Single-dose intravenous iron infusion versus red blood cell transfusion for the treatment of severe postpartum anaemia: a randomized controlled pilot study.

BACKGROUND AND OBJECTIVES: There are no randomized trials comparing intravenous iron to RBC transfusion for the treatment of severe postpartum anaemia. The objectives of this study were to evaluate the feasibility of randomizing women with severe postpartum anaemia secondary to postpartum haemorrhage to RBC transfusion or intravenous iron, and to describe patient-reported outcomes, and haematological and iron parameters. MATERIALS AND METHODS: Women with a postpartum haemorrhage exceeding 1000 ml and an Hb between 5·6 and 8·1 g/dl were randomized to 1500 mg of intravenous iron (n = 7) isomaltoside or RBC transfusion (n = 6). Participants completed the Multidimensional Fatigue Inventory and Edinburgh Postnatal Depression Scale, and blood samples were drawn at inclusion, daily during the first week and at weeks 3, 8 and 12. RESULTS: We screened 162 women and included 13 (8%). There was no significant difference between groups in fatigue or depression scores. RBC transfusion was associated with a higher Hb on day 1, inhibition of reticulocytosis during the first week and low iron levels. Intravenous iron was associated with increased reticulocytosis during the first week, repleted iron stores and a higher Hb in weeks 3-12. CONCLUSION: This pilot study shows that intravenous iron could be an attractive alternative to RBC transfusion in severe postpartum anaemia, and that a larger trial is needed and feasible.

Phenylhydrazine administration accelerates the development of experimental cerebral malaria.

Phenylhydrazine (PHZ) treatment is generally used to enhance parasitemia in infected mice models. Transient reticulocytosis is commonly observed in iron-deficient anemic hosts after treatment with iron supplementation, and is also associated with short-term hemolysis caused by PHZ treatment. In this study, we investigated the relationship between reticulocytosis and cerebral malaria (CM) in a murine model induced by PHZ administration before Plasmodium berghei ANKA (PbA) infection. Mortality and parasitemia were checked daily. Pro-inflammatory cytokines and IL-10 were quantified by ELISA. The expression of CXCL9, CXCL10, CCL5, and CXCR3 mRNAs was determined by real-time PCR. Brain sequestration of CD4(+) and CD8(+) T cells and populations of splenic Th1 CD4(+) T cells, dendritic cells (DCs), CD11b(+) Gr1(+) cells, and regulatory T cells (Tregs) were assessed by FACS. PHZ administration dramatically increased parasitemia from day 3 to day 5 post infection (p.i.) compared with the untreated control infected mice group; also, CM developed at day 5 p.i., compared with day 7 p.i. in untreated control infected mice, as well as significantly decreased blood-brain barrier function (P < 0.001). PHZ administration during PbA infection significantly increased the expression of CXCL9 (P <0.05) and VCAM-1 (P <0.001) in the brain, increased the expression of CXCL10, CCL5 and CXCR3, and significantly increased the recruitment of CD4(+) and CD8(+) T cells (P <0.001 and P <0.01, respectively) as well as CD11b(+) Gr1(+) cells to the brain. In addition, PHZ administration significantly increased the numbers of IL-12-secreting DCs at days 3 and 5 p.i. compared to those of untreated control infected mice (P <0.001 and P <0.01, respectively). Consequently, the activation of CD4(+) T cells, especially the expansion of the Th1 subset (P <0.05), was significantly and dramatically enhanced and was accompanied by marked increases in the production of protein and/or mRNA of the Th1-type pro-inflammatory mediators, IFN-γ and TNF-α (P <0.01 for both for protein; P <0.05 for TNF-α mRNA). Our results suggest that, compared to healthy individuals, people suffering from reticulocytosis may be more susceptible to severe malaria infection in malaria endemic areas. This has implications for the most appropriate selection of treatment, which may also cause reticulocytosis in patients living in such areas.

Efficacy of green tea extract in two exercise models.

