A. C. Muller Kobold

Staphylococcal acid phosphatase binds to endothelial cells via charge interaction; a pathogenic role in Wegener’s granulomatosis?

The majority of patients with Wegener’s granulomatosis (WG) are chronic nasal carriers of Staphylococcus aureus. Chronic nasal carriage of S. aureus is associated with an increased risk of developing a relapse of the disease. The mechanism by which this occurs is still unknown. We hypothesized that a cationic protein of S. aureus, staphylococcal acid phosphatase (SAcP), acts as a planted antigen and initiates glomerulonephritis and vasculitis in patients with WG. In order to test the hypothesis that SAcP can act as a planted antigen in WG, we studied the ability of SAcP to bind to human umbilical vein endothelial cells (HUVEC) and human glomerular endothelial cells. We also studied whether this binding can be prevented by preincubation with an anionic protein, and whether binding of SAcP activates endothelial cells. We also evaluated whether antibodies in sera of patients with WG are able to bind to endothelial cell‐bound SAcP. The results show that SAcP can act as a planted antigen by binding to both types of endothelial cells in a concentration‐dependent manner. Binding of concentrations as low as 4 μg/ml can be detected on HUVEC within 5 min of incubation. Binding of SAcP to endothelial cells was charge‐dependent but did not activate endothelial cells. Finally, endothelial cell‐bound SAcP was recognized by sera of patients with WG. The data suggest a possible pathogenic role for SAcP by acting as a planted antigen thereby initiating glomerulonephritis and vasculitis in patients with WG.

Monocyte intracellular cytokine production during human endotoxaemia with or without a second in vitro LPS challenge: effect of RWJ-67657, a p38 MAP-kinase inhibitor, on LPS-hyporesponsiveness

In the present study, we investigated the effect of RWJ‐67657, a p38 MAP kinase inhibitor, upon in vivo LPS‐induced monocyte cytokine production and upon monocyte LPS‐hyporesponsiveness. Thirty minutes before a single injection of LPS (4 ng/kg BW), healthy male volunteers received a single oral dose of RWJ‐67657 at increasing dosages (0–1400 mg). Blood samples (pre‐medication, 3, 6 and 24 h after LPS) were immediately incubated with LPS (reflecting LPS‐hyporesponsiveness) or without LPS (reflecting in vivo monocyte stimulation) for 4 h at 37°C. Following red blood cells lysis and white blood cell permeabilization, cells were labelled with α‐CD14‐FITC and α‐IL‐1β, α‐IL‐12 or α‐TNFα (PE‐labelled), fixed, and analysed using flow cytometry. In vivo LPS injection resulted in an increased percentage of circulating monocytes producing IL‐1β, TNFα and IL‐12 only at 3 h after the LPS injection. This was dose‐dependently inhibited by RWJ‐67657 treatment. LPS‐hyporesponsiveness to in vitro LPS treatment was most prominent at 3 and 6 h after the in vivo LPS injection; compared with pre‐medication monocytes, at these intervals a reduced percentage of monocytes produced IL‐1β, TNFα or IL‐12 after the in vitro LPS stimulus. At t = 6 h, this LPS‐hyporesponsiveness could dose‐dependently be inhibited by RWJ‐67657 treatment of the volunteers. We therefore conclude that p38 MAP kinase inhibition with RWJ‐67657 inhibited monocyte production of cytokines following in vivo LPS injection. Treatment with RWJ‐67657 also reversed the LPS‐hyporesponsiveness. Whether this result can be extended to the clinical situation remains to be elucidated. Patients with sepsis or an otherwise high risk for multi‐organ failure are potential study groups.

AECA and ANCA in patients with premature atherosclerosis.

