SEARCH · PubMed Health

Results for “Lactoferrin”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources

PubMed1995

Lactoferrin interaction with Actinobacillus actinomycetemcomitans.

The interaction of lactoferrin with Actinobacillus actinomycetemcomitans was examined in a 125I-labeled protein binding assay. The binding of human and bovine lactoferrins reached maximum within 1 h. Lactoferrin binding to the bacterium was pH-dependent and reversible. Scatchard analysis indicated the existence of two different types of binding sites on the bacterium, one with a high affinity constant k alpha approximately 8.8 x 10(-7) M) and the other with a low one (k alpha approximately 1.8 x 10(-6) M). Bacteria in the exponential phase of growth showed higher binding than cells in the stationary phase. Bacteria grown in medium containing serum and/or lysed erythrocytes bound lactoferrin to a lesser extent. Heat-inactivated serum, lysed erythrocytes and other proteins such as mucin and laminin inhibited lactoferrin binding to A. actinomycetemcomitans in a competitive binding assay. Sodium dodecyl sulfate polyacrylamide-gel electrophoresis and Western blot analysis of the cell envelope as well as the outer membrane of A. actinomycetemcomitans revealed lactoferrin-reactive protein bands at 29 kDa and 16.5 kDa. The 29-kDa band displayed a heat-modifiable lactoferrin-reactive form with a molecular weight of 34 kDa. Neither proteinase K-treated cell envelope nor lipopolysaccharide of this bacterium showed reactivity with lactoferrin. These data suggests a specific interaction of lactoferrin with outer membrane proteins of A. actinomycetemcomitans.

Aggregatibacter actinomycetemcomitans↗

PubMed2002

Lactoferrin inhibits the lipopolysaccharide-induced expression and proteoglycan-binding ability of interleukin-8 in human endothelial cells.

Interleukin-8 (IL-8), a C-X-C chemokine bound to endothelium proteoglycans, initiates the activation and selective recruitment of leukocytes at inflammatory foci. We demonstrate that human lactoferrin, an antimicrobial lipopolysaccharide (LPS)-binding protein, decreases both IL-8 mRNA and protein expression induced by the complex Escherichia coli 055:B5 LPS/sCD14 in human umbilical vein endothelial cells. The use of recombinant lactoferrins mutated in the LPS-binding sites indicates that this inhibitory effect is mediated by an interaction of lactoferrin with LPS and CD14s that suppresses the endotoxin biological activity. Furthermore, since dimeric IL-8 and lactoferrin are both proteoglycan-binding molecules, the competition between these proteins for heparin binding was investigated. Lactoferrin strongly inhibited the interaction of radiolabeled IL-8 to immobilized heparin, whereas a lactoferrin variant lacking the amino acid residues essential for heparin binding was not inhibitory. Moreover, this process is specific, since serum transferrin, a glycoprotein whose structure is close to that of lactoferrin, did not prevent the interaction of IL-8 with heparin. These results suggest that the anti-inflammatory properties of lactoferrin during septicemia are related, at least in part, to the regulation of IL-8 production and also to the ability of lactoferrin to compete with chemokines for their binding to proteoglycans.

Cells, Cultured↗

PubMed1995

A retinoic acid response element that overlaps an estrogen response element mediates multihormonal sensitivity in transcriptional activation of the lactoferrin gene.

The lactoferrin gene is highly expressed in many different tissues, and its expression is controlled by different regulators. In this report, we have defined a retinoic acid response element (RARE) in the 5'-flanking region of the lactoferrin gene promoter. The lactoferrin-RARE is composed of two AGGTCA-like motifs arranged as a direct repeat with 1-bp spacing (DR-1). A gel retardation assay demonstrated that it bound strongly with retinoid X receptor (RXR) homodimers and RXR-retinoic acid receptor (RAR) heterodimers as well as chicken ovalbumin upstream promoter transcription factor (COUP-TF) orphan receptor. In CV-1 cells, the lactoferrin-RARE linked with a heterologous thymidine kinase promoter was strongly activated by RXR homodimers in response to 9-cis-retinoic acid (9-cis-RA) but not to all-trans-RA. When the COUP-TF orphan receptor was cotransfected, the 9-cis-RA-induced RXR homodimer activity was strongly repressed. A unique feature of the lactoferrin-RARE is that it has an AGGTCA-like motif in common with an estrogen-responsive element (ERE). The composite RARE/ERE contributes to the functional interaction between retinoid receptors and the estrogen receptor (ER) and their ligands. In CV-1 cells, cotransfection of the retinoid and estrogen receptors led to mutual inhibition of the other's activity, while an RA-dependent inhibition of ER activity was observed in breast cancer cells. Furthermore, the lactoferrin-RARE/ERE showed differential transactivation activity in different cell types. RAs could activate the lactoferrin-RARE/ERE in human leukemia HL-60 cells and U937 cells but not in human breast cancer cells. By gel retardation analyses, we demonstrated that strong binding of the endogenous COUP-TF in breast cancer cells to the composite element contributed to diminished RA response in these cells. Thus, the lactoferrin-RARE/ERE functions as a signaling switch module that mediates multihormonal responsiveness in the regulation of lactoferrin gene expression.

