Validation of the standardization framework SSTR-RADS 1.0 for neuroendocrine tumors using the novel SSTR‑targeting peptide [18F]SiTATE

OBJECTIVES

Somatostatin receptor positron emission tomography/computed tomography (SSTR-PET/CT) using [68Ga]-labeled tracers is a widely used imaging modality for neuroendocrine tumors (NET). Recently, [18F]SiTATE, a SiFAlin tagged [Tyr3]-octreotate (TATE) PET tracer, has shown great potential due to favorable clinical characteristics. We aimed to evaluate the reproducibility of Somatostatin Receptor-Reporting and Data System 1.0 (SSTR-RADS 1.0) for structured interpretation and treatment planning of NET using [18F]SiTATE.

METHODS

Four readers assessed [18F]SiTATE-PET/CT of 95 patients according to the SSTR-RADS 1.0 criteria at two different time points. Each reader evaluated up to five target lesions per scan. The overall scan score and the decision on peptide receptor radionuclide therapy (PRRT) were considered. Inter- and intra-reader agreement was determined using the intraclass correlation coefficient (ICC).

RESULTS

The ICC analysis on the inter-reader agreement using SSTR-RADS 1.0 for identical target lesions (ICC ≥ 85%), overall scan score (ICC ≥ 90%), and the decision to recommend PRRT (ICC ≥ 85%) showed excellent agreement. However, significant differences were observed in recommending PRRT among experienced readers (ER) (p = 0.020) and inexperienced readers (IR) (p = 0.004). Compartment-based analysis demonstrated good to excellent inter-reader agreement for most organs (ICC ≥ 74%), except for lymph nodes (ICC ≥ 53%).

CONCLUSION

SSTR-RADS 1.0 represents a highly reproducible and consistent framework system for stratifying SSTR-targeted PET/CT scans, even using the novel SSTR-ligand [18F]SiTATE. Some inter-reader variability was observed regarding the evaluation of uptake intensity prior to PRRT as well as compartment scoring of lymph nodes, indicating that those categories require special attention during further clinical validation and might be refined in a future SSTR-RADS version 1.1.

CLINICAL RELEVANCE STATEMENT

SSTR-RADS 1.0 is a consistent framework for categorizing somatostatin receptor-targeted PET/CT scans when using [18F]SiTATE. The framework serves as a valuable tool for facilitating and improving the management of patients with NET.

KEY POINTS

SSTR-RADS 1.0 is a valuable tool for managing patients with NET. SSTR-RADS 1.0 categorizes patients with showing strong agreement across diverse reader expertise. As an alternative to [68Ga]-labeled PET/CT in neuroendocrine tumor imaging, SSTR-RADS 1.0 reliably classifies [18F]SiTATE-PET/CT.

Cerebral fat emboli in a patient with paraplegia caused by bilateral femur fractures

Cerebral fat embolism is a rare cause of stroke and therefore an overlooked diagnosis. Often it is seen as a consequence of major bone fractures or after arthroplasty, and can lead to respiratory or circulatory collapse. We present a case of a patient with a history of paraplegia after a thoracic spinal cord injury that developed cerebral fat embolism following a bilateral femur fracture. Since the patient was paraplegic and with an altered mental state upon admission, femoral bone fractures were not initially suspected. The case shows the difficulties in diagnosing this condition.

Gaussian Process-based prediction of memory performance and biomarker status in ageing and Alzheimer's disease-A systematic model evaluation

Neuroimaging markers based on Magnetic Resonance Imaging (MRI) combined with various other measures (such as genetic covariates, biomarkers, vascular risk factors, neuropsychological tests etc.) might provide useful predictions of clinical outcomes during the progression towards Alzheimer's disease (AD). The use of multiple features in predictive frameworks for clinical outcomes has become increasingly prevalent in AD research. However, many studies do not focus on systematically and accurately evaluating combinations of multiple input features. Hence, the aim of the present work is to explore and assess optimal combinations of various features for MR-based prediction of (1) cognitive status and (2) biomarker positivity with a multi-kernel learning Gaussian process framework. The explored features and parameters included (A) combinations of brain tissues, modulation, smoothing, and image resolution; (B) incorporating demographics & clinical covariates; (C) the impact of the size of the training data set; (D) the influence of dimensionality reduction and the choice of kernel types. The approach was tested in a large German cohort including 959 subjects from the multicentric longitudinal study of cognitive impairment and dementia (DELCODE). Our evaluation suggests the best prediction of memory performance was obtained for a combination of neuroimaging markers, demographics, genetic information (ApoE4) and CSF biomarkers explaining 57% of outcome variance in out-of-sample predictions. The highest performance for Aβ42/40 status classification was achieved for a combination of demographics, ApoE4, and a memory score while usage of structural MRI further improved the classification of individual patient's pTau status.

