Prolonged progesterone administration is associated with less frequent cervicovaginal colonization by Ureaplasma urealyticum during pregnancy - Results of a pilot study.

BACKGROUND: Preterm birth is a leading cause of perinatal mortality and morbidity. Heavy cervicovaginal Ureaplasma colonization is thought to play a role in the pathogenesis of preterm birth. The administration of vaginal progesterone has been shown to reduce the incidence of preterm birth in women with short cervical length. Steroid hormones seem to modulate the presence of microorganisms in the vagina. The aim of this study was to assess whether the treatment with vaginal progesterone could reduce the incidence of preterm birth and cervicovaginal colonization by Ureaplasma urealyticum in a cohort of pregnant women with threatened preterm labor. METHODS: A cohort of 63 females who presented with regular contractions and/or short cervical length between 24-32 weeks of gestation were recruited into a prospective study. 70% of patients had been treated with vaginal progesterone prior to recruitment and these patients continued with the treatment until birth. All patients were tested for the presence of cervicovaginal Ureaplasma urealyticum colonization at admission. The primary endpoint was preterm birth before 37 weeks. RESULTS: The incidence of preterm delivery was significantly increased in patients who tested positive for Ureaplasma urealyticum. Prolonged vaginal progesterone administration was associated with less frequent cervicovaginal colonization by U. urealyticum. Cervicovaginal colonization by U. urealyticum and absence of progesterone treatment were identified as two independent risk factors for preterm delivery. CONCLUSIONS: Our results demonstrate the beneficial effects of progesterone administration in reducing the incidence of cervicovaginal colonization by Ureaplasma urealyticum.

Effects of Ureaplasma urealyticum lipid-associated membrane proteins on rheumatoid arthritis synovial fibroblasts.

OBJECTIVES: As an infectious agent might play a role in rheumatoid arthritis (RA) development, this study investigated effects of Ureaplasma urealyticum lipid-associated membrane proteins (UuLAMPs) on RA synovial fibroblast (RASF) proliferation, and tumour necrosis factor (TNF)-α and interleukin (IL)-1ß production by THP-1 macrophages. Possible immunogenic proteins in UuLAMPs were identified. METHODS: RASFs were cultured from synovial tissue from donors with RA. Serum samples from donors with/without RA and with/without U. urealyticum infection were used for immunogenicity analyses. THP-1 macrophages served as a model for synovial macrophages. TNF-α and IL-1ß mRNA levels were assessed using reverse transcription-polymerase chain reaction; protein levels were estimated using enzyme-linked immunosorbent assay. UuLAMPs underwent separation and Western blot analyses. RESULTS: UuLAMPs (0.025-0.4 µg/ml) stimulated RASF proliferation in a dose- and time-dependent manner, and increased TNF-α and IL-1ß levels in THP-1 macrophages. Several immunogenic UuLAMPs were identified, but antibodies to a 25 kDa protein were only found in RA patients with U. urealyticum infection. CONCLUSIONS: UuLAMPs might induce RASF proliferation and proinflammatory cytokine secretion in synovium from RA patients. A 25 kDa U. urealyticum protein might act as a cross-reactive antigen.

Difficulties experienced in defining the microbial cause of pelvic inflammatory disease.