Base Sequence↗

PubMed1989

Comparative analysis of the transferrin and lactoferrin binding proteins in the family Neisseriaceae.

Intact cells of several bacterial species were tested for their ability to bind human transferrin and lactoferrin by a solid-phase binding assay using horseradish peroxidase conjugated transferrin and lactoferrin. The ability to bind lactoferrin was detected in all isolates of Neisseria and Branhamella catarrhalis but not in isolates of Escherichia coli or Pseudomonas aeruginosa. Transferrin-binding activity was similarly detected in most isolates of Neisseria and Branhamella but not in E. coli or P. aeruginosa. The expression of transferrin- and lactoferrin-binding activity was induced by addition of ethylenediamine di-o-phenylacetic acid and reversed by excess FeCl3, indicating regulation by the level of available iron in the medium. The transferrin receptor was specific for human transferrin and the lactoferrin receptor had a high degree of specificity for human lactoferrin in all species tested. The transferrin- and lactoferrin-binding proteins were identified after affinity isolation using biotinylated human transferrin or lactoferrin and streptavidin-agarose. The lactoferrin-binding protein was identified as a 105-kilodalton protein in all species tested. Affinity isolation with biotinylated transferrin yielded two or more proteins in all species tested. A high molecular mass protein was observed in all isolates, and was of similar size (approximately 98 kilodaltons) in all species of Neisseria but was larger (105 kilodaltons) in B. catarrhalis.

Escherichia coli↗

PubMed2002

Effect of lactoferrin on Helicobacter felis induced gastritis.

Lactoferrin possesses antibiotic, antiinflammatory, and immune-modulating properties that may be active against the gastritis-, ulcer- and cancer-inducing bacterium Helicobacter pylori. In vitro testing of bovine and human lactoferrin by several laboratories has shown significant bacteriostatic and bactericidal activity. Subsequent in vivo testing of bovine lactoferrin in animal models of H. pylori infection has shown beneficial effects of this agent. Our laboratory has utilized a mouse model that is infected with the feline strain of this bacterium, H. felis. The resulting gastritis that develops in this model and the effects of bovine lactoferrin and recombinant human lactoferrin (from Aspergillus niger var. awamori, Agennix Inc., Houston, Tex.) treatment were assessed by various measures. Infected animals treated with orally administered lactoferrin showed reversals in all parameters. In addition, when recombinant human lactoferrin was used in combination with low doses of amoxicillin or tetracycline, there was an enhancement in gastritis-reducing activity. Possible mechanisms for these effects of lactoferrin are discussed. Lactoferrin has significant, orally active in vivo actions and should be further investigated for clinical situations involving Helicobacter infections where it may have utility when administered alone and also when given in combination with established antibiotic agents.

Animals↗

PubMed1990

Structural homology of human, bovine, and porcine milk lactoferrins: evidence for shared antigenic determinants.

Although some degree of structural homology has been demonstrated among lactoferrins of different species, other reports suggest that these proteins are immunologically distinct. Human, bovine, and porcine lactoferrins were purified to homogeneity from colostral whey by affinity chromatography on immobilized single-stranded DNA. Evidence for shared antigenic determinants among human, bovine, and porcine lactoferrins was demonstrated by Ouchterlony immunodiffusion and immuno "dot" blots using whole antisera and purified Ig directed against each species of lactoferrin. There was no evidence that human transferrin was recognized by any of the lactoferrin-specific antisera evaluated. The degree of cross-reactivity between the lactoferrins and their trypsin digestion products was also evaluated after SDS-PAGE by immunoblotting. These data demonstrate that human, porcine, and bovine lactoferrins share common antigenic determinants and are likely to be more homologous in tertiary structures than suggested previously. Thus, investigations of human or bovine lactoferrin metabolism in infants that are based upon immunologic methods alone should be conducted cautiously in those cases where the presence of both human and bovine lactoferrin is suspected.

