Total and cause-specific mortality rates in a prospective study of community-acquired hepatitis C virus infection in northern Norway.

Knowledge of the natural course and especially the total and cause-specific mortality of community-acquired chronic HCV infection is limited. The aims of our study were to determine the total and cause-specific mortality in patients infected with chronic hepatitis C in a community-based setting in northern Norway. This prospective cohort study included 1010 HCV-positive patients diagnosed with recombinant immunoblot assay between 1 January 1990 and 1 January 2000, with a median observation time from diagnosis to follow-up of 7 years. Data were collected from medical records in the period between 1 January 2004 and 30 June 2006. Time and cause of death were ascertained from the Norwegian Causes of Death Register. Age-adjusted death rates and standardised mortality ratios (SMRs) were compared with those of the general Norwegian population. In total, 122 deaths were recorded. The Kaplan-Meier estimate of survival was 88% at 14 years. The SMR in the cohort relative to the general population was 6.66. Most of the excess deaths in both genders were because of liver-related causes, those associated with a drug-using lifestyle and suicide. The statistically significant increase in SMRs ranged from 4.2 for death by cancer in women to 64.6 for liver disease in women. There was no statistically significant increase in SMRs from cardiovascular disease in either gender or from cancer in men. In conclusion, our study shows that the death rate in patients infected with hepatitis C is 6.66 times higher than in the general Norwegian population.

HPV mRNA test in women with minor cervical lesions: experience of the University Hospital of North Norway.

In the Norwegian Cervical Cancer Screening Programme tests for detection of human papillomavirus (HPV) are used to triage women with minor cytological cervical lesions. The material in this study comprises samples from 1798 women in the period 2006-2008. The HPV test was performed according to the guidelines of the Norwegian Cancer Registry. The HPV mRNA test (PreTect HPV-Proofer) detects and types 5 high-risk genotypes (16, 18, 31, 33 and 45). The HPV mRNA results were compared to cytology and then biopsy up to December 2009. Women with minor cytological cervical lesions and negative HPV test were followed with a new PAP smear after 12 months. A total of 327 women (18%) were HPV mRNA positive. Of the 1798 women with minor cytological lesions, 232 women (13%) had moderate dysplasia, severe dysplasia or cancer and 144 women (8%) had severe dysplasia or cancer in biopsy. 57% of the women with a positive HPV mRNA test had moderate dysplasia, severe dysplasia or cancer. 37% had severe dysplasia or cancer. The sensitivity of the HPV mRNA test to detect moderate dysplasia, severe dysplasia or cancer was 81%. The specificity for moderate dysplasia, severe dysplasia or cancer was 91%. The negative predictive value (NPV) of the HPV mRNA test for moderate dysplasia, severe dysplasia or cancer was 97%. Of 11 women with cervical cancer, 10 were positive for HPV type 16 or 18. The HPV mRNA test seems more suitable than HPV DNA tests to triage women with minor cytological cervical lesions due to its higher specificity.

Chlamydophila pneumoniae diagnostics: importance of methodology in relation to timing of sampling.

The diagnostic impact of PCR-based detection was compared to single-serum IgM antibody measurement and IgG antibody seroconversion during an outbreak of Chlamydophila pneumoniae in a military community. Nasopharyngeal swabs for PCR-based detection, and serum, were obtained from 127 conscripts during the outbreak. Serum, drawn many months before the outbreak, provided the baseline antibody status. C. pneumoniae IgM and IgG antibodies were assayed using microimmunofluorescence (MIF), enzyme immunoassay (EIA) and recombinant ELISA (rELISA). Two reference standard tests were applied: (i) C. pneumoniae PCR; and (ii) assay of C. pneumoniae IgM antibodies, defined as positive if >or=2 IgM antibody assays (i.e. rELISA with MIF and/or EIA) were positive. In 33 subjects, of whom two tested negative according to IgM antibody assays and IgG seroconversion, C. pneumoniae DNA was detected by PCR. The sensitivities were 79%, 85%, 88% and 68%, respectively, and the specificities were 86%, 84%, 78% and 93%, respectively, for MIF IgM, EIA IgM, rELISA IgM and PCR. In two subjects, acute infection was diagnosed on the basis of IgG antibody seroconversion alone. The sensitivity of PCR detection was lower than that of any IgM antibody assay. This may be explained by the late sampling, or clearance of the organism following antibiotic treatment. The results of assay evaluation studies are affected not only by the choice of reference standard tests, but also by the timing of sampling for the different test principles used. On the basis of these findings, a combination of nasopharyngeal swabbing for PCR detection and specific single-serum IgM measurement is recommended in cases of acute respiratory C. pneumoniae infection.