Clinical assessment of women with pelvic pain was a poor indicator of disease seen at laparoscopy. Thus, of 109 women, 22 at laparoscopy had salpingitis, 19 had adhesions without salpingitis, 20 had endometriosis or ovarian pathology and 48 no observable abnormality. In all laparoscopic categories, Ureaplasma spp. and Mycoplasma hominis, but not Mycoplasma genitalium, were at least as common in the cervix/vagina as Chlamydia trachomatis and equally frequent in the endometrium. However, C. trachomatis had the greatest propensity for spread to the Fallopian tubes. Thus, of 28 women who had C. trachomatis organisms in the vagina/cervix, 13 had them in a Fallopian tube (ratio 2.2:1); the ratio was 6:1 for Neisseria gonorrhoeae, 8:1 for M. genitalium, 21:1 for M. hominis and 31:1 for Ureaplasma spp. M. hominis organisms in a large number were detected most often in women with salpingitis. The likelihood of spread of Ureaplasma urealyticum and U. parvum from the lower to the upper genital tract was about the same and they were detected only once each in a tube, which was not inflamed in either case. Multiple bacteria were often detected at a single site, making it difficult to establish the exact cause of disease. However N. gonorrhoeae was considered to be the sole cause of salpingitis in one woman and the primary or equal primary contributor in four others; C. trachomatis was involved in at least 11 women, mostly as the sole cause or as the primary contributor; M. genitalium was considered the cause in one woman and had possible involvement in three others; and M. hominis was a questionable sole cause in one woman and the primary or equal primary contributor in three. Serologically, C. trachomatis was related to adhesions, without salpingitis, more often (63%) than any other micro-organism. M. genitalium may have been implicated in one case. Serologically, a previous C. trachomatis infection was indicated in 40% of women without an observable laparoscopic abnormality. C. trachomatis in the endometrium and tubes of women without any laparoscopic abnormality suggests subclinical disease, endometritis or endosalpingitis. There was evidence for a smaller proportion (19%) of women without an abnormality having been infected previously with M. genitalium. To some extent this is consistent with the infrequency of acute M. genitalium infections in this cohort of women.

A quantitative analysis of Ureaplasma urealyticum and Ureaplasma parvum compared with host immune response in preterm neonates at risk of developing bronchopulmonary dysplasia.

Multiplex, real-time PCR for the identification of Ureaplasma urealyticum and Ureaplasma parvum was performed on nucleic acids extracted from sequential endotracheal aspirates obtained from preterm neonates born at <29 weeks of gestation and ventilated for more than 48 h admitted to two level 3 neonatal intensive care units. Specimens were obtained shortly after birth and sequentially up until extubation. One hundred fifty-two specimens (93.8%) contained material suitable for analysis. Ureaplasma spp. were identified in 5 of 13 neonates studied. In most cases, the DNA load of the detected Ureaplasma species was low and decreased over time. In addition, changes in detectable Ureaplasma species DNA did not relate to changes in the inflammatory marker C-reactive protein (CRP) or respiratory status. All but two blood samples obtained at times of suspected sepsis were culture positive for other microorganisms; the species cultured were typically coagulase-negative staphylococci and were associated with increased levels of CRP (>10 mg/liter). This study was limited by the small number of patients examined and does not have the power to support or contradict the hypothesis that postnatal lung infection with Ureaplasma parvum is causally related to bronchopulmonary dysplasia (BPD) or adverse respiratory outcomes after preterm birth. However, in this study, increases in CRP levels were not associated with patients in whom Ureaplasma parvum was detected, in contrast to the detection of other bacterial species.

Serum antibodies against genitourinary infectious agents in prostate cancer and benign prostate hyperplasia patients: a case-control study.

