Haptoglobin patterns in cord blood serums

MiR-29b is associated with perinatal inflammation in extremely preterm infants

BACKGROUND

Inflammation is strongly associated with premature birth and neonatal morbidities. Increases in infant haptoglobin, haptoglobin-related protein (Hp&HpRP), and interleukin-6 (IL-6) levels are indicators of intra-amniotic inflammation (IAI) and have been linked to poor neonatal outcomes. Inflammation causes epigenetic changes, specifically suppression of miR-29 expression. The current study sought to determine whether miR-29b levels in cord blood or neonatal venous blood are associated with IAI, identified by elevated IL-6 and Hp, and subsequent clinical morbidities in the infant.

METHODS

We tested 92 cord blood samples from premature newborns and 18 venous blood samples at 36 weeks corrected gestational age. MiR-29b, Hp&HpRP, and IL-6 were measured by polymerase chain reaction and enzyme-linked immunosorbent assay, respectively.

RESULTS

Decreased levels of miR-29b were observed in infants exposed to IAI with elevated Hp&HpRP and IL-6 levels and in infants delivered by spontaneous preterm birth. Lower miR-29 levels were also observed in women diagnosed with histological chorioamnionitis or funisitis and in infants with cerebral palsy. Higher levels of miR-29 were measured in infants small for gestational age and in venous samples from older infants.

CONCLUSIONS

MiR-29 may be an additional biomarker of IAI and a potential therapeutic target for treating poor newborn outcomes resulting from antenatal exposure to IAI.

IMPACT

Decreases in miR-29b are associated with intrauterine inflammation. Hp&HpRP increases are associated with decreased miR-29b. MiR-29b may be an additional biomarker for neonatal outcomes and a potential therapeutic target for intrauterine inflammation.

A murine neonatal model of necrotizing enterocolitis caused by anemia and red blood cell transfusions

Necrotizing enterocolitis (NEC) is an idiopathic, inflammatory bowel necrosis of premature infants. Clinical studies have linked NEC with antecedent red blood cell (RBC) transfusions, but the underlying mechanisms are unclear. Here we report a neonatal murine model to investigate this association. C57BL/6 mouse pups rendered anemic by timed phlebotomy and then given RBC transfusions develop NEC-like intestinal injury with prominent necrosis, inflammation, and submucosal edema/separation of the lamina propria in the ileocecal region and colon within 12-24 h. The anemic intestine is infiltrated by inflammatory macrophages, which are activated in situ by RBC transfusions via a Toll-like receptor (TLR)-4-mediated mechanism and cause bowel injury. Chelation of RBC degradation products with haptoglobin, absence of TLR4, macrophage depletion, and inhibition of macrophage activation is protective. Intestinal injury worsens with increasing severity and the duration of anemia prior to transfusion, indicating a need for the re-evaluation of current transfusion guidelines for premature infants.

Cord Blood Haptoglobin, Cerebral Palsy and Death in Infants of Women at Risk for Preterm Birth: A Secondary Analysis of a Randomised Controlled Trial

BACKGROUND

Antenatal exposure to intra-uterine inflammation results in precocious Haptoglobin (Hp) expression (switch-on status). We investigated the relationships between foetal Hp expression at birth with newborn and childhood outcomes.

METHODS

We evaluated cord blood samples from 921 newborns of women at imminent risk for preterm delivery randomised to either placebo (n = 471, birth gestational age (GA) median [min-max]: 31 [24-41] weeks) or magnesium sulphate (n = 450, GA 31 [24-42] weeks]). Primary outcome was infant death by 1 year and/or cerebral palsy (CP) ≥ 2 years of corrected age. Adjusted odd ratios (aOR) for neonatal and childhood outcomes were calculated controlling for GA, birth weight, sex, and magnesium exposure.

FINDINGS

Primary outcome occurred in 2.8% of offspring. Newborns were classified in three pre-defined categorisation groups by cord blood Hp switch status and IL-6 levels: inflammation-nonexposed (Category 1, n = 432, 47%), inflammation-exposed haptoglobinemic (Category 2, n = 449, 49%), and inflammation-exposed anhaptoglobinemic or hypohaptoglobinemic (Category 3, n = 40, 4%). Newborns, found anhaptoglobinemic or hypohaptoglobinemic (Category 3) had increased OR for intraventricular haemorrhage (IVH) and/or death (aOR: 7.0; 95% CI: 1.4-34.6, p = 0.02) and for CP and/or death (aOR: 6.27; 95% CI: 1.7-23.5, p = 0.006) compared with Category 2. Foetal ability to respond to inflammation by haptoglobinemia resulted in aOR similar to inflammation-nonexposed newborns. Hp1-2 or Hp2-2 phenotypes protected against retinopathy of prematurity (aOR = 0.66; 95% CI 0.48-0.91, p = 0.01).

