The value of cord blood interleukin-6 levels for predicting chorioamnionitis, funisitis and neonatal infection in term premature rupture of membranes

OBJECTIVE

The objective was to determine whether the interleukin-6 (IL-6) level in umbilical cord blood can be used for the prediction of histologic chorioamnionitis, funisitis, fetal membrane cultures and neonatal infection.

STUDY DESIGN

A case-control study was conducted on 30 controls (control group) and on 40 women with term premature rupture of the membranes (PROM group). The interleukin-6 concentration of cord blood was measured. Fetal membranes and newborn blood were cultured. Placentas were examined for histologic chorioamnionitis and funisitis. Receiver operator curve analysis was used to obtain a cut-off value of interleukin-6 concentration for predicting histological and clinical infection.

RESULTS

The mean interleukin-6 level in cord blood was significantly higher in the PROM group (p=0.01). Histological chorioamnionitis and positive placental cultures were significantly higher in the PROM group (p=0.006 and 0.02, respectively). The PROM group had seven (17.5%) cases of funisitis and positive newborn blood cultures while neither was observed in the control group. A cord blood interleukin-6 level >29 pg/ml was found to have 84% sensitivity and 72.5% specificity for predicting positive placental cultures and 74.1% sensitivity and 76.7% specificity for identifying cases of histologic chorioamnionitis. For predicting funisitis and positive newborn cord blood cultures a cord blood interleukin-6 level >39 pg/ml has 100% sensitivity and 81% specificity.

CONCLUSION

Cord blood interleukin-6 level can be a tool for the evaluation of the extent of maternal-fetal infection and guides proper planning of the treatment.

Analysis and cryopreservation of hematopoietic stem and progenitor cells from umbilical cord blood

BACKGROUND

Umbilical cord blood (UCB) is an important source of hematopoietic stem and progenitor cells (HSC/HPC) for the reconstitution of the hematopoietic system after clinical transplantation. Cryopreservation of these cells is critical for UCB banking and transplantation as well as for research applications by providing readily available specimens. The objective of this study was to optimize cryopreservation conditions for CD34+ HSC/HPC from UCB.

METHODS

Cryopreservation of CD34+ HSC/HPC from UCB after mononuclear cell (MNC) preparation was tested in a research-scale setup. Experimental variations were concentration of the cryoprotectant, the protein additive and cell concentration. In addition, protocols involving slow, serial addition and removal of DMSO were compared with standard protocols (fast addition and removal of DMSO) in order to avoid osmotic stress for the cryopreserved cells. Viability and recoveries of MNC, CD34+ cells and total colony-forming units (CFU) were calculated as read-outs. In addition, sterility testing of the collected UCB units before further processing was performed.

RESULTS

The optimal conditions for cryopreservation of CD34+ HPC in MNC preparations were 10% DMSO and 2% human albumin at high cell concentrations (5 x 10(7) MNC/mL) with fast addition and removal of DMSO. After cryopreservation using a computer-controlled freezer, high viabilities (89%) and recoveries for CD34+ cells (89%) as well as for CFU (88%) were observed. Microbial contamination of the collected UCB samples was reduced to a rate of 6.4%.

DISCUSSION

Optimized cryopreservation conditions were developed for UCB MNC in respect of the composition of the cryosolution. In addition, our results showed that fast addition of DMSO is essential for improved cryopreservation and post-thaw quality assessment results, whereas the speed of DMSO removal after thawing has little influence on the recoveries of CD34+ cells and CFU.

The effects of intra-amniotic injection of periodontopathic lipopolysaccharides in sheep

OBJECTIVE

Periodontal disease may cause several complications of pregnancy, including fetal death. The purpose of this study was to investigate in sheep the effects of the intra-amniotic injection of lipopolysaccharide from 3 periodontopathic organisms and to compare these effects with those resulting from similar injection of Escherichia coli lipopolysaccharide. The outcomes that were studied included the rates of fetal death and the features of inflammation and lung maturation in survivors.

STUDY DESIGN

At 118 days of pregnancy, ewes that were bearing single fetuses were allocated at random to receive intra-amniotic injections of saline solution (n = 13 fetuses), or lipopolysaccharide from Porphyromonas gingivalis (in doses from 0.1 to 10 mg [n = 22 fetuses]), Actinobacillus actinomycetemcomitans (10 mg [n = 6 fetuses]; 1 mg [n = 6 fetuses]), Fusobacterium nucleatum (10 mg [n = 6 fetuses]) or Escherichia coli (10 mg [n = 14 fetuses]; 1 mg [n = 7 fetuses]). Surviving fetuses were delivered abdominally at 125 days of gestation (term, 150 days).