Cidofovir inhibits polyomavirus BK replication in human renal tubular cells downstream of viral early gene expression.

The human polyomavirus BK (BKV) causes nephropathy and hemorrhagic cystitis in kidney and bone marrow transplant patients, respectively. The anti-viral cidofovir (CDV) has been used in small case series but the effects on BKV replication are unclear, since polyomaviruses do not encode viral DNA polymerases. We investigated the effects of CDV on BKV(Dunlop) replication in primary human renal proximal tubule epithelial cells (RPTECs). CDV inhibited the generation of viral progeny in a dose-dependent manner yielding a 90% reduction at 40 microg/mL. Early steps such as receptor binding and entry seemed unaffected. Initial large T-antigen transcription and expression were also unaffected, but subsequent intra-cellular BKV DNA replication was reduced by >90%. Late viral mRNA and corresponding protein levels were also 90% reduced. In uninfected RPTECs, CDV 40 microg/mL reduced cellular DNA replication and metabolic activity by 7% and 11% in BrdU and WST-1 assays, respectively. BKV infection increased DNA replication to 142% and metabolic activity to 116%, respectively, which were reduced by CDV 40 microg/mL to levels of uninfected untreated RPTECs. Our results show that CDV inhibits BKV DNA replication downstream of large T-antigen expression and involves significant host cell toxicity. This should be considered in current treatment and drug development.

Chlamydia pneumoniae IgA- and IgG antibodies in young survivors of myocardial infarction. A comparison of antibody detection by a microimmunofluorescence test and an enzyme immunoassay.

OBJECTIVES: Chronic Chlamydia pneumoniae infection is considered as a cardiovascular risk factor and antibodies are commonly analysed by the subjective microimmunofluorescence (MIF) test. We wanted to investigate the C. pneumoniae IgA- and IgG seroprevalence in young survivors of myocardial infarction and matched controls, and to compare the agreement of detecting antibodies between a MIF test and an enzyme immunoassay (EIA). DESIGN: A total of 61 patients hospitalized as a result of myocardial infarction, 51 patients hospitalized with chest pain and negative exercise-ECG and 61 age and sex matched controls (mean age 53.3 years, range 40-60 years) were included in this case-control study. Serological comparisons were expressed as sensitivity, specificity and interrater agreement (K or Kw) of the EIA test related to the MIF test. RESULTS: Presence of IgA (cut off = 16) antibodies was significantly higher in coronary heart patients compared with controls for both assays (P = 0.02 by the MIF and P = 0.05 by the EIA test). The presence of IgG (cut off = 32) antibodies was significantly higher amongst patients (P = 0.05) when analysed by the MIF-test, but not with the EIA-test (P = 0.16). The strength of agreement between the assays was good for both IgA- (Kw = 0.67) and IgG (Kw = 0.79) analyses. However, only 52.8% of the IgA samples classified as strong positive (cut-off = 32) by the MIF test were strong positive by the EIA test (K = 0.56). Only 73.2% of the negative IgG samples (<32) by the MIF-test turned out negative by the EIA-test (K = 0.73). CONCLUSIONS: Dependent on assay and cut-off level, there is an increased C. pneumoniae IgA- and IgG seroprevalence in young survivors of myocardial infarction compared with controls. Despite the subjective interpretation of MIF-titres, the strength of agreement between the EIA and MIF tests was good for both antibody classes. However, misclassification of highly positive IgA samples and negative IgG samples by the MIF test may influence study conclusions. We conclude that the choice of serological method is of major importance when evaluating a possible relationship between C. pneumoniae and coronary heart disease.

