Biomedical subjects

Carlo Brugnara

Publications and source records attributed to Carlo Brugnara.

At least 19 recordsLinked to original sources

PubMed2006

Effect of complete protein 4.1R deficiency on ion transport properties of murine erythrocytes.

Moderate hemolytic anemia, abnormal erythrocyte morphology (spherocytosis), and decreased membrane stability are observed in mice with complete deficiency of all erythroid protein 4.1 protein isoforms (4.1(-/-); Shi TS et al. J Clin Invest 103: 331, 1999). We have examined the effects of erythroid protein 4.1 (4.1R) deficiency on erythrocyte cation transport and volume regulation. 4.1(-/-) mice exhibited erythrocyte dehydration that was associated with reduced cellular K and increased Na content. Increased Na permeability was observed in these mice, mostly mediated by Na/H exchange with normal Na-K pump and Na-K-2Cl cotransport activities. The Na/H exchange of 4.1(-/-) erythrocytes was markedly activated by exposure to hypertonic conditions (18.2 +/- 3.2 in 4.1(-/-) vs. 9.8 +/- 1.3 mmol/10(13) cell x h in control mice), with an abnormal dependence on osmolality (EC(50) = 417 +/- 42 in 4.1(-/-) vs. 460 +/- 35 mosmol/kgH(2)O in control mice), suggestive of an upregulated functional state. While the affinity for internal protons was not altered (K(0.5) = 489.7 +/- 0.7 vs. 537.0 +/- 0.56 nM in control mice), the V(max) of the H-induced Na/H exchange activity was markedly elevated in 4.1(-/-) erythrocytes (V(max) 91.47 +/- 7.2 compared with 46.52 +/- 5.4 mmol/10(13) cell x h in control mice). Na/H exchange activation by okadaic acid was absent in 4.1(-/-) erythrocytes. Altogether, these results suggest that erythroid protein 4.1 plays a major role in volume regulation and physiologically downregulates Na/H exchange in mouse erythrocytes. Upregulation of the Na/H exchange is an important contributor to the elevated cell Na content of 4.1(-/-) erythrocytes.

Animals↗

PubMed2006

Protective effects of S-nitrosoalbumin on lung injury induced by hypoxia-reoxygenation in mouse model of sickle cell disease.

Nitric oxide (NO) is a potential new therapeutic agent for sickle cell disease (SCD). We investigated the effects of NO donor on hypoxia-induced acute lung injury that occurs when transgenic sickle cell SAD mice are exposed to chronic hypoxia, a model for lung vasoocclusive sickle cell events. In wild-type and SAD mice, intraperitoneal injection of S-nitrosoalbumin (NO-Alb) produced no significant hematologic changes under room air conditions, whereas it induced mild temporary hypotension and inhibition of platelet aggregation. NO-Alb administration (300 mg/kg ip twice a day, equivalent to 7.5 microM NO) in wild-type and SAD mice exposed to 46 h of hypoxia (8% oxygen) followed by 2 h of normoxia resulted in 1) reduction of the hypoxia-induced increase in blood neutrophil count, 2) prevention of hypoxia-induced increased IL-6 and IL-1beta levels in bronchoalveolar lavage, 3) reduction of the lung injury induced by hypoxia-reoxygenation, 4) prevention of thrombus formation, and 5) prevention of hypoxia-induced increase of lung matrix metalloproteinase-9 gene expression. These effects provide new insights into the possible use of NO-Alb in the treatment of acute lung injury in SCD.

Anemia, Sickle Cell↗

PubMed2006

Quantitative trait loci for baseline erythroid traits.