Oral administration of green tea extract in a dose of 6 mg/kg twice a day (before and after exercise) over 2 weeks significantly increased swimming times on week 1 and 2 in comparison with control animals receiving water. The 7-day and final exhaustive running in rats was accompanied by a significant decrease in spleen weight and iron serum levels associated with developed reticulocytosis. Administration of green tea extract in a dose of 12 mg/kg once a day (before exercise) for 2 weeks did not affect the duration of the running, but prevented the decrease in serum iron and spleen weight, that, along with a significantly increased concentration of reduced glutathione in erythrocytes, can indicate a normalizing effect of green tea extract on hemopoiesis and stimulating effect on the antioxidant system of erythrocytes.

Plasmodium products contribute to severe malarial anemia by inhibiting erythropoietin-induced proliferation of erythroid precursors.

Low reticulocytosis, indicating reduced red blood cell (RBC) output, is an important feature of severe malarial anemia. Evidence supports a role for Plasmodium products, especially hemozoin (Hz), in suppressed erythropoiesis during malaria, but the mechanism(s) involved remains unclear. Here, we demonstrated that low reticulocytosis and suppressed erythropoietin (Epo)-induced erythropoiesis are features of malarial anemia in Plasmodium yoelii- and Plasmodium berghei ANKA-infected mice, similar to our previous observations in Plasmodium chabaudi AS-infected mice. The magnitude of decreases in RBC was a reflection of parasitemia level, but low reticulocytosis was evident despite differences in parasitemia, clinical manifestation, and infection outcome. Schizont extracts and Hz from P. falciparum and P. yoelii and synthetic Hz suppressed Epo-induced proliferation of erythroid precursors in vitro but did not inhibit RBC maturation. To determine whether Hz contributes to malarial anemia, P. yoelii-derived or synthetic Hz was administered to naive mice, and the development of anemia, reticulocytosis, and RBC turnover was determined. Parasite-derived Hz induced significant decreases in RBC and increased RBC turnover with compensatory reticulocytosis, but anemia was not as severe as that in infected mice. Our findings suggest that parasite factors, including Hz, contribute to severe malarial anemia by suppressing Epo-induced proliferation of erythroid precursors.

Clinical picture and laboratorial evaluation in human loxoscelism.

Loxosceles spiders are found globally, especially in South and North America. In Brazil, approximately 10,000 cases of Loxosceles spp. spider bites are reported annually. Herein we analyzed 81 patients diagnosed as either cutaneous or cutaneous-hemolytic loxoscelism, in a geographical area where most accidents are caused by Loxosceles gaucho, and we report their clinical and laboratory data obtained during week 1 and 2 after the bite. Massive hemolysis was noticed in only 2 cases, but high serum bilirubin and LDH levels, suggestive of hemolysis, were noticed in 25 cases on admission. Anemia was not frequent (14.7%), and reticulocytosis was particularly noticed during week 2 (in 56% of patients). High D-dimer levels were suggestive of endothelial cell activation and intravascular thrombin generation, but thrombocytopenia was noticed in only 17.6% of patients in week 1. Acute kidney injury (AKI) only occurred in patients with massive hemolysis. The definitive diagnosis of overt disseminated intravascular coagulation (DIC) could not be established on admission. Fever was associated with the presence of hemolysis (p = 0.03). Altogether, these findings provide evidence that mild hemolysis is frequent in loxoscelism and suggest that AKI is uncommon, exclusively occurring in patients with massive hemolysis.

Energy production and redox status of rat red blood cells after reticulocytosis induced by various treatments.

Stimulated erythropoiesis and reticulocytosis can be induced by daily bleeding, or by phenylhydrazine (PHZ) treatment. We compared the in vivo effects of PHZ and bleeding treatment on haematological, energy and redox status parameters in red blood cells (RBC) of rats. The results showed that all followed haematological parameters were significantly lower in bleeding, compared to PHZ-treated rats. PHZ induced even 2.58-fold higher reticulocytosis as compared to bleeding treatment. Although PHZ induced higher reticulocytosis, respiration intensity and energy production was lower than in bleeding-induced reticulocytes. These alterations were the consequence of increased superoxide anion and peroxynitrite concentrations in PHZ-treated rats. Bleeding treatment resulted in increased activity of an antioxidative enzyme, superoxide dismutase. In conclusion, differences in these two experimental models for reticulocytosis may be used as tools for appropriate pharmacological testing of redox-active substances considering energy and redox processes, as well as apoptosis pathways.