BACKGROUND: Infection plays a role in the pathogenesis of many human malignancies. Whether prostate cancer (PCa) - an important health issue in the aging male population in the Western world - belongs to these conditions has been a matter of research since the 1970 s. Persistent serum antibodies are a proof of present or past infection. The aim of this study was to compare serum antibodies against genitourinary infectious agents between PCa patients and controls with benign prostate hyperplasia (BPH). We hypothesized that elevated serum antibody levels or higher seroprevalence in PCa patients would suggest an association of genitourinary infection in patient history and elevated PCa risk. METHODS: A total of 434 males who had undergone open prostate surgery in a single institution were included in the study: 329 PCa patients and 105 controls with BPH. The subjects' serum samples were analysed by means of enzyme-linked immunosorbent assay, complement fixation test and indirect immunofluorescence for the presence of antibodies against common genitourinary infectious agents: human papillomavirus (HPV) 6, 11, 16, 18, 31 and 33, herpes simplex virus (HSV) 1 and 2, human cytomegalovirus (CMV), Chlamydia trachomatis, Mycoplasma hominis, Ureaplasma urealyticum, Neisseria gonorrhoeae and Treponema pallidum. Antibody seroprevalence and mean serum antibody levels were compared between cases and controls. Tumour grade and stage were correlated with serological findings. RESULTS: PCa patients were more likely to harbour antibodies against Ureaplasma urealyticum (odds ratio (OR) 2.06; 95% confidence interval (CI) 1.08-4.28). Men with BPH were more often seropositive for HPV 18 and Chlamydia trachomatis (OR 0.23; 95% CI 0.09-0.61 and OR 0.45; 95% CI 0.21-0.99, respectively) and had higher mean serum CMV antibody levels than PCa patients (p = 0.0004). Among PCa patients, antibodies against HPV 6 were associated with a higher Gleason score (p = 0.0305). CONCLUSIONS: Antibody seropositivity against the analyzed pathogens with the exception of Ureaplasma does not seem to be a risk factor for PCa pathogenesis. The presence or higher levels of serum antibodies against the genitourinary pathogens studied were not consistently associated with PCa. Serostatus was not a predictor of disease stage in the studied population.

Cytokine production by peripheral blood mononuclear cells of women with a history of preterm birth.

Preterm birth is associated with elevated production of pro-inflammatory cytokines such as TNFalpha at the maternal-fetal interface. Previous studies have suggested that women with a history of preterm birth produce aberrantly strong inflammatory responses to bacterial lipopolysaccharide (LPS). However many intrauterine infections in women are associated with pathogens including Ureaplasma urealyticum, Mycoplasma hominis and Streptococcus agalactiae (group B streptococcus) that contain pro-inflammatory factors other than LPS. We evaluated whether peripheral blood leukocytes from women with a history of preterm birth produce elevated amounts of TNFalpha upon stimulation with pathogens associated with preterm birth and if pre-treatment with aspirin, an anti-inflammatory medication, decreases the ex vivo production of this cytokine. Heat-killed bacteria elicited increased TNFalpha production from leukocytes in a dose-dependent manner, but no differences in TNFalpha production between leukocytes from women with preterm birth and control women with term birth were detected. In women who consumed aspirin each day for one week, TNFalpha production was increased in leukocytes from control women stimulated with Escherichia coli and U. urealyticum, but was reduced or unchanged in leukocytes from women with preterm birth. Similar trends were observed for a subset of samples stimulated with U. urealyticum and assayed for IL-6, IL-10, IL-1beta and TNFalpha by bead array. We conclude that leukocytes from women with a history of preterm birth do not have elevated pro-inflammatory responses to pathogens, and that reproductive history is associated with different effects of aspirin on pro-inflammatory cytokine production.

Local inflammatory response in choriodecidua induced by Ureaplasma urealyticum.

Ureaplasma urealyticum is the bacterial species most often connected with preterm birth, although it often colonises the amniotic fluid without any adverse effects. The induction of preterm labour seems to depend on whether the bacteria produce an inflammatory reaction. In vitro stimulation of choriodecidual tissue with high amounts of U. urealyticum or with lipopolysaccharide induced a qualitatively similar inflammatory response detected by the production of tumour necrosis factor alpha, followed by secretion of anti-inflammatory cytokine interleukin-10 and of prostaglandin E2. Lower quantities of bacteria failed to induce any response.

[Immunoregulation of vasoactive intestinal peptide on rat Leydig cells].

