Extreme Reticulocytosis After Splenectomy in a Patient With Hemoglobin Mizuho.

BACKGROUND: Patients with Hb Mizuho may be splenectomized at a young age to decrease their need for blood transfusions. OBSERVATIONS: Transfusion-dependency decreased dramatically in a 4-year-old white boy with Hb Mizuho after splenectomy. Surprisingly, he developed reticulocytosis (>1000×10 9 /L) with a peak reticulocyte percentage of 49%, and erythrocyte abnormalities, including Heinz bodies, Howell-Jolly bodies, and basophilic stippling. Manual reticulocyte counting and flow cytometric measurement with anti-CD71 antibodies supported a truly elevated reticulocyte count. CONCLUSIONS: We propose possible explanations for the extreme reticulocytosis that arose postsplenectomy and compare the reticulocyte count in the present case with previously published cases.

Novel perspectives regarding the physiologic mechanisms by which gliflozins induce reticulocytosis and erythrocytosis.

Gliflozins provide a breakthrough in the management of type-2 diabetes. In addition to facilitating normoglycemia, these sodium-glucose cotransporter type 2 (SGLT2) inhibitors attenuate obesity, hypertension, dyslipidemia, and fluid retention, reduce cardiovascular morbidity, retard the progression of renal dysfunction, and improve survival. The administration of gliflozins also triggers erythropoietin (EPO) production, with the consequent induction of reticulocytosis and erythrocytosis. The mechanism(s) by which gliflozins induce erythropoiesis is a matter of debate. Whereas the canonical pathway of triggering EPO synthesis is through renal tissue hypoxia, it has been suggested that improved renal oxygenation may facilitate EPO synthesis via noncanonical trails. The latter proposes that recovery of peritubular interstitial fibroblasts producing erythropoietin (EPO) is responsible for enhanced erythropoiesis. According to this hypothesis, enhanced glucose/sodium reuptake by proximal tubules in uncontrolled diabetes generates cortical hypoxia, with injury to these cells. Once transport workload declines with the use of SGLT2i, they recover and regain their capacity to produce EPO. In this short communication, we argue that this hypothesis is incorrect. First, there is no evidence for interstitial cell injury related to hypoxia in the diabetic kidney. Tubular, rather than interstitial cells are prone to hypoxic injury in the diabetic kidney. Moreover, hypoxia, not normoxia, stimulates EPO synthesis by hypoxia-inducible factors (HIFs). Hypoxia regulates EPO synthesis as it blocks HIF prolyl hydroxylases (that initiate HIF alpha degradation), hence stabilizing HIF signals, inducing HIF-dependent genes, including EPO located in the deep cortex, and its production is initiated by the apocrinic formation of HIF-2, colocalized in these same cells.

Effect of neonatal reticulocytosis on glucose 6-phosphate dehydrogenase (G6PD) activity and G6PD deficiency detection: a cross-sectional study.

BACKGROUND: Screening for G6PD deficiency in newborns can help prevent severe hemolysis, hyperbilirubinemia, and bilirubin encephalopathy, as recommended by the World Health Organization (WHO). It has been speculated that the presence of a high number of reticulocytes in newborns interferes with the diagnosis of G6PD deficiency since reticulocytes contain higher amounts of G6PD enzyme than mature erythrocytes. Therefore, the purposes of this study were to assess the effect of reticulocytosis in the determination of blood G6PD activity in Thai newborns by using a novel automated UV-based enzymatic assay and to validate the performance of this assay for the detection of G6PD deficiency in newborn samples. METHODS: The levels of reticulocytes and G6PD activity were measured in blood samples collected from 1,015 newborns. G6PD mutations were identified using TaqMan® SNP genotyping assay, PCR-restriction fragment length polymorphism (PCR-RFLP), and direct sequencing. The correlation between the levels of reticulocytes and G6PD activity was examined. The performance of the automated method was compared with that of the fluorescent spot test (FST) and the standard quantitative assay. RESULTS: The automated assay detected G6PD deficiency in 6.5% of the total newborn subjects compared to 5.3% and 6.1% by the FST and the standard method, respectively. The minor allele frequencies (MAFs) of G6PD ViangchanG871A, G6PD MahidolG487A, and G6PD UnionC1360T were 0.066, 0.005, and 0.005, respectively. The reticulocyte counts in newborns with G6PD deficiency were significantly higher than those in normal male newborns (p < 0.001). Compared with normal newborns after controlling for thalassemias and hemoglobinopathies, G6PD-deficient patients with the G6PD ViangchanG871A mutation exhibited elevated reticulocyte counts (5.82 ± 1.73%, p < 0.001). In a group of G6PD normal newborns, the percentage of reticulocytes was positively correlated with G6PD activity (r = 0.327, p < 0.001). However, there was no correlation between G6PD activity and the levels of reticulocytes in subjects with G6PD deficiency (r = -0.019, p = 0.881). The level of agreement in the detection of G6PD deficiency was 0.999, while the area under the receiver operating characteristic (AUC) curve demonstrated that the automated method had 98.4% sensitivity, 99.5% specificity, 92.4% positive predictive value (PPV), 99.9% negative predictive value (NPV), and 99.4% accuracy. CONCLUSIONS: We report that reticulocytosis does not have a statistically significant effect on the detection of G6PD deficiency in newborns by both qualitative and quantitative methods.