Diagnostic accuracy of SSR-PET/CT compared to histopathology in the identification of liver metastases from well-differentiated neuroendocrine tumors

BACKGROUND

Histopathology is the reference standard for diagnosing liver metastases of neuroendocrine tumors (NETs). Somatostatin receptor-positron emission tomography / computed tomography (SSR-PET/CT) has emerged as a promising non-invasive imaging modality for staging NETs. We aimed to assess the diagnostic accuracy of SSR-PET/CT in the identification of liver metastases in patients with proven NETs compared to histopathology.

METHODS

Histopathologic reports of 139 resected or biopsied liver lesions of patients with known NET were correlated with matching SSR-PET/CTs and the positive/negative predictive value (PPV/NPV), sensitivity, specificity, and diagnostic accuracy of SSR-PET/CT were evaluated. PET/CT reading was performed by one expert reader blinded to histopathology and clinical data.

RESULTS

133 of 139 (95.7%) liver lesions showed malignant SSR-uptake in PET/CT while initial histopathology reported on 'liver metastases of NET´ in 127 (91.4%) cases, giving a PPV of 91.0%. Re-biopsy of the initially histopathologically negative lesions (reference standard) nevertheless diagnosed 'liver metastases of NET' in 6 cases, improving the PPV of PET/CT to 95.5%. Reasons for initial false-negative histopathology were inadequate sampling in the sense of non-target biopsies. The 6 (4.3%) SSR-negative lesions were all G2 NETs with a Ki-67 between 2-15%.

CONCLUSION

SSR-PET/CT is a highly accurate imaging modality for the diagnosis of liver metastases in patients with proven NETs. However, we found that due to the well-known tumor heterogeneity of NETs, specifically in G2 NETs approximately 4-5% are SSR-negative and may require additional imaging with [18F]FDG PET/CT.

Systematic review of response criteria and endpoints in autoimmune hepatitis by the International Autoimmune Hepatitis Group

BACKGROUND & AIMS

Autoimmune hepatitis (AIH) has been well characterised and codified through the development of diagnostic criteria. These criteria have been adapted and simplified and are widely used in clinical practice. However, there is a need to update and precisely define the criteria for both treatment response and treatment.

METHODS

A systematic review was performed and a modified Delphi consensus process was used to identify and redefine the response criteria in autoimmune hepatitis.

RESULTS

The consensus process initiated by the International Autoimmune Hepatitis Group proposes that the term 'complete biochemical response' defined as 'normalization of serum transaminases and IgG below the upper limit of normal' be adopted to include a time point at 6 months after initiation of treatment. An insufficient response by 6 months was a failure to meet the above definition. Non-response was defined as '<50% decrease of serum transaminases within 4 weeks after initiation of treatment'. Remission is defined as liver histology with a Hepatitis Activity Index <4/18. Intolerance to treatment was agreed to stand for 'any adverse event possibly related to treatment leading to potential drug discontinuation'.

CONCLUSIONS

These definitions provide a simple and reproducible framework to define treatment response and non-response, irrespective of the therapeutic intervention. A consensus on endpoints is urgently required to set a global standard for the reporting of study results and to enable inter-study comparisons. Future prospective database studies are needed to validate these endpoints.

LAY SUMMARY

Consensus among international experts on response criteria and endpoints in autoimmune hepatitis is lacking. A consensus on endpoints is urgently required to set a global standard for the reporting of study results and to enable the comparison of results between clinical trials. Therefore, the International Autoimmune Hepatitis Group (IAIHG) herein presents a statement on 5 agreed response criteria and endpoints: complete biochemical response, insufficient response, non-response, remission, and intolerance to treatment, which can be used to guide future reporting.