Laboratory diagnosis of respiratory diseases: PCR versus serology.

We present a comparison between serology and genetic detection of three bacterial pathogens causing lower respiratory tract infection (LRI). We evaluated serology and PCR for the detection of Mycoplasma pneumoniae, Bordetella pertussis and Chlamydia pneumoniae from 1712 nasopharyngeal and serum samples. For 856 nasopharyngeal samples, average PCR time was 7.2 days, the parallel serum samples was 13 days. Automated extraction of nucleic acids reduces average PCR time to 6.7 days.

Lactoferrin and cyclic lactoferricin inhibit the entry of human cytomegalovirus into human fibroblasts.

Lactoferrin is mainly produced by polymorphonuclear leukocytes and has been demonstrated in mammalian milk and external secretions. Lactoferrin is an iron-binding, multifunctional protein and may play an important role in immune regulation and in defense mechanisms against bacteria, fungi and viruses. Lactoferricin is a potent antimicrobial peptide generated from the N-terminal part of lactoferrin by pepsin cleavage. We demonstrate that lactoferrins from different species and its N-terminal peptide lactoferricin (particularly the cyclic form) inhibit expression of early and late antigens, as well as production of infectious viral progeny during human cytomegalovirus (HCMV) infection in vitro. Iron-saturated lactoferrin did not affect HCMV antigen expression. Heparin had the same effects as iron-depleted lactoferrin. Yet, mixtures of lactoferrin and heparin did not inhibit HCMV multiplication i.e. lactoferrin and heparin seemed to mutually block each other's antiviral activities. HCMV-infected cells exposed to lactoferrin and cyclic lactoferricin contained less intracellular virus than unexposed cells. The antiviral activity of cyclic lactoferricin was more than seven-fold weaker than that of the maternal molecule. Lactoferrin and cyclic lactoferricin prevented HCMV entrance into the host cell.

Interference of the antimicrobial peptide lactoferricin B with the action of various antibiotics against Escherichia coli and Staphylococcus aureus.

The antimicrobial peptide, lactoferricin, can be generated upon gastric pepsin cleavage of lactoferrin. We have examined the interaction of lactoferricin of bovine origin, Lf-cin B, with the antibiotics penicillin G, vancomycin, gentamicin, colistin, D-cycloserine and erythromycin against E. coli ATCC 25922 and Staphylococcus aureus ATCC 25923. We demonstrated synergism between Lf-cin B and erythromycin against E. coli, and partial synergism between Lf-cin B and penicillin G, vancomycin and gentamicin against E. coli. Only penicillin G acted in partial synergism with Lf-cin B against S. aureus. Lf-cin B antagonized vancomycin and gentamicin against S. aureus in low concentration. We conclude that Lf-cin B may facilitate the uptake of antibiotics across the cell envelope.

Antibacterial effects of lactoferricin B.

The antimicrobial peptide, lactoferricin, can be generated upon gastric pepsin cleavage of lactoferrin. We have examined the inhibitory efficacy of lactoferricin of bovine origin (Lf-cin B) on Escherichia coli, Proteus mirabilis and Staphylococcus aureus with or without a cell wall. We found that spheroplasts and protoplasts had a lower MIC than their counterparts with a cell wall. We also compared the efficacies of Lf-cin B (17-31) made of all L-amino acids and all D-amino acids. The peptide made of all D-amino acids was more active than the corresponding L-enantiomer. Furthermore, we examined the influence of Lf-cin B on the motility of E. coli and the influence of temperature on the susceptibility of bacteria exposed to Lf-cin B. Bacteria exposed to sub-MIC of Lf-cin B lost their motility. Bacteria exposed to Lf-cin B at 20 degrees C were more sensitive to Lf-cin B than when exposed at 37 degrees C. These findings indicate that the cell envelope is a limiting step for Lf-cin B to exert its antibiotic effect. We cannot rule out a receptor-mediated first step for Lf-cin B (17-31).

