Intravenous flucloxacillin treatment is associated with a high incidence of hypokalaemia.

Intravenous flucloxacillin is one of the most frequently used high-dose penicillin therapies in hospitalized patients, forming the cornerstone treatment of invasive Staphylococcus aureus infection. Being a nonreabsorbable anion, flucloxacillin has been suggested to cause hypokalaemia, although the frequency and magnitude of this unwanted effect is unknown. In a retrospective cohort, we investigated the incidence and extent of hypokalaemia after initiation of intravenous flucloxacillin or ceftriaxone therapy. In total, 77 patients receiving flucloxacillin (62% male, mean age 70.5 years) and 84 patients receiving ceftriaxone (46% male, mean age 70.8 years) were included. Hypokalaemia occurred significantly more often in patients receiving flucloxacillin than ceftriaxone (42% vs 14%, p < 10-4 ). Moreover, follow-up potassium levels were significantly lower during flucloxacillin therapy. In general, women were more prone to develop hypokalaemia than men. In conclusion, intravenous flucloxacillin use is associated with a striking incidence of hypokalaemia. Therefore, standardized potassium measurements are necessary.

Effectiveness of Long-term Doxycycline Treatment and Cognitive-Behavioral Therapy on Fatigue Severity in Patients with Q Fever Fatigue Syndrome (Qure Study): A Randomized Controlled Trial.

Background: Approximately 20% of patients with acute Q fever will develop chronic fatigue, referred to as Q fever fatigue syndrome (QFS). The objective of this randomized controlled clinical trial was to assess the efficacy of either long-term treatment with doxycycline or cognitive-behavioral therapy (CBT) in reducing fatigue severity in patients with QFS. Methods: Adult patients were included who met the QFS criteria according to the Dutch guideline: a new onset of severe fatigue lasting ≥6 months with significant disabilities, related to an acute Q fever infection, without other somatic or psychiatric comorbidity explaining the fatigue. Using block randomization, patients were randomized between oral study medication and CBT (2:1) for 24 weeks. Second, a double-blind randomization between doxycycline (200 mg/day, once daily) and placebo was performed in the medication group. Primary outcome was fatigue severity at end of treatment (EOT; week 26), assessed with the Checklist Individual Strength subscale Fatigue Severity. Results: Of 155 patients randomized, 154 were included in the intention-to-treat analysis (doxycycline, 52; placebo, 52; CBT, 50). At EOT, fatigue severity was similar between doxycycline (40.8 [95% confidence interval {CI}, 37.3-44.3]) and placebo (37.8 [95% CI, 34.3-41.2]; difference, doxycycline vs placebo, -3.0 [97.5% CI, -8.7 to 2.6]; P = .45). Fatigue severity was significantly lower after CBT (31.6 [95% CI, 28.0-35.1]) than after placebo (difference, CBT vs placebo, 6.2 [97.5% CI, .5-11.9]; P = .03). Conclusions: CBT is effective in reducing fatigue severity in QFS patients. Long-term treatment with doxycycline does not reduce fatigue severity in QFS patients compared to placebo. Clinical Trials Registration: NCT01318356.

A comparison of the diagnostic value of MRI and 18F-FDG-PET/CT in suspected spondylodiscitis.

PURPOSE: The purpose of this study was to evaluate the diagnostic value of 18F-fluorodeoxyglucose (FDG) positron emission tomography and computed tomography (PET/CT scan) and magnetic resonance imaging (MRI) in diagnosing spondylodiscitis and its complications, such as epidural and paraspinal abscesses. METHODS: From January 2006 to August 2013 patients with a clinical suspicion of spondylodiscitis, with an infection, or with fever of unknown origin were retrospectively included if 18F-FDG-PET/CT and MRI of the spine were performed within a 2-week time span. Imaging results were compared to the final clinical diagnosis and follow-up data were collected. RESULTS: Sixty-eight patients were included of whom 49 patients were diagnosed with spondylodiscitis. MRI showed an overall sensitivity of 67 % and specificity of 84 %. Diagnostic accuracy was 58 %, when MRI was performed within 2 weeks after the start of symptoms and improved to 82 %, when performed more than 2 weeks after onset of symptoms. 18F-FDG-PET/CT showed a sensitivity of 96 % and a specificity of 95 %, with no relation to the interval between the scan and the start of symptoms. CONCLUSIONS: As compared to MRI, 18F-FDG-PET/CT has superior diagnostic value for detecting early spondylodiscitis. After 2 weeks both techniques perform similarly.