INTERPRETATION

Foetal ability to switch-on Hp expression in response to inflammation was associated with reduction of IVH and/or death, and CP and/or death. Foetuses unable to mount such a response had an increased risk of adverse outcomes.Trial Registration: clinicaltrials.gov Identifier: NCT00014989.

Identification of haptoglobin switch-on status in archived placental specimens indicates antenatal exposure to inflammation and potential participation of the fetus in triggering preterm birth

OBJECTIVE

Haptoglobin (Hp) has key immunoregulatory roles that vary with phenotype (Hp1-1, Hp2-1, Hp2-2). Cord blood Hp expression is switched-off in the normal fetus. We hypothesized that in the setting of fetal inflammation placenta becomes inundated with Hp of fetal origin that in turn modulates the output of PGE₂ and MMP-9 in a phenotype dependent manner.

METHODS

Placentas from 40 pregnancies complicated by preterm birth (PTB) (<37 weeks), without (n = 15) or with (n = 25) intra-amniotic infection and histological chorioamnionitis (HCA) were scored for intensity of Hp immunostaining. Hp mRNA levels were evaluated by PCR. Cord blood Hp levels, switch-on status and phenotypes were determined by ELISA and Western blotting. Using a villous trophoblast explant system we investigated if Hp can modulate the release of PGE₂ and MMP-9 in the presence or absence of lipopolysaccharide (LPS).

RESULTS

All cases with HCA had positive Hp immunoreactivity within fetal vascular spaces. Hp staining intensity correlated with cord blood Hp levels and IL-6. Placentas with and without HCA had similar Hp mRNA levels suggesting Hp immunostaining in the fetal spaces is of fetal rather than placental origin. Both Hp1-1 and Hp2-2 up-regulated PGE₂ release in the presence of LPS (2-fold over the LPS level, P < .05), without affecting MMP-9 concentrations.

CONCLUSIONS

Fetal Hp switch-on status, a marker of antenatal exposure to intra-amniotic infection/inflammation, can be reliably established through evaluation of archived placental specimens. In the setting of infection/inflammation, Hp enhances placental PGE₂ output thereby supporting the role of the fetus in triggering parturition.

Proteomics/diagnosis of chorioamnionitis and of relationships with the fetal exposome

Proteomics, a relatively young science, originally emerged as a complement to genomics research. By definition, the goal of proteomics is to provide a snapshot of all the proteins within an organism, tissue or biological sample at a given moment. Proteomics has the ability to single out one or more proteins (biomarkers) that change consistently in affected subjects as compared to those disease-free. From a proteomics perspective, chorioamnionitis poses both challenges and opportunities. Challenges relate to the dynamic course of the inflammatory process, and compartmentalization of the gestational sac in relation to the maternal compartment. An inability to evaluate the amniotic fluid non-invasively and repeatedly for meaningful changes in its proteome, and lack of a true gold standard for diagnosis of inflammation and/or infection, represent additional challenges. On the other hand, the unbiased and holistic nature of proteomics offers a real opportunity to improve the current diagnostic and prognostic algorithms for chorioamnionitis. Even at this current stage there are reasons to believe that proteomic biomarkers will improve the understanding of how chorioamnionitis programs or affects the fetus in utero, thus defining its exposome (sum of interactions between genetic make-up of the fetus and the intrauterine environment) of pregnancies affected by infection and/or inflammation. This review summarizes the results of proteomics studies that have aimed or reached these goals.

Proteomics mapping of cord blood identifies haptoglobin "switch-on" pattern as biomarker of early-onset neonatal sepsis in preterm newborns

Background

Intra-amniotic infection and/or inflammation (IAI) are important causes of preterm birth and early-onset neonatal sepsis (EONS). A prompt and accurate diagnosis of EONS is critical for improved neonatal outcomes. We sought to explore the cord blood proteome and identify biomarkers and functional protein networks characterizing EONS in preterm newborns.

Methodology/Principal Findings

We studied a prospective cohort of 180 premature newborns delivered May 2004-September 2009. A proteomics discovery phase employing two-dimensional differential gel electrophoresis (2D-DIGE) and mass spectrometry identified 19 differentially-expressed proteins in cord blood of newborns with culture-confirmed EONS (n = 3) versus GA-matched controls (n = 3). Ontological classifications of the proteins included transfer/carrier, immunity/defense, protease/extracellular matrix. The 1^st-level external validation conducted in the remaining 174 samples confirmed elevated haptoglobin and haptoglobin-related protein immunoreactivity (Hp&HpRP) in newborns with EONS (presumed and culture-confirmed) independent of GA at birth and birthweight (P<0.001). Western blot concurred in determining that EONS babies had conspicuous Hp&HpRP bands in cord blood (“switch-on pattern”) as opposed to non-EONS newborns who had near-absent “switch-off pattern” (P<0.001). Fetal Hp phenotype independently impacted Hp&HpRP. A Bayesian latent-class analysis (LCA) was further used for unbiased classification of all 180 cases based on probability of “antenatal IAI exposure” as latent variable. This was then subjected to 2^nd-level validation against indicators of adverse short-term neonatal outcome. The optimal LCA algorithm combined Hp&HpRP switch pattern (most input), interleukin-6 and neonatal hematological indices yielding two non-overlapping newborn clusters with low (≤20%) versus high (≥70%) probability of IAI exposure. This approach reclassified ∼30% of clinical EONS diagnoses lowering the number needed to harm and increasing the odds ratios for several adverse outcomes including intra-ventricular hemorrhage.