AIM: To study the regulation of immune function of rat Leydig cells by vasoactive intestinal peptide (VIP). METHODS: Rat Leydig cells were seperated and infected by UU, with or without the incubation with VIP. The expression of FasL on Leydig cells in different group was analysed by flow cytometry(FCM). The mRNA expression of IL-1, IL-6, TGF-beta and FasL of Leydig cells in different group was identified by RT-PCR. SD rats were infected by UU with or without the injection of VIP, and the testis tissnes of each group were har vested and observed under transmission electron microscope. RESULTS: When testis was infected by UU, VIP up-regulated the mRNA expression of IL-1, IL-6, and TGF-beta, and down-regulated the expression of FasL in vitro. In addition, there was significant difference in testis morphous of rats from different group. CONCLUSION: VIP could regulate the expression pattern of IL-1, IL-6, TGF-beta and FasL by Leydig cells, which may contribute to maintain immune privilege of the testis. VIP could regulate rat Leydig cell immune function.

Characterization of the macrophage-stimulating activity from Ureaplasma urealyticum.

PROBLEM: Intra-amniotic infection is the most common cause of preterm labor. Infections are thought to cause preterm labor by increasing the production of proinflammatory cytokines at the maternal-fetal interface. Experiments with cell culture and animal models have indicated that bacterial lipopolysaccharide (LPS) increases the production of proinflammatory cytokines in reproductive tissues. The majority of intrauterine infections, however, are associated with Ureaplasma urealyticum, which does not contain LPS. Therefore, we performed a series of experiments to understand better the bacterial factor(s) that are responsible for the proinflammatory effects of U. urealyticum. METHOD OF STUDY: U. urealyticum was cultivated in 3-4 L 10B broth, harvested by centrifugation, washed with saline and frozen at -85 degrees C until use. Cells were then extracted with Triton X-114 and the macrophage-stimulating activity (MSA) of the preparations was studied by evaluating their ability to stimulate tumor necrosis factor-alpha production by a monocytic cell line (THP-1 cells). Additional studies involved testing the sensitivity of the detergent extracts to heating, alkaline hydrolysis and proteinase K digestion. Interaction of Triton X-114 extracts with Toll-like receptor (TLR)-2 and TLR-4 was evaluated using cell lines transfected with one of these receptors, CD14 and a reporter gene. RESULTS: Extraction of U. urealyticum with Triton X-114 demonstrated that the MSA preferentially partitioned to the detergent phase. The MSA of the detergent extracts was abrogated by proteinase K digestion or alkaline hydrolysis but only partially inhibited by heating. Further studies suggested that the detergent extracts could activate both TLR-2 and TLR-4. CONCLUSION: These experiments suggest that the MSA of U. urealyticum is lipophilic, sensitive to alkaline hydrolysis and proteinase K digestion, partially sensitive to heating. These properties are consistent with the activity being due to a lipoprotein. Unlike other Mycoplasma species, the MSA of U. urealyticum appears to interact with both TLR-2 and TLR-4. Purification of the molecule(s) that regulate this activity may provide good therapeutic targets for anti-inflammatory strategies to prevent preterm labor caused by intrauterine infection with U. urealyticum.

Screening of an antigen target for immunocontraceptives from cross-reactive antigens between human sperm and Ureaplasma urealyticum.

Epidemiologic studies indicated that some infertile men who were infected with Ureaplasma urealyticum displayed positive antisperm antibodies in their serum and/or semen. The purpose of this study was to investigate the possible mechanism of antisperm antibodies production after infection with U. urealyticum and to analyze the relationship between U. urealyticum and infertility. The existence of cross-reactive antigens (61, 50, and 25 kDa) between U. urealyticum and human sperm membrane proteins was confirmed. Among the cross-reactive antigens, the urease complex component UreG of U. urealyticum was determined. By searching the Swiss-Prot protein database, a pentapeptide identity (IERLT) between UreG and human nuclear autoantigenic sperm protein (NASP) was found. Furthermore, using Western blot analysis and enzyme-linked immunosorbent assay, the cross-reaction between the NASP and UreG was verified. Both anti-rUreG antibody and the antiserum against the synthetic peptide NASP393-408 containing the pentapeptide inhibited mouse sperm egg binding and fusion. After immunization by rUreG or the synthetic peptide, 81.2 and 75% female mice became sterile, respectively. The effect on fertility in mice immunized with the synthetic peptide was reversible. These findings proved for the first time that it was feasible to screen antigens for immunocontraceptives from cross-reactive antigens between sperm and microorganisms which induce infertility.

