Flexible bronchoscopy in the diagnosis of pulmonary infiltrates following autologous peripheral stem cell transplantation for advanced breast cancer.

Flexible bronchoscopy is an important tool in the diagnosis of pulmonary complications following bone marrow transplantation. However, the value of this procedure in autologous peripheral stem cell transplant (APSCT) recipients with pulmonary complications is not well defined. We retrospectively evaluated the diagnostic yield of 27 consecutive bronchoscopies done on 23 APSCT recipients following high-dose chemotherapy for breast cancer. FB resulted in a positive diagnosis in 16 cases (59%). Broncheoalveolar lavage (BAL) was performed on all patients, and transbronchial biopsies (TBB) were carried out in 14. TBB were diagnostic in 10 (71%), with pulmonary drug toxicity as the most common finding (n = 8), followed by metastatic breast cancer (n = 2). BAL was diagnostic in six (22%): bacterial pneumonia (n = 3), aspergillosis (n = 2), Pneumocystis carinii pneumonia (n = 1) and Influenza B (n = 1). The procedure was well tolerated with no major complications except a small pneumothorax in one patient that did not require chest tube insertion. In conclusion, flexible bronchoscopy is a useful tool in the evaluation of pulmonary complications following APSCT for breast cancer. TBB can be done safely with relatively high diagnostic yield. Pulmonary drug toxicity is the most common pathological finding.

High-dose chemotherapy and hematopoietic stem cell transplantation for breast cancer: past or future?

Given that each year in the United States 180,000 new cases of breast cancer are diagnosed, with about 44,000 women succumbing to the disease, and that breast cancer is the second leading cause of cancer-related death in women, it is clear that existing therapy fails a large number of patients. Recently, a number of novel strategies have been developed in attempts to improve survival. These include agents used at very high dose requiring stem cell support. High-dose chemotherapy (HDC) with hematopoietic stem cell transplantation (HSCT), most frequently in the form of peripheral blood progenitor cell transplantation (PBPCT), is an highly active treatment approach in appropriate patients and the current data relating to this modality will be reviewed here. This article will attempt to place the recent randomized studies in perspective, to highlight the strengths and limitations of the data, and to offer some thoughts on future directions for the field.

Nonablative allogeneic hematopoietic stem cell transplantation.

During the past few years there has been an explosion of knowledge in nonablative allogeneic stem cell transplantation. This approach to transplantation relies more on the creation of "immunologic space" for engraftment rather than the more traditional approach of creating "physical space" by the application of either intensive radiation or chemical therapy. Nonablative allogeneic stem cell transplantation holds the promise of allowing powerful alloimmune responses to eradicate disease processes while minimizing the initial treatment-related morbidity and mortality, and it appears to be the necessary enabling platform by which to apply allogeneic cellular therapy. Intuitively, this approach should broaden the eligibility for potentially curative allogeneic transplantation in various disease categories, reduce initial hospitalization costs, and at the same time have a positive impact on quality of life. We review the current published data relating to this approach including the underlying principles, the preparative regimen, disease indications, preliminary results in hematologic and solid malignancies, and certain correlative immunologic evaluations.

High-dose chemotherapy and CD34-selected peripheral blood progenitor cell transplantation for patients with breast cancer metastatic to bone and/or bone marrow.

