Sex-Based Clinical Outcome in Advanced NSCLC Patients Undergoing PD-1/PD-L1 Inhibitor Therapy-A Retrospective Bi-Centric Cohort Study

Simple Summary

Retrospective analyses suggest that men treated with immune-checkpoint inhibitor (ICI) monotherapy for non-small cell lung cancer (NSCLC) have better outcomes than women. However, female patients have more favorable responses when chemotherapy (CHT) is given together with ICI. We aimed to explore the clinical impact of such sex differences in two cohorts, receiving ICI monotherapy or ICI-CHT combination, respectively. We found no significant difference in outcomes between men and women treated with either therapeutic regimen. However, known predictive factors for ICI response such as the expression of programmed-death ligand 1 (PD-L1) on tumor cells or patient performance status had significant implications for men rather than for women. Our results warrant increased research efforts to clarify sex-specific differences in anti-tumor immune response mechanisms and in the efficacy of ICI therapies, especially in women.

Abstract

Men with non-small cell lung cancer (NSCLC) have a more favorable response to immune-checkpoint inhibitor (ICI) monotherapy, while women especially benefit from ICI-chemotherapy (CHT) combinations. To elucidate such sex differences in clinical practice, we retrospectively analyzed two cohorts treated with either ICI monotherapy (n = 228) or ICI-CHT combination treatment (n = 80) for advanced NSCLC. Kaplan–Meier analyses were used to calculate progression-free (PFS) and overall survival (OS), influencing variables were evaluated using Cox-regression analyses. No significant sex differences for PFS/OS could be detected in either cohort. Men receiving ICI monotherapy had a statistically significant independent impact on PFS by Eastern Cooperative Oncology Group performance status (ECOG) ≥2 (hazard ratio (HR) 1.90, 95% confidence interval (CI): 1.10–3.29, p = 0.021), higher C-reactive protein (CRP; HR 1.06, 95%CI: 1.00–1.11, p = 0.037) and negative programmed death-ligand 1 (PD-L1) status (HR 2.04, 95%CI: 1.32–3.15, p = 0.001), and on OS by CRP (HR 1.09, 95%CI: 1.03–1.14, p = 0.002). In men on ICI-CHT combinations, multivariate analyses (MVA) revealed squamous histology (HR 4.00, 95%CI: 1.41–11.2, p = 0.009) significant for PFS; and ECOG ≥ 2 (HR 5.58, 95%CI: 1.88–16.5, p = 0.002) and CRP (HR 1.19, 95%CI: 1.06–1.32, p = 0.002) for OS. Among women undergoing ICI monotherapy, no variable proved significant for PFS, while ECOG ≥ 2 had a significant interaction with OS (HR 1.90, 95%CI 1.04–3.46, p = 0.037). Women treated with ICI-CHT had significant MVA findings for CRP with both PFS (HR 1.09, 95%CI: 1.02–1.16, p = 0.007) and OS (HR 1.11, 95%CI: 1.03–1.19, p = 0.004). Although men and women responded similarly to both ICI mono- and ICI-CHT treatment, predictors of response differed by sex.

Association between vitamin D, antimicrobial peptides and urinary tract infection in infants and young children

AIM

Vitamin D stimulates production of the endogenous antimicrobial peptides cathelicidin and β-defensin-2, which are expressed in the urinary tract. We investigated vitamin D status and levels of cathelicidin and β-defensin-2 and their association with urinary tract infection (UTI).

METHODS

The study included 120 children under three years of age: 76 children with UTIs and 44 otherwise healthy children with congenital hydronephrosis. Serum 25-hydroxycholecalciferol levels were measured by direct competitive electro-chemiluminescence immunoassay, and plasma cathelicidin and β-defensin-2 concentrations were analysed by enzyme-linked immunosorbent assay.

RESULTS

We found that vitamin D insufficiency and deficiency are prevalent in young children (21%). Serum vitamin D levels negatively correlated with age and were significantly lower in girls. Levels of vitamin D positively correlated with levels of cathelicidin but not with β-defensin-2. Low concentrations of vitamin D were associated with UTIs in girls, but we did not see any correlation with the recurrence of infection at one-year follow-up.

CONCLUSION

Vitamin D deficiency is common and may prove to be a risk factor for UTIs especially in girls. We hypothesise that adequate supplementation with vitamin D may become a way to prevent first-time UTIs.

Statins influence epithelial expression of the anti-microbial peptide LL-37/hCAP-18 independently of the mevalonate pathway

Anti-microbial resistance increases among bacterial pathogens and new therapeutic avenues needs to be explored. Boosting innate immune mechanisms could be one attractive alternative in the defence against infectious diseases. The cholesterol-lowering drugs, statins, have been demonstrated to also affect the immune system. Here we investigate the effect of statins on the expression of the human cathelicidin anti-microbial peptide (CAMP) LL-37/hCAP-18 [encoded by the CAMP gene] and explore the underlying mechanisms in four epithelial cell lines of different origin. Simvastatin induced CAMP expression in bladder epithelial cells telomerase-immortalized uroepithelial cells (TERT-NHUCs), intestinal cells HT-29 and keratinocytes HEKa, but not in airway epithelial cells A549. Gene induction in HEKa cells was reversible by mevalonate, while this effect was independent of the cholesterol biosynthesis pathway in TERT-NHUCs. Instead, inhibition of histone deacetylases by simvastatin seems to be involved. For HT-29 cells, both mechanisms may contribute. In addition, simvastatin increased transcription of the vitamin D-activating enzyme CYP27B1 which, in turn, may activate LL-37/hCAP-18 production. Taken together, simvastatin is able to promote the expression of LL-37/hCAP-18, but cell line-specific differences in efficacy and the involved signalling pathways exist.

The impact of vitamin D on the innate immune response to uropathogenic Escherichia coli during pregnancy

Urinary tract infections are highly common during pregnancy, and can cause serious complications for the mother and baby. Vitamin D, predominantly obtained from the sunlight, is known to have an effect on the urothelium, with immunomodulatory capacity against Escherichia coli infection. However, its influence at this site remains to be further explored. This study therefore investigated its impact during pregnancy in a population of women who have the possibility of adequate year-round sun exposure. Serum from pregnant Ugandan women (n = 32) in each trimester of pregnancy, from women after delivery (n = 29) and from never-pregnant controls (n = 25) was collected. 25-Hydroxyvitamin D (25-OHD), cathelicidin LL-37, human β-defensin 2, interleukin (IL)-8 and soluble CD14 serum concentrations were measured by chemiluminescence immunoassay or ELISA. The ability of serum to inhibit E. coli growth was tested. The immunomodulatory capacities of these serum samples and 1,25-dihydroxyvitamin D3 were investigated in urothelial cells. Increases in 25-OHD and LL-37 levels were observed as pregnancy progressed, peaking in the third trimester. Serum 25-OHD levels were higher in multigravidae than in primigravidae, and correlated positively with maternal age. IL-8 levels were lower in the third trimester than in the first trimester, increased after delivery, but remained below those of never-pregnant women. Similarly, soluble CD14 concentrations increased after delivery. As gestation advanced, serum had an increased capacity to inhibit E. coli growth. In vitro, it modulated the IL-8 response to infection in a vitamin D concentration-dependent manner. Our findings demonstrate that increasing vitamin D levels as pregnancy advances modulate the innate immune system towards a protective response to infection.

Markers of innate immune activity in patients with type 1 and type 2 diabetes mellitus and the effect of the anti-oxidant coenzyme Q10 on inflammatory activity

Major long-term complications in patients with diabetes are related to oxidative stress, caused by the hyperglycaemia characteristic for diabetes mellitus. The anti-oxidant coenzyme Q10 (CoQ10) has therefore been proposed as a beneficial supplement to diabetes treatment. Apart from its anti-oxidative function, CoQ10 appears to modulate immune functions by largely unknown mechanisms. The aim of this study was therefore to investigate the effect of CoQ10 on antimicrobial peptides and natural killer (NK) cells, both innate immune components implicated in the pathogenesis of diabetes and diabetes-associated long-term complications such as cardiovascular disease. We determined serum levels of antimicrobial peptides and the phenotype of NK cells isolated from peripheral blood of patients with type 1 (T1DM) or type 2 diabetes mellitus (T2DM) and from healthy controls. In addition, the same parameters were determined in diabetic patients after a 12-week period of CoQ10 supplementation. Two antimicrobial peptides, the human cathelicidin antimicrobial peptide (CAMP) and the human beta defensin 1 (hBD1), were reduced in serum from patients with T1DM. This defect was not reversible by CoQ10 supplementation. In contrast, CoQ10 reduced the levels of circulating hBD2 in these patients and induced changes in subset distribution and activation markers in peripheral NK cells. The results of the present study open up novel approaches in the prevention of long-term complications associated to T1DM, although further investigations are needed.