Lactoferricin of bovine origin is more active than lactoferricins of human, murine and caprine origin.

The antimicrobial peptide lactoferricin is generated by gastric pepsin cleavage of lactoferrin. We have examined the antimicrobial activity of lactoferricins derived from lactoferrin of human, murine, caprine and bovine origin with minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) against E. coli ATCC 25922 and S. aureus ATCC 25923. We found that lactoferricin of bovine origin (Lf-cin B) was the most efficacious of the lactoferricins tested. By comparing the linear and cyclic Lf-cin B we found the cyclic peptide to be the most active. Lactoferricin B was moderately active against E. coli ATCC 25922 and S. aureus ATCC 25923, but had no activity against P. mirabilis or Y. enterocolitica. Lf-cin B showed good activity against C. albicans, C. tropicalis and C. neoformans.

Modulation of blood cell activation by four commonly used anticoagulants.

In the past years, our group has made several observations suggesting that blood cells behave differently and when stimulated, release different levels of cytokines, depending on which anticoagulant the blood has been drawn into. The aim of this study was therefore to compare the effect of the four anticoagulants EDTA, citrate, heparin and hirudin on monocyte, neutrophil (PMN), and platelet function in human whole blood. Human whole blood was employed as an ex vivo model of cytokine production and protein secretion, and lipopolysaccharide (LPS) induced tissue factor (TF) activity in monocytes and LPS induced tumor necrosis factor alpha (TNF alpha) release were chosen as parameters of monocyte activation. Platelet factor 4 (PF4) secretion and LPS induced lactoferrin release were chosen as parameters of platelet and PMN activation, respectively. When human whole blood was stimulated with 5 ng/ml LPS for 2 h, TF activity in monocytes isolated from EDTA blood was found to be 2.9 mU/10(6) cells, whereas TF activity in monocytes isolated from citrated, heparinized and hirudinized blood was 14.7, 24.7 and 28.5 mU/10(6) cells, respectively. TNF alpha concentrations in platelet poor plasma (PPP) isolated from whole blood stimulated with 5 ng/ml LPS for 2 h was increased with 200, 400 and 350% in citrated, heparinized and hirudinized blood respectively, as compared to EDTA blood. Next, the effect of the anticoagulant on PMN secretion was measured. PPP isolated from whole blood incubated with 5 ng/ml LPS for 90 min contained 1170 ng/ml (EDTA blood), 2880 ng/ml (citrated blood), 4220 ng/ml (heparinized blood), and 5520 ng/ml lactoferrin (hirudinized blood). When studying the platelet parameter PF4, whole blood was incubated without any stimuli for 60 min, and we found that heparin PPP contained 1180 ng/ml PF4, while hirudin PPP contained 469 ng/ml, citrate PPP 440 ng/ml, and EDTA PPP 217 ng/ml PF4, respectively. Finally, the low molecular weight heparin compound Fragmin had no enhancing effect on PF4 levels in whole blood. It is concluded that the anticoagulant used in in vitro experiments has a large influence on the parameters measured.

Spread of subclinical Chlamydia pneumoniae infection in a closed community.