POS1314 JUVENILE IDIOPATHIC ARTHRITIS IN THE CONTEXT OF THE CORONAVIRUS DISEASE 19 PANDEMIC: IMPACT ON THE DECREASE IN TREATMENT AND THE RETURN TO SCHOOL

Background:

The SARS-CoV-2 pandemic has induced an exceptional sanitary crisis, potentially having an impact on treatment continuation, for juvenile idiopathic arthritis (JIA) patients receiving immunosuppressive therapies. In France, after the first lockdown from March to May 2020, many parents and children were then also concerned about whether reopening plans for school could ensure the safety of students, despite data concerning children with COVID-19 seem reassuring, and very few of them develop severe forms of the disease (1, 2, 3).

Objectives:

Our objectives were to evaluate the impact of the COVID-19 pandemic on the therapeutic management of JIA, the frequency of returning to school after the first lockdown period and the prevalence of SARS-CoV-2 infection at the time of the survey.

Methods:

JIA patients under 18 years of age, usually treated with disease-modifying anti-rheumatic drugs (DMARDs) were prospectively included during their outpatient visit and completed a standardized questionnaire. Data regarding the general characteristics of the participants, medical history, SARS-CoV-2 infection, characteristics of JIA subtypes and treatment modifications were collected.

Results:

A total of 173 patients from 8 different expert centers were included between May and August 2020. Their mean age was 11.6 years (± 4.1 years), and most of them 31.2% (54/173) had a rheumatoid factor-negative polyarticular JIA. Fifty percent (86/172) were treated with methotrexate, and 72.5% (124/171) were treated with bDMARDs. DMARD treatment modification in relation to the pandemic was observed in 4.0% (7/173) of participants, our results reflect good adherence of the patient/parents to their immunosuppressive treatments. 49.1% (81/165) of the patients did not return to school due to a personal/parental decision in 69.9% (55/81) of cases, due to anxiety of the patient/parents regarding COVID-19. Two patients were diagnosed positive for SARS-CoV-2 infection.

Conclusion:

This study suggests that JIA patients treated with DMARDs continued their treatment during the pandemic. In contrast, parents’ reluctance was a major obstacle for returning to school. Therefore, more solidified school reopening strategies should be developed.

References:

[1]Filocamo G, et al. “Absence of severe complications from SARS-CoV-2 infection in children with rheumatic diseases treated with biologic drugs.” J Rheumatol. 25 avr 2020;

[2]Tagarro A, et al. “Screening and Severity of Coronavirus Disease 2019 (COVID-19) in Children in Madrid, Spain.” JAMA Pediatr. 8 avr 2020;

[3]Lu X, et al. « SARS-CoV-2 Infection in Children”. N Engl J Med. 23 avr 2020;382(17):1663-5.

Acknowledgements:

We would like to thank all the participants involved in this clinical research and six medical students who helped completing the forms: Margaux Blondel, Alice Bonnod, Marie Desval, Béatrice Dordain, Gabrielle Fagnet, and Madouc De Saint Martin Pernot.

Disclosure of Interests:

None declared

Efficacy of Retreatment After Failed Direct-acting Antiviral Therapy in Patients With HCV Genotype 1-3 Infections

Hepatitis C virus infection is causing chronic liver disease, cirrhosis, and hepatocellular carcinoma. By combining direct-acting antivirals (DAAs), high sustained virologic response rates (SVRs) can be achieved. Resistance-associated substitutions (RASs) are commonly observed after DAA failure, and especially nonstructural protein 5A (NS5A) RASs may impact retreatment options.^1-3 Data on retreatment of DAA failure patients using first-generation DAAs are limited.^4-7 Recently, a second-generation protease- and NS5A-inhibitor plus sofosbuvir (voxilaprevir/velpatasvir/sofosbuvir [VOX/VEL/SOF]) was approved for retreatment after DAA failure.⁸ However, this and other second-generation regimens are not available in many resource-limited countries or are not reimbursed by regular insurance, and recommendations regarding the selection of retreatment regimens using first-generation DAAs are very important. This study aimed to analyze patients who were re-treated with first-generation DAAs after failure of a DAA combination therapy.