Serotyping of Proteus mirabilis clinical strains based on lipopolysaccharide O-polysaccharide and core oligosaccharide structures

The aim of this work was to serotype Proteus mirabilis urinary tract infection (UTI) strains based on chemically defined O-antigens with the use of two clinical collections from Sweden and Poland consisting of 99 and 24 UTI strains, respectively. A simple two-step serotyping scheme was proposed using enzyme immunoassay with heat-stable surface antigens of Proteus cells and immunoblotting with isolated lipopolysaccharides (LPSs). Using polyclonal anti-P. mirabilis rabbit antisera, 50 Swedish and 8 Polish strains were classified into serogroups O10, O38, O36, O30, O17, O23, O9, O40, O49, O27, O5, O13, O24, O14, and O33. From the Swedish strains, 10 belonged to serogroup O10 and five to each of serogroups O38, O36, and O9. Therefore, none of the O-serogroups was predominant. The majority of the serotyped clinical strains possess acidic O-antigens containing uronic acids and various acidic non-carbohydrate substituents. In immunoblotting, antisera cross-reacted with both O-antigen and core of LPSs. The core region of 19 LPSs bound a single serum, and that of 12 LPSs bound more than two sera. Following bioinformatic analysis of the available sequences, a molecular approach to the prediction of Proteus core oligosaccharide structures was proposed. The identification of the core type of P. mirabilis R110, derived from a serogroup O3 wild strain, using restriction fragments length polymorphism analysis of galacturonic acid transferase is shown as an example. In summary, the most frequent O-serogroups among P. mirabilis UTI stains were identified. The diversity of serological reactions of LPSs is useful for serotyping of P. mirabilis clinical isolates. A possible role of the acidic components of O-antigens in UTI is discussed.

Genetic relatedness and virulence gene profiles of Escherichia coli strains isolated from septicaemic and uroseptic patients

We investigated the relationship between clonality and virulence factors (VFs) of a collection of Escherichia coli strains isolated from septicaemic and uroseptic patients with respect to their origin of translocation. Forty septicaemic and 30 uroseptic strains of E. coli were tested for their phylogenetic groupings, genetic relatedness using randomly amplified polymorphic DNA (RAPD), biochemical fingerprinting method (biochemical phenotypes [BPTs]), adherence to HT-29 cells and the presence of 56 E. coli VF genes. Strains belonging to phylogenetic groups B2 and D constituted 93% of all strains. Fifty-four (77%) strains belonged to two major BPT/RAPD clusters (A and B), with cluster A carrying significantly (P = 0.0099) more uroseptic strains. The degree of adhesion to HT-29 cells of uroseptic strains was significantly (P = 0.0012) greater than that of septicaemic strains. Of the 56 VF genes tested, pap genes was the only group that were found significantly (P < 0.0001) more often among uroseptic isolates. Phylogenetic group B2 contained a significantly higher number of strains carrying pap genes than those in group D. We conclude that uroseptic E. coli are clonally different from septicaemic strains, carry more pap genes and predominantly adhere more to the HT-29 cell model of the gut.

[Study of medicine: "full" load as a parameter for the organization of a successful curriculum]

QUESTION

The licensing regulations for doctors (AAppO) allow medical faculties a wide range of possibilities in their implementation. Are there parameters which are easy to survey and which at the same time contribute to the speedy detection of possible undesirable developments?

METHOD

The results of a retrospective student evaluation of the preclinical period clearly revealed that there are extreme fluctuations in the "perceived" stress of students in Semester one to four. In succession, classes were restructured so that stress was as equally balanced as possible throughout the four semesters.

RESULTS

Over a period of half a decade, the "perceived" stress of students in the four semesters of the preclinical period was stabilised at an optimum level. At the same time, the students' satisfaction with organisation of curriculum increased and their exam results improved significantly.

CONCLUSIONS

The parameter "perceived" stress has been conducive to developing the curriculum to such an extent that teaching in Lübeck has improved considerably. Simultaneously, new space for development has been created for both students and lecturers, which makes it possible to shape the academic aspect of medical studies in a more challenging manner.

Virulence characteristics of Escherichia coli strains causing acute cystitis in young adults in Iran

BACKGROUND

Escherichia coli strains that cause cystitis posses virulence properties that facilitate their colonisation and persistence in the bladder. In Iran, despite the high number of the urinary tract infections, very few studies has been done to determine the role of these virulence properties in the pathogenesis of E. coli cyctitis.

PATIENTS AND METHODS

Eighty-seven strains of E. coli, isolated from young adults with cystitis in Shiraz, Iran, were examined for the expression of type 1 and P-fimbriae, mannose resistant haemagglutination, haemolysin production, aerobactin-mediated iron uptake, O:K serotypes, biochemical phenotypes (BPTs) and their antibiotic susceptibility patterns.

RESULTS

Seventy-six percent of the strains expressed multiple virulence properties. There was a significant correlation between the presence of aerobactin and the expression of type 1 fimbriae. All P-fimbriated strains produced aerobactin with 50% of them also coexpressing haemolysin. Of the 29 different O:K serotypes identified, 42% belonged to serotypes not commonly found among European serotypes associated with UTI. Strains of O groups 4 and 6 expressed more virulence factors than the others. A high resistance against ampicillin, trimethoprim and cotrimoxasol was observed among the isolates with 53% of the isolates showing multiresistance to these three antibiotics. Certain BPTs were also found among O:K serotypes with some containing strains of the same virulence profile.

CONCLUSION

We conclude that certain colonal groups of E. coli are commonly associated with cystitis in young adults in Iran with strains possessing a combination of aerobactin and type 1 fimbriae being the dominant ones and belonging to serotypes not commonly found in Europe. We also conclude that the multiple antibiotic resistant E. coli strains causing cyctitis are highly prevalent in this part of the country.

Enhanced chemokine response in experimental acute Escherichia coli pyelonephritis in IL-1beta-deficient mice

The aim of the present study was to investigate the effects of IL-1beta and Escherichia coli on the expression and secretion of MIP-2, the mouse equivalent to human IL-8, MCP-1 and RANTES in the kidneys of mice with acute pyelonephritis. Female Bki NMRI, as well as IL-1beta deficient mice and their wild-type littermates, were transurethrally infected with either E. coli CFT 073 or injected with NaCl 0.9% (w/v) and thereafter obstructed for 6 h. The Bki NMRI mice were killed at 0, 24, 48 h and 6 days and the IL-1beta-deficient mice at 48 h. Chemokine mRNA and protein levels peaked at 24 h for the tested chemokines with the mRNA expression localized in the tubular epithelial cells and for MIP-2 also in neutrophils. Obstruction per se, also induced a chemokine expression similar to E. coli infection although at a lower level. Interestingly, MIP-2 levels were higher in the IL-1beta deficient mice as compared with the wild-type littermates. Likewise, the inflammatory changes were more frequent and, when present, more widespread in the IL-1beta-deficient mice than in the wild-type mice. Stimulation of a human renal tubular epithelial cell line (HREC), A498 and of primary human mesangial cells (HMC) with the same bacterial antigen depicted gene expression of the same chemokines. A rapid release of IL-8 and MCP-1 was observed from both cell types. RANTES response was delayed both in the HREC and the HMC. We conclude that acute E. coli pyelonephritis induces a MIP-2/IL-8, MCP-1 and RANTES expression and secretion localized primarily to the epithelial cells and that this production is confirmed after in vitro stimulation with the same bacterial antigen of human epithelial and mesangial cells. Blockade of induction of chemokine response may thus be an attractive target for possible therapeutic intervention.

