroid cells in mice with aplastic anemia induced by 20% benzene. Consistently, histochemical staining revealed BJBDT increased the bone marrow and stromal cells as well as decreased macrophages and adipocytes in bone marrow tissues of mice with aplastic anemia. Taken together, the results suggest that BJBDT can enhance hematopoiesis via hematopoietic cytokine-mediated JAK2/STAT5 pathway as a potent hematopoietic candidate. Copyright © 2010 John Wiley & Sons, Ltd.

Musings on genome medicine: enzyme-replacement therapy of the lysosomal storage diseases

The lysosomal storage diseases, such as Gaucher's disease, mucopolysaccharidosis I, II and IV, Fabry's disease, and Pompe's disease, are rare inherited disorders whose symptoms result from enzyme deficiency causing lysosomal accumulation. Until effective gene-replacement therapy is developed, expensive, and at best incomplete, enzyme-replacement therapy is the only hope for sufferers of rare lysosomal storage diseases. Preventive strategies involving carrier detection should be a priority toward the successful management of these conditions.

[Evaluation of a prospective therapeutic protocol in adult patients with nonsevere aplastic anemia in South Tunisia]

INTRODUCTION

Immunosuppressive drugs are usually used in the treatment of acquired aplastic anemia (AAA). The aim of this study was to evaluate the efficiency of a prospective therapeutic protocol using cyclosporine and androgens in the treatment of adult patients with nonsevere AAA.

METHODS

Twenty-nine patients diagnosed and treated at the University Hospital of Sfax (Tunisia), during a 10-year period (1991-2000) were included. In addition to symptomatic treatment (transfusion, antibiotics), all the patients received a specific treatment including two drugs: cyclosporine 5mg/kg per day and androgens 0,5mg/kg per day.

RESULTS

The response rate at three, six and 12 months were 48, 75, and 87%, respectively. Survival rate was 52% at one year, and 37% at five and 10 years. The main toxicities were hepatic, renal, and hypertension, observed in 53, 16 and 15%, respectively. These toxicities were reversible in 65, 87 and 100% of the cases, respectively.

CONCLUSION

The response and survival rates in our series are quite satisfactory when compared to those obtained with other immunosuppressive drugs (cyclosporine and antilymphocyte serum) in the literature. The addition of androgens in our patients seemed to potentiate the immunosuppression induced by ciclosporin, but secondary toxic effects were more common.

HLA association is different in children and adults with severe acquired aplastic anemia

BACKGROUND

Severe aplastic anemia (SAA) is defined as pancytopenia caused by bone marrow failure. The pathogenesis of SAA is thought to involve autoimmune processes. Increased susceptibility to autoimmunity has been shown to be associated with several different HLA alleles. In SAA, few large studies based on data mainly from adults describe a positive HLA correlation with HLA-DR2 (DRB1*15) and HLA-B14.

PROCEDURE

This study explored the HLA constitution of 181 children with SAA who were enrolled in the prospective multi-center study SAA94 between January 1994 and January 2002. The control group consisted of 303 healthy individuals of comparable demographic background. Allelic frequencies between patients and controls are compared using Fisher's exact test.

RESULTS

In our pediatric cohort, we describe a positive association with HLA-B14 (P = 0.0039), but no association of HLA-DR2 with SAA.

CONCLUSION

HLA associations appear to be different in children and adults with SAA. This might point towards a difference in pathophysiology between at least part of the children and adults.

Facilitating cells: Novel promoters of stem cell alloengraftment and donor-specific transplantation tolerance in the absence of GVHD

Bone marrow transplantation (BMT) is the treatment of choice for many hematological malignancies and immunopathologies. Unfortunately, success is often impeded by engraftment failure and graft-versus-host disease (GVHD). A rare bone marrow population known as the facilitating cell (FC) has been identified which facilitates stem cell engraftment and circumvents these obstacles in murine experimental models. This review discusses the identification and characterization of this rare population and provides an emerging portrait of FC origin, ontogeny and function. The promotion of durable stem cell engraftment in MHC disparate recipients, GVHD inhibition and tolerance induction by the FC suggests that future therapies in hematopoietic cell transplantation and tolerance induction for solid organ transplants may be significantly improved through the application of FC transplantation.

Childhood aplastic anaemia in Lucknow, India: Incidence, organochlorines in the blood and review of case reports following exposure to pesticides

OBJECTIVES

A hospital-based case-control study, the first in India, was conducted to determine the incidence of childhood aplastic anaemia in and around Lucknow in the backdrop of organochlorine levels in the blood and review the database for any association between the disease and exposure to pesticides.

DESIGN AND METHODS

A total of 25 cases of childhood aplastic anaemia were identified as per established criteria and enrolled over the study period of 1 year. Their blood organochlorine levels were determined using a gas-liquid chromatograph equipped with an electron capture detector.

RESULTS

The annual incidence of childhood aplastic anaemia in and around Lucknow was found to be 6.8 cases per million which is higher than many countries (e.g., France, Brazil, UK, and United States) but lower than those reported in Sweden, China and an European-Israeli collaborative study. Blood levels of alpha-HCH, gamma-HCH, delta-HCH, total-HCH, and p, p'-DDE were higher in children with aplastic anaemia than in those of controls; only alpha-HCH differed significantly (P < 0.05).

CONCLUSIONS

Although this pilot study, with limited statistical power, did not support any association between exposure to organochlorines and risk of childhood aplastic anaemia, a possible association between the two could not be ruled out in view of several cases identified following exposure to pesticides.

Further development of a model of chronic bone marrow aplasia in the busulphan-treated mouse

Aplastic anaemia (AA) in man is an often fatal disease characterized by pancytopenia of the peripheral blood and aplasia of the bone marrow. AA is a toxic effect of many drugs and chemicals (e.g. chloramphenicol, azathioprine, phenylbutazone, gold salts, penicillamine and benzene). However, there are no widely used or convenient animal models of drug-induced AA. Recently, we reported a new model of chronic bone marrow aplasia (CBMA = AA) in the busulphan (BU)-treated mouse: eight doses of BU (10.50 mg/kg) were administered to female BALB/c mice over a period of 23 days; CBMA was evident at day 91/112 post-dosing with significantly reduced erythrocytes, platelets, leucocytes and nucleated bone marrow cell counts. However, mortality was high (49.3%). We have now carried out a study to modify the BU-dosing regime to induce CBMA without high mortality, and investigated the patterns of cellular responses in the blood and marrow in the post-dosing period. Mice (n = 64/65) were dosed 10 times with BU at 0 (vehicle control), 8.25, 9.0 and 9.75 mg/kg over 21 days and autopsied at day 1, 23, 42, 71, 84, 106 and 127 post-dosing (n = 7-15); blood and marrow samples were examined. BU induced a predictable bone marrow depression at day 1 post-dosing; at day 23/42 post-dosing, parameters were returning towards normal during a period of recovery. At day 71, 84, 106 and 127 post-dosing, a stabilized, late-stage, nondose-related CBMA was evident in BU-treated mice, with decreased erythrocytes, platelets and marrow cell counts, and increased MCV. At day 127 post-dosing, five BU-treated mice showed evidence of lymphoma. In this study, mortality was low, ranging from 3.1% (8.25 mg/kg BU) to 12.3% (9.75 mg/kg BU). It is concluded that BU at 9.0 mg/kg (or 9.25 mg/kg) is an appropriate dose level to administer (10 times over 21 days) to induce CBMA at approximately day 50-120 post-dosing.

