Intracellular neutrophil myeloperoxidase level in pediatric patients: significant age and gender variability

Hematologic profiles and development of innate immune function in healthy Holstein calves during the pre-weaning period

BACKGROUND

The development and state of innate immune cell function during the first 90 days of life in dairy calves have not been fully described.

OBJECTIVE

This transversal study attempted to examine the changes that occur in circulating blood cells and the innate immune response in healthy calves from birth to 89 days of age.

METHODS

Healthy Holstein calves represent three windows of development, G1 from 1 to 7 days old (n = 26), G2 from 30 to 40 days old (n = 28), and G3 from 60 to 89 days old (n = 36) were sampled once each from a single herd. A few biomarkers of the general health and innate and inflammatory immune responses were measured.

RESULTS

The youngest calves had the lowest red blood cell (RBC) counts, cell hemoglobin concentration means (CHCMs), red cell distribution widths (RDWs), and cell hemoglobin contents of mature red blood cells (CHm) compared with the other groups. They also had the lowest iron concentrations and highest intracellular myeloperoxidase indices. However, white blood cell (WBC) and lymphocyte concentrations gradually increased from G1 to G3. G2 calves had the lowest serum protein concentrations and highest number of innate immune cells compared with the other groups. Calves were able to mount phagocytic and ROS responses from birth.

CONCLUSIONS

The physiologic responses of circulating blood cells and innate immune responses in dairy calves are shown according to age. Neonates had limitations in several RBC and WBC indices and immunologic responses that would likely impact overall vigor and health. Fortunately, these limitations resolve by 90 days of age.

Myeloperoxidase and Advanced Oxidation Protein Products in the Cerebrospinal Fluid in Women and Men with Parkinson's Disease

Background: Myeloperoxidase (MPO) and advanced oxidation protein products, or AOPP (a type of MPO-derived chlorinated adducts), have been implicated in Parkinson´s disease (PD). Human MPO also show sex-based differences in PD. The objective was to study the relationship of MPO and AOPP in the cerebrospinal fluid (CSF) with motor features of idiopathic PD in male and female patients. Methods: MPO concentration and activity and AOPP content were measured in the CSF and serum in 34 patients and 30 controls. CSF leukocytes and the integrity of the blood-brain barrier were evaluated. Correlations of MPO and AOPP with clinical variables were examined. Results: The blood-brain barrier was intact and CSF leukocyte count was normal in all patients. CSF MPO concentration and activity were similar in the cohort of patients and controls, but CSF MPO content was significantly higher in male patients than in PD women (p = 0.0084). CSF MPO concentration correlated with disease duration in male and female patients (p < 0.01). CSF MPO concentration was significantly higher in men with disease duration ≥12 years versus the remainder of the male subjects (p < 0.01). Changes in CSF MPO in women were not significant. Serum MPO concentration and activity were significantly higher in all PD patients relative to controls (p < 0.0001). CSF MPO was not correlated with serum MPO. Serum AOPP were detected in all patients, but CSF AOPP was undetectable in 53% of patients. AOPP were not quantifiable in controls. Conclusions: CSF MPO is not a good biomarker for PD because mean CSF MPO concentration and activity are not different between the cohort of patients and controls. CSF MPO concentration positively correlated with disease duration in men and women, but CSF MPO is significantly enhanced only in male patients with disease duration longer than 12 years. It can be hypothesized that the MPO-related immune response in early-stage PD might be weak in all patients, but then the MPO-related immune response is progressively enhanced in men, not women. Since the blood-brain barrier is intact, and CSF MPO is not correlated with serum MPO, CSF myeloperoxidase would reflect MPO content in brain cells, not blood-derived cells. Finally, serum AOPP was detected in all patients, but not controls, which is consistent with the occurrence of chlorinative stress in blood serum in PD. The study of CSF AOPP as biomarker could not be assessed because the ELISA assay was hampered by its detection limit in the CSF.

Establishment of sex-specific reference intervals for automated haematology analyser-delivered research parameters in healthy Korean adults: a retrospective database review

OBJECTIVES

Automated haematology analysers measure various parameters of relevance to clinical research along with routine complete blood count (CBC)-related components. We aimed to establish ethnicity-specific and sex-specific reference intervals for 26 research-specific parameters as well as 18 routinely reported components using a large cohort of healthy Korean adults. The necessity of requiring separate sex-specific reference intervals for each parameter was also examined.

DESIGN

A retrospective database review.

SETTING

Single tertiary-care hospital of approximately 375 physicians and 530 nurses.