Increased expression of CD25 and HLA-DR on lymphocytes recruited into the peritoneal cavity in non-infected CAPD patients

The impact of uremia per se, peritoneal dialysis (PD) and hemodialysis (HD) treatment was evaluated on characteristics of lymphocytes. CD4, CD8, CD25 and HLA-DR were analyzed, with flow cytometry, in lymphocytes prepared from peripheral blood of uremic (n = 10) and hemodialysis patients (n = 10). Peritoneal dialysate was also obtained from patients on CAPD (n = 12). A decreased relative and absolute lymphocyte count was observed in peripheral blood from uremic, HD and CAPD patients compared to healthy controls (p < 0.03, p < 0.03 and p < 0.02, respectively). On the other hand, the relative distribution of lymphocytes was significantly higher in peritoneal dialysate compared to peripheral blood of CAPD patients (p < 0.02). Likewise, the absolute CD4 positive lymphocyte count was lower in the peripheral blood from uremic. HD and CAPD patients as compared to healthy controls (p < 0.001, respectively). In CAPD patients the relative distribution of CD4 positive cells (p < 0.001) was lower, while quantitative CD25 level (p < 0.01) and the relative count of HLA-DR (p < 0.0001) was increased in the peritoneal dialysate compared to blood. Taken together a selective activation of lymphocytes in peritoneal dialysate as compared to peripheral blood from uremic, HD and CAPD patients was observed. The altered biological function of the inflammatory cells may therefore explain the increased susceptibility to infectious diseases.

Antibodies against a truncated Staphylococcus aureus fibronectin-binding protein protect against dissemination of infection in the rat

Staphylococcus aureus bacteraemia (SAB) originating from local infections can lead to severe secondary infections such as endocarditis. The protective effect of antibodies against secondary infections was studied in a rat model, where a local joint infection leads to bacteraemia and endocarditis on damaged aortic valves. In this study, immunizations with a truncated D2-domain of the S. aureus fibronectin-binding protein displayed on a cow-pea mosaic virus (CPMV-D) carrier induced protection against endocarditis (P < 0.05). Opsonization of S. aureus with antibodies raised against CPMV-D stimulated both neutrophil activity and macrophage phagocytosis in vitro. Furthermore, intravenous administration of these antibodies protected mice from weight loss due to SAB.

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.

Escherichia coli-induced expression of IL-1 alpha, IL-1 beta, IL-6 and IL-8 in normal human renal tubular epithelial cells

The aim of the present study was to investigate whether the IL-1 family cytokines, in addition to IL-6 and IL-8, could be induced in normal human cortical epithelial cells in response to bacterial stimuli. Human renal tissue was obtained from 9 patients undergoing elective tumour nephrectomy. Renal cortical epithelial cells of tubular origin were prepared from the unaffected tissue. The proximal tubular cells were stimulated for 2, 6 and 24 h with a heat-inactivated pyelonephritogenic Escherichia coli strain DS-17. Cultured unstimulated tubular cells served as controls. IL-1 alpha, IL-1 beta, IL-1 receptor antagonist, IL-6, IL-8, IL-10, TNF-alpha, G-CSF and GM-CSF were analysed using immunohistochemistry at the single cell level. The nonstimulated cells were found to express low levels of IL-6 and IL-8 (mean value < 3% of total cells). In contrast, E. coli exposure resulted in significantly increased incidences of IL-6 and IL-8 expressing cells (mean values approximately 18% of total cells) peaking within two hours of stimulation (P < 0.008 and P < 0.02 versus non-stimulated cells, respectively). A gradual decrease was thereafter observed at 6 and 24 h, respectively, although persistently higher compared to controls. A different kinetic response was found for IL-1 alpha, IL-1 beta and IL-1 receptor antagonist-expressing cells, which peaked 24 h after E. coli stimulation (mean values 3--10%) (P < 0.008, P < 0.02, P < 0.02 versus non-stimulated cells, respectively). Low levels of TNF-alpha and GM-CSF were found in 3 of the 9 donated epithelial cells, peaking at 2 h, and IL-10 and G-CSF producing cells in 1 patient each. In conclusion we found that heat-inactivated pyelonephritic E. coli induced a proinflammatory cytokine response in the normal human proximal tubular cells including the IL-1 family, IL-6 and IL-8.

Meconium induces expression of inducible NO synthase and activation of NF-kappaB in rat alveolar macrophages

Meconium aspiration causes intensive inflammatory reactions in the lungs, and may lead to neonatal respiratory disorder. Infiltrated inflammatory cells, particularly macrophages, play an important role in such an inflammation. A rat alveolar macrophage cell line (ATCC8383) was exposed to meconium alone or in combination with dexamethasone, budesonide, or interferon-gamma. Nitric oxide (NO) accumulation in the supernatant of the cell culture was detected by Griess reaction, and mRNA of inducible NO synthase (iNOS) expression was detected by reverse transcriptase-PCR. Nuclear factor-kappa B was analyzed by electrophoretic mobility shift assay, and iNOS location and nuclear factor-kappa B transactivation were determined by immunostaining. Our results showed that meconium was capable of inducing production of NO and expression of iNOS in alveolar macrophages in a dose- (1-25 mg/mL, p < 0.05) and time- (4-48 h, p < 0.05) dependent manner. This capability of meconium could be further enhanced in the presence of interferon-gamma (100 IU/mL, p < 0.05). Budesonide (10(-4)-10(-10) M) or dexamethasone (10(-4)-10(-6) M) effectively inhibited the meconium-induced NO production (p < 0.05). Using the protein synthesis inhibitor cycloheximide, we demonstrated that meconium directly induced iNOS in macrophages. Furthermore, meconium also triggered nuclear factor-kappa B activation, a mechanism possibly responsible for the iNOS expression. Our findings suggest that meconium is a potent inflammatory stimulus, resulting in iNOS expression, leading to overproduction of NO from the macrophages, which may be of pathogenic importance in meconium aspiration syndrome. In vitro steroids down-regulated the iNOS expression, thus suggesting a potential to down-regulate NO-mediated inflammation in neonates with meconium aspiration syndrome.

Tetanus antibody levels of female volunteers after injection with solvent/detergent-treated human tetanus immunoglobulin (Tetabulin S/D)

BACKGROUND AND OBJECTIVES

The aim of this study was to analyse the increase of antitetanus titre in volunteers following injection with human tetanus immunoglobulin (HTI).

MATERIALS AND METHODS

Twelve females with tetanus antibody titres of < or = 0.05 international units (IU)/ml were injected with 500 IU of human tetanus immunoglobulin (Tetabulin S/D). The tetanus antibody titres were determined before injection, and after 30 h, 48 h and 4 days.

RESULTS

A fast and sustained increase of protective tetanus antibody levels was observed in 10 of 12 volunteers. No adverse events related to the study drug were reported.

CONCLUSIONS

HTI confers rapid and effective immunity to tetanus.

Activation of nuclear factor kappaB and induction of inducible nitric oxide synthase by Ureaplasma urealyticum in macrophages

Chronic lung disease (CLD) of prematurity is an inflammatory disease with a multifactorial etiology. The importance of Ureaplasma urealyticum in the development of CLD is debated, and steroids produce some improvement in neonates with this disease. In the present study, the capability of U. urealyticum to stimulate rat alveolar macrophages to produce nitric oxide (NO), express inducible nitric oxide synthase (iNOS), and activate nuclear factor kappaB (NF-kappaB) in vitro was characterized. The effect of NO on the growth of U. urealyticum was also investigated. In addition, the impact of dexamethasone and budesonide on these processes was examined. We found that U. urealyticum antigen (> or =4 x 10(7) color-changing units/ml) stimulated alveolar macrophages to produce NO in a dose- and time-dependent manner (P<0.05). This effect was further enhanced by gamma interferon (100 IU/ml; P<0.05) but was attenuated by budesonide and dexamethasone (10(-4) to 10(-6) M) (P<0.05). The mRNA and protein levels of iNOS were also induced in response to U. urealyticum and inhibited by steroids. U. urealyticum antigen triggered NF-kappaB activation, a possible mechanism for the induced iNOS expression, which also was inhibited by steroids. NO induced by U. urealyticum caused a sixfold reduction of its own growth after infection for 10 h. Our findings imply that U. urealyticum may be an important factor in the development of CLD. The host defense response against U. urealyticum infection may also be influenced by NO. The down-regulatory effect of steroids on NF-kappaB activation, iNOS expression, and NO production might partly explain the beneficial effect of steroids in neonates with CLD.