Hyporegenerative anemia in anti-M-associated hemolytic disease of the fetus.

BACKGROUND: The anti-M antibody can lead to hemolytic disease of the fetus and newborn (HDFN) and adverse fetal outcomes, especially in the Asian population. However, fetal erythropoiesis resulting from M alloimmunization needs further investigation. STUDY DESIGN AND METHODS: We analyzed erythropoiesis in eight fetuses with M alloimmunization and compared them with the fetuses affected by anti-D. They were matched as pairs according to the gestational age of diagnosis and the hematocrit before treatment. Paired t-tests or paired Wilcoxon rank-sum tests were conducted to compare the difference in the cord blood indexes. Pearson correlation analysis was used to evaluate the correlativity between hematocrit and the reticulocyte percentage in the two groups. RESULTS: The fetuses in the MN group had lower reticulocyte count and percentage than those in the RhD group (p < .05). All of the fetal reticulocyte production indexes (RPIs) in the MN group were less than 2, indicating an inadequate hemopoietic response to anemia, while the majority of the RPIs in the RhD group (85.7%) were significantly higher (p = .003), with 6 cases greater than 2.5. Hematocrit was negatively correlated with reticulocyte percentage (y = 54.7-171.7x, r2  = 0.825, p = .005) in the RhD group, while no significant correlation was found in the MN group. No difference in the number of IUT, interval, or the fetal outcome was found between the two groups. CONCLUSION: Fetal reticulocytopenia provided direct evidence of an inadequate hemopoietic response in HDFN due to anti-M, leading to hyporegenerative anemia. Once the IgG component of anti-M is detected, close monitoring should be considered.

Deficient mitophagy pathways in sickle cell disease.

Sickle cell disease (SCD) is characterised by chronic haemolysis and oxidative stress. Herein, we investigated 30 SCD patients and found 40% with elevated mitochondria levels (SS-mito+ ) in their mature red blood cells, while 60% exhibit similar mitochondria levels compared to the AA group (SS-mito- ). The SS-mito+ patients are characterised by higher reticulocytosis and total bilirubin levels, lower foetal haemoglobin, and non-functional mitochondria. Interestingly, we demonstrated decreased levels of mitophagy inducers, PINK1 and NIX, and higher levels of HSP90 chaperone in their red cells. Our results highlighted for the first time an abnormal retention of mitochondria in SCD linked with mitophagy-related proteins.

Systemic deficiency of mouse arachidonate 15-lipoxygenase induces defective erythropoiesis and transgenic expression of the human enzyme rescues this phenotype.