Animals↗

PubMed1999

Restricted spatiotemporal expression of lactoferrin during murine embryonic development.

Lactoferrin is a member of the transferrin family of iron-binding glycoproteins. Lactoferrin is induced by estrogen in the mouse uterus during early pregnancy. However, the expression and function, if any, of lactoferrin in the preimplantation embryo during this developmental period has not been investigated. In the current study, the spatiotemporal expression of lactoferrin during murine embryogenesis was examined using in situ hybridization and immunohistochemical analyses. Lactoferrin expression was first detected in the 2-4 cell fertilized embryo and continued until the blastocyst stage of development. Interestingly, at the 16-cell stage, coinciding with the first major differentiation step in the embryo, lactoferrin messenger RNA (mRNA) is synthesized by the inner cells, whereas the protein is selectively taken up by the outside cells. This differential pattern of lactoferrin messenger RNA and protein localization continues until the blastocyst stage, with expression almost absent in the hatched blastocyst. Lactoferrin expression does not resume in the embryo until the latter half of gestation, where it is first detected in neutrophils of the fetal liver at embryonic day 11.5 and later in epithelial cells of the respiratory and digestive systems. Our results show that lactoferrin is expressed in a tightly regulated spatiotemporal manner during murine embryogenesis and suggest a novel paracrine role for this protein in the development of the trophoectodermal lineage during preimplantation development.

Animals↗

PubMed2002

Effects of bovine lactoferrin by the intramammary infusion in cows with staphylococcal mastitis during the early non-lactating period.

To evaluate the clinical effects of bovine lactoferrin on staphylococcal mastitis in Holstein cows during the early non-lactating period, 41 mammary quarters were selected randomly from 36 cows on 3 dairy farms. Twelve quarters were infused intramammarily with bovine lactoferrin. Twenty-nine quarters were infused with antibiotic as a control. In the bovine lactoferrin-infused group, 91.7% of mastitic quarters were cured at 7 days after calving, compared with 48.3% in the control group. Furthermore, the changes in mammary secretion induced by the infusion of bovine lactoferrin were investigated. Mean numbers of staphylococci in mammary gland secretions were significantly decreased in both 5 bovine lactoferrin-infused quarters and 5 antibiotic-infused control quarters (p<0.05). Unlike in the control quarters, the mean total cell concentration in the mammary gland secretions increased in bovine lactoferrin-infused quarters. Similar results were obtained in 6 healthy quarters which were infused with bovine lactoferrin. In these quarters, the cell population contained mainly phagocytes such as polymorphonuclear leukocytes and cells positive for CD11b which is known as a complement receptor. The mean concentration of C3 in mammary gland secretions was significantly increased in 5 mastitic quarters infused with bovine lactoferrin (p<0.05), but showed no significant change in 5 mastitic control quarters. These results suggested that bovine lactoferrin treatment for staphylococcal mastitis in the early non-lactating period might increase the rate of cure through the induction of innate immunity in the host.

Animals↗

PubMed2003

New sensitive method for the measurement of lysozyme and lactoferrin for the assessment of innate mucosal immunity. part I: time-resolved immunofluorometric assay in serum and mucosal secretions.

Mucous peristalsis, mucus and immunity proteins, such as lysozyme and lactoferrin, are part of humoral innate immunity. The aim of this study was to develop a quantitative method, a time-resolved-immunofluorometric assay, to measure lysozyme and lactoferrin in sera, saliva, stools and cervico-vaginal secretions. This method was validated in 51 healthy subjects. Linearity for lysozyme was between 1.02 and 25 microg/l and for lactoferrin between 1.02 and 100 microg/l. The detection limit was 0.5 microg/l for lysozyme and 1 microg/l for lactoferrin. Albumin and alpha1-antitrypsin were measured by immuno-nephelometry to calculate salivary, intestinal and cervico-vaginal coefficients of excretion. Lysozyme and lactoferrin were present in all types of mucosal surfaces. Very high concentrations of lysozyme and lactoferrin were found in cervico-vaginal fluid (166.2 and 72.7 mg/l, respectively), compared to the concentrations found in the other mucosal fluids. Lysozyme in stools was produced at the rate of 0.42 mg/d compared to 0.02 mg/d lactoferrin production. Lysozyme and lactoferrin greatly exceeded the values expected from the molecular weight-affected seepage from plasma, suggesting primarily local synthesis in healthy subjects. Quantitative measurement of lysozyme and lactoferrin can aid in the assessment of the activity of mucus-associated lymphoid tissues in innate immunity, and can help in further understanding of the role of these proteins in mucosal diseases.