Post-liver-transplant anemia: etiology and management

Anemia is common after liver transplantation, with the incidence ranging from 4.3% to 28.2% depending on the criteria used to define anemia. The cause of anemia is unidentified in the majority of patients, and it is likely to be multifactorial. Immunosuppressive-medication-induced bone marrow suppression is perhaps the most common cause of unexplained anemia. Chronic blood loss, iron deficiency, hemolysis, and renal insufficiency are other potential causes of chronic anemia. Rare causes, somewhat unique to transplantation, include aplastic anemia, graft-versus-host disease (GVHD), and lymphoproliferative disease. Anemia due to immunosuppressive medication is challenging, since almost all drugs currently used for this purpose cause anemia, but the renal-sparing property of sirolimus may benefit the subgroup in which renal insufficiency is contributing to anemia. Aplastic anemia is seen in young patients transplanted for non-A, non-B, non-C, fulminant hepatic failure. It is thought to be immunologically mediated, secondary to an unknown viral infection, and is associated with a grave prognosis. GVHD is another infrequent (approximately 1% of transplant recipients) but serious cause of severe anemia that carries a dismal prognosis. Lymphoproliferative disorder, too may rarely rare cause anemia and it may respond to reduction of immunosuppression. Recipients of solid-organ transplants do not mount a significant increase in erythropoietin in response to anemia. In conclusion, though there are no data on the response of anemia to erythropoietin in liver transplant recipients, it appears to benefit other solid-organ-transplant recipients with anemia.

Hematopoietic stem cell transplantation for severe aplastic anemia--experience of an institute in Taiwan

Hematopoietic stem cell transplantation (HSCT) is an accepted treatment strategy for patients with severe aplastic anemia (SAA). We report our experience in a general hospital in Taiwan. From March 1985 to July 2001, 79 consecutive SAA patients, 46 male and 33 female, with a median age of 22 (4-43) years, received 80 courses of transplantation. Cyclophosphamide and total body radiation were used for the conditioning regimen, and cyclosporine-A and methotrexate for graft-versus-host disease (GVHD) prevention. Patients were followed for a median of 39 months (from 8 days to 194 months). Myeloid and platelet engraftment occurred in a median of 15 (8-27) days and 18 (8-77) days, respectively. Three patients had primary and three patients secondary graft failure. Five patients (6.8%) had grade II-IV acute GVHD in 73 evaluable patients. Chronic GVHD occurred in 23 (34.8%) patients, with extensive stage in six. Only two patients had CMV disease. The projected 3- and 5-year overall survival rates estimated by the Kaplan-Meier method were 76.08 and 74.13%, respectively. Age at transplant, non-sibling donor, mononuclear cell dose, grade II-IV acute GVHD, interval from diagnosis to transplant, and red blood cell and platelet transfusion before transplant were poor prognostic factors for overall survival by univariate analysis. Grade II-IV acute GVHD was the only prognostic factor affecting overall survival after multivariate Cox regression analysis (P=0.040). In conclusion, SAA patients receiving HSCT have good long-term survival. The low incidence of acute GVHD in our patients may be related to ethnicity.

Pregnancy associated aplastic anemia: maternal and fetal outcome

AIM

To study the maternal and fetal outcome in cases of aplastic anemia associated with pregnancy.

METHOD

Retrospective analysis of seven cases of aplastic anemia diagnosed during pregnancy.

RESULT

Four patients had an overall successful pregnancy outcome. These were all cases of non-severe aplastic anemia. There was one case each of intrauterine and neonatal death in the severe aplastic anemia group. There was one maternal mortality.

CONCLUSION

Maternal and fetal outcome is poor in severe aplastic anemia.

Involvement of cytotoxic granules in the apoptosis of aplastic anaemia

To study the involvement of cytotoxic granules in apoptosis of aplastic anaemia (AA), we analysed bone marrow clot sections of AA for apoptosis and perforin, granzyme B and T-cell intracellular antigen-1 (TIA-1) expression. Perforin, TIA-1 expression and apoptosis were significantly increased in AA patients compared with control subjects, but granzyme B was not. TIA-1 was significantly correlated with apoptotic cells of AA. No correlation was found between perforin and apoptotic cells of AA. These results suggest that perforin and TIA-1 play a role in the pathogenesis of AA. TIA-1 is implicated as an effector in the apoptosis of AA.

A new model of busulphan-induced chronic bone marrow aplasia in the female BALB/c mouse

Aplastic anaemia (AA) is characterized by hypocellular marrow, pancytopenia, and risk of severe anaemia, haemorrhage and infection. AA is often idiopathic, but frequently occurs after exposure to drugs/chemicals. However, the pathogenesis of AA is not clearly understood, and there are no convenient animal models of drug-induced AA. We have evaluated regimens of busulphan (BU) administration in the mouse to produce a model of chronic bone marrow aplasia showing features of human AA. Mice were given 8 doses of BU at 0, 5.25 and 10.50 mg/kg over 23 days; marrow and blood samples were examined at 1, 19, 49, 91 and 112 days after dosing. At day 1 post dosing, in mice treated at 10.50 mg/kg, nucleated marrow cells, CFU-GM and Erythroid-CFU were reduced. Similarly, peripheral blood erythrocytes, leucocytes, platelets and reticulocytes were reduced. At day 19 and 49 post dosing, there was a trend for parameters to return towards normal. However, at day 91 and 112 post dosing, values remained significantly depressed, with a stabilized chronic bone marrow aplasia. At day 91 and 112 post dosing, marrow cell counts, CFU-GM and Erythroid-CFU were decreased; marrow nucleated cell apoptosis and c-kit+ cell apoptosis were increased; peripheral blood erythrocyte, leucocyte, and platelet counts were reduced. We conclude that this is a model of chronic bone marrow aplasia which has many interesting features of AA. The model is convenient to use and has potential in several areas, particularly for investigations on mechanisms of AA pathogenesis in man.

Allergy development after bone marrow transplantation from a non-atopic donor

BACKGROUND

Transfer of allergy from atopic bone marrow donors to recipients is known to occur. Development of allergy in a non-atopic patient transplanted from a non-atopic donor is an unfamiliar phenomenon in clinical practice.

OBJECTIVES

To clarify the course of events causing a bone marrow recipient to acquire an allergic disease in such non-conducive circumstances.

METHODS

Full medical history, prick and intradermal skin tests, and serum IgE levels were obtained from both donor and recipient patients. DNA and red blood cell phenotype analyses were used to detect the degree of chimerism.

RESULTS

Only the recipient patient showed positive specific IgE antibodies and skin tests to house dust mite. The recipient patient displayed 100% donor chimera, based on all engraftment markers sought.

CONCLUSION

Full engraftment after allogeneic bone marrow transplantation may be associated with modulation of T and B cell function, which in turn could cause the onset of allergic disease after bone marrow transplantation.