Arachidonic acid 15-lipoxygenases (ALOX15) are lipid peroxidizing enzymes, which has previously been implicated in the maturational breakdown of intracellular organelles and plasma membrane remodeling during reticulocyte-erythrocyte transition. Conventional Alox15-/- mice are viable, develop normally but do not exhibit a major defective erythropoietic phenotype. To characterize the putative in vivo relevance of Alox15 for red blood cell development, we explored the impact of systemic inactivation of the Alox15 gene on mouse erythropoiesis. We found that Alox15-/- mice exhibited reduced erythrocyte counts, elevated reticulocyte counts and red cell hyperchromia. The structure of the plasma membrane of Alox15-/- erythrocytes is altered and a significant share of the red cells was present as echinocytes and/or acanthocytes. An increased share of the Alox15-/- erythrocytes cells were annexin V positive, which indicates a loss of plasma membrane asymmetry. Erythrocytes of Alox15-/- mice were more susceptible to osmotic hemolysis and exhibited a reduced ex vivo life span. When we transgenically expressed human ALOX15 in Alox15-/- mice under the control of the aP2 promoter the defective erythropoietic system was rescued and the impaired osmotic resistance was normalized. Together these data suggest the involvement Alox15 in the maturational remodeling of the plasma membrane during red cell development.

Severe Hyperkalemia Immediately After Birth.

BACKGROUND Hyperkalemia is an important cause of arrhythmias and a medical emergency that requires urgent treatment. The etiology is usually multifactorial. It is most frequently caused by impaired potassium secretion, followed by transcellular potassium shifts and an increased potassium load. CASE REPORT A male newborn developed monomorphic ventricular tachycardia 2 hours after birth. He was born in the 35th week of gestation by urgent C-section following placental abruption. Laboratory results showed hemolytic anemia (Hb 99 g/L, Hct 0.31) with increased bilirubin levels and reticulocytosis, thrombocytopenia (39×109/L), hypoglycemia (0.8 mmol/L), and severe hyperkalemia (9.8 mmol/L). Umbilical artery blood gas analysis showed hypoxemia with acidosis (pO2 3.8 kPa, pH 7.21, pCO2 7.84 kPa, HCO3 23.3 mmol/L, BE -5 mmol/L). Creatinine (102 µmol/L) and urea (9.8 mmol/L) were mildly elevated. Inflammatory markers were also increased (CRP 26 mg/L, blood leukocyte count 24×109/L). Early-onset sepsis, caused by Candida albicans, was confirmed approximately 24 hours after birth. Non-invasive ventilation with 35-40% O2 was necessary due to transient tachypnea. The neonate received a transfusion of packed red blood cells, a 10% glucose infusion, and empirical antibiotic therapy. Hyperkalemia accompanied by arrhythmias was treated with calcium gluconate, insulin, Sorbisterit enema, and, finally, by exchange transfusion. CONCLUSIONS We report a case of severe hyperkalemia in a newborn immediately after birth. Making a decision as early as possible regarding exchange transfusion is essential in patients with hyperkalemia with electrocardiogram changes and hemodynamic instability.

von Willebrand factor in experimental malaria-associated acute respiratory distress syndrome.

BACKGROUND: Malaria-associated acute respiratory distress syndrome (MA-ARDS) is a lethal complication of severe malaria, characterized by marked pulmonary inflammation. Patient studies have suggested a link between von Willebrand factor (VWF) and malaria severity. OBJECTIVES: To investigate the role of VWF in the pathogenesis of experimental MA-ARDS. METHODS: Plasmodium berghei NK65-E (PbNK65) parasites were injected in Vwf+/+ and Vwf-/- mice. Pathological parameters were assessed following infection. RESULTS: In accordance with patients with severe malaria, plasma VWF levels were increased and ADAMTS13 activity levels were reduced in experimental MA-ARDS. ADAMTS13- and plasmin-independent reductions of high molecular weight VWF multimers were observed at the end stage of disease. Thrombocytopenia was VWF-independent because it was observed in both Vwf+/+ and Vwf-/- mice. Interestingly, Vwf-/- mice had a shorter survival time compared with Vwf+/+ controls following PbNK65 infection. Lung edema could not explain this shortened survival because alveolar protein levels in Vwf-/- mice were approximately two times lower than in Vwf+/+ controls. Parasite load, on the other hand, was significantly increased in Vwf-/- mice compared with Vwf+/+ mice in both peripheral blood and lung tissue. In addition, anemia was only observed in PbNK65-infected Vwf-/- mice. Of note, Vwf-/- mice presented with two times more reticulocytes, a preferential target of the parasites. CONCLUSIONS: This study suggests that parasite load together with malarial anemia, rather than alveolar leakage, might contribute to shortened survival in PbNK65-infected Vwf-/- mice. VWF deficiency is associated with early reticulocytosis following PbNK65 infection, which potentially explains the increase in parasite load.