A substantial genetic contribution underlies variation in baseline peripheral blood counts. We performed quantitative trait locus/loci (QTL) analyses to identify chromosome (Chr) regions harboring genes influencing the baseline erythroid parameters in F2 intercrosses between NZW/LacJ, SM/J, and C57BLKS/J inbred mice. We identified multiple significant QTL for red blood cell (RBC) count, hemoglobin (Hgb) and hematocrit (Hct) levels, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean cell hemoglobin concentration (CHCM). We identified four RBC count QTL: Rbcq1 (Chr 1, peak LOD score at 62 cM,), Rbcq2 (Chr 4, 60 cM), Rbcq3 (Chr 11, 34 cM), and Rbcq4 (Chr 10, 60 cM). Three MCV QTL were identified: Mcvq1 (Chr 7, 30 cM), Mvcq2 (Chr 11, 6 cM), and Mcvq3 (Chr 10, 60 cM). Single significant loci for Hgb (Hgbq1, Chr 16, 32 cM), Hct (Hctq1, Chr 3, 42 cM), and MCH (Mchq1, Chr 10, 60 cM) were identified. The data support the existence of a common RBC/MCH/MCV locus on Chr 10. Two QTL for CHCM (Chcmq1, Chr 2, 48 cM; Chcmq2, Chr 9, 44 cM) and an interaction between Chcmq2 with a locus on Chr 19 were identified. These analyses emphasize the genetic complexity underlying the regulation of erythroid peripheral blood traits in normal populations and suggest that genes not previously recognized as significantly impacting normal erythropoiesis exist.

Animals↗

PubMed2006

Suppression of Fas-FasL coexpression by erythropoietin mediates erythroblast expansion during the erythropoietic stress response in vivo.

Erythropoietin (Epo) is the principal regulator of the erythropoietic response to hypoxic stress, through its receptor, EpoR. The EpoR signals mediating the stress response are largely unknown, and the spectrum of progenitors that are stress responsive is not fully defined. Here, we used flow cytometry to identify stress-responsive Ter119+CD71highFSChigh early erythroblast subsets in vivo. In the mouse spleen, an erythropoietic reserve organ, early erythroblasts were present at lower frequencies and were undergoing higher rates of apoptosis than equivalent cells in bone marrow. A high proportion of splenic early erythroblasts coexpressed the death receptor Fas, and its ligand, FasL. Fas-positive early erythroblasts were significantly more likely to coexpress annexin V than equivalent, Fas-negative cells, suggesting that Fas mediates early erythroblast apoptosis in vivo. We examined several mouse models of erythropoietic stress, including erythrocytosis and beta-thalassemia. We found a dramatic increase in the frequency of splenic early erythroblasts that correlated with down-regulation of Fas and FasL from their cell surface. Further, a single injection of Epo specifically suppressed early erythroblast Fas and FasL mRNA and cell-surface expression. Therefore, Fas and FasL are negative regulators of erythropoiesis. Epo-mediated suppression of erythroblast Fas and FasL is a novel stress response pathway that facilitates erythroblast expansion in vivo.

Animals↗

PubMed2006

Teaching pediatric laboratory medicine to pathology residents.

CONTEXT: Laboratory data are essential to the medical care of fetuses, infants, children, and adolescents. However, the performance and interpretation of laboratory tests on specimens from these patients, which may constitute a significant component of the workload in general hospitals and integrated health care systems as well as specialized perinatal or pediatric centers, present unique challenges to the clinical pathologist and the laboratory. Therefore, pathology residents should receive training in pediatric laboratory medicine. OBJECTIVE: Children's Health Improvement through Laboratory Diagnostics, a group of pathologists and laboratory scientists with interest and expertise in pediatric laboratory medicine, convened a task force to develop a list of curriculum topics, key resources, and training experiences in pediatric laboratory medicine for trainees in anatomic and clinical pathology or straight clinical pathology residency programs and in pediatric pathology fellowship programs. DATA SOURCES: Based on the experiences of 11 training programs, we have compiled a comprehensive list of pediatric topics in the areas of clinical chemistry, endocrinology, hematology, urinalysis, coagulation medicine, transfusion medicine, immunology, microbiology and virology, biochemical genetics, cytogenetics and molecular diagnostics, point of care testing, and laboratory management. This report also includes recommendations for training experiences and a list of key texts and other resources in pediatric laboratory medicine. CONCLUSIONS: Clinical pathologists should be trained to meet the laboratory medicine needs of pediatric patients and to assist the clinicians caring for these patients with the selection and interpretation of laboratory studies. This review helps program directors tailor their curricula to more effectively provide this training.

Child↗

PubMed2005

Regulation of K-Cl cotransport by protein phosphatase 1alpha in mouse erythrocytes.