Comparative analysis of the in vitro proliferation and expansion of hematopoietic progenitors from patients with aplastic anemia and myelodysplasia

Aplastic anemia (AA) and myelodysplasia (MDS) show great similarities in their biology. To date, however, it is still unclear to what extent hematopoietic progenitor cells (HPCs) from AA and MDS share biological properties and what the functional differences are between them. In trying to address this issue, in the present study we have analyzed, in a comparative manner, the proliferation and expansion capacities of bone marrow (BM) progenitor cells from AA and MDS in response to recombinant cytokines. BM samples from normal subjects (NBM) and patients with AA and MDS were enriched for HPC by immunomagnetic-based negative selection. Selected cells were cultured in the absence (control) or in the presence of early-acting cytokines (Mix I), or early-, intermediate- and late-acting cytokines (Mix II). Proliferation and expansion were assessed periodically. In NBM and MDS cultures apoptosis was also determined. In NBM cultures, Mix I induced a nine-fold increase in total cell numbers and a 3.6-fold increase in colony-forming cell (CFC) numbers. In Mix II-supplemented cultures, total cells were increased 643-fold, and CFC 12.4-fold. In AA cultures, no proliferation or expansion were observed in Mix I-supplemented cultures, whereas only a four-fold increase in total cell numbers was observed in the presence of Mix II. In MDS cultures, a 12-fold increase in total cells and a 2.9-fold increase in CFC were observed in the presence of Mix I; on the other hand, Mix II induced a 224-fold increase in total cells and a 5.9-fold increase in CFC. Apoptosis was reduced in cytokine-supplemented cultures from NBM. In contrast, Mix II induced a significant increase in the rate of apoptosis in MDS cultures. Our results demonstrate that, as compared to their normal counterparts, AA and MDS progenitors are deficient in their proliferation and expansion potentials. Such a deficiency is clearly more pronounced in AA cells, which seem to be unable to respond to several cytokines. MDS progenitors, on the other hand, are capable to proliferate and expand in response to cytokines; however, their rate of apoptosis is increased by intermediate- and late-acting cytokines, so that the overall proliferation and expansion are significantly lower than those of normal progenitor cells.

Superior growth of glycophosphatidy linositol-anchored protein-deficient progenitor cells in vitro is due to the higher apoptotic rate of progenitors with normal phenotype in vivo

OBJECTIVE

Recently, phenotypically normal CD34 cells from the marrow of patients with paroxysmal nocturnal hemoglobinuria (PNH) were reported to show impaired growth and elevated Fas receptor expression as compared to glycophosphatidylinositol-anchored protein (GPI-AP)-deficient CD34 cells and CD34 cells from normal individuals. These results are consistent with the theory that PNH cells have an intrinsic growth advantage, but their superior expansion in vitro could also be the outcome of selective extrinsic pressure in vivo.

MATERIAL AND METHODS

Growth characteristics, competitive features, and susceptibility to apoptosis of sorted normal or GPI-AP-deficient CD34(+) cells derived from PNH patients were assessed in suspension and methylcellulose cultures.

RESULTS

When we directly compared the growth of patients' CD34 cells, separated based on expression of GPI-AP CD55 and CD59, in most of the patients studied, mutant CD34 cells showed higher progeny production and outgrew phenotypically normal CD34 cells derived from PNH patients in mixing experiments. However, their proliferation rate did not exceed that of control CD34 cells. To determine whether deficient growth of phenotypically normal CD34 cells in PNH was secondary to a pre-existing in vivo insult, we determined the fraction of apoptotic cells within fresh normal and PNH CD34 cells. Normal CD34 cells from PNH patients showed a high proportion of apoptotic cells and higher Fas expression, while GPI-AP-deficient and control CD34 cells showed similar, low rates of apoptosis. After correction for pre-existing apoptosis, the proliferation potential of normal and PNH CD34 cells was similar.

CONCLUSIONS

These results strongly suggest that clonal expansion of GPI-AP-deficient progenitor cells from PNH patients is due to their selection in the hostile marrow environment of the patient.

Bone marrow samples from patients with aplastic anemia are not infected with parvovirus B19 and Mycobacterium tuberculosis

The majority of patients with aplastic anemia (AA) have an idiopathic form of the disease. The aim of this study was to detect the presence of parvovirus B19 DNA and Mycobacterium tuberculosis (MTB) DNA by nested polymerase chain reaction (N-PCR) assays in the bone marrow biopsy samples from 30 patients with idiopathic AA. Serologic assays for parvovirus B19 were based on indirect antibody capture enzyme-linked immunosorbent assay. Our results indicate that neither parvovirus B19 DNA nor MTB DNA could be demonstrated in any of the bone marrow samples by N-PCR. Moreover, IgM antibody against parvovirus B19 also was undetectable in the serum samples of 17 patients. Thus, our results suggest that parvovirus B19 and MTB are not associated with AA and, consequently, do not have a role in the pathogenesis of this disease.

Sequential Variations in the Content of Bone Marrow Colony-forming Cells in Individual Patients with Aplastic Anemia Before and After Immunosuppressive Therapy; Hematopoiesis

Previous studies have shown that the levels of hematopoietic progenitor cells (colony-forming cells; CFC) are drastically reduced in the vast majority of patients with aplastic anemia (AA). This has been observed both in patients before and after immunosuppressive therapy. In those studies, however, both groups of patients were usually formed by different individuals, thus it was not possible to follow the kinetics of such cells in each particular patient. In the present study, we have determined the content of myeloid and erythroid CFC in individual AA patients before and after therapy. Treated patients were studied at two different times (8-18 months apart) to detect any possible variations due to the ongoing treatment. At diagnosis, the levels of both myeloid and erythroid CFC were drastically reduced, as compared to normal bone marrow, in all the patients studied. This correlated with very low levels of leukocytes and hemoglobin in circulation. After the patients entered an immunosuppressive treatment, all of them showed significant increments in their CFC levels, and this correlated with increments in their hematological parameters in peripheral blood. However, in most patients CFC levels were still below the normal range. When the second sample after treatment was obtained, great variations in CFC numbers were observed. In terms of erythroid CFC levels, a further increase was seen in most patients, and this correlated with a further increase in hemoglobin levels. In contrasts, the levels of myeloid CFC were increased in only some of the patients, whereas in others, significant reductions were evident. Interestingly, in this latter group of patients, CFC never reached the levels observed before treatment. Our results indicate that, in a significant proportion of patients, a common pattern seems to exist. That is to say, low CFC numbers are present before treatment; an increase in the numbers of such cells results as an effect of the immunosuppressive therapy and further variations in CFC numbers (within individual limits that may differ significantly from one patient to another) take place as long as the treatment continues. Finally, we observed a correlation between CFC levels and the clinical status of the patients, i.e., those patients that showed a complete or a partial response to treatment showed higher levels of both myeloid and erythroid CFC than those patients that did not respond to therapy.

Arthroplasty of the hip in patients with aplastic anemia

BACKGROUND

Patients with aplastic anemia are now living longer and therefore are at increased risk for the development of osteonecrosis of the hip. However, studies on the results of arthroplasty for the treatment of osteoarthritis of the hip in patients with aplastic anemia are lacking.