Fifty women with breast cancer metastatic to bone or bone marrow involvement on light microscopy at the time of initial evaluation were treated with high-dose chemotherapy (HDC) and peripheral blood progenitor cell (PBPC) transplantation with CD34(+) cell selection using the Isolex 300i system. All patients received induction chemotherapy. PBPC were mobilized with chemotherapy and granulocyte colony-stimulating factor. The median CD34(+) progenitor purity was 94.7% (range 72-98.7%) and recovery 38.4% (range 21-60%). Forty-eight hours after HDC with cyclophosphamide, cisplatin and carmustine, PBPC were reinfused. Median time to neutrophil count >0.5 x 10(9)/l was 9 (range 9-12) days and to platelet transfusion independence 11 (4-30) days. These data demonstrate that selected CD34(+) PBPCs allow rapid hematologic reconstitution after HDC. During follow-up, 23% of patients developed herpes zoster. Two patients developed cytomegalovirus infections. Three patients developed fungal infections. The development of these infections was not associated with steroid use but appeared more frequently in patients with diabetes mellitus. Seventy-four per cent of patients received steroids for pulmonary toxicity. Treatment-related mortality was 4%. Progression-free survival and overall survival at 35 months was 22.4% and 40.5%, with a median of 11.4 months and 15.4 months, respectively.

Bone marrow and peripheral blood hematopoietic stem cell transplantation: focus on autografting.

This review focuses on certain of the principles involved in high-dose chemotherapy and radiation therapy along with autologous hematopoietic stem cell transplantation for the treatment of certain malignancies. In addition, the evidence, wherever possible based on randomized data, for the application of this approach in certain malignancies is reviewed. The malignancies highlighted include acute myeloid leukemia, acute lymphoblastic leukemia, non-Hodgkin lymphoma, Hodgkin disease, and breast cancer.

Cardiac sequelae of doxorubicin and paclitaxel as induction chemotherapy prior to high-dose chemotherapy and peripheral blood progenitor cell transplantation in women with high-risk primary or metastatic breast cancer.

Doxorubicin plus paclitaxel has been shown to be an active regimen for metastatic breast cancer and is now frequently used as adjuvant therapy for high-risk primary breast cancer. Initial studies reported a higher than expected rate of cardiac toxicity with this regimen. We studied 105 patients with either high-risk primary breast cancer or metastatic breast cancer who were treated with doxorubicin (60 mg/m2) and 3-h infusions of paclitaxel (175 mg/m2) cycled every 3 weeks. Patients received three cycles of chemotherapy for high-risk primary or four cycles for metastatic disease. Patients then proceeded to high-dose chemotherapy (HDC) (STAMP I cyclophosphamide, cisplatin and carmustine) and peripheral blood progenitor cell transplantation (PBPCT). Patients underwent radionuclide multi-gated angiograms (MUGA) before and following induction chemotherapy and following HDC. During induction chemotherapy 40 (38%) of the patients had a reduction in left ventricular ejection fraction (LVEF). Fourteen had a decrease of 20% or greater and two were mildly symptomatic from CHF. There was additional reduction in the LVEF after HDC with a median value for LVEF of 59% (range, 20-78%). During HDC 10 patients developed clinical signs of congestive heart failure (CHF). Five patients responded to diuretic therapy and did not require any additional treatment. Four patients responded to vasodilation and/or digoxin with improvement in cardiac function. A clinically significant decrease in cardiac function was found in a small number of patients after induction chemotherapy and HDC with PBPCT. The majority of the patients tolerated this regimen without problems. Although there was a decline in LVEF as measured by radionuclide MUGA this did not prevent the majority of patients from proceeding with HDC. Bone Marrow Transplantation (2000).

High-dose chemotherapy and peripheral blood progenitor cell transplantation in the treatment of breast cancer.