The K-Cl cotransport (KCC) is an electroneutral-gradient-driven-membrane transport system, which is involved in regulation of red cell volume. Although the regulatory cascade of KCC is largely unknown, a signaling pathway involving phosphatases and kinases has been proposed. Here, we investigated the expression and the activity of protein phosphatase 1(PP-1) isoforms in mouse red cells, focusing on two models of abnormally activated KCC: mice genetically lacking the two Src-family tyrosine kinases, Hck and Fgr, (hck-/-fgr-/-) and the SAD transgenic sickle-cell-mice. The PP-1alpha, PP-1gamma, PP-1delta isoforms were expressed at similar levels in wild-type, hck-/-fgr-/- and SAD mouse erythrocytes and in each case were predominantly localized to cytoplasm. The PP-1alpha activity was significantly higher in both membrane and cytosol fractions of hck-/-fgr-/- and of SAD erythrocytes than in those of wild-type red cells, suggesting PP-1alpha as a target of the Hck and Fgr kinases. The PP2, a specific inhibitor of Src-family kinase, significantly increased KCC activity in wild-type mouse red cells, but failed to modify the already increased KCC activity in SAD erythrocytes. The lag-time for activation of KCC was considerably reduced in both hck-/-fgr-/- and SAD erythrocytes, suggesting that the rate limiting activation steps in both strains are freed from their tonic inhibition. Sulfhydryl reduction by dithiothreitol (DTT) lowered KCC activity only in SAD red cells, but did not affect the PP2-treated erythrocytes. These data suggest up-regulation of KCC in SAD red cells is mainly secondary to oxidative damage, which most likely reduces or removes the tonic KCC inhibition resulting from PP-1alpha activity controlled in turn by Src-family kinases.

Animals↗

PubMed2005

Quantitative trait loci for baseline white blood cell count, platelet count, and mean platelet volume.

A substantial genetic contribution to baseline peripheral blood counts has been established. We performed quantitative trait locus/loci (QTL) analyses to identify chromosome (Chr) regions harboring genes influencing the baseline white blood cell (WBC) count, platelet (Plt) count, and mean platelet volume (MPV) in F(2) intercrosses between NZW/LacJ, SM/J, and C57BLKS/J inbred mice. We identified six significant WBC QTL: Wbcq1 (peak LOD score at 38 cM, Chr 1), Wbcq2 (42 cM, Chr 3), Wbcq3 (0 cM, Chr 15), Wbcq4 (58 cM, Chr 1), Wbcq5 (82 cM, Chr 1), and Wbcq6 (8 cM, Chr 14). Three significant Plt QTL were identified: Pltq1 (24 cM, Chr 2), Pltq2 (36 cM, Chr 7), and Pltq3 (10 cM, Chr 12). Two significant MPV QTL were identified, Mpvq1 (62 cM, Chr 15) and Mpvq2 (44 cM, Chr 8). In total, the WBC QTL accounted for up to 31% of the total variance in baseline WBC count, while the Plt and MPV QTL accounted for up to 30% and 49% of the total variance, respectively. These analyses underscore the genetic complexity underlying these traits in normal populations and provide the basis for future studies to identify novel genes involved in the regulation of mammalian hematopoiesis.

Alleles↗

PubMed2005

Screening healthy infants for iron deficiency using reticulocyte hemoglobin content.

CONTEXT: Current clinical practice relies on hemoglobin to detect iron deficiency, which misses infants not yet anemic and places them at higher risk for neurocognitive impairment. Reticulocyte hemoglobin content (CHr) has never been compared with hemoglobin for screening healthy infants. OBJECTIVES: To evaluate CHr for detecting iron deficiency without anemia in healthy 9- to 12-month-old infants and to compare CHr with hemoglobin in screening for iron deficiency in this population. A secondary objective was to explore the association between CHr and subsequent development of anemia. DESIGN, SETTING, AND PATIENTS: A prospective observational cohort study of 202 healthy 9- to 12-month-old infants from an urban, hospital-based, primary care clinic in Boston, Mass, who were screened for iron deficiency between June 2000 and April 2003, and followed up for a median of 5.6 months. MAIN OUTCOME MEASURES: Iron deficiency (transferrin saturation <10%) and anemia (hemoglobin <11 g/dL). RESULTS: Of 202 infants enrolled, 23 (11.4%) had iron deficiency and 6 (3%) had iron deficiency and anemia. Iron-deficient and non-iron-deficient infants had significantly different values for all measured hematological and biochemical markers for iron deficiency. Optimal CHr cutoff for detecting iron deficiency was 27.5 pg (sensitivity, 83% and specificity, 72%); a hemoglobin level of less than 11 g/dL resulted in a sensitivity of 26% and a specificity of 95%. Reticulocyte hemoglobin content was more accurate overall than hemoglobin was for detecting iron deficiency (area under the receiver operating characteristic curve, 0.85 vs 0.73; P = .007). A CHr of less than 27.5 pg without anemia at initial screening was associated with subsequent anemia when screened again in the second year of life (risk ratio, 9.1; 95% confidence interval, 1.04-78.9; P = .01). CONCLUSIONS: A CHr of less than 27.5 pg is a more accurate hematological indicator of iron deficiency compared with hemoglobin of less than 11 g/dL in these healthy 9- to 12-month-old infants. Further studies are warranted to determine whether CHr should be the preferred screening tool in the early detection of iron deficiency in infants.