METHODS

Twenty-six primary hip prostheses (one bipolar prosthesis fixed with cement, two bipolar prostheses fixed without cement, three hybrid total hip prostheses, and twenty total hip prostheses fixed without cement) were implanted, between March 1990 and May 1992, in nineteen patients who had been diagnosed with aplastic anemia. A specific prospective protocol was followed for the perioperative transfusion of platelets and blood. Twenty-five hips were replaced because of osteonecrosis of the femoral head, and one was replaced because of a femoral neck fracture. The patients were followed prospectively, with preoperative and serial postoperative Harris hip ratings as well as radiographs, for a minimum of six years or until death.

RESULTS

No patient had excessive perioperative bleeding or a postoperative infection. After a mean duration of follow-up of seventy-nine months (range, seventy-two to ninety-five months), two patients had died with the original implant in place. No patients were lost to follow-up. The mean Harris hip score was 55 points (range, 42 to 68 points) preoperatively and 87 points (range, 56 to 95 points) at the time of the latest follow-up. At the time of this writing, no hip had been revised. One patient with a bipolar prosthesis had radiographic evidence of femoral loosening and will probably require revision. A second patient had some medial protrusion of a bipolar prosthesis, with mild symptoms. All of the acetabular components that had been fixed without cement and all of the other femoral components appeared to be stable on radiographs after a minimum of seventy-two months of follow-up.

CONCLUSIONS

Total hip arthroplasty can be performed safely in patients with aplastic anemia. In the present intermediate-term study, the durability of implant fixation was maintained and the clinical results demonstrated a sustained increase in function of the hip.

Lenograstim: an update of its pharmacological properties and use in chemotherapy-induced neutropenia and related clinical settings

Lenograstim is the glycosylated recombinant form of human granulocyte colony stimulating factor. The drug is used to reduce the risk of life-threatening infection in patients with neutropenia, particularly after cytotoxic chemotherapy. Lenograstim accelerates neutrophil recovery significantly after chemotherapy, with beneficial effects on clinical end-points such as incidence of laboratory-confirmed infection and length of hospital stay. Chemotherapy dose intensity has also been increased in patients receiving lenograstim, notably those with breast or small cell lung cancer, although improvements in tumour response and survival have not been demonstrated. Lenograstim also assists neutrophil recovery in patients undergoing bone marrow transplantation, and stimulates the production of peripheral blood stem cells (PBSCs) for autologous transfusion after aggressive chemotherapy. Lenograstim also mobilises CD34+ cells more efficiently in unit dose terms than filgrastim and has been used successfully to mobilise PBSCs from healthy donors for allogeneic transplantation. Randomised trials have shown increases in rates of disease remission after lenograstim therapy in patients with acute myeloid leukaemia, with no evidence of stimulation of malignant blasts. The drug has also shown potential in the mobilisation of nonmalignant PBSCs for autotransplantation in patients with chronic myeloid leukaemia. Other studies show efficacy of lenograstim in patients with acute lymphoblastic leukaemia, aplastic anaemia, in children with severe chronic neutropenia and in the reversal of neutropenia related to antiviral therapy in patients with AIDS, although data are not extensive. Cost analyses of lenograstim have been carried out from a hospital perspective, although results have been inconclusive. Cost-effectiveness or cost-benefit data are lacking at present. Lenograstim is well tolerated, with bone pain and injection site reactions being reported most frequently in clinical trials.

CONCLUSIONS

Lenograstim has been confirmed as a valuable adjunct to minimise the haematological toxicity of myelosuppressive chemotherapy in patients with malignant disease. The drug also enhances neutrophil recovery in patients undergoing stem cell rescue, and assists PBSC mobilisation. Data indicate clinical benefit with lenograstim in myeloid disorders, with no evidence of malignant blast cell proliferation. Further studies are required to assess more fully the pharmacoeconomic implications of the use of lenograstim and other recombinant growth factors, to provide more data on the efficacy of the drug in the management of disease-related neutropenia, and to clarify fully its position relative to filgrastim.

Immunosuppressive treatment of aplastic anemia with antithymocyte globulin and cyclosporine

Immunosuppression is the treatment modality for the majority of patients with aplastic anemia, most of whom are not candidates for allogeneic stem-cell transplantation. Antithymocyte globulin (ATG) or antilymphocyte globulin (ALG) have proven to be essential components of all regimens. Initial response rates can be improved by the addition of cyclosporine A (CsA), and this combination has become the standard of care for appropriate patients. Several new approaches to immunosuppression are being studied, including the optimal timing of administration of these drugs, the use of novel immunosuppressive agents, and the addition of early- and late-acting hematopoietic growth factors.

A case of aplastic anaemia in pregnancy

Aplastic anaemia in pregnancy is an extremely rare condition with high maternal morbidity and mortality rates. Intensive haematological support remains the mainstay of therapy and a successful obstetric outcome can be best accomplished with the close clinical collaboration of the haematologist and the obstetrician as occurred with our patient reported here.

Successful cytokine treatment of aplastic anemia following living-related orthotopic liver transplantation for non-A, non-B, non-C hepatitis

The relationship between aplastic anemia and viral hepatitis is well recognized, and such patients usually have a high mortality. We successfully treated a case of aplastic anemia following living-related orthotopic liver transplantation (LROLT) for non-A, non-B, non-C hepatitis. A 2-yr-old boy with fulminant hepatic failure from non-A, non-B, non-C hepatitis received LROLT. Before transplantation, he had pancytopenia which was probably hepatitis associated, and viral suppression was suspected after bone marrow (BM) biopsy. After the transplantation, he developed progressive pancytopenia and a diagnosis of aplastic anemia was made via BM biopsy. With immunosuppressant agents (cyclosporine, methylprednisolone), cytokine therapy (granulocyte-colony stimulating factor (G-CSF), macrophage-colony stimulating factor (M-CSF), recombinant human erythropoietin (rhEPO)) was effectual and the patient recovered from pancytopenia. He was discharged from the hospital 57 d after the liver transplantation and remains well 1 yr after LROLT. Combined cytokine therapy with high doses of G-CSF, M-CSF and rhEPO appeared to be effective in the treatment of aplastic anemia following liver transplantation for non-A, non-B, non-C hepatitis. Since M-CSF activates macrophages, it may have contributed to the graft rejection. Careful consideration should be given to the use of high-dose M-CSF in liver transplant patients.

Effect of FLT3 Ligand and Granulocyte Colony-Stimulating Factor on Expansion and Mobilization of Facilitating Cells and Hematopoietic Stem Cells in Mice: Kinetics and Repopulating Potential

We have previously identified a cellular population in murine bone marrow that facilitates engraftment of highly purified hematopoietic stem cells (HSC) across major histocompatibility complex (MHC) barriers without causing graft-versus-host disease. Here we investigated the effect of flt3 ligand (FL) and granulocyte colony-stimulating factor (G-CSF) on the mobilization of facilitating cells (FC) and HSC into peripheral blood (PB). Mice were injected with FL alone (day 1 to 10), G-CSF alone (day 4 to 10), or both in combination. The number of FC (CD8+/βTCR−/γδTCR−) and HSC (lineage−/Sca-1+/c-kit+) was assessed daily by flow cytometry. Lethally irradiated allogeneic mice were reconstituted with PB mononuclear cells (PBMC). FL and G-CSF showed a highly significant synergy on the mobilization of FC and HSC. The peak efficiency for mobilization of FC (21-fold increase) and HSC (200-fold increase) was reached on day 10. Our data further suggest that the proliferation of FC and HSC induced by FL in addition to the mobilizing effect mediated by G-CSF might be responsible for the observed synergy of both growth factors. Finally, the engraftment potential of PBMC mobilized with FL and G-CSF or FL alone was superior to PBMC obtained from animals treated with G-CSF alone. Experiments comparing the engraftment potential of day 7 and day 10 mobilized PBMC indicate that day 10, during which both FC and HSC reached their maximum, might be the ideal time point for the collection of both populations. © 1998 by The American Society of Hematology.