RESULTS

When compared with Escherichia coli lipopolysaccharide at similar dosages, periodontopathic lipopolysaccharides had high rates of fetal lethality. Only 6 of 22 fetuses that were exposed to intra-amniotic Porphyromonas gingivalis lipopolysaccharide survived doses of 0.1 to 10 mg, and only 3 of 6 fetuses survived 10-mg Actinobacillus actinomycetemcomitans lipopolysaccharide. Escherichia coli lipopolysaccharide did not cause fetal loss when given at doses of 10 mg (n = 14 fetuses) or 1 mg (n = 7 fetuses). Fetuses that survived exposure to these lipopolysaccharides showed features of inflammation in amniotic fluid and cord blood at birth and enhanced lung maturation.

CONCLUSION

Lipopolysaccharides from these 3 periodontopathic organisms have much higher rates of fetal lethality than Escherichia coli lipopolysaccharide but can cause similar intrauterine inflammatory responses and improvements in lung volumes in survivors. Sources of inflammation that are distant from the uterus may underlie a proportion of unexplained stillbirth and other complications of pregnancy.

Potential Substitution of Cord Blood for Infant Blood in the Neonatal Sepsis Evaluation

BACKGROUND

Evaluation of sepsis accounts for one third of all nursery triage admissions. If umbilical cord blood could be accurately substituted for infant blood, it would spare infants the discomfort of an invasive procedure and save both time and resources. While awaiting 48-hour blood culture results, we decide on clinical management based on whether the white blood cell (WBC) immature to total (I:T) granulocyte ratio is >or=0.2.

OBJECTIVES

Our goal was to assess the correlation of complete blood count (CBC), I:T ratio and blood culture results between umbilical cord and infant blood.

METHODS

We conducted a prospective cohort study comparing CBC/differential and blood culture results of paired samples of umbilical cord and infant blood from term newborns.

RESULTS

We sent 113 paired samples of cord and infant venous blood for CBC/differential and blood culture. All 113 umbilical cord and infant blood cultures were negative, yielding a false-positive blood culture rate of zero. For 92% of babies, both the cord and infant blood I:T ratio were <0.2 or both were >or=0.2. Cord and infant WBC, hematocrit and platelet counts were moderately to highly correlated.

CONCLUSION

We conclude that cord blood can be safely substituted for infant blood in routine sepsis evaluations of asymptomatic, term infants based on both the low false-positive cord blood culture rate and the significant association between high I:T ratios in cord and infant blood.

Microbial contamination of hematopoietic progenitor cell grafts-incidence, clinical outcome, and cost-effectiveness: an analysis of 735 grafts

BACKGROUND

Screening of progenitor cell grafts (marrow, peripheral blood, and cord blood) for microbial contamination is required by the standards of AABB. Clinical sequelae from infusion of these contaminated grafts, however, is uncommon.

STUDY DESIGN AND METHODS

A retrospective analysis of 735 consecutive marrow and peripheral blood progenitor cell harvests between 1998 and 2003 was performed. Analysis included incidence, clinical outcome, and cost outcomes of positive blood cultures and antibiotic therapy.

RESULTS

Thirty-three of 735 (4.5%) harvests were contaminated. The incidence of microbial contamination varied with the source of the graft (4 of 26 [15%] were cord blood, 8 of 177 [4.5%] were marrow, and 21 of 532 [3.9%] were peripheral blood). Coagulase-negative Staphylococcus (n=22) and Propionibacterium acnes (n=8) were most frequently isolated. Potentially pathogenic organisms were isolated in 6 of 735 (0.81%) grafts (methicillin-sensitive Staphylococcus aureus, 4; methicillin-resistant S. aureus, 1; and Enterobacter cloacae, 1). The estimated total cost of surveillance was approximately $81,585. The cost of vancomycin therapy in 4 patients who received prophylactic antibiotic therapy was approximately $10,000. No adverse sequelae followed infusion of contaminated grafts.

CONCLUSION

Clinical sequelae following infusion of microbially contaminated progenitor cells is extremely rare. Prophylactic empiric antibiotics may be unnecessary. Routine microbial surveillance of progenitor cell grafts is a low-yield procedure.

IL-8 concentrations in maternal serum, amniotic fluid and cord blood in relation to different pathogens within the amniotic cavity

OBJECTIVE

The association between elevated interleukin (IL)-8 concentrations in amniotic fluid and preterm delivery is well described. Little consideration has been given to the impact of different groups of microorganisms within the amniotic cavity on IL-8 concentration.

METHODS

We collected amniotic fluid, placental tissue and amniotic membranes during preterm cesarean sections for bacterial culture. In addition, we determined IL-8 concentrations in maternal serum, amniotic fluid and cord blood and correlated them with the various intra-amniotic pathogens isolated by bacterial culture.