Adolescent↗

PubMedDate not supplied

Lactoferrin-protector against oxidative stress and regulator of glycolysis in human erythrocytes.

Binding of lactoferrin (Lf) to its membrane receptors requires an electron for the reduction of Fe(3+)LF to Fe(2+)LF. It is possible that glyceraldehyde -3-phosphate dehydrogenase, a glycolytic enzyme part of the erythrocyte membrane, delivers that electron. Then Lf, obtaining an electron from the coenzyme NADH, might stimulate glycolysis, which requires the oxidised state of the coenzyme NAD+. Such possibility is supported by the finding that another extracellular e- acceptor--potassium ferricyanide activates glycolysis by the similar mechanism. Present results show that ferricyanide inhibited the specific 59Fe-lactoferrin binding to its erythrocyte membrane receptors. It may be assumed that ferricyanide competes with lactoferrin for an electron which leads to decrease of the binding of 59Fe-lactoferrin to its receptors. Lactoferrin (50 and 100 nM), similar to ferricyanide, increased the accumulation of lactate (respectively by 25% and 30%). These results support the assumption that ferricyanide and lactoferrin are final acceptors of a common electron transport chain connected with the regulation of glycolysis. We established an antioxidative effect of lactoferrin on erythrocytes, which was expressed as: a) an influence on content and on activity of intracellular antioxidants--namely an enhancement of the content of reduced glutathione; b) a decreased content both of products of lipid peroxidation (thiobarbituric acid reactive substances) and hemolysis under normal conditions and oxidative stress. Lactoferrin is capable to bind metal ions and thus to block their catalytic participation in the oxidative disturbances of the membrane. In most of our experiments there were no metal ions in the incubation mixtures (except those stimulating oxidative stress). Our results showed that Lf limited both the generation of thiobarbituric acid reactive substances and hemolysis in the absence of metal ions in the media, as well as in their presence. These facts suggest that probably the antioxidative property of lactoferrin is glycolysis stimulation, leading to increased formation of ATP, which is necessary to maintain the ion gradient, membrane potential and morphology of the erythrocyte.

Antioxidants↗

PubMed1994

Mechanisms of lactoferrin-induced leukocyte-endothelial cell adhesion in postcapillary venules.

OBJECTIVE: The objective is to determine the contributions of electrostatic charge, endothelial cell adhesion glycoproteins (P- and E-selectins), and histamine to lactoferrin-induced leukocyte adhesion in postcapillary venules. METHODS: Rat mesentery was prepared for intravital microscopic observation. Erythrocyte velocity, vessel diameter, leukocyte rolling velocity, number of adherent and emigrated leukocytes, and velocity, flux, and number of rolling leukocytes were monitored in mesenteric venules (25-35 microns initial diameter). After control measurements were obtained for all parameters, lactoferrin, other cationic proteins (histone or alpha-chymotrypsinogen A), or transferrin (an anionic iron-binding protein) were infused into the superior mesenteric artery, with repeat measurements taken 20 min into the infusion period. In other lactoferrin experiments, animals were treated with either a monoclonal antibody (MAb) directed against P- or E-selectin, an H1- or H2-histamine receptor antagonist, or diamine oxidase (histaminase). RESULTS: Increased numbers of rolling and adherent leukocytes were observed during infusion of lactoferrin, histone, or alpha-chymotrypsinogen A but not with transferrin. The leukocyte-endothelial cell adhesion (LECA) elicited by lactoferrin was substantially greater than that induced by histone and alpha-chymotrypsinogen A. The P-selectin MAb completely prevented lactoferrin-induced LECA, whereas the E-selectin MAb had no effect. Diamine oxidase and the H1- (but not the H2-) receptor antagonist were also effective in attenuating lactoferrin-induced LECA. CONCLUSIONS: These results indicate that lactoferrin-induced LECA results from histamine-mediated expression of P-selectin on venular endothelial cells. The cationic nature of lactoferrin accounts for only a small part of its proadhesive actions.