Long-term administration of G-CSF for aplastic anaemia is closely related to the early evolution of monosomy 7 MDS in adults

There is an increasing incidence of the evolution of myelodysplastic syndrome (MDS) from aplastic anaemia (AA) with immunosuppressive treatment. In paediatric patients G-CSF is also reported to increase MDS evolution, but this process is not precisely understood in children or in adults. Therefore risk factors of MDS evolution in adults are evaluated here. Of 72 patients, five developed MDS. In 47 patients without cyclosporine (CyA) or antithymocyte globulin (ATG) therapy, only one developed MDS with trisomy 8, 242 months after diagnosis. But of 25 patients treated with either CyA or ATG, four developed monosomy 7 MDS within 3 years. Of these 25 patients, 18 were treated with G-CSF and the four patients (22.2%) who developed MDS were found in this group. The cumulative dose and the duration of G-CSF administration were significantly elevated in patients who developed MDS when compared with those who did not, 822.3 +/- 185.0 v 205.4 +/- 25.5 microg/kg (P<0.05) and 187.5 +/- 52.5 v 72.0 +/- 24.6 d (P<0.002), respectively. However these two values for CyA did not differ significantly. Statistically, treatment with CyA, G-CSF and combined G-CSF and CyA were significantly related to MDS evolution. The administration of G-CSF for more than a year was the most important factor (P=0.00). These results suggested that a close relationship exists between G-CSF and subsequent monosomy 7 MDS from AA in adults who receive immunosuppressive therapy. Long-term administration of G-CSF should be prohibited in order to prevent MDS evolution.

Effect of FLT3 Ligand and Granulocyte Colony-Stimulating Factor on Expansion and Mobilization of Facilitating Cells and Hematopoietic Stem Cells in Mice: Kinetics and Repopulating Potential

We have previously identified a cellular population in murine bone marrow that facilitates engraftment of highly purified hematopoietic stem cells (HSC) across major histocompatibility complex (MHC) barriers without causing graft-versus-host disease. Here we investigated the effect of flt3 ligand (FL) and granulocyte colony-stimulating factor (G-CSF) on the mobilization of facilitating cells (FC) and HSC into peripheral blood (PB). Mice were injected with FL alone (day 1 to 10), G-CSF alone (day 4 to 10), or both in combination. The number of FC (CD8+/βTCR−/γδTCR−) and HSC (lineage−/Sca-1+/c-kit+) was assessed daily by flow cytometry. Lethally irradiated allogeneic mice were reconstituted with PB mononuclear cells (PBMC). FL and G-CSF showed a highly significant synergy on the mobilization of FC and HSC. The peak efficiency for mobilization of FC (21-fold increase) and HSC (200-fold increase) was reached on day 10. Our data further suggest that the proliferation of FC and HSC induced by FL in addition to the mobilizing effect mediated by G-CSF might be responsible for the observed synergy of both growth factors. Finally, the engraftment potential of PBMC mobilized with FL and G-CSF or FL alone was superior to PBMC obtained from animals treated with G-CSF alone. Experiments comparing the engraftment potential of day 7 and day 10 mobilized PBMC indicate that day 10, during which both FC and HSC reached their maximum, might be the ideal time point for the collection of both populations. © 1998 by The American Society of Hematology.

Severe aplastic anemia of neonatal onset: a single-center retrospective study of six children

We report severe aplastic anemia of neonatal onset diagnosed in six girls between 1985 and 1995 in a single center. Initial blood cell counts (mean age 3.8 days old, 1 to 15 days) showed thrombocytopenia (six of six), anemia (four of six), and neutropenia (two of six). Neutrophil counts gradually decreased below 0.5 x 10(9)/L, and severe aplastic anemia occurred in three patients by 3 months of age and in all patients by 1 year of age. Lymphocyte number and functions were normal. In all children bone marrow biopsy showed hypocellularity for age and absence of fibrosis, blasts, lymphocytic infiltrates, and cytologic abnormalities. Blood and medullary cytogenetic studies were normal. A search for known constitutional, viral, or toxic causes was negative. Immunosuppressive therapy failed to restore hematopoiesis (three of six). Five children received a bone marrow transplantation at an average age of 9 months (range 2.7 to 29 months). One child is alive and well after a human leukocyte antigen-identical bone marrow transplantation, whereas the other four died. Both congenital onset and the high rate of familial involvement suggest that this condition may be inherited.

Hematologic response in patients with aplastic anemia after long-term administration of recombinant human granulocyte colony-stimulating factor and erythropoietin

Twenty patients with aplastic anemia underwent long-term administration (10 weeks) of recombinant human granulocyte colony-stimulating factor (rhG-CSF) in doses from 50 to 800 micrograms/m2 per day by intravenous infusion or 50 to 100 micrograms/m2 per day by subcutaneous injection and re-combinant human erythropoietin (rhEPO) in doses ranging from 2000 to 8000 IU/m2 per day by intravenous injection three times a week for at least 4 weeks. The goal was to evaluate whether therapy ameliorated pancytopenia in these patients as well as to determine its safety. All assessable patients showed a substantial increase in absolute neutrophil count, with a recovery of myeloid components (granulocyte series) in the bone marrow, after 2 to 10 weeks of treatment. An increase > 1.5 g/dL in hemoglobin (Hb) concentration was observed in 2 patients (10%). A decrease > 50% in red cell transfusion requirement was observed in 2 patients (10%). Seven patients showed recovery of neutropenia, anemia, and platelet count. In addition, there was no serious infection before or during therapy, and side effects were mild. Of the 20 patients, 3 showed a dramatic improvement in severe anemia after 10 weeks of treatment accompanying a recovery of erythroid components in the bone marrow. They no longer require red cell transfusions and have had normal Hb concentrations and normal ferrokinetics. These results indicate that long-term administration of rhG-CSF and rhEPO may benefit some patients with aplastic anemia. Further studies will be necessary to elucidate the mechanism by which rhGCSF and rhEPO stimulate hematopoiesis and improve hematologic abnormalities in these patients.