RESULTS

IL-8 concentrations were determined in amniotic fluid in 107 cases, in cord blood in 185 cases and in maternal blood in 158 cases. Women with intra-amniotic Ureaplasma urealyticum infection had significantly higher amniotic fluid concentrations of IL-8 than those without (P< 0.001). In cord blood, we found significantly elevated IL-8 concentrations due to intra-amniotic infection with U. urealyticum (P=0.045) and other pathogens (P=0.04). In maternal sera, we found no significant elevation of maternal IL-8 in any of the groups.

CONCLUSION

Intrauterine infection with U. urealyticum seems to play a profound role in the cascade of inflammation and increases IL-8 concentrations in amniotic fluid and cord blood.

The humane collection of fetal bovine serum and possibilities for serum-free cell and tissue culture

Fetal bovine serum (FBS) is a common supplement to in vitro culture media. A workshop was organized to discuss whether or not fetuses might suffer when blood is withdrawn, and to discuss serum replacement methods. When bovine fetuses are exposed after slaughter of the dam, they can suffer only if they inflate their lungs with air and increase their blood oxygen to levels compatible with awareness. Preventing fetuses from breathing air or killing them by an efficient method, according to clearly defined safeguards, ensures that fetal blood collection is humane. Since serum is a supplement of unknown composition, which could be contaminated with unwanted factors, there are scientific and safety reasons for omitting FBS from culture media. Several media have been developed in which minimal or no animal derived components are present. Also, different cell types have been adapted to serum-free media. As yet, no standard serum free media are present, and each cell type requires its own medium composition. Among other recommendations, the establishment of a public database with information on cell types and their serum-free medium composition is proposed.

Selective impairment of TLR-mediated innate immunity in human newborns: neonatal blood plasma reduces monocyte TNF-alpha induction by bacterial lipopeptides, lipopolysaccharide, and imiquimod, but preserves the response to R-848

Newborns are at increased risk of overwhelming infection, yet the mechanisms underlying this susceptibility are incompletely defined. In this study we report a striking 1- to 3-log decrease in sensitivity of monocytes in human neonatal cord blood, compared with monocytes in adult peripheral blood, to the TNF-alpha-inducing effect of multiple TLR ligands, including bacterial lipopeptides (BLPs), LPS, and the imidazoquinoline compound, imiquimod. In marked contrast, TNF-alpha release in response to R-848, a TLR ligand that is a congener of imiquimod, was equivalent in newborn and adult blood. Differences in ligand-induced TNF-alpha release correlated with divergent ligand-induced changes in monocyte TNF-alpha mRNA levels. Newborn and adult monocytes did not differ in basal mRNA or protein expression of TLRs or mRNA expression of functionally related molecules. Newborn monocytes demonstrated diminished LPS-induced, but equivalent R-848-induced, phosphorylation of p38 mitogen-activated protein kinase and altered BLP- and LPS-induced acute modulation of cognate receptors, suggesting that the mechanism accounting for the observed differences may be localized proximal to ligand recognition by surface TLRs. Remarkably, newborn plasma conferred substantially reduced BLP-, LPS-, and imiquimod-induced TNF-alpha release on adult monocytes without any effect on R-848-induced TNF-alpha release, reflecting differences in a plasma factor(s) distinct from soluble CD14. Impaired response to multiple TLR ligands may significantly contribute to immature neonatal immunity. Conversely, relative preservation of responses to R-848 may present unique opportunities for augmenting innate and acquired immunity in the human newborn.

Congenital syphilis in a Nairobi maternity hospital

OBJECTIVE

To assess adverse pregnancy outcome associated with maternal syphilis and congenital syphilis rate based on FTA-ABS-19s-IgM.

DESIGN

Descriptive cross-sectional study.

SETTING

Pumwani Maternity Hospital (PMH), the largest maternity unit in Nairobi, Kenya.

SUBJECTS

Rapid Plasma Reagin reactive women and their live born infants.

MAIN OUTCOME MEASURES

Syphilis serology in pregnant women, FTA-ABS-19s-IgM in cord blood and pregnancy outcome.

RESULTS

Three hundred and seventy seven out of 12,414 women (3%) were RPR+. 4.0% of RPR+ and 1.4% of RPR- women delivered a stillbirth (OR 3.0, p<0.001). 19% of RPR+ and 10% of RPR- had low birth weight deliveries (OR 2.1, p<0.001). Mothers untreated for syphilis during pregnancy had significantly more preterm births (18.5% vs 9.2%, OR 2.3, p=0.026), and more stillbirths (5.4% vs 1.0%, OR 6.3, p=0.044). Of the 200 randomly selected cord bloods of RPR+ women, 142 (72%) were TPHA+. Nine (6.3%) of the 142 TPHA+ cords were FTA-ABS-19s-IgM+.