Downregulatory cytokines in tracheobronchial aspirate fluid from infants with chronic lung disease of prematurity

Chronic lung disease of prematurity (CLD) is associated with an inflammatory response in the preterm lung and increased levels of proinflammatory cytokines in tracheobronchial aspirate fluid (TAF). We investigated TAF levels of transforming growth factor-beta1 (TGF-beta1), interleukin-10 (IL-10), interleukin-4 (IL-4) and interleukin-12 (IL-12) cytokines possibly important in downregulating the proinflammatory response and/or inducing lung fibrosis in infants with developing and established CLD. Infants with CLD (n = 24) were compared with preterm infants with RDS that resolved (n = 22) and postoperative infants without lung disease (n = 23). TAF levels of TGF-beta1, IL-10, IL-4 and IL-12 were studied by quantitative enzyme immunoassay. Levels of TGF-beta1 were significantly higher during the first week of life in infants who developed CLD, remained high at 2 wk and past 4 wk of age. TAF levels of TGF-beta1 did not decrease significantly in six infants with CLD after treatment with steroids. TAF IL-10 was detected in 12/46 (26%) preterm infants. Infants with CLD or RDS were more likely to have measurable TAF levels of IL-10, compared with the postoperative infants without lung disease (p < 0.02 and 0.04, respectively). TAF levels of IL-4 or IL-12 were below the detection limits in all samples.

CONCLUSIONS

We have demonstrated a sustained increase of TGF-beta1 levels in TAF from preterm infants who develop CLD, suggesting an important role for TGF-beta1 in the fibrotic response in the CLD lung. The elevated TGF-beta1 levels, combined with an absent or irregular secretion of IL-4, IL-10 and IL-12, can have importance for the increased tendency for the development of CLD in preterm infants.

Renal cytokine responses in acute Escherichia coli pyelonephritis in IL-6-deficient mice

The aim of this study was to investigate the influence of IL-6 on mortality, bacterial growth and cytokine expression in experimental acute pyelonephritis. Female IL-6-deficient mice and their wild-type counterparts, 8-10 weeks old, were infected with Escherichia coli CFT 073 or injected with NaCl 0.9% (w/v) via the urethra and thereafter obstructed for 6 h. Animals were killed at 48 h, 6 days or 8 weeks and cytokine and bacterial renal levels were assessed at each time point. We found that IL-6-deficient mice had increased mortality and extensive renal bacterial growth on day 6, compared with wild-type mice (P < 0.05) and the histopathological changes were generally more severe and widespread in the IL-6-deficient mice. Peak mRNA expression of IL-1beta, IL-4, IL-10, IL-12 and interferon-gamma (IFN-gamma) occurred 48 h after infection in both IL-6 knock out and wild-type mice. Transforming growth factor-beta (TGF-beta) levels also peaked at 48 h in E. coli-infected wild-type mice, while in the IL-6-deficient strain both TGF-beta mRNA and protein levels were significantly lower at 48 h than wild-type levels (P < 0.0008 and P < 0.03, respectively) and remained stationary throughout the study period. Animals injected with NaCl 0.9% (w/v) displayed a similar decrease in TGF-beta expression (P < 0.02). When splenocytes from the IL-6-deficient mice were incubated with murine recombinant IL-6, TGF-beta levels increased to those of wild-type mice. No increase was observed when splenocytes from wild-type mice were incubated with the same doses of rIL-6. We therefore conclude that IL-6 plays an important role in bacterial clearance and directly influences the TGF-beta levels in experimental acute pyelonephritis. We also demonstrate that urethral obstruction per se induces an increase in TGF-beta the magnitude of which is decreased in IL-6-deficient mice.

Ureaplasma urealyticum-induced production of proinflammatory cytokines by macrophages

Ureaplasma urealyticum is relatively common in the respiratory tract of very low birth weight infants and has been hypothesized to be involved in the development of chronic lung disease. The purpose of this study was to investigate whether U. urealyticum could stimulate macrophages to produce proinflammatory cytokines in vitro, which are early pathologic changes in the lung during the development of chronic lung disease. A human monocytic cell line (THP-1) differentiated to macrophages, a rat alveolar macrophage cell line (Nr8383), and human lung macrophages from tracheobronchial aspirate fluid in preterm infants were exposed to U. urealyticum antigen for 24 h. The protein levels of human IL-6, tumor necrosis factor-alpha (TNF-alpha), and rat TNF-alpha were measured with ELISA. Rat IL-6 was analyzed with a specific bioassay. The mRNA levels of these cytokines were detected by reverse transcriptase-PCR. The production of TNF-alpha and IL-6 increased after stimulation with U. urealyticum in both the human and rat macrophage cell lines. In tracheobronchial aspirate fluid macrophages, U. urealyticum increased the production of TNF-alpha from 14 to 84% and IL-6 from 46 to 268% above control levels. U. urealyticum also induced gene expression of TNF-alpha and IL-6. In conclusion, U. urealyticum could be an important factor in the development of chronic lung disease because of its ability to induce alveolar macrophage proinflammatory cytokine production.

Angiotensin II type 1 receptor antagonist (losartan) down-regulates transforming growth factor-beta in experimental acute pyelonephritis

PURPOSE

To study the effect of an angiotensin II type 1 receptor antagonist, losartan, on cytokine expression, kidney growth and renal scarring in experimental acute pyelonephritis.

MATERIALS AND METHODS

Female Bki NMRI mice, 8 weeks old were infected with E. coli CFT 073 via the urethra. Mice were divided into four groups; either left untreated; or treated with NaCl 0.9%; or an angiotensin II type 1 receptor antagonist, losartan, in doses of 1 mg. or 40 mg. /kg. body weight. The treatment was given daily i.p. for 48 hours, 3 weeks or 8 weeks respectively. Kidneys were weighed and sectioned for histo-pathology and in situ hybridization for mRNA of IL-1beta, TNF-alpha, IL-4, IL-6, IL-10, IL-12, TGF-beta and IFN-gamma. Homogenized kidneys were used for EIA of TGF-beta and bacterial growth.

RESULTS

The mRNA expression of the studied cytokines generally peaked at 48 hours in all four groups. In animals treated with losartan, kidney TGF-beta, IFN-gamma and IL-6 decreased significantly at 3 and 8 weeks as compared with controls, untreated or those treated with NaCl, (p <0.005 respectively). Infection was associated with a declining kidney weight, also in the presence of losartan. A 50% reduction of the spread of renal scarring was observed in the losartan treated group, but this did however not reach significance. The proportion of kidneys showing bacterial growth was not influenced by losartan although in these kidneys the mean bacterial counts at 3 weeks were significantly higher in the losartan treated mice (p <0.006).

CONCLUSIONS

Losartan is associated with downregulation of TGF-beta, IFN-gamma and IL-6 and may, in combination with antimicrobial therapy, reduce the risk of cortical renal scarring in recurrent acute pyelonephritis in infants.

Human cervical ripening, an inflammatory process mediated by cytokines

An extensive remodelling process, referred to as cervical ripening, takes place in the cervical tissue during pregnancy and labour. It is recognized as softening and dilation of the cervical canal, and starts as a slow process during pregnancy, becoming rapid close to partum. In this study we focus on cytokines as possible mediators of this final remodelling. mRNA levels for interleukin (IL)-8, IL-6 and granulocyte colony-stimulating factor (G-CSF) were upregulated in the ripe postpartum cervical tissue (n = 8) compared to the unripe state (n = 9). Likewise, released cytokine concentrations increased from non-pregnant (n = 11) to the term-pregnant group (n = 13) with a further increase at partum (n = 16). IL-8 concentrations increased 4-fold from non-pregnant to term-pregnant (P<0.01), and a further 10-fold to postpartum state (P<0.0001). Concentrations of IL-6 and G-CSF were similarly increased. Specific IL-8 immunostaining was identified in the epithelia of pregnant cervical tissue (n = 7) and was most pronounced in the epithelia and stroma of postpartum tissue (n = 4). In conclusion, IL-8, IL-6 and G-CSF increase in the human cervix during the ripening process, indicating their important role in the cervical remodelling. These data demonstrate that cervical ripening is similar to an inflammatory process.