[Frequency of different infectious agents persistence in mononuclear leukocytes of blood and synovial fluid in patients with rheumatoid arthritis].

The study of persistence in mononuclear leukocytes (ML) of blood and synovial fluid of 218 patients with rheumatoid arthritis (RA) Cytornegalovirus (CMV), the 1-st and 2-nd types of Herpes virus simplex (VH), Epstain-Barr virus (VEB), Mycoplasma arthritidis (Ma), Mycoplasma fermentans (Mf), Ureaplasma urealiticum (U), Chlamidia trachomatis (Ct), viruses of Hepatitis B and C was carry out by direct and indirect immunofruorescence, immunoenzymatic analysis and polymerase chain reaction. An increased frequency of contamination of blood ML with infectious agents in patients with RA was established (57,4% compared with 16,7% in control group). The following infectious agents were revieled more frequently: in ML of blood and synovial fluid the Ma (relatively 20,5% and 15,9%), Mf (15,6% and 13,2%), Ct (18,4% and 13,2%), VH (27,1% and 10,5%), VEB (12,7% and 5,3%) and CMV (11,2% and 7,9%). Types of frequency dynamics of ML contamination with these infectious agents in different time phases of RA were determined.

Biovar diversity of Ureaplasma urealyticum in amniotic fluid: distribution, intrauterine inflammatory response and pregnancy outcomes.

OBJECTIVE: The objective of this study was to determine the distribution of two biovars of Ureaplasma urealyticum (parvo and T960) in human amniotic fluid and to examine whether the magnitude of the intrauterine inflammatory response and pregnancy outcomes are different between patients with microbial invasion of the amniotic cavity with "parvo biovar" and those with "T960 biovar". STUDY DESIGN: This cohort included 77 preterm singleton pregnancies (gestational age < 37 weeks) in whom U. urealyticum was detected from amniotic fluid using the polymerase chain reaction (PCR). Amniotic fluid was obtained by transabdominal amniocentesis. Amniotic fluid was cultured for aerobic and anaerobic bacteria as well as mycoplasmas. U. urealyticum was biotyped by PCR methods. Amniotic fluid inflammatory response was determined by amniotic fluid white blood cell count and interleukin-6 concentration. RESULTS: 1) The "parvo biovar" was detected in 82% (63/77) and "T960 biovar" was in 18% (14/77) of cases; 2) U. urealyticum was isolated by conventional culture method from amniotic fluid in 56% (35/63) of cases with positive for "parvo biovar" and in 50% (7/14) of cases with positive for "T960 biovar"; 3) There were no significant differences in the median gestational age at amniocentesis, gestational age at delivery, birth weight, amniotic fluid white blood cell count, amniotic fluid interleukin-6 concentration and the rates of clinical chorioamnionitis, histologic chorioamnionitis, funisitis and neonatal morbidity between patients in the two biovar groups. CONCLUSIONS: 1) The "parvo biovar" is more frequently isolated from amniotic fluid of preterm gestations than the "T960 biovar"; 2) Biovar diversity of U. urealyticum in amniotic fluid was not associated with different pregnancy outcome and magnitude of the intraamniotic inflammatory response.

Ureaplasma urealyticum induces apoptosis in human lung epithelial cells and macrophages.