CONCLUSIONS

Stillbirth and low birth weight rates were high in RPR+ untreated pregnant women and treatment significantly improved pregnancy outcome. Based on very stringent laboratory criteria (FTA-ABS-19s-IgM), 6.3% of live born infants with TPHA+ cord blood were considered syphilis infected.

Microbial screening of UC blood units by an automated culture system: effect of delayed testing on bacterial detection

BACKGROUND

Microbial screening is a mandatory test for banked UC blood (UCB) to comply with the code of good manufacturing practice (GMP). Cord blood banks (CBBs) are not always closely located to a GMP-licensed microbiology laboratory, resulting in time delays for transport of specimens prior to microbiological testing. This study investigated the influence of >/=24 h delays in initiating automated microbial screening on the detection of bacteria in UCB, by analysis of specimens deliberately spiked with bacteria and the recovery of bacteria from cryopreserved spiked-UCB.

MATERIALS AND METHODS

UCB was processed according to standard CBB procedures and spiked with Staphylococcus epidermidis or Escherichia coli [2-2000 colony forming units (CFU)/mL]. Spiked-UCB (0.5 mL) was (1) held at room temperature (RT) and inoculated into pediatric BacT/Alert bottles (bioMérieux) at Days 1, 4 and 7 (delayed inoculation); and (2) inoculated directly (Day 0) into replicate BacT/Alert bottles and held at RT for 1, 4 or 7 days before loading onto the BacT/ALERT system (delayed loading). Spiked-UCB samples were cryopreserved. Bacterial counts were quantitated on horse blood agar plates.

RESULTS

Bacterial growth in UCB spiked with a single bacterium was capable of detection by the BacT/ALERT system. S. epidermidis grew in all conditions of delayed testing (ie. delayed inoculation and delayed loading). E. coli failed to grow under conditions of delayed inoculation but grew at all time points of delayed loading. S. epidermidis and E. coli were recovered from cryopreserved spiked-UCB.

DISCUSSION

Inoculation of culture bottles as soon as possible after sample preparation is preferable. Bacteria can maintain viability in BacT/ALERT bottles inoculated and held at RT for up to 7 days prior to automated culture testing. Bacteria can be successfully recovered from cryopreserved UCB.

[Is the mother's bacterial vaginosis with PROM a significant factor for intrauterine infection of the fetus in preterm labor before 32 weeks of gestation]

OBJECTIVE

Bacterial vaginosis of pregnant woman is an important factor of appearance of the PROM in result of intrauterine infections on every stage of pregnancy. Frequency exist of intrauterine infection evaluate from 1 to 10% pregnancies. Clinical chorio-amnionitis complicates 1-5% of term pregnancies, but nearly 25% of preterm deliveries and really increase morbidity and mortality of newborns and they are also a reason of mothers morbidity. A condition of recognition the intrauterine infections is ascertainment of infection factor risk of mother and appearance of clinic symptoms of newborns. The aim of this work was a valuation of dependence between bacterial flora taken from cervics uteri of pregnant woman with PROM who gave birth with preterm below 32 weeks and a presence of clinic and laboratory symptoms of infections and the presence of bacterial flora in blood culture of the newborns.

MATERIAL AND METHODS

37 pregnant women at the age from 20 to 43 hospitalized in Department Perinatology ICZMP between 1999-2001 because of PROM and a threat of preterm labor at the fetal age from 24 to 32 weeks were taken by an analysis. The average time of amniotic liquid outflowing before the labor was 11.1 days +/- 8.63, average length persistence of pregnancy was 27.6 hbd +/- 1.85, average born mass was 1029 g +/- 187.5. Laboratory factors and clinics symptoms chorionamnionitis, bacteriology cultures of swabs from cervics uteri and information of the labor of pregnant women were analyzed. Diagnostics of newborns contained: making of blood cultures and skin, nose, throat, urine cultures, estimation WBC and level CRP, estimation of lungs X-ray.

RESULTS

In result of bacteriology cultures from cervics uteri of mothers gained bacteria of frequent occurrence: Staphylococcus epiderm.--27%, E. coli--19%, Streptococcus gr. B--10.8%, Enterococcus foecalis--8.1%. In result of bacteriology cultures of newborns blood gained bacteria of frequent occurrence: Staphylococcus epiderm.--13.5%, Staphylococcus haemolitycus--10.8%, Klebsiella pneumoniae--10.8%, Pseudomonas aeruginosa--8.1%. In 97.3% cases at newborns appeared inborn infections in a shape of pneumonia confirmed by X-ray. Confirmation of intrauterine infection in histopathology examination of the placenta in a shape of chorionamnionitis was shown in 25 cases, in other words in 67.5%. Positive results of pathogenic bacteriology flora cultures taken from cervics uteri was in 50% pregnant woman, however in 43% of newborns bacteriology cultures of the blood were positive. In none of the analyzed preterm labor cases with PROM bacterial flora from positive cultures taken from cervics uteri of mothers did not correlate with bacterial flora found in blood cultures of newborns.