Chlamydia pneumoniae infections may spread subclinically. The present investigation took place in a military setting. Sera drawn when the conscripts had entered their military service 2 months previously had been kept frozen and were available. In a camp with 500 people, 35 (7%) developed clinical symptoms of pneumonia. The infection was serologically verified with C. pneumoniae-specific micro-immunofluorescence technique. Of 40 healthy controls, 21 turned out to fulfil the serological criteria of infection, thus, representing subclinical cases. These 21 cases, when extrapolated to the whole camp, equalled a rate of 49% which, added to the 7% of pneumonic cases, gave a total infection rate of 56%. Pre-existing IgG antibodies were demonstrated in 10% of the pneumonic cases, 48% of the subclinical cases, and 89% of the non-infected, healthy controls. Without the access to pre-epidemic sera permitting us to establish 4-fold titre rises, the spread of subclinical C. pneumoniae infection would have been noted at 5%, and not 49% as here demonstrated.

Early response in septicemia in newborns and their mothers. Effect of Escherichia coli, Streptococcus agalactiae and tumor necrosis factor on lactoferrin release and the generation of tissue thromboplastin.

Using a whole blood in vitro model, we have investigated the effect of Escherichia coli (E. coli), Streptococcus agalactiae (group B streptococci, GBS) and tumor necrosis factor alpha (TNF) on the generation of lactoferrin (LF), interleukin-1 beta (IL-1) and tissue thromboplastin (TPL) in healthy newborns at term and their mothers. E. coli (at a final concentration of 10(7)/ml) significantly increased the release of LF in whole blood from newborns after 20 as well as 60 min stimulation, and in samples from their mothers after 60 min stimulation. A significant increase in the release of LF was observed in both newborns and their mothers after 20 and 60 min stimulation with TNF (at a final concentration of 1000 pg/ml). A combination of TNF/E. coli or TNF/GBS never gave any significant additional stimulatory effect. After stimulation with E. coli or GBS (both at a final concentration of 10(7)/ml) for 60 min a significant increase in production of TNF and TPL was observed in newborns. In newborns a significant increase in production of TNF and TPL was observed also after 20 min stimulation with E. coli. TNF (at a final concentration of 1000 pg/ml) significantly increased the generation of TPL after 20 and 60 min stimulation in both groups. There was a tendency for a greater release of LF and generation of TNF and TPL in samples from newborns compared with their mothers, but the differences were not statistically significant. E. coli, GBS and TNF had no significant effect on the production of IL-1.

Early response in neonatal septicemia. The effect of Escherichia coli, Streptococcus agalactiae and tumor necrosis factor on the generation of lactoferrin.

Using an in vitro model, we report the early effect of Escherichia coli (E. coli), Streptococcus agalactiea (group B streptococci, GBS) and recombinant tumor necrosis factor alpha (TNF) on the release of lactoferrin (LF) and the generation of interleukin-1 (IL-1) due to E. coli, using heparinized whole blood from healthy full-term newborns. We wanted to find a dose response relationship between lactoferrin generation on the one hand and the amount of E. coli, GBS and TNF on the other hand. In a final concentration of 10(7) per ml both bacteria increased the release of LF significantly. The response to E. coli was immediate and mg/l +/- 0.29 mg/l, E. coli 1.83 mg/l +/- 0.76 mg/l, p less than 0.001). GBS was a less potent stimulant than E. coli and the response was only apparent after 20 minutes (mean +/- S.D.: 1.06 mg/l +/- 0.49 mg/l, p less than 0.01). TNF in a concentration of 10000 pg/ml as well as 1000 pg/ml increased the release of LF significantly (after 20 minutes mean +/- S.D.: 1.09 mg/l +/- 0.42 mg/l and 0.97 mg/l +/- 0.36 mg/l, respectively), whereas a concentration of 100 pg/ml had no effect. Whole blood incubated with different preparations of LF for 20 minutes did not increase the generation of LF significantly. No significant changes in IL-1 levels were observed. Lactoferrin had bacteriostatic but no bactericidal effect on GBS and Streptococcus mutans.

The production of tumour necrosis factor, tissue thromboplastin, lactoferrin and cathepsin C during lipopolysaccharide stimulation in whole blood.