Each year in the USA, 180,000 new cases of breast cancer are diagnosed and about 44,000 women die of the disease. Current primary treatment consists of adjuvant chemotherapy and hormone therapy, and statistics show that combination chemotherapy favorably influences the outcomes in both node-negative and node-positive primary disease. However, a significant number of breast cancer patients succumb to the disease, and nearly every patient diagnosed with metastatic breast cancer will be dead within five years. High-dose chemotherapy (HDC) and peripheral blood progenitor cell transplantation (PBPCT) are based upon laboratory and clinical observations of the ability to modify growth properties of quiescent and replicating cancer cells. A large number of HDC and PBPCT regimens have been evaluated for treatment of metastatic breast cancer, and recent autologous bone marrow transplantation data indicate that three HDC regimens (CPB, CTCb and cytoxan and thiotepa) predominate. Unfortunately, negative media coverage surrounding and subsequent to the presentation of preliminary findings reported at the May 1999 American Society of Clinical Oncologists, that were not allowed adequate follow-up time for full analysis of treatment results, has had a detrimental effect on the ability to conduct trials in this area. Several randomized trials have been conducted in both the metastatic and high risk primary disease settings. Thorough analysis of these studies indicates an evaluable improvement in favor of HDC and PBPCT in three of the four randomized studies performed in metastatic breast cancer and two of the four high risk primary studies. Also, initial evaluations found that quality of life appeared comparable in patients receiving either HDC or not. Each randomized trial studied asks a different question and, depending on the intensity of HDC regimen, the intensity and duration of the standard dose chemotherapy control and the schedule of events in relation to induction chemotherapy, the outcomes may be quite variable. Still, certain general trends are indentifiable. HDC alone will not completely cure breast cancer and should be considered as part of an overall therapeutic plan. In some of these studies, significantly longer follow-up is required before definitive analysis can be completed.

Deliberations and evaluations of the approaches, endpoints and paradigms for iron dietary recommendations.

Iron deficiency severe enough to cause anemia is associated with significant morbidity while uncontrolled iron absorption which occurs in disorders such as hereditary hemochromatosis causes multiorgan failure and early death. Preliminary data from the Third National Health and Nutrition Examination Survey demonstrate that the prevalence of iron deficiency anemia in the United States is now very low. This implies that the current iron consumption is adequate for most individuals. An important unresolved question relates to the necessity for further reducing the prevalence of iron deficiency without anemia. More information is required to determine whether this lesser degree of iron deficiency is harmful. Recent survey data indicate that concomitantly with the reduced prevalence of iron deficiency there has been a rise in serum ferritin concentrations in American men and postmenopausal women. These findings have led to concern about the effectiveness of the physiological mechanisms for limiting storage accumulation in normal individuals and carriers of the hemochromatosis gene when dietary iron content is high. Furthermore, recent epidemiological observations suggest that a modest increase in iron stores (in a range previously considered safe) is a possible risk factor for ischemic heart disease and cancer; however, a causal relationship remains to be proven. Nonetheless, because there is no known benefit of high iron storage status, it seems prudent to avoid further increases in and possibly to reduce the dietary iron intake of men and postmenopausal women. Mean intake in these groups exceeds the current RDA by a significant margin. Therefore, the sources of dietary iron as well as other factors contributing to high serum ferritin values have to be defined. Also, efforts should be made to increase the awareness of professionals and the public about the possible risks of excessive dietary iron. The complexity of the Western diet and an incomplete understanding of all of the factors affecting serum ferritin concentrations make it very difficult to specify a safe upper range for daily iron intake at the present time.

Assessment of iron status.

OBJECTIVE: To review the clinical assessment of iron deficiency and excess. CONCLUSIONS: Two key iron-related proteins in the human body are ferritin which is the iron storage protein, and the transferrin receptor, which controls the entry of iron-bearing transferrin to cells. Intact ferritin and truncated transferrin-receptor molecules are present in serum in direct quantitative proportion to their total tissue content. Ferritin and transferrin-receptor production are precisely and reciprocally regulated at a posttranscriptional level. This is achieved by an iron-responsive element-binding protein that interacts with iron-responsive elements in the mRNA of each, but with contrary effects. Increases in serum ferritin reflect increased storage iron and increases in serum transferrin receptor reflect cellular iron deficits. The combined use of these two measurements allows accurate definition of the entire range of body iron status. This is valid even in situations where assessment of iron status has been notoriously problematic, including periods of rapid growth, in pregnancy, in conditions associated with inflammation, and in trained athletes.

Current issues in iron deficiency.