Treatment of the anemia of aplastic anemia patients with recombinant human erythropoietin in combination with granulocyte colony-stimulating factor: a multicenter randomized controlled study. Multicenter Study Group

A multicenter randomized controlled study was undertaken in order to determine whether epoetin beta (EPO) ameliorates the anemia in aplastic anemia (AA) patients treated with granulocyte colony-stimulating factor (G-CSF). Enrolled patients were randomized into 3 groups: group C receiving G-CSF alone as the control; group L receiving G-CSF and 200 IU/kg of EPO; group H receiving G-CSF and 400 IU/kg of EPO. Throughout the study, the dose and the administration interval of G-CSF were adjusted to maintain neutrophil counts between 1000 and 5000 microliters EPO was administered subcutaneously for 12 wk as the first step in treatment and when favorable effects were observed over this period, treatment was continued for another 12 wk as the second step in treatment. Significant erythroid responses were defined as increases in untransfused hemoglobin values > 1.0 g/dl or > 50% decreases in RBC transfusion requirements over the treatment period. Of 131 patients enrolled, 88 patients allocated to groups L and H were evaluated for toxicity to EPO and 110 were evaluated for erythroid responses. Four of the 31 patients (12.9%) in group C, 6 of the 41 patients (14.6%) of group L, and 14 of the 38 patients (36.8%) of group H showed erythroid responses in the first step in treatment. The erythroid responses of group H were significantly higher than those of the other 2 groups (p < 0.05). The significant effects of EPO were due to erythroid responses in non-severe AA. Responding patients were significantly different from non-responders with regard to disease severity, hemoglobin concentration, reticulocyte count, serum endogenous erythropoietin levels and serum transferrin receptors; non-severe AA patients were more likely to respond to EPO, and responding patients had lower serum EPO and higher hemoglobin concentration, reticulocyte count and serum transferrin receptors than non-responders. The response rate increased in the second step in treatment, suggesting that long-term treatment improved the efficacy of EPO. No serious side-effects were observed. From these results, we conclude that EPO given in combination with G-CSF is a safe and effective alternative for the treatment of anemia of a subset of AA patients.

Antithymocyte immunoglobulin in severe aplastic anemia and bone marrow transplantation

OBJECTIVE

To review antithymocyte immunoglobulin (ATG) and its current role in the treatment of severe aplastic anemia (SAA), focusing on ATG in immunosuppressive therapy compared with bone marrow transplantation (BMT).

DATA SOURCES

A MEDLINE search (1966 to 1996) of English-language literature and human subjects pertaining to ATG and BMT therapy in SAA was performed. Additional literature was obtained from reference lists of pertinent articles identified through the search.

STUDY SELECTION AND DATA EXTRACTION

All articles were considered for possible inclusion in the review. Pertinent information, as judged by the authors, was selected for discussion.

DATA SYNTHESIS

The hallmark of SAA is pancytopenia and bone marrow hypoplasia. Although the etiology in a majority of cases remains unknown, current data implicate an immune-mediated destruction of stem cells. ATG is a potent immunosuppressive agent and has emerged as an important therapy for patients with SAA. The exact mechanism of immunosuppressive action is not fully understood, although ATG appears to disrupt cell-mediated immune responses resulting in inhibition or altered T-cell function. Numerous trials have evaluated the use of ATG both as monotherapy and in combination with other immunosuppressive agents. Treatment with ATG in SAA has demonstrated a 40-70% response rate. Data suggest that intensive immunosuppressive therapy with ATG in combination with cyclosporine may provide the optimal immunosuppressive treatment. Questions still remain concerning complications and long-term survival of the patients. Although more than a 2-year follow-up shows a decline in mortality, a plateau in the survival curve was not achieved. BMT is a potential treatment for SAA. Although there is a high initial mortality due to treatment-related toxicities, successful marrow engraftment provides a cure for SAA. Many patients (75-90%) experience long-term survival after allogenic BMT. Age, donor availability, and severity of disease limit the number of eligible patients.

CONCLUSIONS

Due to excellent results with BMT, it has become the therapy of choice for selected patients with SAA. For patients who are not eligible for BMT, intensive immunosuppressive therapy with ATG and cyclosporine is recommended. Further study to better understand the pathogenesis of SAA and prevent treatment-related complications is essential to provide the best care to all patients.

Bone marrow transplantation for sickle cell disease

BACKGROUND

We investigated the risks and benefits of allogeneic bone marrow transplantation in children with complications of sickle cell disease.

METHODS

Twenty-two children less than 16 years of age who had symptomatic sickle cell disease received marrow allografts from HLA-identical siblings between September 1991 and April 1995. The indications for transplantation included a history of stroke (n = 12), recurrent acute chest syndrome (n = 5), and recurrent painful crises (n = 5). Patients were prepared for transplantation with busulfan, cyclophosphamide, and antithymocyte globulin.

RESULTS

Twenty of the 22 patients survived, with a median follow-up of 23.9 months (range, 10.1 to 51.0), and 16 patients had stable engraftment of donor hematopoietic cells. In three patients the graft was rejected and sickle cell disease recurred; in a fourth patient graft rejection was accompanied by marrow aplasia. In 1 of the 16 patients with engraftment, there was stable mixed chimerism. Two patients died of central nervous system hemorrhage or graft-versus-host disease. Kaplan-Meier estimates of survival and event-free survival at four years were 91 percent and 73 percent, respectively. Among patients with a history of acute chest syndrome, lung function stabilized; among patients with prior central nervous system vasculopathy who had engraftment, stabilization of cerebrovascular disease was documented by magnetic resonance imaging.

CONCLUSIONS

Allogeneic stem-cell transplantation can be curative in young patients with symptomatic sickle cell disease.

Deficiency of CD34+ c-kit+ and CD34+38- hematopoietic precursors in aplastic anemia after immunosuppressive treatment

To characterize the persistent abnormalities of hematopoiesis in aplastic anemia (AA) after immunosuppression with antilymphocyte globulin (ALG), we analyzed the quantity, phenotype, and growth properties of hematopoietic progenitor cells in 13 patients who received ALG treatment. Flow cytometry (FACS) revealed a deficiency of CD34+ cells in bone marrow (BM) of all patients. This deficiency was most severe (40-fold) in 4 patients in AA relapse. In 9 patients in remission, CD34+ cells were reduced 2-10-fold and showed no correlation with the ALG-induced improvement of peripheral blood cell counts. The proportion of CD34+ cells carrying c-kit receptors was abnormally low (2-10-fold below normal) in 5 of 13 AA patients. These patients also displayed low levels of c-kit mRNA by reverse transcription-polymerase chain reaction (RT-PCR). Furthermore, the CD34+ cell population was almost completely depleted of CD34+CD38- early hematopoietic progenitors in all AA patients. The proportion of CD34+ cells expressing lineage differentiation antigens CD33, CD71, and CD45RA in AA was increased, as compared to control BM. Formation of hematopoietic colonies by FACS-purified CD34+ cells was nearly absent in 4 relapsed patients, normal in 4 of 9, and decreased (up to 10-fold) in 5 of 9 patients in remission. The degree of impairment of colony-forming ability by AA progenitors correlated well with the reduction of CD34+ c-kit+ cells. The best proliferative response of CD34+ cells was observed in the presence of stem cell factor and, in some cases, fit3 ligand. Our results indicate that the disease process in AA depletes immature BM progenitors, thus providing a plausible explanation for persistent defects in colony-forming ability and long-term regenerative capacity of AA marrow after immunosuppression. Analysis of the immunophenotypes and the proliferative properties of purified progenitors may be useful for estimating degree of hematopoietic recovery in ALG-treated patients.