Monitoring, documenting and reporting the quality of antibiotic use in the Netherlands: a pilot study to establish a national antimicrobial stewardship registry.

BACKGROUND: The Dutch Working Party on Antibiotic Policy is developing a national antimicrobial stewardship registry. This registry will report both the quality of antibiotic use in hospitals in the Netherlands and the stewardship activities employed. It is currently unclear which aspects of the quality of antibiotic use are monitored by antimicrobial stewardship teams (A-teams) and can be used as indicators for the stewardship registry. In this pilot study we aimed to determine which stewardship objectives are eligible for the envisioned registry. METHODS: We performed an observational pilot study among five Dutch hospitals. We assessed which of the 14 validated stewardship objectives (11 process of care recommendations and 3 structure of care recommendations) the A-teams monitored and documented in individual patients. They provided, where possible, data to compute quality indicator (QI) performance scores in line with recently developed QIs to measure appropriate antibiotic use in hospitalized adults for the period of January 2015 through December 2015 RESULTS: All hospitals had a local antibiotic guideline describing recommended antimicrobial use. All A-teams monitored the performance of bedside consultations in Staphylococcus aureus bacteremia and the prescription of restricted antimicrobials. Documentation and reporting were the best for the use of restricted antimicrobials: 80% of the A-teams could report data. Lack of time and the absence of an electronic medical record system enabling documentation during the daily work flow were the main barriers hindering documentation and reporting. CONCLUSIONS: Five out of 11 stewardship objectives were actively monitored by A-teams. Without extra effort, 4 A-teams could report on the quality of use of restricted antibiotics. Therefore, this aspect of antibiotic use should be the starting point of the national antimicrobial stewardship registry. Our registry is expected to become a powerful tool to evaluate progress and impact of antimicrobial stewardship programs in hospitals.

Genetic variation in TLR10 is not associated with chronic Q fever, despite the inhibitory effect of TLR10 on Coxiella burnetii-induced cytokines in vitro.

Coxiella burnetii, the causative agent of Q fever, is recognized by TLR2. TLR10 can act as an inhibitory receptor on TLR2-derived immune responses. Therefore, we investigated the role of TLR10 on C. burnetii-induced cytokine production and assessed whether genetic polymorphisms in TLR10 influences the development of chronic Q fever. HEK293 cells, transfected with TLR2, TLR10 or TLR2/TLR10, and human peripheral blood mononuclear cells (PBMCs) in the presence of anti-TLR10, were stimulated with C. burnetii. In both assays, the absence of TLR10 resulted in increased cytokine responses after C. burnetii stimulation. In addition, the effect of single nucleotide polymorphisms (SNPs) in TLR10 was examined in healthy volunteers whose PBMCs were stimulated with C. burnetii Nine Mile or the Dutch outbreak isolate C. burnetii 3262. Individuals bearing SNPs in TLR10 displayed increased cytokine production upon C. burnetii 3262 stimulation. Furthermore, 139 chronic Q fever patients and 220 controls were genotyped for TLR10 N241H, I775V and I369L. None of these polymorphisms were associated with increased susceptibility to chronic Q fever. In conclusion, TLR10 has an inhibitory effect on in vitro cytokine production by C. burnetii, but the presence of TLR10 polymorphisms does not lead to an increased risk of developing chronic Q fever.

Recognition of Coxiella burnetii by toll-like receptors and nucleotide-binding oligomerization domain-like receptors.