Autoimmunity is suggested to play a pathogenetic role in premature atherosclerosis. Since atherosclerosis and vasculitis seem pathogenetically related, we hypothesized that ANCA, an important antibody in vasculitis, plays a role in atherosclerosis as well. We therefore investigated the prevalence of ANCA in patients with premature atherosclerosis and related the presence of these antibodies to levels of AECA and markers of inflammation. Methods & Results: In a cohort of 286 patients with premature atherosclerosis the prevalence of ANCA was 5.6% (16/286). All had perinuclear ANCA. More females were ANCA-positive (8M/8F vs. 200M/70F, p=0.03). In a nested case-control study, comparing the 16 ANCA-positive patients with 32 controls, levels of AECA were higher in the first (7.32±0.91U vs. 5.52±0.41U, p<0.05). Conclusion: ANCA does not seem to play a major role in premature atherosclerosis. Whether elevated levels of AECA in ANCA-positive patients with premature atherosclerosis reflect more extended vascular di...Autoimmunity is suggested to play a pathogenetic role in premature atherosclerosis. Since atherosclerosis and vasculitis seem pathogenetically related, we hypothesized that ANCA, an important antibody in vasculitis, plays a role in atherosclerosis as well. We therefore investigated the prevalence of ANCA in patients with premature atherosclerosis and related the presence of these antibodies to levels of AECA and markers of inflammation. Methods & Results: In a cohort of 286 patients with premature atherosclerosis the prevalence of ANCA was 5.6% (16/286). All had perinuclear ANCA. More females were ANCA-positive (8M/8F vs. 200M/70F, p=0.03). In a nested case-control study, comparing the 16 ANCA-positive patients with 32 controls, levels of AECA were higher in the first (7.32±0.91U vs. 5.52±0.41U, p<0.05). Conclusion: ANCA does not seem to play a major role in premature atherosclerosis. Whether elevated levels of AECA in ANCA-positive patients with premature atherosclerosis reflect more extended vascular disease remains to be determined.

The predictive power of serum S-100B for non-sentinel node positivity in melanoma patients.

BACKGROUND Completion lymph node dissection (CLND) in sentinel node (SN) positive melanoma patients leads to substantial morbidity and costs, while only approximately 20% have a metastasis in non-sentinel nodes (NSNs). The aim of this study was to investigate if the biomarkers S-100B and Lactate Dehydrogenase (LDH) are associated with NSN positivity, to identify patients in whom CLND could safely be omitted. METHODS All SN positive patients who underwent CLND at the University Medical Centre Groningen between January 2004 and January 2015 were analysed. Patient and tumor characteristics, and serum S-100B and LDH values measured the day before CLND were statistically tested for their association with NSN positivity. RESULTS NSN positivity was found in 20.6% of the 107 patients undergoing CLND. Univariate analysis revealed male gender (p = 0.02), melanoma of the lower extremity (p = 0.05), Breslow thickness (p = 0.004), ulceration (p = 0.04), proportion of involved SNs (p = 0.045) and S-100B value (p = 0.01) to be associated with NSN positivity. LDH level was not significantly associated with positive NSNs (p = 0.39). In multivariable analysis, S-100B showed to have the strongest association with NSN positivity, within its reference interval of 0.20 μg/l (p = 0.02, odds ratio 5.71, 95% confidence interval 1.37-23.87). CONCLUSION In this study, the preoperatively measured S-100B value is the strongest predictor for NSN positivity in patients planned for CLND. Fluctuations of the S-100B level within the reference interval might give important clues about residual tumor load. Although further validation will be needed, this new closer look of S-100B could be of value in patient selection for CLND in the future.

Synovial calprotectin: a potential biomarker to exclude a prosthetic joint infection