Bone marrow transplantation in pediatric patients with severe aplastic anemia: cyclophosphamide and anti-thymocyte globulin conditioning followed by recombinant human granulocyte-macrophage colony stimulating factor

PURPOSE

Graft rejection remains a serious problem in patients transplanted for severe aplastic anemia. Although additional immunosuppression with irradiation may decrease graft failure, significant sequelae may ensue. We evaluated a nonirradiation containing conditioning regimen for children with severe aplastic anemia with matched sibling donors utilizing cyclophosphamide and anti-thymocyte globulin (ATG). To accelerate myeloid recovery, GM-CSF was used posttransplant.

PATIENTS AND METHODS

Twelve patients, with a median age of 3 years underwent BMT from HLA identical sibling (n = 11) or syngeneic (n = 1) donors. Conditioning was cyclophosphamide 50 mg/kg x 4 days and anti-thymocyte globulin 30 mg/kg x 3 days. GM-CSF was administered at 10 micrograms/kg until a neutrophil count of 1,000 was achieved. Cyclosporine alone was used for graft-versus-host disease prophylaxis.

RESULTS

All patients achieved durable engraftment at follow-up of 5-51 + months, with the exception of the identical twin. Median time to neutrophil counts > 200/microliters, 500/microliters, and 1,000/microliters were 12, 13, and 15 days, respectively. Acute GVHD of less than or equal to grade II occurred in four patients; one patient had grade III. This has resolved in all but one.

CONCLUSION

The nonradiation conditioning regimen of cyclophosphamide/ATG appears to achieve durable engraftment in transfused children with matched sibling donors. GM-CSF may accelerate myeloid recovery without exacerbating GVHD, but its contribution to allogeneic transplant required further study.

Anti-thymocyte globulin treatment of a patient for paroxysmal nocturnal haemoglobinuria-aplastic anaemia syndrome: complement activation and transient decrease of the PNH clone

Paroxysmal nocturnal haemoglobinuria (PNH) is an acquired clonal stem cell disorder resulting in insufficient and defective haematopoesis associated frequently with aplastic anaemia (AA). A deficiency of the glycosyl phosphatidylinositol (GPI)-anchored complement activation regulatory proteins CD55 and CD59 is responsible for an increased sensitivity of erythrocytes to complement attack leading to chronic intravascular haemolysis with haemoglobinuria. In this study we investigated the effects of complement activation caused by anti-thymocyte globulin (ATG) treatment on the PNH clone in a patient affected with the PNH/AA-syndrome. Fluid phase complement components C3, C4, C6 and terminal complement complex (TCC) were assayed by ELISA. CD55, CD59 and cell-associated TCC were monitored by flow cytometry. ATG treatment resulted in profound systemic complement activation which led to a decrease in the levels of native C3 and C4 to 65% and 40%, respectively, of the original levels on day 5 and of C6 and TCC to 61% and 23%, respectively, on day 10. A return to pre-treatment levels was observed for C3 by day 15, for C6 by day 30 and for C4 by day 90. Flow cytometry revealed that the deficiency in the GPI-anchored protein was restricted to granulocytes, while lymphocytes remained unaffected. Cell-bound TCC increased by 1.67-fold and 2.37-fold on day 5 and day 10, respectively, decreasing to 1.40-fold and 1.30-fold on day 15 and day 30, respectively. The percentage of PNH granulocytes as identified by the absence of the CD55- and CD59-antigens exhibited a temporary decrease from 72% on day 0 to 65% on day 5 and 59% on day 10 and returned thereafter to the original percentage of 70% by day 15 and exceeding this level to 76% on day 30 and 79% on day 90. We report profound activation of the classical pathway of the complement cascade and the terminal complement complex by the globulin leading to a transient decrease of the PNH clone, presumably due to subsequent lysis of the PNH cells devoid of complement regulatory proteins.

Overproduction of inhibitory hematopoietic cytokines by lipopolysaccharide-activated peripheral blood mononuclear cells in patients with aplastic anemia

The aim of this study was to measure the level of cytokines produced by peripheral blood mononuclear cells (PBMNC) in patients with aplastic anemia (AA) and to determine their effect on the clonal growth of normal bone marrow (BM) cells. Twenty-one patients with AA and 11 normal controls were enrolled in this study. Medium conditioned by PBMNC of AA patients in the presence of lipopolysaccharide (LPS) was found to be suppressive to the colony growth of normal BM cells. Thus, we further determined the presence in the PBMNC-conditioned medium (CM) of both inhibitory cytokines: macrophage inflammatory protein-1 alpha (MIP-1 alpha), tumor necrosis factor-alpha (TNF-alpha), transforming growth factor-beta 2 (TGF-beta 2), and interferon-gamma (IFN-gamma), and stimulatory cytokines: interleukin-3 (IL-3) and stem cell factor (SCF). Spontaneous production of MIP-1 alpha was higher in the AA patients than the normal controls (1887 +/- 174 pg/ml vs 1643 +/- 93 pg/ml), but the difference was not significant. After LPS stimulation, the production of MIP-1 alpha was markedly increased in the AA patients, and its level was significantly higher than that of the normal controls (2360 +/- 149 pg/ml vs 1517 +/- 92 pg/ml, p = 0.0022). The level of TNF alpha was also higher in the AA patients. However, IFN-gamma, TGF-beta 2, SCF, and IL-3 were not detectable in the PBMNC-CM of either AA patients or normals. The myelopoietic suppressing effect of AA-PBMNC-CM from each AA patient was significantly blocked by pretreatment with anti-TNF-alpha, resulting in a colony-forming enhancement of 174% +/- 12%. A similar effect was noted in six of 11 AA patients by pretreatment with anti-MIP-1 alpha. We conclude that TNF alpha and MIP-1 alpha can be overproduced by the PBMNC of some AA patients, which may play a role in the progression of AA.

Persistent growth impairment of bone marrow stroma after antilymphocyte globulin treatment for severe aplastic anaemia and its association with relapse

Bone marrow from 65 patients with aplastic anaemia (AA) was tested for stroma growth in short term cultures (2 weeks) and for colony formation by haemopoietic precursor cells during the course of their disease. In 18 untreated patients, mean stroma growth was 30% of normal and colony formation was virtually absent. After treatment with immunosuppression (IS), as estimated from 90 examinations in 54 patients, stroma growth was approximately 50% and colony growth approximately 10% of normal. Growth impairment of stroma and haemopoietic precursors persisted for 10 and more years after IS. Results of 2-week stroma cultures were compared with results of long term bone marrow cultures in 10 AA patients and 4 controls. At 2 weeks, growth of aplastic marrow was delayed compared to normal, but this difference became less evident with prolonged incubation time. In vitro growth abnormalities were compared with the clinical evolution after IS. The development of late haematological complications (paroxysmal nocturnal haemoglobinuria (PNH)) and myelodysplastic syndrome (MDS), did not correlate with the degree of stroma growth impairment. However, relapse of aplasia was associated with poor stroma growth: 8/29 patients with stroma confluence of < or = 30% during haematological remission versus 1/25 with stroma confluence of > 30% relapsed. We conclude that (i) the haematopoietic microenvironment is frequently coinvolved in the disease process of AA, (ii) a defect is detected in short term rather than in long term stroma cultures and, (iii) relapse is more frequent in patients with poor stroma growth.