Chronic lung disease (CLD) of prematurity remains a significant cause of morbidity among premature infants. It is a multifactorial disorder and characterized by an early increased number of neutrophils and alveolar macrophages, with later architectural epithelial and endothelial cell damage. Recently, apoptosis of type 2 pneumocytes in the lung of preterm neonates with acute and chronic lung disease has been examined and apoptosis of mesenchymal cells was detected in the chronic stage of bronchopulmonary dysplasia. Infection and inflammatory responses in the lungs play important roles. However, the contribution of Ureaplasma urealyticum to the development of CLD is debated. We found that U. urealyticum induced apoptosis in human type II lung epithelial cells (A549 cell line) and macrophages (derived from human monocytic cell line THP-1) by measuring the outer leaflets translocation of phosphatidylserine (flow cytometry analysis and fluorescence microscopy assessment), DNA fragmentation analysis, cell morphology changes such as diminution in cell volume, increased cytoplasmic staining, and nuclear pyknosis (hematoxylin and eosin staining) and viable counting (trypan blue exclusion). Anti-TNF-alpha monoclonal antibody partially protected the macrophages from undergoing apoptosis after infection with U. urealyticum. Our findings imply that U. urealyticum might be involved in impairing lung structure and host immune response during the development of CLD.

Characterization of a murine model of Ureaplasma urealyticum pneumonia.

Ureaplasma urealyticum respiratory tract colonization in preterm infants has been associated with a high incidence of pneumonia and the development of bronchopulmonary dysplasia. However, study of this human pathogen has been hampered by the absence of animal models. We have developed the first juvenile mouse model of Ureaplasma pneumonia and characterized the histopathology during the month following inoculation. C3H/HeN mice were inoculated intratracheally with a mouse-adapted clinical Ureaplasma isolate (biovar 2) or sham inoculated with 10B broth. Culture of lung homogenates and PCR of DNA from bronchoalveolar lavage fluid (BAL) confirmed the presence of Ureaplasma in 100% of inoculated animals at 1 day, 60% at 2 days, 50% at 3 days, and 25% at 7 and 14 days. Ureaplasma was undetectable 28 days postinoculation. There were marked changes in BAL and interstitial-cell composition with increased number of polymorphonuclear leukocytes 1 to 2 days and 14 days postinoculation and macrophages at 2 and 14 days postinoculation. The Ureaplasma infection caused a persistent focal loss of airway ciliated epithelium and a mild increase in interstitial cellularity. There were no differences in BAL protein concentration during the first 28 days, suggesting that pulmonary vascular endothelial barrier integrity remained intact. Comparison of BAL cytokine and chemokine concentrations revealed low levels of tumor necrosis factor alpha (TNF-alpha) at 3 days and monocyte chemoattractant protein 1 at 7 days in Ureaplasma-infected mice but a trend toward increased TNF-alpha at 14 days and increased granulocyte-macrophage colony-stimulating factor and interleukin-10 at 28 days. These data suggest that Ureaplasma alone may cause limited inflammation and minimal tissue injury in the early phase of infection but may promote a mild chronic inflammatory response in the later phase of infection (days 14 to 28), similar to the process that occurs in human newborns.

Induction of human macrophage vascular endothelial growth factor and intercellular adhesion molecule-1 by Ureaplasma urealyticum and downregulation by steroids.