Learning-based screening of hematologic disorders using quantitative phase imaging of individual red blood cells.

We present a rapid and label-free method for hematologic screening for diseases and syndromes, utilizing quantitative phase imaging (QPI) and machine learning. We aim to establish an efficient blood examination framework that does not suffer from the drawbacks of conventional blood assays, which are incapable of profiling single cells or require labeling procedures. Our method involves the synergistic employment of QPI and machine learning. The high-dimensional refractive index information arising from the QPI-based profiling of single red blood cells is processed to screen for diseases and syndromes using machine learning, which can utilize high-dimensional data beyond the human level. Accurate screening for iron-deficiency anemia, reticulocytosis, hereditary spherocytosis, and diabetes mellitus is demonstrated (>98% accuracy) using the proposed method. Furthermore, we highlight the synergy between QPI and machine learning in the proposed method by analyzing the performance of the method.

Persistent reticulocytosis in a case of poodle macrocytosis.

A healthy 14-year-old, male neutered, Miniature Poodle was found to have a persistent erythrocyte macrocytosis and reticulocytosis with a normal and stable HCT. The hematologic features of macrocytosis, increased Howell-Jolly bodies, and metarubricytosis, in the absence of anemia or other cytopenias, combined with the cytologic evidence of bone marrow erythroid dysplasia, including megaloblastosis, binuclearity, increased mitotic activity, and nuclear fragmentation, are consistent with previous reports of congenital dyserythropoiesis termed poodle macrocytosis. We speculate that the additional presence of persistent reticulocytosis in the absence of an identifiable stimulus for accelerated erythropoiesis may represent a phenotypic variation of this inherited condition, and the morphologic abnormalities of the dyserythropoiesis are described.

Nocturnal oxyhemoglobin desaturation and arteriopathy in a pediatric sickle cell disease cohort.

OBJECTIVE: The purpose of this study of sickle cell disease (SCD) was to determine whether arteriopathy, measurable as intracranial vessel signal loss on magnetic resonance angiography (MRA), was associated with low nocturnal hemoglobin oxygen saturation (SpO2) or hemolytic rate, measurable as reticulocytosis or unconjugated hyperbilirubinemia. METHODS: Ninety-five East London children with SCD without prior stroke had overnight pulse oximetry, of whom 47 (26 boys, 39 hemoglobin SS; mean age 9.1 ± 3.1 years) also had MRA, transcranial Doppler (TCD), steady-state hemoglobin, and reticulocytes within 34 months. Two radiologists blinded to the other data graded arteriopathy on MRA as 0 (none) or as increasing severity grades 1, 2, or 3. RESULTS: Grades 2 or 3 arteriopathy (n = 24; 2 with abnormal TCD) predicted stroke/TIA compared with grades 0 and 1 (log-rank χ2 [1, n = 47] = 8.1, p = 0.004). Mean overnight SpO2 correlated negatively with reticulocyte percentage (r = -0.387; p = 0.007). Despite no significant differences across the degrees of arteriopathy in genotype, mean overnight SpO2 was higher (p < 0.01) in those with grade 0 (97.0% ± 1.6%) than those with grades 2 (93.9 ± 3.7%) or 3 (93.5% ± 3.0%) arteriopathy. Unconjugated bilirubin was not associated but reticulocyte percentage was lower (p < 0.001) in those with grade 0 than those with grades 2 and 3 arteriopathy. In multivariable logistic regression, lower mean overnight SpO2 (odds ratio 0.50, 95% confidence interval 0.26-0.96; p < 0.01) predicted arteriopathy independent of reticulocyte percentage (odds ratio 1.47, 95% confidence interval 1.15-1.87; p = 0.003). CONCLUSION: Low nocturnal SpO2 and reticulocytosis are associated with intracranial arteriopathy in children with SCD. Preventative strategies might reduce stroke risk.

Apert syndrome - clinical case.