Animals↗

PubMed2003

Supplemental lactoferrin improves health and growth of Holstein calves during the preweaning phase.

Lactoferrin is a milk protein that exhibits broad-spectrum antimicrobial properties. Previous studies indicated that supplemental lactoferrin may alter the microbial populations in the gut of nonruminants and increase preweaning weight gains in calves. In the present study, 40 Holstein calves were used to examine the effects of supplemental lactoferrin (0, 1, 2, or 3 g/d) on health, growth, and feed intake from 3 d of age to 2 wk postweaning. Lactoferrin was mixed and fed with a nonmedicated milk replacer. Calves were housed in individual pens and offered a textured, nonmedicated starter and water for ad libitum consumption. Body weight and heart girth were measuredweekly. Intakes of milk replacer and starter were determined daily. Fecal consistency was monitored three times per week. Calves were weaned when they met certain criteria based on body weight gain and starter intake. Preweaning fecal score responded quadratically, with the group fed 1 g/d of lactoferrin having the lowest score. Overall and preweaning number of days medicated responded in the same manner as fecal score. Preweaning average daily gain and gain-to-feed ratio increased linearly with lactoferrin supplementation, whereas postweaning gain-to-feed ratio decreased linearly with lactoferrin. Overall average daily heart girth gain increased linearly with lactoferrin. Body weight, weaning age, and dry matter intake were not different among treatments. Based on the observed improved gain-to-feed ratios, increased average daily gains, improved fecal scores, and reduced morbidity in preweaned calves, it appears that lactoferrin may be a beneficial supplement in the diets of neonatal calves prior to weaning.

Animals↗

PubMed1987

One-step isolation of lactoferrin using immobilized monoclonal antibodies.

Immunoaffinity columns made with monoclonal antibodies to either human or bovine lactoferrins were prepared to isolate human lactoferrin or bovine lactoferrin from milks by a single chromatographic step. Recoveries of human lactoferrin and bovine lactoferrin were 98 and 97%, respectively. The human lactoferrin recovered from defatted human colostrum was 98% pure with 93% iron-binding capacity. Amount of recovered bovine lactoferrin, as well as purity and iron-binding capacity, varied widely depending on the source of bovine milks and pretreatments (particularly pasteurization temperature). The best source to isolate bovine lactoferrin was raw skim milk yielding a protein 97% pure and with a 99% iron-binding capacity. Thus, immunoaffinity chromatography provides an effective one-pass isolation of highly pure human or bovine lactoferrin with reasonable recovery and iron-binding capacity.

Animals↗

PubMed1992

Synthesis of lactoferrin and transport of transferrin in the lactating mammary gland of sheep.

Two iron-binding proteins, lactoferrin and transferrin, are present in ruminant milk. Lactoferrin commonly has been assumed to be a product of mammary synthesis, but the origin of milk transferrin has not been elucidated. The objective of this experiment was to study the synthesis and distribution of these two proteins in the mammary gland of sheep. Explants from lactating mammary gland of sheep have been cultured in the presence of [3H]leucine to determine rates of synthesis of lactoferrin and transferrin. After incubation, [3H]lactoferrin was found, but labeled transferrin was not. The capacity of the mammary gland to synthesize lactoferrin decreased markedly in the first 24 h of lactation. Immunohistochemical techniques were utilized to identify the locations of lactoferrin and transferrin in the mammary gland. Transferrin was found in the colostrum contained in the alveolar lumen, in the cytoplasm of the secretory cells, and in the connective tissue between the mammary acini. High concentration of transferrin was found in the basal membrane of the secretory alveolar cells, mainly in those near capillary vessels. Lactoferrin was found in the colostrum and in the cytoplasm of secretory cells with a more homogeneous distribution than transferrin. The connective tissue stained negative for lactoferrin. These results suggest that, although lactoferrin is synthesized by mammary gland of the sheep, transferrin comes from blood serum, probably by a receptor-mediated mechanism of transcytosis.

Animals↗

PubMed1993

Thermal behavior of bovine lactoferrin in water and its relation to bacterial interaction and antibacterial activity.