CONCLUSIONS

On a base of analyzed values PROM of mothers with bacterial vaginosis is the important factor risk of the evolution of intrauterine infections of newborns, besides did not ascertain the dependence between the values of bacteriology cultures taken from cervics uteri of mothers and the values of bacteriology cultures of the newborns blood with clinic symptoms of intrauterine infection.

Some statistical methods for investigating the date of birth as a disease indicator

Some methods of temporal statistics are presented and proposed for investigating the date of birth as a disease predictor. A subject's birthday is proposed to be used as a continuous variable with a circular distribution, a special type of interval scale without a true zero point. Three types of endpoints are then considered: a dichotomous endpoint; a continuous endpoint; and time-to-event. A study of otitis media is used for illustration. We found, for example, that children born in late winter to early spring tend to have higher cord blood pneumococcal antibody concentration and lower risk of disease as compared to those born in summer to early fall perhaps due largely to exposure to indoor pollution by pregnant mothers.

Coxiella burnetii seropositivity in parturient women is associated with adverse pregnancy outcomes

OBJECTIVE

We conducted a cohort study of parturient women in an area with endemic Q fever infection to determine whether those seropositive for Coxiella burnetii had evidence of adverse birth outcomes.

STUDY DESIGN

From June 1997 to November 1998, the cord blood of all women delivered at our health center was tested for antibodies to C burnetii by indirect immunofluorescence antibody test by using purified whole cell strain Nine Mile antigens. A titer of 1:8 or greater to either phase I or phase II antigens was considered seropositive. Placentas of a sample of cases and seronegative controls had polymerase chain reaction and culture performed.

RESULTS

Evidence of prior infection with C burnetii was found in 3.8% (291/7658) of all parturient women. In a multivariate logistic regression, an association was seen between seropositivity (phase I titer >or= 1:8 or phase II titer >or= 1:32) and newborn gestational age >or=36 weeks (phase I antibody, odds ratio [OR] 2.4, 95% CI 1.3-4.3, P =.005; phase II antibody, OR 1.9, 95% CI 1.02-3.7, P =.04). Women with phase I antibody were more likely to have a prior or current neonatal death (phase I OR 3.2, 95% CI 1.09-9.3, P =.03). No placental samples from 153 seropositive or 93 seronegative women had Q fever by polymerase chain reaction or culture.

CONCLUSION

About 4% of parturient women in this endemic area have evidence of previous exposure to C burnetii and this exposure is associated with adverse pregnancy outcomes. The pathogenesis of this association remains to be determined.

[The probability of microbiological contamination during the collection and processing of umbilical cord blood]

To study the pathogens incidences in cord blood and the efficiency of different detective methods, 60 samples were drawn and reserved from collected and processed cord blood, respectively. The BACTEC 9050 system, improved Martin/thioglycollate broth (22 degrees C) and thioglycollate broth (35 degrees C) were employed to detected bacteria (including fungus) at the same time. Two hundred and six cord blood serum samples were used to detect the HBV DNA and HCV RNA by molecular biology technique, HBsAg, Anti-HBC, Anti-HCV, Anti-HCMV-IgM, HTLV-1, HTLV-2, HIV-1 and HIV-2 by ELISA and RBC agglutination test were used to detect the TPHA. Results showed that using BACTEC 9050 system, the incidence of bacteria and fungus was 3.33% and 0% respectively in collected cord blood; in processed cord blood, the rates increased to 6.67% and 1.67%, respectively. The sensitivity of BACTEC 9050 was higher than that of Martin/thioglycollate broth (22 degrees C/35 degrees C) culture. In 206 serum samples, the positive rate of HBV DNA was 5.8%, HCV RNA was 2.4%, HBsAg was 2.4%, HCMV-IgM was 1.89%, HCV was 2.4% and Anti-HBC was 29.4%. In those samples that Anti-HBC was positive, the positive rate of HBV DNA was 6.7%. It was concluded that the incidences of microbiological contamination in cord blood were high. The routine culture system would lead to false negative results of obligate anaerobes. It was necessary to replace the current culture system with improved system, such as BACTEC 9050 system. The molecular biology technique would make up for the default of ELISA.

[A study on ways of intrauterine infection of chlamydia trachomatis]

OBJECTIVE

To study the route of intrauterine infection of chlamydia trachomatis (CT).