Anemia, Iron-Deficiency↗

PubMed2005

Genetic influences on peripheral blood cell counts: a study in baboons.

Interperson differences in peripheral blood cell counts in healthy individuals result from genetic and environmental influences. We used multivariate genetic analyses to assess the relative impact of genes and environment on baseline blood cell counts and indices using a pedigreed colony of baboons, an animal with well-documented analogies to human blood physiology. After accounting for age, sex, and weight, we found that genetic influences explain a significant proportion of the remaining variability, ranging from a low of 13.7% for mean corpuscular hemoglobin concentration (MCHC) to a high of 72.4% for red blood cell (RBC) number. Genes influence 38.5% of the variation in baseline white blood cell (WBC) count, a characteristic that correlates with mortality in both the general human population and clinically defined subgroups such as individuals with sickle-cell disease. We examined the interaction between pairs of traits and identified those that share common genetic influences (pleiotropy). We unexpectedly observed that the same gene or group of genes influences both WBC count and mean platelet volume (MPV). We anticipate that this approach will ultimately lead to discovery of novel insights into the biology of related traits, and ultimately identify important genes that affect hematopoiesis.

Animals↗

PubMed2005

Evidence for a protective role of the Gardos channel against hemolysis in murine spherocytosis.

It has been shown that mice with complete deficiency of all 4.1R protein isoforms (4.1-/-) exhibit moderate hemolytic anemia, with abnormal erythrocyte morphology (spherocytosis) and decreased membrane stability. Here, we characterized the Gardos channel function in vitro and in vivo in erythrocytes of 4.1-/- mice. Compared with wild-type, the Gardos channel of 4.1-/- erythrocytes showed an increase in Vmax (9.75 +/- 1.06 vs 6.08 +/- 0.09 mM cell x minute; P < .04) and a decrease in Km (1.01 +/- 0.06 vs 1.47 +/- 1.02 microM; P < .03), indicating an increased sensitivity to activation by intracellular calcium. In vivo function of the Gardos channel was assessed by the oral administration of clotrimazole, a well-characterized Gardos channel blocker. Clotrimazole treatment resulted in worsening of anemia and hemolysis, with decreased red cell survival and increased numbers of circulating hyperchromic spherocytes and microspherocytes. Clotrimazole induced similar changes in 4.2-/- and band 3+/- mice, indicating that these effects of the Gardos channel are shared in different models of murine spherocytosis. Thus, potassium and water loss through the Gardos channel may play an important protective role in compensating for the reduced surface-membrane area of hereditary spherocytosis (HS) erythrocytes and reducing hemolysis in erythrocytes with cytoskeletal impairments.

Anemia, Hemolytic↗

PubMed2005

Protein phosphatase 1alpha is tyrosine-phosphorylated and inactivated by peroxynitrite in erythrocytes through the src family kinase fgr.