This brief review of developments relating to iron deficiency during the past year covers three main areas: iron supplementation, the regulation of iron absorption, and the use of the serum transferrin receptor for the assessment of iron status. The intermittent administration of iron supplement once or twice weekly rather than daily has been advocated by international health agencies in recent years, but radioiron absorption studies in human subjects have failed to demonstrate any absorptive advantage of the intermittent schedule. The value of prophylactic iron supplementation in elderly blood donors was evaluated and shown to offer limited benefit in maintaining donation frequency. A recent model of the regulation of iron absorption involving erythropoietic and store regulators is discussed and a recent article indicating a potential non-hematopoietic effect of hematopoietic growth factors on iron absorption by the gastrointestinal mucosal cell is reviewed. A new measure of functional iron deficiency, namely the serum transferrin receptor, is discussed, with particular reference to its mechanism of production and its great value in distinguishing iron deficiency anemia from the anemia of chronic disease.

Interleukin-11 enhances gastrointestinal absorption of iron in rats.

The effect of parenteral administration of IL-11 on gastrointestinal iron absorption was evaluated. A significant increase in the absorption of 59Fe-tagged food iron fed to fasting rats was observed when two subcutaneous injections of IL-11 were given 48 and 24 h prior to testing. Relatively similar increases of 25% were observed with IL-11 doses of 300, 600 and 1000 micrograms/kg for each injection. The increase in absorption did not appear to be related to changes in erythropoiesis. These findings raise the possibility that the enhanced absorption of iron which occurs with ineffective erythropoiesis may in part be mediated by multifunctional haemopoietic growth factors.

Transferrin reduces the production of soluble transferrin receptor.

The effect of homologous diferric transferrin from which contaminating transferrin receptor has been removed by monoclonal antibody affinity chromatography on soluble transferrin receptor concentrations was studied in K562 cells and HL60 cells in culture. Diferric transferrin in K562 cells caused a dose-dependent decrease in cellular receptor expression, a dose-dependent increase in cellular ferritin content, and a reduction in soluble receptor concentration which was of greater proportional magnitude than the reduction in cell receptor content. In HL60 cells, while there was a dose-dependent increase in cellular ferritin, cellular receptor content was relatively unaffected, while there was a consistent reduction in soluble receptor concentration. In both cells, the inhibitory effect of diferric transferrin on soluble receptor concentration was evident as early as 3 hr into the incubation. Apotransferrin, by contrast, did not reduce soluble receptor concentration. While elemental iron was capable of producing similar changes in cellular receptor and ferritin content, it had no inhibitory effect on proportional soluble receptor content. Studies employing other proteins, including human and bovine serum albumin, human lactoferrin, and rat ferritin, had no inhibitory effect on soluble receptors concentration, thus confirming the specificity of the findings. Control studies excluded an assay artifact as the explanation for the current findings. Prior contrary reports appear completely explained by the combination of soluble transferrin receptor contaminating the transferrin employed for study and a systematic difference in the assays employed between free and transferrin-bound receptor.

Serum transferrin receptor in hereditary hemochromatosis and African siderosis.

The present investigation evaluated the serum transferrin receptor concentration in subjects with nontransfusional iron overload who were identified in two separate studies on the basis of a serum ferritin level above 400 micrograms/L. Subjects with preclinical hereditary hemochromatosis were evaluated in the first study and those with the African form of iron overload in the second. In the first study, hereditary hemochromatosis was identified in 14 white men on the basis of a persistent elevation in transferrin saturation above 55%. The serum receptor concentration was elevated above the upper cut-off of 8.5 mg/L in two of the subjects, but the mean receptor of 6.1 +/- 1.4 mg/L (mean +/- 2 SE) did not differ significantly from the normal mean for this assay of 5.6 +/- 0.3 mg/L. In the same study, 60 control subjects with secondary iron overload were identified on the basis of a serum ferritin persistently above 400 micrograms/L, with a normal serum C-reactive protein concentration but with a transferrin saturation < 55%. Three of these subjects had an elevated serum receptor concentration but the mean value of 5.5 +/- 0.4 mg/L did not differ from normals nor from subjects with hemochromatosis. In the second study, 49 black Africans with iron overload were divided into those with or without an elevated transferrin saturation. The mean serum receptor concentration of 5.0 +/- 0.8 mg/L and 4.5 +/- 0.4 mg/L, respectively, did not differ statistically. It was concluded that there is no evidence of generalized dysregulation of the transferrin receptor in hemochromatosis or African siderosis.