BACKGROUND: Infection with Coxiella burnetii can lead to acute and chronic Q fever. Toll-like receptor 1 (TLR1), TLR2, TLR4, TLR6, nucleotide-binding oligomerization domain receptor 1 (NOD1), NOD2, and the mitogen-activated protein kinases are central in the innate immune response against microorganisms, but little is known about their role in the recognition of C. burnetii in humans. METHODS: Human peripheral blood mononuclear cells (PBMCs) were stimulated with C. burnetii Nine Mile and the Dutch outbreak isolate C. burnetii 3262. TLRs were inhibited using specific antibodies or antagonists. Additionally, the influence of human polymorphisms in TLRs and Nod-like receptors (NLRs) on C. burnetii-induced cytokine production was assessed. RESULTS: Inhibition of TLR2, p38, JNK, and ERK led to decreased cytokine responses in C. burnetii-stimulated human PBMCs. Humans with polymorphisms in TLR1 and NOD2 had reduced cytokine production, compared with humans with wild-type genotypes, after stimulation. Interestingly, polymorphisms in TLR6 led to decreased cytokine production after C. burnetii 3262 stimulation but not after C. burnetii Nine Mile stimulation. CONCLUSIONS: The TLR1/TLR2 heterodimer and NOD2 are important recognition receptors for the induction of cytokine responses against C. burnetii in humans. Furthermore, an interesting finding was the divergent recognition of C. burnetii Nine Mile and C. burnetii 3262.

Genetic Variation in Pattern Recognition Receptors and Adaptor Proteins Associated With Development of Chronic Q Fever.

BACKGROUND: Q fever is an infection caused by Coxiella burnetii. Persistent infection (chronic Q fever) develops in 1%-5% of patients. We hypothesize that inefficient recognition of C. burnetii and/or activation of host-defense in individuals carrying genetic variants in pattern recognition receptors or adaptors would result in an increased likelihood to develop chronic Q fever. METHODS: Twenty-four single-nucleotide polymorphisms in genes encoding Toll-like receptors, nucleotide-binding oligomerization domain-like receptor-2, αvß3 integrin, CR3, and adaptors myeloid differentiation primary response protein 88 (MyD88), and Toll interleukin 1 receptor domain-containing adaptor protein (TIRAP) were genotyped in 139 patients with chronic Q fever and in 220 controls with cardiovascular risk-factors and previous exposure to C. burnetii. Associations between these single-nucleotide polymorphisms and chronic Q fever were assessed by means of univariate logistic regression models. Cytokine production in whole-blood stimulation assays was correlated with relevant genotypes. RESULTS: Polymorphisms in TLR1 (R80T), NOD2 (1007fsX1), and MYD88 (-938C>A) were associated with chronic Q fever. No association was observed for polymorphisms in TLR2, TLR4, TLR6, TLR8, ITGAV, ITGB3, ITGAM, and TIRAP. No correction for multiple testing was performed because only genes with a known role in initial recognition of C. burnetii were included. In the whole-blood assays, individuals carrying the TLR1 80R-allele showed increased interleukin 10 production with C. burnetii exposure. CONCLUSIONS: Polymorphisms in TLR1 (R80T), NOD2 (L1007fsX1), and MYD88 (-938C>A) are associated with predisposition to development of chronic Q fever. For TLR1, increased interleukin 10 responses to C. burnetii in individuals carrying the risk allele may contribute to the increased risk of chronic Q fever.

Differentiation of Acute Q Fever from Other Infections in Patients Presenting to Hospitals, the Netherlands

Differentiating acute Q fever from infections caused by other pathogens is essential. We conducted a retrospective case-control study to evaluate differences in clinical signs, symptoms, and outcomes for 82 patients with acute Q fever and 52 control patients who had pneumonia, fever and lower respiratory tract symptoms, or fever and hepatitis, but had negative serologic results for Q fever. Patients with acute Q fever were younger and had higher C-reactive protein levels but lower leukocyte counts. However, a large overlap was found. In patients with an indication for prophylaxis, chronic Q fever did not develop after patients received prophylaxis but did develop in 50% of patients who did not receive prophylaxis. Differentiating acute Q fever from other respiratory infections, fever, or hepatitis is not possible without serologic testing or PCR. If risk factors for chronic Q fever are present, prophylactic treatment is advised.

Chronic Q fever diagnosis­ consensus guideline versus expert opinion

Chronic Q fever, caused by Coxiella burnetii, has high mortality and morbidity rates if left untreated. Controversy about the diagnosis of this complex disease has emerged recently. We applied the guideline from the Dutch Q Fever Consensus Group and a set of diagnostic criteria proposed by Didier Raoult to all 284 chronic Q fever patients included in the Dutch National Chronic Q Fever Database during 2006­2012. Of the patients who had proven cases of chronic Q fever by the Dutch guideline, 46 (30.5%)would not have received a diagnosis by the alternative criteria designed by Raoult, and 14 (4.9%) would have been considered to have possible chronic Q fever. Six patients with proven chronic Q fever died of related causes. Until results from future studies are available, by which current guidelines can be modified, we believe that the Dutch literature-based consensus guideline is more sensitive and easier to use in clinical practice.