Aims Recently, several synovial biomarkers have been introduced into the algorithm for the diagnosis of a prosthetic joint infection (PJI). Alpha defensin is a promising biomarker, with a high sensitivity and specificity, but it is expensive. Calprotectin is a protein that is present in the cytoplasm of neutrophils, is released upon neutrophil activation and exhibits antimicrobial activity. Our aim, in this study, was to determine the diagnostic potential of synovial calprotectin in the diagnosis of a PJI. Patients and Methods In this pilot study, we prospectively collected synovial fluid from the hip, knee, shoulder and elbow of 19 patients with a proven PJI and from a control group of 42 patients who underwent revision surgery without a PJI. PJI was diagnosed according to the current diagnostic criteria of the Musculoskeletal Infection Society. Synovial fluid was centrifuged and the supernatant was used to measure the level of calprotectin after applying a lateral flow immunoassay. Results The median synovial calprotectin level was 991 mg/L (interquartile range (IQR) 154 to 1787) in those with a PJI and 11 mg/L (IQR 3 to 29) in the control group (p < 0.0001). Using a cutoff value of 50 mg/L, this level showed an excellent diagnostic accuracy, with an area under the curve of 0.94. The overall sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) was 89%, 90%, 81% and 95% respectively. The NPV was 97% in the nine patients with a chronic PJI. Conclusion Synovial calprotectin may be a valuable biomarker in the diagnosis of a PJI, especially in the exclusion of an infection. With a lateral flow immunoassay, a relatively rapid quantitative diagnosis can be made. The measurement is cheap and is easy to use.

Efficacy of Home Telemonitoring versus Conventional Follow-up: A Randomized Controlled Trial among Teenagers with Inflammatory Bowel Disease

Background and Aims Conventional follow-up of teenagers with inflammatory bowel diseases [IBD] is done during scheduled outpatient visits regardless of how well the patient feels. We designed a telemonitoring strategy for early recognition of flares and compared its efficacy with conventional follow-up. Methods We used a multicentre randomized trial in patients aged 10-19 years with IBD in clinical remission at baseline. Participants assigned to telemonitoring received automated alerts to complete a symptom score and send a stool sample for measurement of calprotectin. This resulted in an individual prediction for flare with associated treatment advice and test interval. In conventional follow-up the health check interval was left to the physicians discretion. The primary endpoint was cumulative incidence of disease flares. Secondary endpoints were percentage of participants with a positive change in quality-of-life and cost-effectiveness of the intervention. Results We included 170 participants [84 telemonitoring; 86 conventional follow-up]. At 52 weeks the mean number of face-to-face visits was significantly lower in the telemonitoring group compared to conventional follow-up [3.6 vs 4.3, p < 0.001]. The incidence of flares [33 vs 34%, p = 0.93] and the proportion of participants reporting positive change in quality-of-life [54 vs 44%, p = 0.27] were similar. Mean annual cost-saving was €89 and increased to €360 in those compliant to the protocol. Conclusions Telemonitoring is as safe as conventional follow-up, and reduces outpatient visits and societal costs. The positive impact on quality-of-life was similar in the two groups. This strategy is attractive for teenagers and families, and health professionals may be interested in using it to keep teenagers who are well out of hospital and ease pressure on overstretched outpatient services. Trial registration NTR3759 [Netherlands Trial Registry].

Prevalence and pathophysiology of early dumping in patients after primary Roux-en-Y gastric bypass during a Mixed Meal Tolerance Test.

BACKGROUND Early dumping is a poorly defined and incompletely understood complication after Roux-en-Y gastric (RYGB). OBJECTIVE We performed a mixed-meal tolerance test in patients after RYGB to address the prevalence of early dumping and to gain further insight into its pathophysiology. SETTING The study was conducted in a regional hospital in the northern part of the Netherlands. METHODS From a random sample of patients who underwent primary RYGB between 2008 and 2011, 46 patients completed the mixed-meal tolerance test. The dumping severity score for early dumping was assessed every 30 minutes. A sum score at 30 or 60 minutes of ≥5 and an incremental score of ≥3 points were defined as indicating a high suspicion of early dumping. Blood samples were collected at baseline, every 10 minutes during the first half hour, and at 60 minutes after the start. RESULTS The prevalence of a high suspicion of early dumping was 26%. No differences were seen for absolute hematocrit value, inactive glucagon-like peptide-1, and vasoactive intestinal peptide between patients with or without early dumping. Patients at high suspicion of early dumping had higher levels of active glucagon-like peptide-1 and peptide YY. CONCLUSION The prevalence of complaints at high suspicion of early dumping in a random population of patients after RYGB is 26% in response to a mixed-meal tolerance test. Postprandial increases in both glucagon-like peptide-1 and peptide YY are associated with symptoms of early dumping, suggesting gut L-cell overactivity in this syndrome.