Expression of and cytokine activation by Escherichia coli curli fibers in human sepsis

Curli organelles are expressed by commensal Escherichia coli K12 and by Salmonella typhimurium at temperatures <37 degrees C, which bind serum proteins and activate the contact-phase system in vitro. This study demonstrates, by means of an anti-CsgA (curli major subunit) antibody, that a significant fraction of E. coli isolates (24 of 46) from human blood cultures produce curli at 37 degrees C in vitro. Serum samples from 12 convalescent patients with sepsis, but not serum from healthy controls, contained antibodies against CsgA (n=12). This study further demonstrates that a curli-expressing E. coli strain and a noncurliated mutant secreting soluble CsgA induce significantly (P<.05) higher levels of proinflammatory cytokines (tumor necrosis factor-alpha, interleukin [IL]-6, and IL-8) in human macrophages differentiated from THP-1 cells. These data, therefore, provide direct evidence that curli are expressed in vivo in human sepsis and suggest a possible role for curli and CsgA in the induction of proinflammatory cytokines during E. coli sepsis.

Soluble interleukin-1 receptor type II levels are elevated in cerebrospinal fluid in Alzheimer's disease patients

Evidence from epidemiological, clinical and experimental studies favour the hypothesis that inflammatory events are part of the neuropathology in Alzheimer's disease. Proinflammatory cytokines such as interleukin-1 (IL-1), interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha) have been found in activated microglia in the vicinity of amyloid plaques in Alzheimer's disease brain. In the present study, the levels of soluble IL-1 receptor type II (sIL-1R type II), IL-1 receptor antagonist (IL-1ra), IL-1beta, IL-6 and TNF-alpha were analyzed in cerebrospinal fluid (CSF) samples from Alzheimer's disease patients and control subjects. The levels of sIL-1R type II were significantly higher in CSF from Alzheimer's disease patients than in CSF samples from control subjects (38.5+/-8 pg/ml (mean+/-S.E.M.) vs. 7.9+/-4 pg/ml, p<0.05). Measurements of the proinflammatory cytokines IL-6 and TNF-alpha showed no significant difference between the two groups, and the levels of IL-1beta and IL-1ra in the present material were too low to permit detection. The increased levels of sIL-1R type II may reflect a compensatory mechanism to balance an increased release of IL-1 receptor agonists in the Alzheimer's disease brain.

Increased levels of transforming growth factor beta 1 and basic fibroblast growth factor in patients on CAPD: a study during non-infected steady state and peritonitis

Long-term influence of continuous ambulatory peritoneal dialysis (CAPD) on concentrations of transforming growth factor beta1 (TGF-beta1) and basic fibroblast growth factor (bFGF) in the peritoneal effluent, and the effect of peritonitis on these cytokines were investigated. TGF-beta1 and bFGF were assayed in effluent samples from dialysate bags collected during the initial week of treatment with CAPD and at 5 months. To determine the effect of peritonitis, dialysate bags were collected on admission to the hospital and on days 3 and 10 and also during non-infected steady state. Serum was drawn prior to infection and on days 1 and 10. TGF-beta1 increased more than threefold during the longitudinal follow-up period, median concentrations of 35 pg/ml to 106 pg/ml (P<0.05). No change in bFGF was seen during this initial 5 months. TGF-beta1 was increased on the first day of peritonitis (median concentration 169 pg/ml) and reached its maximum on day 3 of infection, (median concentration 216 pg/ml) (P<0.05 vs non-infected state, median concentration 39 pg/ml). Basic FGF reached a maximum on day three of infection (median concentration 7.7 pg/ml; P=0.01 vs non-infected state) and then slowly declined. In conclusion, TGF-beta1 is influenced by CAPD treatment per se, and together with bFGF is increased during peritonitis, indicating its importance in the peritoneum and its potential involvement in the development of tissue fibrosis and eventually ultrafiltration failure.

Soluble interleukin-6 receptor, interleukin-10 and granulocyte colony-stimulating factor in acute pyelonephritis: relationship to markers of bacterial virulence and renal function

BACKGROUND

Cytokines and cytokine receptors are involved in the systemic and local inflammatory response in patients with urinary tract infections.

METHODS

We examined urine and serum concentrations of soluble IL-6 receptor (sIL-6R), IL-10 and granulocyte colony-stimulating factor (G-CSF) in 29 women with acute pyelonephritis caused by Escherichia coli 2 weeks after the infection, during the subsequent episode of cystitis or asymptomatic bacteriuria and also later when the same patients were free from bacteriuria. Concentrations of sIL-6R, IL-10 and G-CSF were related to the expression of five virulence markers of E. coli and to glomerular filtration rate (GFR) after pyelonephritis.

RESULTS

On admission because of acute pyelonephritis the serum concentration of sIL-6R was similar to that of 12 healthy controls. Two weeks after the infection when all patients had received antibiotic treatment, the serum concentration of sIL-6R was significantly higher compared to that on admission (p < 0.001) and also higher compared to healthy controls (p = 0.001). Patients with increased concentrations of sIL-6R in serum 2 weeks after infection had significantly lower GFR at follow-up (p < 0.05). Patients with acute pyelonephritis had higher concentrations of G-CSF and IL-10 in serum compared to healthy subjects (p < 0.001 and p = 0.06, respectively). G-CSF in serum was higher in patients infected by E. coli producing cytotoxic necrotizing factor (p < 0.05). Patients infected by strains producing hemolysin had lower concentrations of sIL-6R (p < 0.001). Patients with detectable levels of the anti-inflammatory cytokine IL-10 in serum had significantly higher concentrations of IL-6 and the soluble tumor necrosis factor receptors I and II in serum as compared to patients in whom IL-10 was not detectable (p < 0.001, p = 0.001 and p < 0.05, respectively.

CONCLUSION

These investigations, together with our previous findings summarized in this paper, contribute to an increased understanding of the local and systemic inflammatory response arising in response to acute pyelonephritis.

Granulocyte stimulating factor in patients on peritoneal dialysis and LPS stimulated peripheral blood mononuclear cells

Dialysate and serum levels of granulocyte-colony stimulating factor (G-CSF), granulocyte macrophage colony stimulating factor (GM-CSF) and leukemia inhibitory factor (LIF) were analyzed in patients with continuous ambulatory peritoneal dialysis (CAPD). Samples from the peritoneal effluent and from serum were obtained during the first months of dialysis and during peritonitis from the first three dialysate bags drained on the day of admittance and form nightbags on days three and ten. Serum samples were drawn on days one and ten. On the first day of infection G-CSF was detected in twelve out of fifteen samples in the dialysate and reached its peak median level, 443 pg/ml, in the first drained bag and thereafter decreased significantly. Also in serum a peak, 190 pg/ml, was observed on the first day. LIF was found in six of ten analyzed dialysate samples, with a peak median level of 77 pg/ml on day one, while only four of ten patients had detectable GM-CSF. Peripheral blood mononuclear cells from non-infected CAPD patients were stimulated with lipopolysaccharide and G-CSF levels in the supernatants increased significantly (P < 0.05) after 6 h stimulation. We conclude that G-CSF is produced locally in the dialysate during the acute stage of peritonitis and to a lesser extent also systemically. These findings are in line with G-CSF production after LPS stimulation of peripheral blood mononuclear cells.

Difference in the blood monocyte phenotype between uremic patients and healthy controls: its relation to monocyte differentiation into macrophages in the peritoneal cavity

The phenotypic alterations between blood monocytes from 11 patients with end-stage renal disease, who had been on peritoneal dialysis for less than one week, and blood monocytes from 10 healthy controls, were analyzed. In addition, peritoneal macrophages in the dialysate effluent were enclosed. Analysis of functional receptor density was performed using immunostaining and flow cytometry. The phenotypic characterization was selected to represent various biological functions such as adhesion, phagocytosis (CD11b/CD18, CD11c/CD18, CD16), antigen-presentation (HLA-DR, ICAM-1), differentiation (transferrin receptor, CD71), receptor for LPS (CD14) and initiation of the coagulation cascade (Tissue factor, CD142). The proportion of CD16-positive blood monocytes and the quantitative level of ICAM-1 were higher in the patient group, compared to healthy controls. A significant increase in the quantitative level of CD11b/CD18, CD11c/CD18, HLA-DR and ICAM-1, transferrin receptor, CD14 and CD16, was found on peritoneal macrophages, compared to monocytes, harvested both from the corresponding patients, as well as from healthy donors. In contrast, we did not find any significant differences in the expression of tissue factor between monocytes and peritoneal macrophages. In conclusion, phenotypic differences exist between monocyte populations in the blood circulation of CAPD patients, and healthy individuals. We also show that transmigration of monocytes into the peritoneal cavity implies a selective up-regulation of functional receptors, preferentially related to adhesion, and antigen-presentation in a steady-state situation in non-infected CAPD patients.