METHODS

Seven hundred and seventy-two cervical samples from in women and 105 matched maternal-labom neonatal samples composed of cervical samples, cord blood, amniotic fluid, conjunctival and nasopharyngeal samples of neonate were detected by PCR-SSCP and DNA sequencing technique.

RESULTS

CT were detected in 87 of 772 (11.3%) cervical samples. In the 81 matched maternal-infant samples from pregnant women with cervical CT-positive, CT were not detected in all of the cord blood samples. In the 30 CT-positive neonatal samples, 26 were from cases of vaginal delivery and 4 from cases of caesarean section. Statistical analysis showed a significant difference between the groups of caesarean section and the vaginal delivery (P < 0.01). Four of 11 amniotic fluid samples with CT-positive were obtained during caesarean section in which 3 were without premature rupture of membranes (PROM), SSCP patients were same between maternal samples and matched neonatal samples. The sequences of amplified DNA fragments also showed the same results between maternal and match neonatal samples. No samples were found CT-positive in 24 matched maternal-infant samples from cervical CT-negative women.

CONCLUSIONS

An ascending transmission from cervix to amniotic cavity was the major route for CT intrauterine infection. Transplacental passage of chlamydial infection was not confirmed. Rates of vertical transmission were significantly lower in caesarean section group than that of vaginal delivery group with maternal cervical chlamydial positive.

Ralstonia pickettii bacteraemia in a cord blood transplant recipient

A seven-year old boy with acute lymphoblastic leukemia underwent an HLA mismatched cord blood transplant. He developed grade 2 mucositis requiring morphine infusion and grade 3-4 hyperacute graft-versus-host disease affecting the skin, gastrointestinal tract, and liver requiring pulse methylprednisolone. On days 21, 23, and 24 post-transplant, blood culture obtained through the central line and periphery were positive for Ralstonia pickettii. The same strain (with the same biochemical profile and antibiotic susceptibility pattern) was also recovered from surveillance throat swab cultures from day 11 to day 24 and surveillance rectal swab cultures from day 16 to day 24. The patient responded to intravenous cefoperazone/sulbactam and ciprofloxacin and blood culture became negative 3 days after commencement of the antibiotics. Although R. pickettii is of low virulence and is a frequent contaminant of blood cultures, it should not be overlooked when it is repeatedly recovered from sterile body fluids, especially in immunocompromised hosts.

Microbial contamination of cord blood stem cells

BACKGROUND AND OBJECTIVES

After storage, low levels of contaminating bacteria in standard blood components can reach bacteraemic levels, causing severe transfusion-associated sepsis. For cord blood (CB), the significance of low levels of contaminating bacteria and the optimal detection method is unknown and not supported by available guidelines.

MATERIALS AND METHODS

Spiking experiments and testing of various subfractions of CB units were used to determine the behaviour of bacteria during centrifugation, freezing and thawing. For routine testing of CB, different volumes were compared for the detection of potential pathogens and micro-organisms of low pathogenicity.

RESULTS

Centrifugation, as applied to CB fractionation, does not show concentration of bacteria in any particular fraction and supports the possibility of culture of waste fractions. Dimethylsulphoxide (DMSO) and freezing does not affect the viability of bacteria under the conditions used in this study. Owing to the low contamination level, a large sample volume of 20 ml was more sensitive than a 10-ml sample volume. Eighty five per cent of the isolated strains can be considered to be of low pathogenicity.

CONCLUSION

When an optimal waste fraction sample volume of 20 ml was cultured, the contamination rate of CB was found to be approximately 13%, with low levels of < 1 colony-forming unit (CFU)/ml. Such levels of bacteria of low pathogenicity are expected to be of clinical importance only when CB is expanded in vitro for a prolonged period of time.

Maternal transmission of Helicobacter pylori in the perinatal period

OBJECTIVES

Studies indicate that Helicobacterpylori (HP) infection is closely related to gastric mucosa lesions and well-differentiated gastric cancer. In Japan, the HP-positive rate in childhood is 5-6%, which is similar to other developed countries, and in regard to the infection route, oral infection is considered important. To our knowledge there have been no reports on mother-to-child transmission and in this study we investigated maternal HP infection status to determine the potential of mother-to-child transmission in the perinatal period.

METHODS

After obtaining informed consent from 1,588 pregnant women, mother's blood and cord blood were collected at delivery to measure HP antibody (Helico-G). Gastric contents from the neonates were cultured to isolate H. pylori (Skirrow medium). Vaginal discharge (73 women) and dental plaque scraping swabs (48 women) were collected before delivery, and milk (66 women) was collected after delivery from 212 HP antibody-positive pregnant women to detect H. pylori by PCR.