Apert syndrome - acrocephalosyndactyly - is a rare autosomal dominant disorder representing 1:65 000 cases of living newborns. Characteristic malformations of the Apert syndrome are early craniostenosis, microviscerocranium and II-V finger syndactyly of hand and toes with proximal phalanx of the bilateral thumb "in delta". It is difficult to determine prenatal diagnosis in the second quarter, when examining the morphology of fetal signs; the dysmorphism signs appeared in the third pregnancy quarter. We present here the case of a newborn with Apert syndrome that was born prematurely in our Clinic after a monitored pregnancy, where there was issued a suspicion of cranio-facial dysmorphism, malposition and malformation of the feet and hands in the third quarter of prenatal pregnancy. The diagnosis of Apert syndrome was placed on clinical signs, laboratory and genetic tests. The clinical outcome of the baby in the maternity was favorable, the therapeutic management being established by a multidisciplinary team. Immediate complications were due to the case of prematurity: respiratory distress syndrome and the characteristics of the syndrome: micrognathia and naso-facial dysmorphism, syndactyly, bilateral foot metatarsus adductus.

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.

Reticulocytosis in screen-printing workers exposed to 2-butoxyethanol and 2-ethoxyethanol

BACKGROUND: Studies on the hematologic toxicity of ethylene glycol ethers in humans are limited. Therefore, the aim of this study was to examine the association between exposure to solvents (containing 2-butoxyethanol and 2-ethoxyethanol) and hematological effects. METHODS: Thirty-four screen-printing workers who were exposed to 2-butoxyethanol and 2-ethoxyethanol and 37 non-exposed clerical workers were selected using data from the health care facilities that provided regular health screening services. Student's t-tests and Pearson's chi-square tests were used to compare differences in hematological parameters between the exposed and the control groups. A multivariate analysis was performed using the multiple logistic regression models to adjust for other variables. RESULTS: The chi-square test showed the reticulocyte percentages and corrected reticulocyte counts to be significantly higher in the exposed group. The t-tests showed a significant increase in white blood cell counts, reticulocyte percentages, and corrected reticulocyte count (i.e., reticulocyte index) in the exposed group, with p-values of 0.002, 0.004, and 0.002, respectively. Multivariate analysis showed the odds ratio for the corrected reticulocyte counts to be 16.30 for the exposed group, when compared with that of the control group. CONCLUSIONS: Exposure to 2-butoxyethanol and 2-ethoxyethanol was significantly associated with reticulocytosis, necessitating the implementation of preventive measures for workers prone to occupational exposure to ethylene glycol ethers.

Spurious reticulocyte profiles in dogs with large form babesiosis: a retrospective study.

BACKGROUND: Erroneously high reticulocyte counts (pseudoreticulocytosis) have been reported in dogs with leukemia. Pseudoreticulocytosis and an abnormal reticulocyte profile were observed in a dog with large form babesiosis presented at our institution. OBJECTIVES: The aims of this retrospective study were to determine if dogs with babesiosis and other dogs had abnormal reticulocyte profiles, and to correlate these profiles with the primary diagnosis. METHODS: All canine CBCs obtained with the Sysmex XT-2000iV or Procyte DX were reviewed. Cases of large form babesiosis were identified and their reticulocyte dot plots were analyzed. Dogs with abnormal reticulocyte profiles but without microscopically apparent intraerythrocytic Babesia piroplasms were identified. The reticulocyte profiles and fluorescence ratios of dogs with and without babesiosis were compared. RESULTS: Twenty of 92 dogs with babesiosis had abnormal reticulocyte profiles, including 8 with a separation between the reticulocyte and mature RBC plots or a continuum of reticulocytes from the RBC plot but with a higher density of dots in the middle of the "comet tail" than in the left quarter of the dot plot. Thirteen of 6980 dogs without Babesia on the blood smear had abnormal reticulocyte profiles, including 3 with leukemia. The medium-fluorescence reticulocyte ratios tended to be higher in dogs with babesiosis and abnormal dot plots than in other dogs, whereas the high-fluorescence ratio was higher in one dog with leukemia. CONCLUSION: Abnormal reticulocyte dot plots and atypical reticulocyte fluorescence ratios may occur in dogs with babesiosis and alert clinical pathologists to consider this diagnosis.