Haemophilus influenzae and Streptococcus pyogenes group A challenge induce a Th1 type of cytokine response in cells obtained from tonsillar hypertrophy and recurrent tonsillitis

We have previously shown that tonsil tissue both from children with tonsillar hypertrophy and recurrent tonsillitis is colonized and invaded by Haemophilus influenzae and Streptococcus pyogenes group A. In order to evaluate if these bacteria are involved in the immunopathogenesis of these two conditions, tonsillar cells from both groups were stimulated in vitro with intact, heat-inactivated H. influenzae or S. pyogenes A. The immunoreactivity was evaluated by assessing the induction of cytokine production (IL-1 alpha, IL-1 beta, TNF-alpha, IL-6, IL-8, IL-2, IFN-gamma, IL-4, TNF-beta and IL-10), which was detected at the single-cell level. All cytokines studied except IL-4 were induced in both groups after stimulation with H. influenzae or S. pyogenes A. The dominating cytokines were IL-1 beta, IFN-gamma and TNF-beta. No major differences in the cytokine pattern or number of cytokine-producing cells were noticed between the two patient cohorts after H. influenzae stimulation. Activation by S. pyogenes A bacteria gave rise to higher frequencies of IFN-gamma- and TNF-beta-synthesizing cells in the recurrent tonsillitis group. The incidence of CD4-, CD8-positive T cells and CD40-positive B cells was comparable between the two groups while the MAC-387-positive macrophages were significantly higher in the recurrent tonsillitis groups. In conclusion, a Th1 type of cytokine response was found in both groups following stimulation with H. influenzae or S. pyogenes A.

Soluble receptors to tumour necrosis factor and interleukin-6 in urine during acute pyelonephritis

We compared the urinary concentrations of soluble TNF-I (sTNF-RI), TNF-II receptors, and soluble IL-6 receptor (sIL-6R) standardized to urinary creatinine concentrations, in children with acute pyelonephritis, in children with non-renal fever and in healthy controls. These levels were related to the acute inflammatory response in the kidneys and later renal scarring, as determined by acute and 1-y follow-up with 99mTC-dimercaptosuccinic acid scintigraphy (DMSA). The concentrations of the soluble receptors were measured using enzyme immunoassay (EIA). The urinary levels of sTNF-RI were significantly higher in children with acute pyelonephritis (median 1320 pg/mmol) than in children with non-renal fever, children 6 weeks after acute pyelonephritis and healthy controls (873, 251 and 477 pg/mumol, respectively). Median sTNF-RII urine levels were also higher in acute pyelonephritis (4123 pg/mumol) than in the three control groups (2000, 964 and 1850 pg/mumol, respectively). In contrast, the highest urinary sIL-6R concentrations were found in healthy children (median 420 pg/mumol), compared to those with acute pyelonephritis (235 pg/mumol), children with non-renal fever and children 6 weeks after pyelonephritis (137 and 50 pg/mumol, respectively). No significant difference was found in any of the urinary soluble receptor levels in children with or without DMSA uptake defects at the acute or the 1-y follow-up scintigraphy. In conclusion, although the urinary soluble TNF receptor levels were higher during acute pyelonephritis, this observation was not useful for deciding which children needed follow-up after acute pyelonephritis.

Early increase of TNF alpha and IL-6 in tracheobronchial aspirate fluid indicator of subsequent chronic lung disease in preterm infants

AIM

To investigate if early changes in concentrations of proinflammatory cytokines in tracheobronchial aspirate fluid (TAF) from preterm infants could be used to detect infants at risk of chronic lung disease (CLD) and help in the selection of patients for early steroid treatment.

METHODS

Twenty eight preterm infants less than 34 weeks of gestation (median 26 weeks) were intubated and daily measurements of TAF concentrations of tumour necrosis factor alpha (TNF alpha) and the interleukins IL-1 beta, IL-6, and IL-8 were made, using enzyme immunoassay techniques.

RESULTS

Seventeen of the infants developed CLD. The infants who developed CLD had significantly increased concentrations of TNF alpha, IL-1 beta, IL-6 on days 2 and 3. TNF alpha, IL-6, and IL-8 concentrations were significantly related to gestational age and duration of supplemental oxygen; TNF alpha, IL-6, and IL-8 concentrations also correlated with length of time on the ventilator.

CONCLUSION

These data indicate that tracheobronchial aspirate fluid cytokine concentrations may be used as a predictor of subsequent CLD and may help select a group of preterm infants at high risk of developing CLD for early treatment.

Cytokine gene expression during experimental Escherichia coli pyelonephritis in mice

PURPOSE

We studied nine inflammatory and immunoregulatory cytokines in acute pyelonephritis and urethral obstruction in mice to better understand the processes underlying kidney inflammation and scarring.

MATERIALS AND METHODS

Experimental acute pyelonephritis was established in Bki NMRI outbred mice by bladder inoculation of Escherichia coli, followed by 6 h urethral obstruction. The numbers of cytokine mRNA expressing cells for interleukin-1 (IL-1), IL-4, IL-6, IL-10, IL-12, tumor necrosis factor alpha (TNF-alpha), TNF-beta, transforming growth factor beta (TGF-beta) and interferon gamma (IFN-gamma) were determined in the kidneys and spleens from the infected, non-infected but obstructed and untouched mice using in situ hybridization with radio-labelled oligonucleotide probes at 12 h, 48 h and 6 d after release of the urethral obstruction.

RESULTS

Kidney cell expression of IL-1, IL-6 and TNF-alpha mRNA was observed already at 12 h and persisted on day 6 in the infected animals. A significant proinflammatory cytokine response occurred also in the non-infected obstructed animals, albeit later and at lower levels. A marked increase of IL-4, IL-10, TGF-beta and IFN-gamma mRNA producing cells was also found in the kidneys of these two groups again with higher levels in the infected animals. Very high numbers of splenocytes expressing mRNA for IL-1 were observed especially in the infected animals. A high proportion of splenocytes further expressed mRNA for IL-6, TNF-alpha, IL-4, IL-10, IFN-gamma and TGF-beta, again with highest numbers in the infected group of animals.

CONCLUSIONS

The present study extends previous knowledge about the local and systemic cytokine expression profiles during acute pyelonephritis and after urethral obstruction. Of particular interest was the marked kidney cell expression of mRNA for TGF-beta, presumed to be important both for obstructive and post-infectious renal scarring.

Interleukin-8 is a mediator of the final cervical ripening in humans

OBJECTIVE

The aim of the present study was to investigate the presence of interleukin-8 (IL-8) in the human cervix and whether the levels of interleukin-8 could be related to the ripening process during pregnancy.

STUDY DESIGN

Cervical biopsies were obtained in twelve term pregnant and in eight vaginally delivered women. Seven non-pregnant fertile women served as controls. After homogenisation and centrifugation, IL-8 levels were determined in the supernatant by an enzyme-immunoassay (EIA).

RESULTS

In women at term, the concentration of IL-8 increased six-fold from median 330 pg/ml to median 2190 pg/ml (P < 0.001). After the final cervical ripening it increased in additional 11-fold to median 26,100 pg/ml (P < 0.001). These changes are highly significant.

CONCLUSION

To our knowledge, this is the first time IL-8 has been identified in human cervix. Our results support the involvement of IL-8 in the connective tissue remodelling during the final cervical ripening just before onset of labour.

Interleukin-10, interferon gamma, interleukin-2, and soluble interleukin-2 receptor alpha detected during peritonitis in the dialysate and serum of patients on continuous ambulatory peritoneal dialysis

OBJECTIVE

To analyze interleukin (IL)-10, interferon gamma (IFN-gamma), IL-2, and soluble IL-2 receptor alpha (sIL-2R alpha) in the dialysate and serum of patients on continuous ambulatory peritoneal dialysis (CAPD).

