Israel Medical Association Journal

Background: The pathogenesis of anemia associated with acute infection in children has not been well delineated.

Objectives: To characterize this type of anemia in children with acute infection, mainly in relation to iron status.

Methods: These two cross-sectional studies compared the prevalence and severity of anemia between outpatient febrile children and age-matched non-febrile controls.

Results: In part 1 of the study, children with acute infection (n=58) had a significant decrease in hemoglobin levels compared with 54 non-febrile controls. Mean corpuscular volume (MCV) did not change this association. Moreover, there was no significant difference in MCV, mean cell hemoglobin or red cell distribution width values between the two groups. Regarding part 2, of the 6534 blood counts obtained in community clinics, 229 were defined as “bacterial infection.” Chart survey confirmed this diagnosis. White blood cell level was significantly inversely associated with hemoglobin level (r = -0.36, P < 0.0001). Anemia was significantly more prevalent among children with bacterial infection compared to those without: 21.4% vs. 14.1% (P = 0.002). Mean values of iron status parameters were all within normal limits.

Conclusions: Acute illness is associated with anemia. The pathogenesis of this anemia does not appear to be associated with disruption of iron metabolism.

Background: Polymorphonuclear leukocyte priming and low grade inflammation are related to severity of kidney disease. Erythropoietin-receptor is present on PMNLs[1].

Objectives: To evaluate the effect of 20 weeks of EPO[2]-alpha treatment on PMNL characteristics in relation to the rate of kidney function deterioration in patients with chronic kidney disease.

Methods: Forty anemic chronic kidney disease patients, stage 4-5, were assigned to EPO and non-EPO treatment for 20 weeks. A group of 20 healthy controls was also studied. PMNL priming and PMNL-derived low grade inflammation were estimated, in vivo and ex vivo, before and after EPO treatment: The rate of superoxide release, white blood cells and PMNL counts, serum alkaline phosphatase and PMNL viability were measured. EPO-receptor on PMNLs was assayed by flow cytometry. The effect of 20 weeks of EPO treatment on kidney function was related to the estimated glomerular filtration rate.

Results: EPO treatment attenuated superoxide release ex vivo and in vivo and promoted PMNL survival ex vivo. Decreased low grade inflammation was reflected by reduced WBC[3] and PMNL counts and ALP[4] activity following treatment. EPO retarded the deterioration in GFR[5]. The percent of PMNLs expressing EPO-R[6] was higher before EPO treatment and correlated positively with the rate of superoxide release. After 20 weeks of EPO treatment the percent of PMNLs expressing EPO-R was down-regulated.

Conclusions: These non-erythropoietic properties of EPO are mediated by EPO-R on PMNLs, not related to the anemia correction. A new renal protection effect of EPO via attenuation of PMNL priming that decreases systemic low grade inflammation and oxidative stress is suggested.

Objectives: To compare leukocyte counts and blood levels of various inflammatory cytokines in children and adults diagnosed with community-acquired bronchopneumonia.

Methods: We prospectively evaluated all pediatric and adult patients admitted for bronchopneumonia based on clinical and chest X-ray findings.. Blood was drawn for complete blood count and serum concentration of the following cytokines: granulocyte colony-stimulating factor, interleukins-6, 8 and 10, interferon-gamma, tumor necrosis factor, as well as matrix metalloproteinase-9 and intercellular adhesion molecule-1.

Results: There were 31 children and 32 adults. The patients in both groups had similar parameters of infection severity. None of them required admission to the Intensive Care Unit. Mean (± SD) leukocyte counts in the pediatric and adult groups were 21,018/mm (± 10,420) and 12,628/mm (± 6735) respectively (P = 0.02). Age was inversely correlated with leukocytes in the pediatric group (P = 0.0001). A significant inverse correslation was also found between age and platelet counts. Although cuytokine levels in both groups were not significantly different, age was

Conclusions: The immune response in community-aquired bronchopneumonia is, at least partly, age-dependent.

Background: Cigarette smoking is a well-known risk factor for the development of endothelial dysfunction and the progression of atherosclerosis. Oxidative stress and inflammation have recently been implicated in endothelial dysfunction.

Objectives: To assess the concomitant contribution of polymorphonuclear leukocytes to systemic oxidative stress and inflammation in cigarette smokers.

Methods: The study group comprised 41 chronic cigarette-smoking, otherwise healthy males aged 45.0 ± 11.5 (range 31–67 years) and 41 male non-smokers aged 42.6 ± 11.3 (range 31–65) who served as the control group. The potential generation of oxidative stress was assessed by measuring the rate of superoxide release from separated, phorbol 12-myristate 13-acetate-stimulated PMNL[1] and by plasma levels of reduced (GSH) and oxidized (GSSG) glutathione. Inflammation was estimated indirectly by: a) determining the in vitro survival of PMNL, reflecting cell necrosis; b) in vivo peripheral PMNL counts, reflecting cell recruitment; and c) plasma alkaline phosphatase levels, indicating PMNL activation and degranulation.

Results: PMA[2]-stimulated PMNL from cigarette smokers released superoxide at a faster rate than PMNL from the controls. Smokers had decreased plasma GSH[3] and elevated GSSG[4] levels. In vitro incubation of control and smokers' PMNL in sera of smokers caused necrosis, while control sera improved smoker PMNL survival. Smokers' PMNL counts, although in the normal range, were significantly higher than those of controls. Plasma ALP[5] levels in smokers were significantly higher than in controls and correlated positively with superoxide release and PMNL counts.

Conclusions: Our study shows that PMNL in smokers are primed in vivo, contributing concomitantly to systemic oxidative stress and inflammation that predispose smokers to endothelial dysfunction, and explains in part the accelerated atherosclerosis found in smokers.

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[1] PMNL = polymorphonuclear leukocytes

[2] PMA = phorbol 12-myristate 13-acetate

[3] GSH = reduced glutathione

[4] GSSG = oxidized glutathione

[5] ALP = alkaline phosphatase

The leukocyte NADPH oxidase catalyzes the reduction of oxygen to O₂- (superoxide) at the expense of NADPH. The O₂- then dismutes to H₂O₂, which serves to oxidize Cl- to HOCl, a potent microbicidal agent that is used by leukocytes to kill invading microorganisms. This oxidation is catalyzed by myeloperoxidase. O₂ is also used to make other microbicidal oxidants, some in reactions with nitric oxide. The oxidase itself is highly complex, consisting of four unique subunits and Rac2. In the resting cell, two of the subunits, p22PHOX and gp91PHOX, are located in the membrane, and the other two, p47PHOX and p67PHOX, are in the cytosol. The electron-carrying components of the oxidase are

located in gp91PHOX; the NADPH binding site is generally regarded to be in gp91PHOX as well, but there is some evidence that it may be in p67PHOX. When the oxidase is activated, p47PHOX is phosphorylated at specific sites, and the cytosolic components plus Rac2 migrate to the membrane to assemble the active oxidase.