Protein serine/threonine phosphorylation is a significant component of the intracellular signal that together with tyrosine phosphorylation regulates several processes, including cell-cycle progression, muscle contraction, transcription, and neuronal signaling. Cross-talk between phosphoserine/threonine- and phosphotyrosine-mediated pathways is not yet well understood. In this study we found that peroxynitrite, a physiological oxidant formed by the fast radical-radical reaction between the nitric oxide and the superoxide anion, induced tyrosine phosphorylation of the serine/threonine protein phosphatase 1alpha (PP1alpha) in human erythrocytes through activation of src family kinases. We have previously shown in mouse red cells that upregulation of the src kinase fgr phosphorylates PP1alpha, acting as an upstream negative regulator of PP1alpha, and downregulates K-Cl cotransport. Here we found that PP1alpha is a selective substrate of peroxynitrite-activated fgr and that tyrosine phosphorylation of PP1alpha corresponds to an inhibition of its enzymatic activity. Despite fgr activation and PP1alpha downregulation, peroxynitrite stimulated in a dose-dependent fashion the function of the K-Cl cotransporter. In an attempt to understand the mechanism of K-Cl cotransport activation, we found that the effect of peroxynitrite is completely reversed by dithriothreitol, suggesting that peroxynitrite acts as an oxidizing agent by an SH-dependent and PP1alpha-independent mechanism. These findings highlight a novel function of peroxynitrite in regulating the intracellular signal transduction pathways involving serine/threonine phosphorylation and the functional role of proteins that are targets of these phosphatases.

Down-Regulation↗

PubMed2005

An algorithm using reticulocyte hemoglobin content (CHr) measurement in screening adolescents for iron deficiency.

PURPOSE: To evaluate whether the use of an algorithm including reticulocyte hemoglobin content (CHr), a new hematologic parameter, in addition to the screening complete blood count (CBC), improves detection of iron deficiency and iron deficiency anemia in healthy adolescents. METHODS: After initiation of an algorithm using CHr in addition to CBC results for identifying iron-deficient patients in a primary care hospital-based adolescent clinic, we reviewed results of all hematological tests performed in the clinic during an 8-month period. Electronic medical records were screened for health status and inclusion criteria. We determined the number of patients with low hematocrit values, low mean cell volume (MCV), and low CHr. To evaluate the impact of the protocol, we calculated the percentage of cases in which the CHr results suggested a management plan different from that which would have been formulated using the CBC results only. RESULTS: A total of 381 patients (mean age 16.8 +/- 3.1 years) were included in the study. Anemia was diagnosed by the Centers for Disease Control (CDC) guidelines in 63 patients (16.5%), low MCV in 170 patients (44.6%), and a low CHr in 80 (21%) patients. In 68% of anemia cases, a normal CHr suggested that iron deficiency was not the cause of the anemia. Although low MCV values were found in 38 (60.4%) of all anemic cases, mean MCV was significantly (p < 0.001) lower in the 19 cases with a low CHr as well. In 19% of 318 patients with a normal hematocrit (HCT), a low CHr suggested the need for treatment of early iron deficiency. In 103 (27%) cases, CHr suggested a different treatment plan from that which would have been formulated using the screening CBC only. CONCLUSIONS: The use of an algorithm including CHr to screen for iron deficiency anemia may increase the accuracy of diagnosis, enabling early detection and treatment of iron deficiency in adolescents without the need for additional costly iron studies.

Adolescent↗

PubMed2005

5-hydroxymethyl-2-furfural modifies intracellular sickle haemoglobin and inhibits sickling of red blood cells.

In an attempt to find new types of anti-sickling agents that specifically bind to intracellular sickle haemoglobin (HbS) without inhibition by plasma and tissue proteins or other undesirable consequences, we identified 5-hydroxymethyl-2-furfural (5HMF), a naturally occurring aromatic aldehyde, as an agent that fulfils this criterion. Preliminary studies in vitro showed that 5HMF forms a high-affinity Schiff-base adduct with HbS and inhibits red cell sickling by allosterically shifting oxygen equilibrium curves towards the left. Further studies with transgenic (Tg) sickle mice showed that orally administered 5HMF was rapidly absorbed into the bloodstream from the gastrointestinal tract without being destroyed, traversed the red blood cell membrane and specifically bound with, and modified, HbS molecules at levels as high as 90%. Pretreatment of Tg sickle mice with 5HMF inhibited the formation of sickle cells and significantly prolonged survival time under severe hypoxia, compared with untreated mice, which died within 15 min because of sickling-dependent pulmonary sequestration. These results indicate the feasibility of 5HMF as an attractive potential candidate for therapy of sickle cell disease.

Anemia, Sickle Cell↗

PubMed2004

Abnormal regulation of Mg2+ transport via Na/Mg exchanger in sickle erythrocytes.