DESIGN AND PATIENTS

Samples from dialysate bags were collected during the initial month of dialysis. During peritonitis, samples were collected from the first three bags on the day of admittance to the hospital and from the night bags on days 3 and 10. Serum samples were drawn on days 1 and 10.

RESULTS

IL-10 was detected in all dialysate samples except one on the first day of infection, with a peak median level of 50 pg/mL and a slow decrease thereafter. In serum the median levels never exceeded detectable levels. Patients infected with Escherichia coli or Staphylococcus aureus had higher IL-10 levels in dialysate on day 3 as compared to the remaining patients (p < 0.05). If the catheter had to be drawn, because of persistent cloudy dialysate, the IL-10 levels remained elevated for a longer time (p < 0.05). IFN-gamma and IL-2 were detected only in the dialysate of patients infected with either S. aureus or S. epidermidis. Only one serum sample showed increased IFN-gamma. SIL-2R alpha was found in all the serum and dialysis samples from the first day of infection. Contrary to the analyzed cytokines, the receptor showed severalfold higher levels in serum as compared to the dialysate. During the infection the receptor levels in the dialysate increased, while they remained stationary in the serum, indicating a local production.

CONCLUSION

This is the first time IL-10 has been demonstrated in the dialysate during peritonitis in CAPD patients. In view of its role as a suppressor of the immune and inflammatory responses, it is a potentially important observation, which might have clinical implications in the future.

Tumour necrosis factor soluble receptors I and II and interleukin-1 receptor antagonist in acute pyelonephritis in relation to bacterial virulence-associated traits and renal function

Urinary tract infections activate both mucosal and systemic inflammatory responses reflected by elevation of cytokine concentrations in serum and urine. We determined urine and serum concentrations of tumour necrosis factor soluble receptors I and II (sTNFR I and sTNFR II) and interleukin-1 receptor antagonist (IL-1ra) in 41 women with acute pyelonephritis caused by Escherichia coli, 2 weeks after the infection, during a subsequent episode of cystitis or asymptomatic bacteriuria and also later when the same patients were free from bacteriuria. Concentrations of sTNFR I, sTNFR II and IL-1ra were related to the expression of five virulence markers of E. coli, glomerular filtration rate (GFR) and to the concentration of C-reactive protein (CRP) in serum. Patients with acute pyelonephritis had elevated serum concentrations of sTNFR I and sTNFR II compared to healthy women (P < 0.001 for both comparisons). The concentrations of sTNFR I and sTNFR II in urine were significantly higher in patients with acute pyelonephritis compared to controls (P < 0.001 in both cases). The concentration of sTNFR II in urine was higher in patients infected by E. coli producing haemolysin (P = 0.05) and in patients infected by E. coli expressing hydrophobic properties (P = 0.05) compared to patients infected by strains without these virulence traits. Patients who had high concentrations of sTNFR II in serum during acute pyelonephritis had lower GFR at follow-up (r = -0.48, P = 0.05). Patients who responded with a marked increase in CRP had higher sTNFR I and sTNFR II in urine (r = 0.58, P < 0.01 and r = 0.48, P < 0.01, respectively). The concentrations of sTNFR I and sTNFR II in serum and urine decreased during follow-up and were lower 2 weeks after the infection when all patients were free from bacteriuria. IL-1ra in serum was elevated during pyelonephritis (P < 0.001) while that in urine was significantly lower compared to controls (P < 0.001). It is concluded that the increased concentrations of TNF receptors may block the cytotoxic and inflammatory actions and reduce the sensibility of renal cells to TNF alpha-mediated effects.

PCR reaction and dot-blot hybridization to monitor the distribution of oral pathogens within plaque samples of periodontally healthy individuals

The purpose of this study was to determine the distribution of the putative periodontal pathogens Prevotella intermedia, Prevotella nigrescens, the three oral Capnocytophaga species (C. ochracea, C. sputigena, C. gingivalis), as well as Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans in plaque samples of periodontally healthy individuals. We chose a newly developed 16S rDNA directed polymerase chain reaction (PCR) and a previously described dot-blot hybridization assay to detect, differentiate, and quantify these bacteria directly in clinical samples. The subjects of these investigations were 66 sulcus fluid samples from 17 children (ages 3 to 5) attending a kindergarten, 48 sulcus fluid samples from 12 children (ages 9 and 10) from a primary school, and 25 subgingival plaque samples isolated from 6 different periodontally healthy dental students (ages 24 to 27). We were able to demonstrate the presence of P. nigrescens in 54 (kindergarten: 5; primary school: 33; students: 16) samples by PCR and quantified it by dot-blot hybridization. In addition, we found C. ochracea in 12 (kindergarten: 2; primary school: 10) samples by PCR reaction only. The other tested bacterial species were absent by the methods used. Furthermore we confirmed the specificity of our P. nigrescens-PCR in selected samples by enzyme electrophoresis.

Interleukin-1 alpha and interleukin-6 in the urine, kidney, and bladder of mice inoculated with Escherichia coli

After bladder inoculation of mice using the pyelonephritogenic Escherichia coli strain DS17, urinary interleukin-1 alpha (IL-1 alpha) peaked at 0.5 h post infection (mean 233 pg/ml), interleukin-6 (IL-6) at 2 h (mean 572 pg/ml), and leukocyturia at 4 h, all three persisting for more than 24 h. In the kidneys IL-1 alpha peaked at 2 h, persisted over 24 h (mean 900-1,000 pg/ml), and decreased over 2-6 days post inoculation to a mean value of 208 pg/ml. Control kidneys showed low IL-1 alpha values. IL-6 in the kidneys peaked at 5 h (mean 9,999 pg/ml) but normalized, i.e., similar to control kidneys, by 48 h (mean 105 pg/ml). A similar cytokine response, but with tenfold lower levels, was found in the bladder tissue. The isogenic P-negative E. coli mutant DS178 elicited lower IL-6 in the kidneys at 5 h, but persisted in higher numbers in the kidneys at 6 days. Bacterial counts and cytokine levels correlated both in the kidneys and in bladder tissue, (r = 0.50-0.76, P < 0.001). Characterization of the immune response gives a better understanding of the relative importance of different bacterial characteristics for the local inflammatory process and is needed for studies of its pharmacological down-regulation.

Tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-1 receptor antagonist in dialysate and serum from patients on continuous ambulatory peritoneal dialysis

Dialysate and serum levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and IL-1-ra were investigated in 20 patients on continuous ambulatory peritoneal dialysis (CAPD), who altogether had 30 episodes of peritonitis. Bacterial growth was found in 25 (83%) of the dialysate samples. Staphylococcus epidermidis was the single most common microorganism, found in 44% of the culture-verified peritonitis. Samples from dialysate bags were obtained during the first month of dialysis and during peritonitis from the first three bags on day 1 (the day of admittance) and from night bags on days 3 and 10. Serum samples were drawn on days 1 and 10. The peak concentrations of cytokines occurred on the first day of infection. In dialysates, TNF-alpha was elevated in 96% of the patients, with a peak median concentration of 160 pg/mL (range, <15 to 4,400 pg/mL). Seventy-five percent of the dialysates had elevated IL-1-beta, with the highest median level of 52 pg/mL (range, <10 to 940 pg/mL), whereas all patients had elevated IL-1 ra, with a peak median value of 10,300 pg/mL (range, 470 to 79,000 pg/mL). TNF-alpha, IL-1 beta, and IL-Ira were significantly higher than in corresponding noninfected samples (TNF-alpha median value, <15 pg/mL; IL-1 beta, <10 pg/mL; and IL-1-ra, 150 pg/mL; P < 0.0001, P < 0.002, and P < 0.001, respectively). In serum, elevated TNF-alpha levels were found in 92% of the episodes, but the median levels were less than one third of the corresponding lavage levels. IL-1-beta was detected in 8% of the episodes and, although IL-1-ra was found in 92% of the patients, the dialysate levels were more than 15 times higher. In dialysate, a correlation was observed for TNF-alpha and IL-Ira and also between IL-1-beta and IL-Ira. IL-1 beta and IL-1-ra also correlated with the previously analyzed IL-6, and IL-1-beta correlated with the previously analyzed IL-8. Patients infected with high virulent strains had higher cytokine levels as compared with those infected with low virulent strains. In conclusion, our study shows markedly elevated TNF-alpha, IL-1 beta, and IL-1-ra levels in the acute stage in CAPD patients with peritonitis.