The release of tumour necrosis factor (TNF), lactoferrin (LF) and cathepsin C (CC) into plasma and production of thromboplastin (TPL) in monocytes were studied in lipopolysaccharide (LPS) stimulated heparinized whole blood from 10 healthy donors. The influence of dextran 70, haemaccel and methylprednisolone on levels of these parameters were examined. TNF concentration in plasma 5 min after the addition of LPS (0 h) was 250 pg/ml (median), 520 pg/ml after 1 h and 1300 pg/ml after 3 h. The addition of dextran 70 to the blood in addition to LPS at the same intervals gave significantly higher values of 740 pg/ml and 1800 pg/ml after 1 h and 3 h respectively. Unstimulated cells had no TPL but after 1 h with LPS, the TPL activity in incubated cells was 2.3 mU/10(6) monocytes and after 3 h, 2.7 mU/10(6) monocytes. LPS induced the secretion of LF from granulocytes (PMN) and the levels 5 min after the addition of LPS (0 h) were 2.1 mg/l (control 0.2 mg/l) and after 1 h, 5.3 mg/l (control 1.3 mg/l) in plasma after LPS stimulation. Haemaccel enhanced the LPS-induced generation of TPL in monocytes and production of CC. The LPS-induced secretion of LF was, to a small extent, influenced by the three reagents tested. Methylprednisolone (1 mmol/l) reduced the production and appearance of TNF in plasma and the generation of TPL activity in monocytes. This model for stimulating heparinized whole blood is suitable for examination of the production and appearance of cellular factors and the influence of drugs on this production.

Early fall of circulating iron and rapid rise of lactoferrin in septicemia and endotoxemia: an early defence mechanism.

Total serum iron, plasma lactoferrin and circulating leukocytes were measured in piglets during the early phase of severe gram-negative septicemia and endotoxemia in 3 experimental settings: intravenous (i.v.) infusion of lipopolysaccharide (LPS) (n = 8), i.v. infusion of live Escherichia coli (n = 7) and intraperitoneal (i.p.) infusion of E. coli (n = 6). Iron dropped significantly during the first 30 min of LPS infusion from a median of 32 microM to 13.4 microM. A similar decrease in serum iron was demonstrated in the 2 other groups with minimum values at 120 min after the start of E. coli infusion. Plasma levels of lactoferrin increased significantly 120 min after the start of LPS infusion (median 6 mg/l) when compared to preinfusion values (0.25 mg/l). After i.v. infusion of E. coli a significant rise of plasma lactoferrin was demonstrated already 30 min after bacterial infusion (to 2.1 mg/l) compared to preseptic values (0.8 mg/l). This increase was accompanied with a significant drop of circulating leukocytes (to 7.3 x 10(9)/l) compared to before the infusion (17 x 10(9)/l) in the pigs given E. coli i.v. After i.p. E. coli infusion no significant change of plasma lactoferrin was observed. The rapid fall of total serum iron seen during endotoxemia and E. coli septicemia may in part be explained by the release of lactoferrin from granulocytes and the clearance of iron-bound lactoferrin in the blood or peritoneal cavity.

Lactoferrin as an indicator of septicemia and endotoxemia in pigs.

The levels of plasma lactoferrin (LF) in response to endotoxin and Escherichia coli infusions in piglets were studied to obtain exact time relation of plasma LF increase in relation to start of endotoxin and E. coli infusions. A new enzyme-linked immunoassay of swine LF is presented. 13 piglets had a 10-fold rapid increase of plasma LF concentrations after 0.25 mg/kg endotoxin intravenous infusion. The initial rise was 3.4 mg/l/h. 14 piglets, receiving 1 x 10(11) E. coli intravenously, showed a higher increase of plasma LF concentrations, amounting to 6-9 mg/l/h. Thus, plasma LF was an early marker of septicemia and endotoxemia.