Erythrocyte magnesium (Mg2+) deficiency has been demonstrated in sickle cell disease to contribute to erythrocyte dehydration, K loss, and thus sickling. No studies have assessed the functional properties of the Na/Mg exchanger in sickle cell disease. Using Mg(2+)-loaded erythrocytes, we measured Mg2+ efflux induced by extracellular Na+. We estimated that the Na/Mg exchanger had higher maximal velocity, higher affinity for Na+, and lower cooperativity for Mg2+ in sickle than in normal erythrocytes. The activity of the exchanger was markedly decreased by hypotonic and hypertonic conditions in normal erythrocytes but not in sickle erythrocytes. Studies of density-separated erythrocytes showed that the activity of the exchanger decreased as the mean cellular hemoglobin concentration increased in normal but not in sickle erythrocytes. Inhibition of protein kinase C (PKC) activity by calphostin C and chelerythrine increased the activity of the exchanger in normal but not in sickle erythrocytes. Inhibition of serine/threonine phosphatases did not affect the activity of the exchanger in either normal or sickle erythrocytes. Altogether, these data indicate that the Na/Mg exchanger is abnormally regulated in sickle erythrocytes. Therefore, Mg2+ depletion in sickle erythrocytes might be mediated by an up-regulated Na/Mg exchanger, possibly by dephosphorylation of the transporter or a closely associated regulator.

Anemia, Sickle Cell↗

PubMed2004

Physiological roles of the intermediate conductance, Ca2+-activated potassium channel Kcnn4.

Three broad classes of Ca(2+)-activated potassium channels are defined by their respective single channel conductances, i.e. the small, intermediate, and large conductance channels, often termed the SK, IK, and BK channels, respectively. SK channels are likely encoded by three genes, Kcnn1-3, whereas IK and most BK channels are most likely products of the Kcnn4 and Slo (Kcnma1) genes, respectively. IK channels are prominently expressed in cells of the hematopoietic system and in organs involved in salt and fluid transport, including the colon, lung, and salivary glands. IK channels likely underlie the K(+) permeability in red blood cells that is associated with water loss, which is a contributing factor in the pathophysiology of sickle cell disease. IK channels are also involved in the activation of T lymphocytes. The fluid-secreting acinar cells of the parotid gland express both IK and BK channels, raising questions about their particular respective roles. To test the physiological roles of channels encoded by the Kcnn4 gene, we constructed a mouse deficient in its expression. Kcnn4 null mice were of normal appearance and fertility, their parotid acinar cells expressed no IK channels, and their red blood cells lost K(+) permeability. The volume regulation of T lymphocytes and erythrocytes was severely impaired in Kcnn4 null mice but was normal in parotid acinar cells. Despite the loss of IK channels, activated fluid secretion from parotid glands was normal. These results confirm that IK channels in red blood cells, T lymphocytes, and parotid acinar cells are indeed encoded by the Kcnn4 gene. The role of these channels in water movement and the subsequent volume changes in red blood cells and T lymphocytes is also confirmed. Surprisingly, Kcnn4 channels appear to play no required role in fluid secretion and regulatory volume decrease in the parotid gland.

Animals↗

PubMed2004

Iron therapy in the pediatric hemodialysis population.

Iron therapy maintains iron stores and optimizes the response to recombinant human erythropoietin (r-HuEPO) in patients with end-stage renal failure. Information is limited, however, regarding the preferential route of iron administration in pediatric patients receiving hemodialysis. Therefore, we prospectively randomized 35 iron-replete patients (aged >1 to <20 years) to receive up to 16 weeks of maintenance i.v. ( n=17) or daily oral ( n=18) iron. Eligible patients had received hemodialysis for >2 months, had a baseline transferrin saturation [TSAT] >20%, and were receiving maintenance r-HuEPO. Treatment arms were evenly distributed with respect to baseline demographic and clinical characteristics, with no statistically significant differences in baseline hemoglobin (Hb), hematocrit (Hct), reticulocyte Hb content (CHr), serum ferritin (SF), TSAT, or r-HuEPO dose. In the 35 patients, i.v. iron dextran and not oral iron was associated with a significant increase (138.5 to 259.1 ng/ml, P=0.003) in SF. A comparison of the change in SF between the i.v. iron group and the oral iron group was also significant ( P=0.001). Whereas only i.v. iron was associated with a significant decrease in the dose of r-HuEPO (234.0 to 157.6 U/kg per week, P=0.046) and an increase of the CHr (29.2 to 30.1 pg, P=0.049), these changes were not significantly different from those experienced by patients in the oral iron group. In both groups, the Hct remained stable and in neither group was there a significant change in the TSAT. In summary, although both oral and i.v. iron maintained patients in an iron-replete state in this short-term study, only i.v. therapy allowed for a significant improvement in iron stores.