RESULTS

The HP antibody-positive rate for the pregnant women was 29.2%. H. pylori was not detected in the vaginal discharge from HP antibody-positive pregnant women, but dental plaque scraping swabs from 4 women and milk from 4 women was positive.

CONCLUSION

We considered that vertical infection during pregnancy or at delivery is unlikely as a route of mother-to-child HP antibody infection. However, horizontal infection through breast-feeding may occur.

Fetal syphilis: clinical and laboratory characteristics

OBJECTIVE

To examine the pathophysiology of fetal syphilis and correlate hematologic, immunologic, and sonographic findings.

METHODS

Twenty-four women with untreated syphilis during pregnancy were prospectively identified. Sonography with amniocentesis and percutaneous umbilical blood sampling were performed. Darkfield examination, rabbit infectivity testing, and polymerase chain reaction for detection of Treponema pallidum were performed on amniotic fluid. Hematologic and chemical testing of fetal blood was performed using standard techniques. Fetal antitreponemal IgM was detected by Western blot assay. Maternal syphilis was treated with 2.4 to 4.8 million units of benzathine penicillin G intramuscularly. Neonatal outcomes and signs of congenital syphilis were recorded.

RESULTS

Six women had primary, 12 had secondary, and six had early latent syphilis. Sixty-six percent of fetuses (95% confidence interval [CI] 47%, 82%) had either congenital syphilis or detection of Treponema pallidum in amniotic fluid. Sixty-six percent had hepatomegaly, including three fetuses (12.5%, 95% CI 4%, 31%) with ascites. Fetal antitreponemal IgM was detected in three cases. Abnormal liver transaminases were found in 88% (CI 69%, 96%), anemia in 26% (CI 13%, 47%), and thrombocytopenia in 35% (CI 19%, 55%). Maternal treatment was successful in 83% (CI 64%, 93%). Risk of treatment failure was significantly increased when hepatomegaly and ascites were present (P =.01).

CONCLUSION

Findings with fetal syphilis are similar to those of neonatal syphilis. We hypothesize that fetal transaminase elevation occurs early in the course of infection; hematologic abnormalities and hydrops occur later. Severity of disease may be associated with risk of treatment failure.

Collection, processing and cryopreservation of umbilical cord blood for unrelated transplantation

Umbilical cord blood (UCB) transplantation is being used as an alternative source of hematopoietic stem cells for bone marrow reconstitution. Separation and processing of UCB samples in large numbers for storage in cord blood banks ideally needs to be partially automated. The aim of this study was to establish and standardize a method for unrelated cord blood banking as well as the biological characterization of the samples. Up to October 1999, a total of 938 UCB units (mean volume 84.6 +/- 23.6 ml, nucleated cell (NC) count 0.90 +/- 0.37 x 109, total CFU-GM 79 +/- 72 x 104, CD34+ cell count 2.46 +/- 2.72 x 106) had been collected. Twenty-three per cent of all UCB samples had a NC count below 0.4 x 109 and were discarded. The initial bacterial contamination rate was reduced to less than 5% as a result of extensive training in collection procedures. Using a modification of a triple bag system and adding a solution of 6% hydroxyethyl starch, the UCB was separated by two centrifugation steps into three components: buffy coat, red cell and plasma fractions. The overall recoveries for NC, CFU-GM and CD34+ cells were 87.4 +/- 8.5%, 88.8 +/- 6.6% and 90.3 +/- 12.4%, respectively, in a mean final volume of 27 +/- 4.2 ml.

Effects of group B streptococci on cord and adult mononuclear cell interleukin-12 and interferon-gamma mRNA accumulation and protein secretion

Group B streptococci (GBS) are a major cause of early-onset infection in neonates. Neonates, who have defects in neutrophil function that likely contribute to susceptibility to GBS infection, are deficient in the production of the phagocyte activator interferon (IFN)-gamma. GBS-stimulated mRNA accumulation and protein secretion of IFN-gamma and interleukin (IL)-12, a major enhancer of IFN-gamma production, by mixed mononuclear cells (MMCs) from umbilical cord and adult peripheral blood was examined. GBS-exposed cord blood MMCs secreted lower concentrations of both IL-12 and IFN-gamma proteins than did MMCs from adults. IL-12 and IFN-gamma mRNA accumulation was examined by use of comparative reverse transcriptase-polymerase chain reaction. Cord blood MMCs accumulated less mRNA for both IL-12 and IFN-gamma than did adult blood MMC. The deficiency in cord blood cell production of IL-12 may have a role in inadequate IFN-gamma production, which contributes to the unique susceptibility of neonates to GBS infections.

Cord blood as a source of autologous RBCs for transfusion to preterm infants

BACKGROUND

This prospective study was conducted to gain experience as to whether it is technically possible to produce autologous RBCs in additive solution from cord blood (CB), to optimize the blood supply for preterm infants.