Chronic lung disease (CLD) remains a major cause of morbidity for the prematurely born infant. The pathogenesis of CLD is complex and has not been defined entirely. Infection and lung inflammatory events have been thought to play a key role in the development of CLD. However, the contribution of Ureaplasma urealyticum to the development of CLD is debated and steroids produce some improvement in neonates with this disease. The aim of this study was to investigate if U. urealyticum could stimulate macrophages to produce vascular endothelial growth factor (VEGF) and intercellular adhesion molecule-1 (ICAM-1) in vitro, which are potentially associated with both early and later pathological changes in the lung during the development of CLD. In addition, the impact of dexamethasone and budesonide on these processes was examined. We found that U. urealyticum antigen (>/=4 x 10(7) color-changing units/ml) stimulated human macrophages (phorbol 12-myristate 13-acetate-differentiated THP-1 cell line) to produce VEGF and soluble ICAM-1 in a dose-dependent manner (p < 0.05) measured by ELISA. Likewise, cell surface ICAM-1 (CD54) measured by flow cytometry was increased after stimulation with U. urealyticum. This effect was attenuated by budesonide and dexamethasone (p < 0.05). The mRNA expressions of VEGF and ICAM-1 detected by a semi-quantitative reverse transcriptase polymerase chain reaction were also induced in response to U. urealyticum and inhibited by the steroids (p < 0.05). The expression of ICAM-1 was reduced by 85.5% when the TNF-alpha production was neutralized with an anti-TNF-alpha antibody. Our findings imply that U. urealyticum might be involved in the development of CLD of prematurity.

Inhibition of macrophage proinflammatory cytokine expression by steroids and recombinant IL-10.

Chronic lung disease (CLD) of prematurity is a prolonged respiratory failure in very-low-birth-weight neonates. Proinflammatory cytokines have been implicated in the development of CLD. Steroids have been shown to produce some improvement in neonates with this disease. The purpose of this study was to evaluate the downregulation of these proinflammatory cytokines by dexamethasone, budesonide and recombinant IL-10 (rIL-10) in order to elucidate the mechanism of the clinical benefit of steroids in babies. Our results showed that dexamethasone, budesonide and rIL-10 significantly inhibited both IL-6 and TNF-alpha production in the THP-1 cell line stimulated by lipopolysaccharide and Ureaplasma urealyticum antigen. Similar effects were found in macrophages from tracheobronchial aspirate fluid from newborn infants. In the rat alveolar macrophage cell line, steroids inhibited IL-6 and TNF-alpha production, while rat rIL-10 did not significantly decrease production. In conclusion, steroids and human rIL-10 were able to downregulate proinflammatory cytokine production, which may explain the beneficial effect of steroids and suggests that rIL-10 could be tried as an anti-inflammatory agent in neonates with a high risk of CLD.

Monocyte chemoattractant protein-1 and interleukin-8 are increased in bronchopulmonary dysplasia: relation to isolation of Ureaplasma urealyticum.

BACKGROUND: An exaggerated inflammatory response occurs in infants who subsequently develop bronchopulmonary dysplasia (BPD). Ureaplasma urealyticum (Uu) is frequently isolated from cultures of tracheal secretions obtained from very low birth weight infants and is associated with an increased risk of BPD. METHODS: We examined the relationships between isolation of genital mycoplasmas, tracheal aspirate (TA) interleukin-8 (IL-8), and monocyte chemoattractant protein-1 (MCP-1) concentrations and the development of BPD. Serial TAs were obtained prospectively from 35 very low birth weight infants, and IL-8 and MCP-1 concentrations were determined by enzyme-linked immunoadsorbent assay. Tracheal cultures for bacteria and genital mycoplasmas were performed on aspirates obtained during the first 2 days of life. RESULTS: Infants who developed BPD (n=18) were less mature (25.2+/-0.2 vs 27.8+/-0.5 weeks; P<0.001), of lower birth weight (746+/-28 vs 1052+/-41 g; P<0.001), and more likely to have a positive tracheal culture for Uu (39% vs 6%; P=0.026) than those who did not develop BPD (n=17). Tracheal concentrations of IL-8 and MCP-1 were significantly increased in infants who developed BPD (IL-8: P=0.0001; MCP-1: P<0.001, analysis of variance) and correlated with duration of mechanical ventilation and oxygen treatment. Uu-positive infants had an increased incidence of BPD (88% in infants with Uu vs 42% in infants without Uu; P=0.020) and had TA concentrations of IL-8 and MCP-1 that were significantly increased compared with those of Uu-negative infants. CONCLUSIONS: Increased TA concentrations of IL-8 and MCP-1 during the first 2 weeks of life are associated with the development of BPD. Recovery of Uu from TAs is associated with a more robust inflammatory reaction and an increased risk of BPD.