Successful pregnancy following aplastic anaemia

Pregnancy following idiopathic aplastic anaemia is rare and is difficult to manage because of life-threatening episodes of bleeding and infections. Only a handful of cases has been reported in the literature. The pregnancies were unsuccessful in the majority. The present report describes a patient with moderately severe idiopathic aplastic anaemia who was managed with intensive haematological support leading to delivery of a healthy infant by caesarean section. Despite platelet transfusion refractoriness as a result of transfusions prior to pregnancy, adequate platelet transfusions prevented excessive bleeding. The literature is reviewed and management with platelet transfusions is discussed.

Stem-cell factor in aplastic anemia: in vitro expression in bone marrow stroma and fibroblast cultures

In vitro expression of stem-cell factor (SCF) by bone marrow (BM) cells of 30 patients with aplastic anemia (AA) has been analyzed at the mRNA and protein levels. While no deficiencies were found in SCF mRNA expression, low levels of soluble SCF protein were measured in poorly growing AA stroma cultures. The SCF protein concentration in the supernatant and the confluence of AA stroma growth were found to correlate (R = 0.70). Defective proliferation was observed in the majority (20/30) of AA stroma cultures and was paralleled by poor growth of homogeneous cultures of fibroblasts from the same marrow sample. AA stroma growth was enhanced by addition of exogenous SCF in combination with interleukin-11 (IL-11), leukemia inhibitory factor (LIF), and basic fibroblast growth factor (bFGF). Our results demonstrate that deficient growth of stroma cells results in decreased production of SCF. Therefore, SCF and other stroma-derived cytokines may be of therapeutic value in AA patients with documented defects within the BM microenvironment.

Immune suppression therapy in aplastic anemia: influencing factors on response and survival

OBJECTIVES

Immune suppression (IS) therapy has provided another opportunity of cure or improvement in the aplastic anemia patients who cannot receive bone marrow transplantation due to many causes. There are a few reports regarding the factors that affect response, survival and prognosis after IS therapy, including antilymphocyte globulin (ALG) in aplastic anemia. Therefore, we analysed our experience to determine the prognostic factors.

METHODS

Statistically analysed were 172 patients, from April 1982 to July 1992, who were diagnosed as severe aplastic anemia and treated with IS therapy, including ALG, at Catholic University Medical College, St. Mary's Hospital.

RESULTS

Among 172 severe aplastic anemia (SAA) patients who entered the study from April 1982 to July 1992, 144 patients were analysed for response and 122 patient for survival. 58.4% (84/144) responded after the first course of IS therapy. Among those who did not respond on the first course an additional 44% (11/25) responded after the second course of IS therapy. Prognostic factors that might affect the response to the treatment and survival were analysed. In a univariate analysis of patients with no previous history of treatment before is therapy, and a shorter interval between diagnosis and treatment, higher hemoglobin levels before IS therapy, and higher granulocyte counts and combined use use of cyclosporin A(CSA) were positively associated with response (p < 0.05). The combined use of CSA during IS therapy, younger age, lower monthly requirement of platelets transfusion before IS therapy, higher leukocyte counts, higher percent of polymorphonuclear leukocytes, lower percent of lymphocyte, higher bone marrow cellularity and response were positively associated with survival (p < 0.05). In a multivariate analysis, shorter interval between diagnosis and treatment, no combined use of hemopoietic stimulants, such as androgen, and lesser total amount of transfusion were positively associated with Response (p < 0.05). Higher leukocyte counts before IS therapy and the combined use of CSA during IS therapy were significantly associated with longer survival (p < 0.05). Patients with complete or partial response had excellent prognosis (96.7%-100% of 5 year survival rates). In contrast, patients with no response after IS therapy had 45.1% of 5 year survival rates.

CONCLUSIONS

With these results from the retrospective study of IS therapy, we find many valuable factors that have an influence on response or survival. IS therapy improves the survival of responded patients with SAA, and we confirmed that IS therapy is an important therapeutic tool for the SAA patients who are not feasible candidates for bone marrow transplantation.

Trilineage recovery by combination therapy with recombinant human granulocyte colony-stimulating factor and erythropoietin in patients with aplastic anemia and refractory anemia

Ten patients with aplastic anemia (AA) and seven patients with refractory anemia (RA) were treated with recombinant human granulocyte colony-stimulating factor (rhG-CSF) and erythropoietin (rhEpo) in combination. rhG-CSF (5-20 micrograms/kg) and rhEpo (120-720 U/kg) were administered by s.c. injection three times a week for at least six months, and the administration was continued as maintenance therapy for as long as possible when hematological responses were observed. Six (60%) of the ten AA patients and four (58%) of the seven RA patients showed multilineage responses. Of these responders, six patients achieved trilineage recovery. While all of the responders were dependent on red blood cell transfusions and eight of them required platelet transfusions before treatment, they now no longer need transfusions of either red blood cells or platelets. A median treatment duration of 9 (range 1 to 28) months was required to achieve multilineage recovery. The responders showed an ability to maintain the multilineage recovery for 9+ to 47+ months and to tolerate long-term treatment. These results indicate that the long-term treatment with rhG-CSF and rhEpo may benefit a substantial percentage of patients with AA and RA and provide an optional therapy for these patients.

Trilineage response to rhG-CSF with subsequent clonal hematopoiesis in a patient with severe bone marrow aplasia

We treated a patient with severe aplastic anemia with long-term administration of recombinant human granulocyte-colony stimulating factor (rhG-CSF). When a trilineage response of hematopoiesis was obtained after the first treatment, a chromosomal change [45XX, -7] was observed in 20 of the 20 metaphases examined. Later, we were able to show a monoclonal X inactivation pattern in the phosphoglycerate kinase (PGK) gene in the peripheral blood polymorphonuclear leukocytes and mononuclear cells, indicating the presence of clonal hematopoiesis regardless of the disappearance of the karyotype abnormality. We suggest that it is important to pay close attention to the appearance of clonal hematopoiesis during the administration of G-CSF to patients with idiopathic severe bone marrow aplasia.

Myelodysplasia following paroxysmal nocturnal haemoglobinuria: evidence for the emergence of a separate clone

A patient with paroxysmal nocturnal haemoglobinuria (PNH) who developed a myelodysplastic syndrome (MDS) is described. After the onset of myelodysplasia the neutrophils of the patient fully expressed GPI-linked proteins. It is concluded that the myelodysplasia does not originate from transformed PNH stem cells, but represents the emergence of a separate clone arising from an injured marrow.

Aplastic anemia and sudden sensorineural hearing loss

In the present study, the clinical and audiological features of 3 patients with aplastic anemia who subsequently developed sudden sensorineural hearing loss are reported. These patients, for whom a diagnosis of aplastic anemia had previously been confirmed, suddenly developed profound or complete hearing loss accompanied by tinnitus and severe vertigo. In addition to erythrocytopenia and thrombocytopenia, serial hematological examinations revealed a marked drop in the platelet count prior to or just at the time of the acute episode of hearing loss. The prognosis for hearing recovery was poor in each patient. These findings suggest that intracochlear hemorrhage could be a mechanism underlying the sudden sensorineural hearing loss in these patients.