Conclusions/Significance

Antenatal exposure to IAI results in precocious switch-on of Hp&HpRP expression. As EONS biomarker, cord blood Hp&HpRP has potential to improve the selection of newborns for prompt and targeted treatment at birth.

Studies on the transferrins of adult serum, cord serum, and cerebrospinal fluid. The effect of neuraminidase

Nine of the twelve known variants of human transferrin have been resolved by the action of neuraminidase into stepwise patterns of four additional slower moving components whose relative intensities depended upon the concentration of enzyme. These components appeared to represent the stepwise removal of the four sialic acid residues from the transferrin molecule, and at large enzyme concentrations, almost all of the transferrin was reduced to the position of the slowest moving component. In contrast, the electrophoretic mobilities of haptoglobin, ceruloplasmin, and α₂-macroglobulin showed a gradual decrease with increasing neuraminidase concentration. The transferrins of chimpanzees, rhesus and cynomolgus monkeys, and cattle were resolved by neuraminidase into two slower moving components. These experiments suggested that the primate and cattle transferrins contained only two sialic acid residues accessible to the enzyme. Transferrins C, B₂, and D₁ and a cynomolgus monkey transferrin were purified from serum by starch block electrophoresis and cellulose chromatography. Ultracentrifugal analysis could detect no difference in sedimentation rate between transferrin C, the primate transferrin, and neuraminidase-treated transferrin C. The human transferrins showed no variation in amino acid composition, but the cynomolgus transferrin was approximately 20 per cent higher in serine content and 50 per cent lower in glucosamine than human transferrin C. Reactions of antigenic identity were obtained among five human transferrin variants but a reaction of only partial identity was obtained between transferrin C and the cynomolgus transferrin. The transferrin pattern of cord blood showed a prominent band in the position of transferrin C, accompanied by four faint slower moving bands which coincided with the four transferrin components produced by the action of neuraminidase on transferrin C. The transferrin pattern of cerebrospinal fluid in individuals homozygous for serum transferrin C showed two principal components, one of which appeared to contain no sialic acid. Haptoglobin, ceruloplasmin, and α₂-macroglobulin were also present in cerebrospinal fluid.

Factors influencing hypohaptoglobinaemia in newborn in India

An attempt is made to enumerate the effects of some factors on hypohaptoglobinaemia in a sample of 389 infants (along with their mothers) who were classified electrophoretically for haptoglobins (Hp). 85 . 5% of infants were Hp 0-0. There was no direct effect of birth-weight on the frequency of Hp 0-0 but there was a significant interaction between maternal haptoglobin type and birth-weight of newborn, showing an excess of 2-2 among mothers of low birth-weight babies, who were mostly Hp 0-0. Some trend towards reduced Hp 0-0 frequency among premature babies was discernible. There was a significant effect of parity on the frequency of detectable haptoglobin patterns among low birth-weight infants. An increase in the frequency of haptoglobin pattern was observed with increase in parity and birth-weight. The distributions of detectable haptoglobin patterns among newborn and mothers were similar. ABO incompatibility, sex, economic status and caste variation did not show any effects on the frequency of Hp 0-0.

Albumin and transferrin synthesis during development in the rat

In this study, the incorporation of [(14)C]leucine into albumin and transferrin in early rat foetuses, vitelline plus amniotic membranes, chorioallantoic placenta and perinatal rat liver slices was measured and used to detect and compare the rates of synthesis of the two proteins. Albumin synthesis was detected in the body of foetuses from 13 days gestation onwards. Transferrin synthesis was detected only after day 15. Transferrin synthesis was demonstrable in the membranes but not in the chorioallantoic placenta of all the animals investigated, i.e. from 13 to 19 days gestation. Synthesis of albumin and transferrin by the liver of near-term and postnatal animals was shown to correlate with published data on the parenchymal cell number/unit wet wt. of liver. Near-term foetuses synthesized relatively more transferrin than albumin when compared with 10-day postnatal animals. The serum concentrations of the two plasma proteins were also determined. These increased before term whereas the rate of synthesis of albumin and transferrin declined. Postnatally, plasma albumin concentration increased but transferrin concentration decreased, yet the rates of synthesis of both proteins by the liver increased with age. This lack of correlation between the rates of synthesis of the two proteins and their respective plasma concentrations could be explained in part by their increased stability after birth. There was also evidence that the liver haemopoietic cells took up transferrin although they do not synthesize the protein. Thus the decrease in this population of cells during development could also contribute to the discrepancy between liver synthesis and serum concentrations of transferrin.