Long-term intake of a high zinc diet causes iron deficiency anemia accompanied by reticulocytosis and extra-medullary erythropoiesis.

To elucidate the pathophysiology of zinc (Zn)-induced iron (Fe) deficiency anemia (IDA), we examined hemoglobin (Hb) concentrations, hematocrit (Ht) levels, numbers of circulating red blood cells (RBC) and reticulocytes, values of mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC), serum Zn, Fe and erythropoietin (EPO) concentrations and histopathological changes in the bone marrow, spleen and liver using rats fed with a standard or high Zn diet for 20 weeks. Rats fed with the high Zn diet exhibited a significant decrease in Hb concentrations, Ht levels and MCV, MCH and MCHC values, indicating microcytic hypochromic anemia characterized by Fe deficiency. Also, a marked decrease in serum Fe concentrations was seen in rats fed with the high Zn diet relative to rats fed with the standard diet. Interestingly, the number of RBC was comparable in both groups of rats, although a decrease in the number of RBC is ordinarily seen in IDA. There were reticulocytosis and extra-medullary erythropoiesis in the spleen and an increase in serum EPO concentrations in rats fed with the high Zn diet vs. those on the standard diet. These observations suggest that both reticulocytosis and extra-medullary erythropoiesis in the spleen played a role in maintaining the number of RBC in rats fed with the high Zn diet, preventing further progression of anemia. Further, increased production of EPO may be involved in the induction of reticulocytosis and extra-medullary erythropoiesis in the spleen.

Carbamazepine-induced hemolytic and aplastic crises associated with reduced glutathione peroxidase activity of erythrocytes.

Although pure red cell aplasia is a well-known side effect of carbamazepine treatment, intravascular hemolytic anemia is rare. We describe a 5-year-old boy who developed concurrent intravascular hemolytic anemia and erythroblastopenia, probably due to carbamazepine. Carbamazepine treatment was subsequently discontinued, and the patient was treated with red blood cell transfusions, haptoglobin, and methylprednisolone. His hematologic abnormalities were almost fully recovered within 2 weeks. Examination of the patient's and mother's erythrocyte enzyme activities revealed mildly decreased erythrocyte glutathione peroxidase (GSH-Px) activity. We speculate that patients with reduced GSH-Px activity are at a high risk of developing carbamazepine-induced hemolytic crisis and/or aplastic crisis.

An assessment of recombinant human erythropoietin effect on reticulocyte production rate and lifespan distribution in healthy subjects.

PURPOSE: An empirical pharmacodynamic model was developed to assess the effect of recombinant human erythropoietin (rHu-EPO) treatment on the reticulocyte production rate and lifespan distribution. MATERIALS AND METHODS: Single doses of rHu-EPO at levels 20, 40, 60, 90, 120, and 160 kIU were administered to healthy volunteers (n = 8 per dose level). Erythropoietin plasma concentrations as well as hematologic responses were measured up to 42 days. The hematological data were used to determine explicit relationships between reticulocyte and red blood cell counts (RBC) and the reticulocytes' production rate and lifespan distribution. RESULTS: The parameter estimates obtained by simultaneous fitting of the model to the reticulocyte and RBC data revealed that rHu-EPO transiently increased the reticulocyte lifespan from the baseline value of 1.7 days to 3.4 days and the effect lasted for 8.3 days. The dose dependent increase in the reticulocyte production had the maximal value of 77.5 10(9) cells/l/day and was followed by a rebound that was less than 9% of the baseline value. Both reticulocyte and RBC responses were preceded by a dose-independent lag time of 1.7 days. CONCLUSIONS: The effect of rHu-EPO on the reticulocyte production rate and lifespan distribution was characterized. The results of the present study can be further utilized in building more mechanistic pharmacodynamic models of rHu-EPO stimulatory effects.

Interferon-gamma mediates suppression of erythropoiesis but not reduced red cell survival following CpG-ODN administration in vivo.