Identification of the membrane remnants of transferrin receptor with domain-specific antibodies.

Tissue culture studies with K562 and HL60 cells have demonstrated the production of a soluble form of transferrin receptor identical to that identified in human serum. The present study was undertaken to search for membrane remnants of the truncated receptor with peptide antibodies specific for the extracellular and cytoplasmic domain of transferrin receptor. In cell membranes, a 105K remnant was identified that is consistent with truncation of one extracellular domain monomer of the transferrin receptor. In the exosomal fraction of the culture supernatant, a smaller 20K remnant consistent with truncation of both extracellular domains was also demonstrated. These findings provide evidence that soluble receptor is the product of proteolytic cleavage of intact membrane-bound transferrin receptor. Prior studies showing that the concentration of the extracellular domain in exosomes remained stable during incubation in culture supernatant suggest that this cleavage possibly occurs intracellularly.

The physiological significance of circulating transferrin receptors.

A soluble truncated form of the tissue transferrin receptor has been recently identified in human serum. The concentration of this serum receptor appears to reflect the total mass of tissue receptor and is consequently elevated with tissue iron deficiency and enhanced red cell production. When coupled with the serum ferritin, the serum transferrin receptor concentration provides a sensitive, quantitative index of iron status over a wide spectrum. While the physiological significance of the circulating receptor is still unknown, this new laboratory measurement will play an important role in the clinical and epidemiological detection of iron deficiency anemia.

Iron deficiency: the global perspective.

The prevelance of IDA in industrialized countries has declined in recent decades, but there has been little change in the worldwide prevalence. IDA is currently estimated to affect more than 500 million people. Recent studies have indicated that anemia per se, the most common manifestation of iron deficiency, is less important from a public health standpoint than liabilities associated with tissue iron deficiency. The most important of the latter are an impairment in psychomotor development and cognitive function in infants and preschoolers, a deficit in work performance in adults, and an increase in the frequency of low birth weight, prematurity, and perinatal mortality in pregnancy. There have been several recent advances in combatting nutritional iron deficiency. One of the major problems has been in distinguishing iron deficiency from other causes of anemia seen epidemiologically such as malaria, HIV infection, chronic inflammation, hemoglobinopathies, and protein energy malnutrition. When combined with serum ferritin and hemoglobin determinations, the serum transferrin receptor assay is a valuable addition in epidemiologic surveys because it provides a quantitative measure of functional iron deficiency and it distinguishes true IDA from the anemia of chronic disease. The most difficult challenge is to develop effective methods of supplying iron to large segments of a population. Supplementation with iron tablets is suitable for only brief periods of need such as during pregnancy. The poor compliance with existing supplementation programs is believed to be due mainly to the gastrointestinal side effects of oral iron which can be eliminated by the use of a gastric delivery system. The most effective long-term strategy is to increase the intake of bioavailable iron in the diet. The customary approach has been to fortify a food staple such as wheat, rice, sugar, or salt, and thereby increase the iron intake of the entire population. However, because of concerns about the risk of cancer and heart disease in individuals with high iron stores, there is an increasing reluctance to supply iron to individuals who do not require it. A more effective strategy is to fortify food vehicles that are targeted to segments of the population at greatest risk of iron deficiency such as infants and school children. Because of the strong inhibitory properties of diets in regions of the world where iron deficiency is most prevalent, the use of NaFeEDTA has important advantages for food fortification.