Effect of antibiotic streamlining on patient outcome in pneumococcal bacteraemia.

OBJECTIVES: In blood culture-proven pneumococcal infections, streamlining empirical therapy to monotherapy with a penicillin is preferred in order to reduce the use of broad-spectrum antibiotics. However, adherence to this international recommendation is poor, and curiously it is unclear whether antibiotic streamlining may be harmful to individual patients. We investigated whether streamlining in bacteraemic pneumococcal infections is associated with mortality. METHODS: Adults admitted to two Dutch hospitals between 2001 and 2011 with bacteraemic pneumococcal infections were retrospectively included. Detailed clinical data on patient characteristics, comorbidities and severity and outcome of disease were obtained in addition to data on antibiotic treatment. Those eligible for streamlining were selected for further analyses. RESULTS: In the 45.8% of cases (126 of 275) where antibiotic treatment was streamlined, a lower mortality rate was observed (6.3% versus 15.4%, P = 0.021). The decision to streamline was only marginally explained by the 38 determinants accounted for. After correction for potential confounders, the OR for death while streamlining was 0.45 (95% CI: 0.18-1.11, P = 0.082) in all cases and 0.35 (95% CI: 0.12-0.99, P = 0.048) specifically in pneumonia cases. CONCLUSIONS: Our results suggest that streamlining in eligible pneumococcal bacteraemia cases is safe, irrespective of patient characteristics, severity of disease or empirical treatment regimen.

Acute and probable chronic Q fever during anti-TNFα and anti B-cell immunotherapy: a case report.

BACKGROUND: Q fever is caused by the intracellular bacterium Coxiella burnetii. Initial infection can present as acute Q fever, while a minority of infected individuals develops chronic Q fever endocarditis or vascular infection months to years after initial infection. Serology is an important diagnostic tool for both acute and chronic Q fever. However, since immunosuppressive drugs may hamper the humoral immune response, diagnosis of Q fever might be blurred when these drugs are used. CASE PRESENTATION: A 71-year-old Caucasian male was diagnosed with symptomatic acute Q fever (based on positive C. burnetii PCR followed by seroconversion) while using anti-tumor necrosis factor-α (anti-TNFα) drugs for rheumatoid arthritis (RA). He was treated for two weeks with moxifloxacin. After 24 months of follow-up, the diagnosis of probable chronic Q fever was established based on increasing anti-C. burnetii phase I IgG antibody titres in a immunocompromised patient combined with clinical suspicion of endocarditis. At the time of chronic Q fever diagnosis, he had been treated with anti B-cell therapy for 16 months. Antibiotic therapy consisting of 1.5 years doxycycline and hydroxychloroquine was started and successfully completed and no signs of relapse were seen after more than one year of follow-up. CONCLUSION: The use of anti-TNFα agents for RA in the acute phase of Q fever did not hamper the C. burnetii-specific serological response as measured by immunofluorescence assay. However, in the presented case, an intact humoral response did not prevent progression to probable chronic C. burnetii infection, most likely because essential cellular immune responses were suppressed during the acute phase of the infection. Despite the start of anti-B-cell therapy with rituximab after the acute Q fever episode, an increase in anti-C. burnetii phase I IgG antibodies was observed, supporting the notion that C. burnetii specific CD20-negative memory B-cells are responsible for this rise in antibody titres.

Specific interferon γ detection for the diagnosis of previous Q fever.