PARTICIPANTS

This study included 1383 reference individuals (840 men and 543 women).

PRIMARY AND SECONDARY OUTCOME MEASURES

Following the Clinical and Laboratory Standards Institute guidelines for establishing reference intervals, routine CBCs as well as research parameters were measured using an ADVIA 2120i instrument.

RESULTS

All the routine components except for mean platelet volume and per cent lymphocytes differed significantly between men and women. Most research parameters also differed between the sexes; the exceptions were large platelets, platelet dry mass distribution width, per cent basophil saturation, per cent peroxidase saturation and per cent abnormal peroxidase absorption. Despite these differences, separate reference intervals for men and women were required only for two research-specific parameters: 'percentage high cellular haemoglobin' and 'percentage of hyperchromic red blood cells (RBCs)'.

CONCLUSION

Even though most parameters showed significant differences between men and women, none of the evaluated parameters except two RBC-related factors required separate reference intervals for each sex.

Neutrophil Myeloperoxidase Index in Dogs With Babesiosis Caused by Babesia rossi

Babesiosis caused by the virulent tick-borne hemoprotozoan, Babesia rossi, results in a marked systemic inflammatory host response in dogs. Neutrophils form part of the innate immune response and contains myeloperoxidase (MPO) as the predominant component of the neutrophil lysosomal protein in azurophilic granules. The neutrophil myeloperoxidase index (MPXI), determined on the ADVIA hematology analyzer, is a quantitative estimate of intracellular MPO content. Objectives of this study were to: (a) compare MPXI in dogs with babesiosis with healthy control dogs; (b) compare MPXI in dogs that died from babesiosis with dogs that survived and controls; and (c) correlate the MPXI with the previously determined segmented and band neutrophil count and cytokine concentrations in dogs with babesiosis. Data for 140 dogs naturally infected with B. rossi and 20 healthy control dogs were retrospectively evaluated. Neutrophil counts and MPXI were determined on an ADVIA 2120 analyzer. Cytokine concentrations [interleukin (IL)-2, IL-6, IL-8, IL-10, IL-18, granulocyte-macrophage colony stimulating factor (GM-CSF), and monocyte chemo-attractant protein-1 (MCP-1)] were determined using a canine-specific multiplex immunoassay. The mortality rate of the Babesia-infected dogs was 11% (15/140). MPXI was significantly higher in Babesia-infected dogs (P = 0.033), and in Babesia-infected non-survivors (P = 0.011), compared with healthy control dogs. In Babesia-infected dogs a significant positive correlation was found between MPXI and IL-10 (r = 0.211, P = 0.039) and a significant negative correlation was found between MPXI and IL-8 (r = -0.350, P < 0.001). In Babesia-infected non-survivors, significant positive correlations were found between MPXI and IL-2 (r = 0.616, P = 0.033), IL-6 (r = 0.615, P = 0.033), IL-18 (r = 0.613, P = 0.034), GM-CSF (r = 0.630, P = 0.028), and MCP-1 (r = 0.713, P = 0.009). In Babesia-infected survivors, a significant negative correlation was found between MPXI and IL-8 (r = -0.363, P = 0.001). MPXI was correlated with pro-inflammatory cytokines in Babesia-infected dogs that died. The potential of MPXI as a novel marker of inflammation and prognosis in dogs infected with B. rossi, thus warrants further investigation.

Population Pharmacokinetic Modeling With Enterohepatic Circulation for AZD3241 in Healthy Subjects and Patients With Multiple System Atrophy

AZD3241 is a potent and selective myeloperoxidase inhibitor potentially for the treatment of a number of neurodegenerative disorders, including multiple system atrophy (MSA). The objectives of this work were to develop a population pharmacokinetic (PopPK) model for AZD3241 and to investigate the correlation between AZD3241 exposure and myeloperoxidase inhibition. The PopPK model was developed using AZD3241 data from one phase 1 study in healthy subjects and one phase 2 study in patients with MSA. A one-compartment model incorporating a gallbladder compartment for enterohepatic circulation, sequential zero-first order absorption, and first-order elimination adequately described the AZD3241 concentration profiles. The apparent clearance and central volume of distribution were 63.1 L/h (interindividual variability: 34.8%) and 121.9 L (interindividual variability: 44.0%), respectively. The enterohepatic circulation model reasonably captured the second peak of AZD3241, and high-fat food increased the absorption rate by 69%. A linear regression model was applied to describe the relationship between AZD3241 exposure and percentage change from baseline in myeloperoxidase-specific activity. The developed PopPK model was consistent with known pharmacokinetic characteristics of AZD3241. This model can be used to estimate AZD3241 exposure in patients with MSA and could be applied to future pharmacokinetic-pharmacodynamic analyses of AZD3241 in clinical development.