Heat-induced enthalpy changes in different forms of bovine lactoferrin in water were examined by differential scanning calorimetry. Two thermal transitions with varying enthalpies were observed, depending on the iron-binding status of the protein. Iron-saturated lactoferrin was more resistant to heat-induced changes than was the apolactoferrin. Native lactoferrin had two transitional peaks, and pasteurization affected only the low temperature transition. Iron-saturated lactoferrin revealed a single transitional peak that was resistant to pasteurization. However, both protein forms were completely denatured by UHT. The effect of pasteurization and UHT on the protein interaction capacity with bacteria was examined in a 125I-labeled lactoferrin binding-inhibition assay. The ability of native and iron-saturated lactoferrins to bind various bacterial species was unaffected by pasteurization. However, UHT treatment decreased this interaction capacity. Native lactoferrins, both unheated and pasteurized, showed similar antibacterial properties and moderately inhibited Escherichia coli. However, this inhibitory capacity was lost after UHT treatment. Finally, iron-saturated lactoferrin did not inhibit bacterial growth; neither pasteurization nor UHT could change this property. Thus, UHT seems to affect structural as well as certain biological properties of both native and iron-saturated bovine lactoferrins, and pasteurization seems to be a treatment of choice for products containing this protein.

Animals↗

PubMed1999

Lactoferrin expression in human breast cancer.

We analyzed lactoferrin expression in 78 samples from patients with sporadic breast cancer and found 31/78 negative for mRNA expression. Similar results were obtained by immuno-histochemical localization of the lactoferrin protein. We did not find relationship between lactoferrin expression and clinical parameters. We investigated for the absent lactoferrin expression in some cases of breast cancer. In 68 of the samples analyzed, we found an inverse correlation between estrogen receptor expression and lactoferrin expression (P < 0,0001), thus indicating that regulation by the estrogen receptor is not the main element responsible for the expression of lactoferrin in breast cancer. Analysis of methylation of the lactoferrin genomic DNA extracted from the same patients revealed that the degree of methylation does not explain the observed absence of lactoferrin. The 937 bp lactoferrin promoter was investigated for possible mutations. By single-strand conformation polymorphism analysis one polymorphic site was found and characterized.

Breast Neoplasms↗

PubMedDate not supplied

[Ejaculate microflora sensitivity to lactoferrin in chronic prostatitis].

To determine an antimicrobial action of lactoferrin on bacterial flora of ejaculate in chronic prostatitis, we examined 124 patients with various diseases of male reproductive system at the age between 17 and 56. A total of 280 strains were used as test microorganisms (MO). Sensitivity of the latter to lactoferrin was studied with a human lactoferrin apoform. MO isolated from patients with marked dysbiosis were resistant to lactoferrin (94%). MO, not leading in cenosis, were more sensitive to lactoferrin than MO of the main colonies grown after seeding. Reproductive dysfunction was accompanied by higher occurrence of strains resistant to lactoferrin. The least sensitivity to lactoferrin was registered in asthenozoospermia. Lactoferrin resistance of MO may raise MO pathogenicity. When lactoferrin-resistant strains predominate in microbiocenosis, it is an unfavourable prognostic sign in relation to development of complications, primarily subfertility.

Adolescent↗

PubMed1989

Plasma lactoferrin content in pregnancy.

Plasma lactoferrin concentration, leucocyte count, serum prolactin concentration and storage iron status were studied in 313 women at various stages of pregnancy. The mean serum iron value, percentage saturation of transferrin and geometric mean serum ferritin concentrations decreased as pregnancy progressed. In contrast, the total iron-binding capacity showed a highly significant increase with advancing gestation. Plasma lactoferrin concentration showed a mild progressive increase during pregnancy (peaking 29-32 weeks). The increase in lactoferrin concentration was, however, disproportionately small when compared with the concomitant pregnancy-related elevation in leucocyte count. The ratio of plasma lactoferrin concentration to leucocyte count therefore appeared to be abnormally low during pregnancy suggesting an acquired defect of lactoferrin release by leucocytes of pregnant women. It is unlikely that prolactin was the factor responsible for the reduced leucocyte release of lactoferrin. The lactoferrin:leucocyte ratio was already significantly reduced early in pregnancy at a time when prolactin concentration was relatively low. Furthermore, the correlation between prolactin concentration and both lactoferrin concentration and lactoferrin:leucocyte ratio was positive. Pregnancy appears to be associated with an acquired abnormality of leucocyte degranulation, the cause of which is not clear at present.

Adult↗