BACKGROUND: Current practice for diagnosis of Q fever, caused by the intracellular pathogen Coxiella burnetii, relies mainly on serology and, in prevaccination assessment, on skin tests (STs), which both have drawbacks. In this study, C. burnetii-specific interferon γ (IFN-γ) production was used as a new diagnostic tool for previous Q fever, circumventing most of these drawbacks. Our aim was to compare this test to serology and ST. METHODS: One thousand five hundred twenty-five individuals from an endemic area with a risk for chronic Q fever were enrolled. IFN-γ production was measured after in vitro stimulation of whole blood with C. burnetii antigens. Various formats using different C. burnetii antigens were tested. Serology and ST were performed in all individuals. RESULTS: In all assay formats, C. burnetii-specific IFN-γ production was higher (P < .0001) in seropositive or ST-positive subjects than in seronegative and ST-negative subjects. Whole blood incubated for 24 hours with C. burnetii Nine Mile showed optimal performance. After excluding subjects with equivocal serology and/or borderline ST results, IFN-γ production was 449 ± 82 pg/mL in the positive individuals (n = 219) but only 21 ± 3 pg/mL in negative subjects (n = 908). Using Bayesian analysis, sensitivity and specificity (87.0% and 90.2%, respectively) were similar to the combination of serology and ST (83.0% and 95.6%, respectively). Agreement with the combination of serology and ST was moderate (84% concordance; κ = 0.542). CONCLUSIONS: Specific IFN-γ detection is a novel diagnostic assay for previous C. burnetii infection and shows similar performance and practical advantages over serology and ST. Future studies to investigate the clinical value in practice are warranted.

Complement plays a central role in Candida albicans-induced cytokine production by human PBMCs.

In experimental studies, the role of complement in antifungal host defense has been attributed to its opsonizing capability. In this study, we report that in humans an activated complement system mainly augments Candida albicans-induced host proinflammatory cytokine production via C5a-C5aR signaling, while phagocytosis and intracellular killing of Candida are not influenced. By blocking the C5a-C5aR signaling pathway, either with anti-C5a antagonist antibodies or with the C5aR antagonist W-54001, C. albicans-induced IL-6 and IL-1ß levels were significantly reduced. Recombinant C5a augmented cytokine production. In addition, using serum from patients with various complement deficiencies, we demonstrated a crucial role of C5, but not C6 or the membrane attack complex, in C. albicans-induced IL-6 and IL-1ß production in monocytes. These findings reveal a central role of anaphylatoxin C5a in augmenting host proinflammatory cytokine production upon contact with C. albicans, and define the role of the complement system in anti-Candida host defense in humans.

A functional microsatellite of the macrophage migration inhibitory factor gene associated with meningococcal disease.

Macrophage migration inhibitory factor (MIF) is an abundantly expressed proinflammatory cytokine playing a critical role in innate immunity and sepsis and other inflammatory diseases. We examined whether functional MIF gene polymorphisms (-794 CATT(5-8) microsatellite and -173 G/C SNP) were associated with the occurrence and outcome of meningococcal disease in children. The CATT(5) allele was associated with the probability of death predicted by the Pediatric Index of Mortality 2 (P=0.001), which increased in correlation with the CATT(5) copy number (P=0.04). The CATT(5) allele, but not the -173 G/C alleles, was also associated with the actual mortality from meningoccal sepsis [OR 2.72 (1.2-6.4), P=0.02]. A family-based association test (i.e., transmission disequilibrium test) performed in 240 trios with 1 afflicted offspring indicated that CATT(5) was a protective allele (P=0.02) for the occurrence of meningococcal disease. At baseline and after stimulation with Neisseria meningitidis in THP-1 monocytic cells or in a whole-blood assay, CATT(5) was found to be a low-expression MIF allele (P=0.005 and P=0.04 for transcriptional activity; P=0.09 and P=0.09 for MIF production). Taken together, these data suggest that polymorphisms of the MIF gene affecting MIF expression are associated with the occurrence, severity, and outcome of meningococcal disease in children.

The Qure study: Q fever fatigue syndrome--response to treatment; a randomized placebo-controlled trial.

BACKGROUND: Q fever is a zoonosis that is present in many countries. Q fever fatigue syndrome (QFS) is one of the most frequent sequelae after an acute Q fever infection. QFS is characterized by persistent fatigue following an acute Q fever infection, leading to substantial morbidity and a high socio-economic burden. The occurrence of QFS is well-documented, and has been described in many countries over the past decades. However, a treatment with proven efficacy is not available. Only a few uncontrolled studies have tested the efficacy of treatment with antibiotics on QFS. These studies suggest a positive effect of long-term treatment with a tetracycline on performance state; however, no randomized controlled trials have been performed. Cognitive behavioral therapy (CBT) has been proven to be an effective treatment modality for chronic fatigue in other diseases, but has not yet been tested in QFS. Therefore, we designed a trial to assess the efficacy of long-term treatment with the tetracycline doxycycline and CBT in patients with QFS. METHODS/DESIGN: A randomized placebo-controlled trial will be conducted. One-hundred-eighty adult patients diagnosed with QFS will be recruited and randomized between one of three groups: CBT, long-term doxycycline or placebo. First, participants will be randomized between CBT and medication (ratio 1:2). A second double-blinded randomization between doxycycline and placebo (ratio 1:1) will be performed in the medication condition. Each group will be treated for six months. Outcome measures will be assessed at baseline and post intervention. The primary outcome measure is fatigue severity. Secondary outcome measures are functional impairment, level of psychological distress, and Coxiella burnetii PCR and serology. DISCUSSION: The Qure study is the first randomized placebo-controlled trial, which evaluates the efficacy of long-term doxycycline and of cognitive behavioral therapy in patients with QFS. The results of this study will provide knowledge about evidence-based treatment options for adult patients with QFS. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01318356, and Netherlands Trial Register: NTR2797.