Elevated cytokine levels in tracheobronchial aspirate fluids from ventilator treated neonates with bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic lung disease often occurring in ventilator-treated very low birth weight infants. The aetiology of BPD is multifactorial and pulmonary immaturity, high oxygen concentrations, peak inspiratory pressure levels and large tidal volumes during prolonged mechanical ventilation are important factors. We measured in tracheobronchial aspirate fluid (TAF) the concentrations of the pro-inflammatory cytokines tumour necrosis factor alpha, interleukin-1 beta (IL-1 beta), IL-6, IL-8, and IL-1 receptor antagonist in infants requiring artificial ventilation for BPD (n = 17) or respiratory distress syndrome (RDS) (n = 15) or postoperatively after surgery (n = 15). The median levels of all studied cytokines in TAF were higher in infants with BPD without local or systemic corticosteroid treatment compared to the median TAF levels of BPD neonates treated with corticosteroids (P = 0.06-P < 0.01). The neonates with BPD not treated with corticosteroids also showed higher levels of the five studied cytokines in TAF compared to infants on short-time ventilator treatment (P < 0.01-P < 0.001) and compared to neonates with RDS (P = 0.07-P < 0.001). The corticosteroid treated neonates with BPD had TAF cytokine levels approaching those of the control neonates.

CONCLUSION

Tumour necrosis factors alpha, IL-1 beta, IL6, IL8 and IL1ra were markedly elevated in tracheobronchial aspirate fluids from neonates with bronchopulmonary dysplasia. Corticoid treatment seemed to reduce these levels.

Interleukin-1 alpha and interleukin-1 receptor antagonist in the urine of children with acute pyelonephritis and relation to renal scarring

Urinary concentrations of interleukin-1 alpha (IL-1 alpha) and interleukin-1 receptor antagonist (IL-lra) standardized to urinary creatinine concentrations were studied. The median standardized IL-1 alpha creatinine quotient in children with first-time acute pyelonephritis was 3.6 pg/mumol, but was nondetectable in children with recurrent pyelonephritis, children with non-renal febrile conditions and children convalescent after acute pyelonephritis (p < 0.05-0.01). IL-lra levels were also significantly higher in children with acute first-time pyelonephritis (median of 239 pg/mumol) compared to these three groups of children (p < 0.01-0.001). The highest urinary IL-lra levels, however, were found in the healthy controls (median value 1.019; p < 0.001). Both cytokines were higher among children younger than one year compared to older children. The acute IL-1 alpha creatinine quotients were lowest in children with uptake defects on 99mTC-dimercaptosuccinic acid (DMSA) scintigraphy both during the acute infection (reflecting the acute inflammation) (p < 0.001) and 1 year after the acute infection (reflecting permanent kidney scarring) (p < 0.001). In conclusion, persisting high urinary levels of IL-1 alpha were associated with less renal inflammation and scarring.

Amniotic fluid interleukins in Swedish and Mozambican pregnant women

The aim of the study was to investigate inflammatory cytokines, interleukin-1 beta (IL-1 beta), interleukin-1 receptor antagonist (IL-1ra), IL-6, IL-8 in amniotic fluid, in a cohort of Swedish pregnant women from early to late pregnancy and Mozambican late pregnant women with and without signs of histologic chorioamnionitis. Eleven Swedish women were studied from early pregnancy (week 16-17) to late pregnancy (week 37-38). Amniotic fluid was collected via amniocentesis in early pregnancy and also in late pregnancy during elective Caesarean section. From Mozambican women, amniotic fluid was harvested transmurally through the uterus wall during elective Caesarean section. Half of the group of 30 women showed histological signs of chorioamnionitis and half of the group did not show such signs. A statistical, significant increase in IL-1ra, Il-6 and IL-8 values from early to late pregnancy was seen in the Swedish pregnant women. Among the Mozambican women, no statistically significant increase in the above-mentioned interleukins was observed when comparing women with and without histological signs of chorioamnionitis. Term Swedish and Mozambican women did not show differences in cytokine levels. There were no detectable values of IL-1 beta in either Swedish or Mozambican women. IL-1ra, IL-6 and IL-8 increased in amniotic fluid from the second to the third trimester in the Swedish cohort. No correlation was found between histological chorioamnionitis and elevated cytokine levels of amniotic fluid in term pregnant women not in labour. An equally good cytokine response was found among Swedish and Mozambican third-trimester non-labouring women.

Typing of coagulase-negative staphylococci from peritonitis in CAPD-patients by the PhP-CS system and REA

Coagulase-negative staphylococci (CNS) were the most common bacteria causing peritonitis in patients treated with continuous ambulatory peritoneal dialysis (CAPD). In order to investigate if the same clone was responsible for the peritonitis in the different patients and if the exit site was the source of infection we followed 68 patients on CAPD for 2 years. During this period 9 patients had 12 episodes of peritonitis caused by CNS. Cultures were taken from exit site and peritoneal fluid in all patients at peritonitis and during the first study year at monthly intervals. In each culture up to 10 isolates of CNS were randomly collected and frozen. All 437 CNS isolates from the patients with CNS peritonitis were typed using a biochemical typing method and 41 isolates identical by this method were further discriminated by a DNA fingerprinting method. Identical strains were in no case isolated from different patients, indicating that no virulent strain was spread between the patients. The isolates causing the peritonitis were never found at the exist sites before the first day of the peritonitis in any patient. In only two patients was the same strain found at the exit site and in the peritoneal fluid on the first day of peritonitis. It thus seems that no virulent clone of CNS was infecting the patients and we found no evidence of CNS at the exit site causing the peritonitis.

P-fimbriation and haemolysin production are the most important virulence factors in diabetic patients with Escherichia coli bacteraemia: a multivariate statistical analysis of seven bacterial virulence factors

Diabetic patients, as compared to non-diabetic subjects, run an increased risk of acquiring Gram-negative bacteraemia. We therefore studied the prevalence and coexpression of seven bacterial virulence markers of 69 Escherichia coli strains isolated from 64 bacteraemic patients with diabetes mellitus and 67 E. coli strains from faeces of healthy controls. The strains were analyzed for haemolysin (HLY) production, aerobactin-mediated iron uptake (AMI), cytotoxic necrotizing factor (CNF) production, expression of cell surface hydrophobicity, P-fimbriae, mannose-resistant haemagglutination (MRHA) and mannose-sensitive haemagglutination (MSHA). All bacterial properties were significantly more common among the bacteraemic strains (P < 0.02 vs. controls). Correlations between HLY and CNF (P < 0.0004) and between P-fimbriae and MRHA (P < 0.0001), MSHA (P < 0.0002) or AMI (P < 0.05), as well as between MRHA and MSHA (P < 0.0005) were observed. In patients with proteinuria, as sign of diabetic complications in the urinary tract, HLY-negative strains, P-fimbriae-negative strains, and strains which were both HLY-/CNF-negative, were more common (P = 0.04, P < 0.01 and P = 0.048, respectively). Using a multivariate statistical analysis, production of HLY and the expression of P-fimbriae were the two virulence factors with the highest discrimination between bacteraemic and control strains. In conclusion, all virulence factors studied were more prevalent in bacteraemic than in control strains, although HLY and P-fimbriae were shown to be of greatest and independent importance. Low virulent strains (P-fimbriae-, HLY- and CNF-negative) were more prevalent in diabetic patients with signs of renal complications.

Interleukin-6 and interleukin-8 in the urine of children with acute pyelonephritis

Interleukin-6 (IL-6) and interleukin-8 (IL-8) are important mediators of the inflammatory response in serious bacterial infections. We studied the levels of these two cytokines (standardised for urinary creatinine) in the urine of infants and children during and 6 weeks after acute pyelonephritis and in non-renal febrile controls and healthy children without apparent infection. IL-6 was detected in the urine of 52% of children with pyelonephritis compared with 15% of other children (P < 0.001). The median urinary IL-6 level in acute pyelonephritis was 4 pg/mumol compared with undetectable levels in the control group (P < 0.001). IL-8 was detected in 98% of children with pyelonephritis and 42% of other children (P < 0.001). The median concentration of IL-8 was 188 pg/mumol in pyelonephritis; it was undetectable in controls (P < 0.001). IL-8 levels were higher in children less than 1 year of age (P < 0.001).