Ureaplasma urealyticum modulates endotoxin-induced cytokine release by human monocytes derived from preterm and term newborns and adults.

We previously observed that Ureaplasma urealyticum respiratory tract colonization in infants with a birth weight of < or =1,250 g was associated with increases in the tracheal aspirate proinflammatory cytokines tumor necrosis factor alpha (TNF-alpha) and interleukin-8 (IL-8) relative to the counterregulatory cytokine IL-6 during the first week of life (A. M. Patterson, V. Taciak, J. Lovchik, R. E. Fox, A. B. Campbell, and R. M. Viscardi, Pediatr. Infect. Dis. J. 17:321-328, 1998). We hypothesized that U. urealyticum alters the host immune response in the presence of a coinflammatory stimulus (e.g., bacterial infection or hyperoxia) by shifting the balance of cytokine expression towards the proinflammatory cytokines. To test this hypothesis, we compared the release of TNF-alpha, IL-8, IL-6, and IL-10 in vitro by unstimulated and U. urealyticum (with or without lipopolysaccharide [LPS])-stimulated human monocytes from adult peripheral blood and from term and preterm cord blood. U. urealyticum alone and in combination with LPS induced concentration- and development-dependent changes in cytokine release. In vitro inoculation with low-inoculum U. urealyticum (10(3) color-changing units [CCU]) (i) partially blocked the LPS-stimulated IL-6 release by all cells and reduced LPS-stimulated IL-10 release by preterm cells, (ii) stimulated TNF-alpha and IL-8 release by preterm cells, and (iii) augmented LPS-stimulated TNF-alpha release in all cells. In preterm cells, high-inoculum U. urealyticum (10(6) CCU) (i) stimulated TNF-alpha and IL-8, but not IL-6 or IL-10, release and (ii) augmented LPS-stimulated TNF-alpha and IL-8 release. High-inoculum U. urealyticum (i) stimulated release of all four cytokines in term cells and IL-8 release in adult cells and (ii) augmented LPS-induced TNF-alpha, IL-10, and IL-8 release in term cells but did not significantly affect LPS-induced cytokine release in adult cells. We speculate that U. urealyticum enhances the proinflammatory response to a second infection by blocking expression of counterregulatory cytokines (IL-6 and IL-10), predisposing the preterm infant to prolonged and dysregulated inflammation, lung injury, and impaired clearance of secondary infections.

Chronic lung disease of prematurity. The role of intra-uterine infection.

UNLABELLED: The clinical, radiological and pathological features of chronic lung disease have changed from those seen when the condition was first described. Most babies who now develop chronic lung disease have a birth weight below 1000 g and have only mild early respiratory disease, requiring minimal ventilation and low concentrations of inspired oxygen. The underlying pathophysiology of long-term lung damage appears to be a disturbance of the normal alveolar development which is continuing after birth, resulting in emphysematous like lungs with fewer and larger alveoli. Alveolarisation is affected by a number of insults including ventilation, oxygen, nutritional problems, steroids and both antenatal and post-natal infection. A final common pathway for many of these insults is persistence of an acute inflammatory response in the airways. There is good evidence that intra-uterine exposure to pro-inflammatory cytokines, as a consequence of ascending infection, induces both preterm labour and inflammation in the airways which triggers the lung injury sequence before birth. These cytokines have also been shown to have major effects on other organs in the body, in particular their association with brain damage and cerebral palsy. Treatment with antibiotics from birth has not been shown to affect the incidence or severity of chronic lung disease. CONCLUSION: Intra-uterine infection is not only a common cause of preterm onset of labour but also a trigger to lung injury which significantly increases the risk of development of long-term respiratory disease in the newborn infant.