Localizing chronic Q fever: a challenging query.

BACKGROUND: Chronic Q fever usually presents as endocarditis or endovascular infection. We investigated whether 18F-FDG PET/CT and echocardiography were able to detect the localization of infection. Also, the utility of the modified Duke criteria was assessed. METHODS: Fifty-two patients, who had an IgG titre of ≥ 1024 against C. burnetii phase I ≥ 3 months after primary infection or a positive PCR ≥ 1 month after primary infection, were retrospectively included. Data on serology, the results of all imaging studies, possible risk factors for developing proven chronic Q fever and clinical outcome were recorded. RESULTS: According to the Dutch consensus on Q fever diagnostics, 18 patients had proven chronic Q fever, 14 probable chronic Q fever, and 20 possible chronic Q fever. Of the patients with proven chronic Q fever, 22% were diagnosed with endocarditis, 17% with an infected vascular prosthesis, and 39% with a mycotic aneurysm. 56% of patients with proven chronic Q fever did not recall an episode of acute Q fever. Ten out of 13 18F-FDG PET/CT-scans in patients with proven chronic Q fever localized the infection. TTE and TEE were helpful in only 6% and 50% of patients, respectively. CONCLUSIONS: If chronic Q fever is diagnosed, 18F-FDG PET/CT is a helpful imaging technique for localization of vascular infections due to chronic Q fever. Patients with proven chronic Q fever were diagnosed significantly more often with mycotic aneurysms than in previous case series. Definite endocarditis due to chronic Q fever was less frequently diagnosed in the current study. Chronic Q fever often occurs in patients without a known episode of acute Q fever, so clinical suspicion should remain high, especially in endemic regions.

Treatment and Outcome of Culture-Confirmed Mycobacterium marinum Disease.

Background: Mycobacterium marinum is a nontuberculous mycobacterium that causes skin and soft tissue infections. Treatment consists of multiple antibiotics, sometimes combined with surgical debridement. There is little evidence for the choice of antibiotics, the duration of treatment, and the role of susceptibility testing. Methods: We performed a retrospective cohort study of culture-confirmed M. marinum infections in the Netherlands in the 2011-2018 period. Clinical characteristics, in vitro susceptibility, extent of disease, treatment regimens, and outcomes were analyzed. Incidence was assessed from laboratory databases. Results: Forty cases of M. marinum infection could be studied. Antibiotic treatment cured 36/40 patients (90%) after a mean treatment duration of 25 weeks. Failure/relapse occurred in 3 patients, and 1 patient was lost to follow-up. Antibiotic treatment consisted of monotherapy in 35% and 2-drug therapy in 63%. Final treatment contained mostly ethambutol-macrolide combinations (35%). Eleven patients (28%) received additional surgery. We recorded high rates of in vitro resistance to tetracyclines (36% of isolates). Tetracycline resistance seemed correlated with poor response to tetracycline monotherapy. The annual incidence rate was 0.15/100 000/year during the study period. Conclusions: Prolonged and susceptibility-guided treatment results in a 90% cure rate in M. marinum disease. Two-drug regimens of ethambutol and a macrolide are effective for moderately severe infections. Tetracycline monotherapy in limited disease should be used vigilantly, preferably with proven in vitro susceptibility.

Mannose-binding lectin is a critical factor in systemic complement activation during meningococcal septic shock.