Administration, Oral↗

PubMed2004

Automated flow cytometric analysis of blood cells in cerebrospinal fluid: analytic performance.

We compared the performance of an automated method for obtaining RBC and WBC counts and WBC differential counts in cerebrospinal fluid (CSF) samples with the reference manual method. Results from 325 samples from 10 worldwide clinical sites were used to demonstrate the accuracy, precision, and linearity of the method. Accuracy statistics for absolute cell counts showed a high correlation between methods, with correlation coefficients for all reportable absolute counts greater than 0.9. Linearity results demonstrated that the method provides accurate results throughout the reportable ranges, including clinical decision points for WBCs of 0 to 10/microL. Interassay precision and intra-assay precision for the ADVIA 120 (Bayer HealthCare, Tarrytown, NY) method were acceptable at all levels. The ADVIA 120 CSF Assay enumerates and differentiates cells via flow cytometry in a minimally diluted sample, improving the analysis of typically hypocellular CSF samples. Study results demonstrate that the automated ADVIA 120 CSF Assay is an acceptable alternative to the labor-intensive manual method.

Autoanalysis↗

PubMed2004

Daily multivitamins with iron to prevent anemia in high-risk infants: a randomized clinical trial.

OBJECTIVE: The goal of this study was to assess the effectiveness of multivitamins with iron as prophylaxis against iron deficiency and anemia in infancy. METHODS: The study was a double-blinded, randomized, pragmatic, clinical trial conducted at 3 urban primary care clinics. Subjects included healthy, full-term infants who were enrolled at their 6-month well-child visit. Infants were randomly assigned to receive standard-dose multivitamins with or without iron (10 mg/day). Parents administered multivitamins by mouth daily for 3 months. Laboratory results at 9 months of age were analyzed for the presence of anemia and/or iron deficiency. Anemia was defined as hemoglobin level <11.0 g/dL. Iron deficiency was initially defined as any abnormal laboratory value of the following: mean corpuscular volume combined with red cell distribution width or zinc protoporphyrin (with blood lead level <10 microg/dL) for most subjects and ferritin, transferrin saturation, or reticulocyte hemoglobin content for a subset. Subsequent analyses defined iron deficiency as any 2 abnormalities of the above laboratory outcomes, except hemoglobin. RESULTS: The control (n = 138) and intervention (n = 146) groups were equivalent with respect to all important sociodemographic and nutritional variables. At 9 months of age, anemia was found in 21% of infants (n = 58). A total of 229 (81%) had iron deficiency on the basis of 1 abnormal laboratory indicator and 139 (49%) on the basis of 2 abnormal laboratory indicators. No difference existed in the occurrence of anemia and iron deficiency between the intervention and control groups. In the intervention group, 22% and 78% of 138, respectively, were anemic or had 1 abnormal laboratory outcome indicative of iron deficiency. In the control group, 19% and 84% of 144 were anemic or iron deficient. When stratified by adherence, no differences in hematologic outcomes between groups were noted. However, in multivariate logistic regression, infants whose mothers were anemic during pregnancy were 2.15 times more likely than others to have any laboratory abnormality (95% confidence interval: 1.14-4.07). Increasing adherence, regardless of group assignment, was associated with a 0.56 times reduced risk of any abnormality (95% confidence interval: 0.41-0.76). CONCLUSION: On the basis of intention-to-treat analysis, multivitamins with iron was not effective in preventing iron deficiency or anemia in 9-month-old infants. However, effective prevention and treatment of maternal anemia during pregnancy and giving multivitamins with or without additional iron during infancy may prove to be important approaches to the prevention of iron deficiency among high-risk children. Because of the consequences of iron deficiency and its high prevalence among low-income infants, additional investigation in these areas is warranted.

Anemia, Iron-Deficiency↗