Immune function? A missing link in the gender disparity in preterm neonatal outcomes

INTRODUCTION

In neonatology, males exhibit a more severe disease course and poorer prognosis in many pathological states when compared to females. Perinatal brain injury, respiratory morbidity, and sepsis, among other complications, preferentially affect males. Preterm neonates (born <37 weeks gestation) display a particularly marked sexual disparity in pathology, especially at the borders of viability. The sex biases in preterm neonatal outcomes and underlying multifactorial mechanisms have been incompletely explored. Sex-specific clinical phenomena may be partially explained by intrinsic differences in immune function. The distinct immune system of preterm neonates renders this patient population vulnerable, and it is increasingly important to consider biological sex in disease processes and to strive for improved outcomes for both sexes. Areas covered: We discuss the cellular responses and molecular intermediates in immune function which are strongly dependent on sex-specific factors such as the genetic and hormonal milieu of premature birth and consider novel findings in a clinical context. Expert commentary: The role of immune function in the manifestation of sex-specific disease manifestations and outcomes in preterm neonates is a critical prognostic variable. Further mechanistic elucidation will yield valuable translational and clinical information of disease processes in preterm neonates which may be harnessed for modulation.

Association of enteric parasitic infections with intestinal inflammation and permeability in asymptomatic infants of São Tomé Island

The cumulative effect of repeated asymptomatic enteric infections on intestinal barrier is not fully understood in infants. We aimed to evaluate the association between previous enteric parasitic infections and intestinal inflammation and permeability at 24-months of age, in asymptomatic infants of São Tomé Island. A subset of infants from a birth cohort, with intestinal parasite evaluations in at least four points of assessment, was eligible. Intestinal inflammatory response and permeability were assessed using fecal S100A12 and alpha-1-antitrypsin (A1AT), respectively. The cutoff <-1SD for weight-for-length and length-for-age was used to define wasting and stunting. Multivariable linear regression analysis explored if cumulative enteric parasitic infections explained variability of fecal biomarkers, after adjusting for potential confounders. Eighty infants were included. Giardia duodenalis and soil-transmitted helminths (STH) were the most frequent parasites. The median (interquartile range) levels were 2.87 μg/g (2.41-3.92) for S100A12 and 165.1 μg/g (66.0-275.6) for A1AT. Weak evidence of association was found between S100A12 levels and G. duodenalis (p = 0.080) and STH infections (p = 0.089), and between A1AT levels and parasitic infection of any etiology (p = 0.089), at 24-months of age. Significant associations between A1AT levels and wasting (p = 0.006) and stunting (p = 0.044) were found. Previous parasitic infections were not associated with fecal biomarkers at 24 months of age. To summarize, previous asymptomatic parasitic infections showed no association with intestinal barrier dysfunction. Notwithstanding, a tendency toward increased levels of the inflammatory biomarker was observed for current G. duodenalis and STH infections, and increased levels of the permeability biomarker were significantly associated with stunting and wasting.

Myeloperoxidase in blood neutrophils during normal and abnormal menstrual cycles in women of reproductive age

INTRODUCTION

We previously reported that granulocyte colony-stimulating factor (G-CSF) plays a critical role in ovulation, suggesting that neutrophils may maintain ovulation. We assessed myeloperoxidase (MPO), a major and specific enzyme of neutrophils, in women with abnormal and normal menstrual cycles to clarify the relationship between MPO and ovulation.

METHODS

We analyzed MPO activity in blood neutrophils of women with abnormal menstrual cycles (indicative of anovulation, n = 12) and age- and body mass index-matched normal menstrual cycles (indicative of ovulation, n = 24) using two parameters as a marker of MPO, Neut X and mean peroxidase index (MPXI).

RESULTS

MPO of women with abnormal menstrual cycles was significantly lower than that of women with normal menstrual cycles [Neut X: 62.6 ± 1.1 (mean ± standard error of the mean) vs. 66.2 ± 0.3, P = 0.009; MPXI: -0.54 ± 1.66 vs. 4.91 ± 0.53, P = 0.008]. Among women with normal menstrual cycles, MPO was highest in the follicular phase (Neut X: 67.0 ± 0.3; P = 0.033).

CONCLUSION

The difference in MPO between women with abnormal and normal menstrual cycles and the upregulation of MPO before ovulation suggest that neutrophils and MPO are closely related to ovulation.