BACKGROUND: Systemic activation of complement during meningococcal disease is associated with severe disease and poor outcome. The exact mechanism of activation of complement is unknown but is important for future therapies aimed at modulating the complement system in this disease. METHODS: We studied complement activation in a group of 22 patients, including 18 with meningococcal septic shock and 4 with meningococcal disease without shock. Two of the patients with shock were MBL deficient: 1 patient was homozygous and 1 patient was compound heterozygous for exon 1 mutations in the gene for MBL. RESULTS: The MBL-deficient patients had relatively low disease severity and mild disseminated intravascular coagulation (DIC). At admission to the pediatric intensive care unit, the MBL-deficient patients had much lower circulating values of C3bc (indicating common pathway activation) and terminal complement complex (indicating terminal pathway activation) than did MBL-sufficient patients who presented with meningococcal septic shock. Levels of C4bc (indicating classical or lectin pathway activation) and C3bBbP (indicating alternative pathway activation) were also decreased in the MBL-deficient patients. Systemic activation of complement excellently correlated with disease severity and parameters of DIC. Testing of convalescent blood samples from 1 of the MBL-deficient patients in a model of meningococcal sepsis showed that a lack of lectin pathway activation leads to a reduced activation of complement. CONCLUSIONS: This indicates that MBL is critical for the systemic activation of complement seen during meningococcal septic shock.

Influence of innate cytokine production capacity on clinical manifestation and severity of pediatric meningococcal disease.

OBJECTIVE: To analyze the role of the innate production capacity for tumor necrosis factor, interleukin-1beta, interleukin-12, and interleukin-10 in the clinical presentation and severity of meningococcal disease. DESIGN: Whole blood cultures from survivors of severe meningococcal disease obtained median 5.4 yrs after hospitalization were stimulated with meningococcal lipopolysaccharide and heat-killed Neisseria meningitidis bacteria. SETTING: Intensive care unit in academic hospital. PATIENTS: A total of 111 children were included. We classified these patients according to clinical manifestation in four groups: shock (n = 43); both shock and meningitis (n = 11); bacteremia (neither shock nor meningitis, n = 24); and distinct meningitis (n = 33). INTERVENTIONS: : None. MEASUREMENTS AND MAIN RESULTS: The classification into four groups stratifies these patients according to disease severity. No differences in whole blood cytokine production were found between the patients in these four groups. However, within the group of patients who had presented with shock, interleukin-1beta and the interleukin-1beta/interleukin-10 ratio were negatively correlated with disease severity (R = -.35, p = .03 and R = -.33, p = .04, respectively; Pediatric Risk of Mortality score). CONCLUSIONS: Clinical manifestation of meningococcal disease cannot be explained by the innate production capacity of whole blood cultures for the cytokines tumor necrosis factor, interleukin-1beta, interleukin-10, and interleukin-12. In patients who presented with shock, a low production capacity for interleukin-1beta and a low interleukin-1beta/interleukin-10 production ratio was associated with more severe disease.

Macrophage migration inhibitory factor (MIF) in meningococcal septic shock and experimental human endotoxemia.

Macrophage migration inhibitory factor (MIF) is a mediator of innate immunity and important in the pathogenesis of septic shock. Lipopolysaccharide (LPS) and tumor necrosis factor (TNF) alpha are reported to be inducers of MIF. We studied MIF and cytokines in vivo in patients with meningococcal disease, in human experimental endotoxemia, and in whole blood cultures using a newly developed sensitive and specific enzyme-linked immunosorbent assay. Twenty patients with meningococcal disease were investigated. For the human endotoxemia model, 8 healthy volunteers were intravenously injected with 2 ng/kg Escherichia coli LPS. Whole blood from healthy volunteers was incubated with LPS or heat-killed meningococci. Macrophage migration inhibitory factor concentration in blood was increased during meningococcal disease and highest in the patients presenting with shock compared with patients without shock. Plasma concentration of MIF correlated with disease severity, the presence of shock and with the cytokines interleukin (IL) 1beta, IL-10, IL-12, and vascular endothelial growth factor, but not with TNF-alpha. MIF was not detected in blood in experimental endotoxemia, nor after stimulation of whole blood with LPS or meningococci, although high levels of TNF-alpha were seen in both models. In conclusion, MIF is increased in patients with meningococcal disease and highest in the presence of shock. Macrophage migration inhibitory factor cannot be detected in a human endotoxemia model and is not produced by whole blood cells incubated with LPS or meningococci.