STUDY DESIGN AND METHODS

CB was collected from 47 infants with a mean (+/- SD) birth weight of 1717 (+/- 699) g. Whenever possible, RBC components were prepared by standard centrifugation using a six-bag system. All samples were put in sterility testing quarantine for 5 days, and a maximum storage of 14 days from collection to transfusion was specified. The babies were given either the autologous RBCs or standard allogeneic RBC concentrates, if autologous blood was not available.

RESULTS

In 81 percent of the samples, autologous RBC components could be processed (vol, 7-87 mL; Hct, 31-82%). But within the group of extremely low birth weight infants (body weight <1000 g), a mean CB net volume of only 37 mL was collected, and the RBC preparation was successful only in exceptional cases. Three CB samples (8.6%) tested positive in sterility testing. Of the 47 infants, 21 were treated with a total of 62 allogeneic and 4 autologous RBC transfusions. Most infants with a body weight over 1400 g did not need any RBC transfusion.

CONCLUSION

The preparation of autologous RBCs from the CB of preterm infants is technically possible in principle. However, major concerns must be raised as to whether such preparations are of benefit in ensuring safe care of neonates with blood components, with respect to the high rate of bacterial contamination and the limited availability in babies with low birth weight.

Acholeplasma vituli sp. nov., from bovine serum and cell cultures

Organisms isolated from commercial foetal bovine serum and from cell culture lines containing such serum supplements were found to consist of non-helical, non-motile, pleomorphic coccoid forms. One strain (FC 097-2T) cultivated directly from foetal bovine serum was selected for characterization. In ultrastructural examination, individual round cells lacked cell wall structures and cells varied in size, with a mean diameter of about 700 nm. However, variable numbers of cells were filterable through membranes of 300 nm. Optimum growth occurred between 30 and 37 degrees C. The organism fermented glucose, fructose and mannose, but did not hydrolyse arginine. The strain was insensitive to 500 U penicillin ml(-1) and was capable of growing in the absence of serum or cholesterol. The organism was serologically distinct from all 13 currently described species in the genus Acholeplasma and from other sterol-requiring species in the genus Mycoplasma, using growth inhibition, immunoperoxidase and immunofluorescence tests. Strain FC 097-2T was found to have a DNA G+C composition between 37.6 +/- 1 mol% and 38.3 +/- 1 mol%. The genome size was determined to be 2095 kbp. The 16S rDNA sequence of strain FC 097-2T was compared to 16S rDNA sequences of other mollicutes in nucleotide databases. No deposited sequence was found to be identical; the closest relatives were several members of the genus Acholeplasma. On the basis of these findings and other similarities to acholeplasmas in morphology and growth, the absence of a sterol requirement for growth, and similar genomic characteristics, the organism was assigned to the genus Acholeplasma. Strain FC 097-2T is designated the type strain (ATCC 700667T) of a new species, Acholeplasma vituli.

Development of a district Cord Blood Bank: a model for cord blood banking in the National Health Service

The Bristol Cord Blood Bank was established as a pilot project within existing health services to establish cost-effective recruitment, collection and processing suitable for use in the NHS should cord blood become a routine source of haemopoietic stem cells for transplantation in the UK. An important aim of the project was to evaluate the feasibility of establishing a midwifery-based collection network, thus utilising expertise already in place. Collection was performed on the delivery suite immediately after the placenta was delivered. The clinical experience of the midwife collector/counsellors allowed rapid pre-collection assessment of the condition of the cord and placenta. This prevented collection attempts from diseased or otherwise damaged placentas, leading to conservation of resources by preventing collection of most small volume donations. The bank was established within the National Blood Service, Bristol Centre to achieve Good Manufacturing Practice standards and ensure that processing was subject to the same stringency required for other sources of haemopoietic stem cells. Cord blood is an expensive resource. By utilising existing expertise in district Obstetric and National Blood Services, the Bristol Cord Blood Bank may serve as a model for health economic evaluation of cord blood banking of volunteer donations within the NHS.

Randomized placental and cord blood sampling culture in women with preterm and term labour to detect infection

Placental tissue and cord blood from women with preterm and term labour were examined for microorganisms and compared in this randomized prospective study. Of 100 women who delivered during a 12-month period, 50 had preterm labour and 50 had term labour. Samples were taken under sterile conditions for routine culture of anaerobic and aerobic bacteria immediately after delivery of the placenta. Fetal blood cultures were positive for 30% of the preterm group and 18% of the term group, which was statistically significant. Placental tissue cultures were positive for 58% of the preterm group and 28% of the term group. These data support previous reports that infection plays a significant role in preterm labour.