OBJECTIVE: Cytokines released during inflammatory processes have been proposed to play a central role in mediating mechanism(s) leading to anemia. Here, we used CpG-ODN to investigate the effects of a pro-inflammatory response on the pathophysiological processes leading to anemia. METHODS: Naïve and erythropoietin (EPO)-treated mice were injected for 2 days with 100 microg CpG-ODN or control ODN and the effects on the course of red blood cell (RBC) and reticulocyte counts, RBC turnover, and EPO-stimulated maturation of erythroid cells were analyzed. To study the effect of CpG-ODN on erythroid cell maturation in vitro, we obtained primary EPO-responsive cells by treating mice with thiamphenicol (15 mg/g body weight). RESULTS: CpG-ODN-treated mice developed anemia, which persisted for 5 days and was associated with a 50% reduction in EPO-stimulated differentiation of EPOR+ cells to TER119+ erythroblasts. CpG-ODN-induced suppression required accessory cells, including antigen presenting cells, which activated other cells to produce pro-inflammatory cytokines. In vitro neutralization of IFN-gamma, but not IL-12, TNF-alpha, IFN-alpha, IL-1alpha, or IL-1beta, abrogated the erythropoietic suppression induced by CpG-ODN. The anemia observed in CpG-ODN-treated mice was also associated with reduced RBC survival in vivo, as demonstrated by a sevenfold to eightfold higher turnover of biotinylated RBC compared to control ODN-treated mice. In vivo IFN-gamma neutralization confirmed that IFN-gamma contributed to erythropoietic suppression but not reduced RBC survival. CONCLUSIONS: Together, these results demonstrate that CpG-ODN anemia is associated with suppressed erythropoiesis and decreased RBC survival. Importantly, CpG-ODN-induced IFN-gamma was found to be the major factor mediating erythropoietic suppression but not decreased RBC survival.

Stepping up versus standard doses of erythropoietin in preterm infants: a randomized controlled trial.

In this study, it is hypothesized that a planned increase in the dose of recombinant human erythropoietin (rh-EPO) can prevent transfusion in very low birth weight infants. Two different regimens of rh-EPO were administrated, one consisting in increasing dosage up to 5000 U/kg/wk, according to the individual reticulocytes response, and the second in a standard therapy of 1250 U/kg/wk. Fifty-one infants participated. Despite a significant higher reticulocytosis, the study was prematurely terminated due to the results of an interim analysis showing that transfusion was not avoided by increasing the rh-EPO. No significant differences were found between the two regimens concerning transfusion rate, volume transfused, gain in weight, and adverse effects. Progressive titration of rh-EPO to improve the biological response does not leave premature infants free of transfusion.

Inhibitory effect of pyrimidine and purine nucleotides on the multiplication of Babesia gibsoni: possible cause of low parasitemia and simultaneous reticulocytosis in canine babesiosis.

The present study was conducted to determine the cause of low parasitemia and simultaneous reticulocytosis in canine babesiosis. The parasitemia was significantly decreased in in vitro cultures of Babesia gibsoni by the pretreatment of host canine erythrocytes with lead acetate, which is a specific inhibitor of pyrimidine 5'-nucleotidase subclass I (P5N-I). The serum from dogs chronically infected with B. gibsoni did not decrease the activities of hexokinase, glucose-6-phosphate dehydrogenase or 6-phosphogluconate dehydrogenase in canine reticulocytes, although it was previously reported that this serum had inhibitory effects on both the maturation of reticulocytes and the canine P5N-I and purine-specific 5'-nucleotidase activities. Furthermore, the in vitro multiplication of B. gibsoni was significantly inhibited by pyrimidine nucleotides such as cytidine 5'-monophosphate (5'-CMP), which is preferentially catalyzed by P5N-I and also inhibits the morphological maturation of canine reticulocytes. Purine nucleotides such as inosine 5'-monophosphate (5'-IMP) also had an inhibitory effect on the multiplication of this parasite. These results suggest that nucleotides such as 5'-CMP and 5'-IMP might accumulate in young erythrocytes and/or serum in dogs infected with B. gibsoni as a result of the decreased activity of erythrocyte 5'-nucleotidase, and the accumulation of these nucleotides might inhibit the multiplication of this parasite and simultaneously retard the maturation of reticulocytes. The results obtained from the in vitro examinations in the present study may partially clarify the relationship between low parasitemia and simultaneous reticulocytosis in vivo in canine babesiosis.