Low-frequency transcranial stimulation of pre-supplementary motor area alleviates levodopa-induced dyskinesia in Parkinson's disease: a randomized cross-over trial

Levodopa-induced dyskinesia gradually emerges during long-term dopamine therapy, causing major disability in patients with Parkinson disease. Using pharmacodynamic functional MRI, we have previously shown that the intake of levodopa triggers an excessive activation of the pre-supplementary motor area in Parkinson disease patients with peak-of-dose dyskinesia. In this pre-registered, interventional study, we tested whether the abnormal responsiveness of the pre-supplementary motor area to levodopa may constitute a ‘stimulation target’ for treating dyskinesia. A gender-balanced group of 17 Parkinson disease patients with peak-of-dose dyskinesia received 30 min of robot-assisted repetitive transcranial magnetic stimulation, after they had paused their anti-Parkinson medication. Real-repetitive transcranial magnetic stimulation at 100% or sham-repetitive transcranial magnetic stimulation at 30% of individual resting corticomotor threshold of left first dorsal interosseous muscle was applied on separate days in counterbalanced order. Following repetitive transcranial magnetic stimulation, patients took 200 mg of oral levodopa and underwent functional MRI to map brain activity, while they performed the same go/no-go task as in our previous study. Blinded video assessment revealed that real-repetitive transcranial magnetic stimulation delayed the onset of dyskinesia and reduced its severity relative to sham-repetitive transcranial magnetic stimulation. Individual improvement in dyskinesia severity scaled linearly with the modulatory effect of real-repetitive transcranial magnetic stimulation on task-related activation in the pre-supplementary motor area. Stimulation-induced delay in dyskinesia onset correlated positively with the induced electrical field strength in the pre-supplementary motor area. Our results provide converging evidence that the levodopa-triggered increase in pre-supplementary motor area activity plays a causal role in the pathophysiology of peak-of-dose dyskinesia and constitutes a promising cortical target for brain stimulation therapy.

Pneumopathies graves liées au COVID-19 : facteurs prédictifs de mortalité après traitement par tocilizumab

Introduction

Matériels et méthodes

Résultats

Conclusion

Residual Flow Inside the Woven EndoBridge Device at Follow-Up: Potential Predictors of the Bicêtre Occlusion Scale Score 1 Phenomenon

BACKGROUND AND PURPOSE

The Woven EndoBridge (WEB) device is an established technique for the treatment of intracranial aneurysms. Occasionally, persistent opacification inside the WEB lumen can be observed at follow-up (previously described as Bicêtre Occlusion Scale Score 1). We evaluated potential risk factors of this phenomenon, hypothesizing that initial deviation of the WEB device from the aneurysm axis, size of the aneurysmal neck surface, or inappropriate WEB sizing correlates with Bicêtre Occlusion Scale Score 1 findings.

MATERIALS AND METHODS

We systematically reviewed all patients treated with the WEB device between February 2014 and December 2018 in our neurointerventional center. Patients with midterm follow-up DSA available were considered for aneurysm evaluation applying the Bicêtre Occlusion Scale Score. WEB angle deviation from the aneurysm axis, neck widths, and WEB sizes were collected.

RESULTS

We included 65 patients with 67 intracranial aneurysms. Eleven of 67 (16.4%) intracranial aneurysms showed the Bicêtre Occlusion Scale Score 1 phenomenon at follow-up. Anterior-posterior projections of WEB axis deviation (angles measured in degrees) were significantly different between the Bicêtre Occlusion Scale Score 1 cohort (median ± interquartile range, 17 ± 17) and all other Bicêtre Occlusion Scale Scores (median ± interquartile range, 7 ± 11; P = .023), whereas in lateral projections, no significant difference was observed (median ± interquartile range, 10 ± 10 versus 8 ± 9; P = .169). Neck or aneurysm recurrence, but not the Bicêtre Occlusion Scale Score 1 phenomenon, occurred significantly more often in patients with inappropriate WEB sizing compared with appropriate WEB sizing (median ± interquartile range, 1 ± 1.3 versus 0 ± 0; P < .001/P = .664).

CONCLUSIONS

The Bicêtre Occlusion Scale Score 1 phenomenon is associated with an initial deviation of the WEB device from the aneurysm axis but does not correlate with aneurysmal neck surface measurements or WEB sizing.

Tocilizumab therapy reduced intensive care unit admissions and/or mortality in COVID-19 patients

INTRODUCTION

No therapy has yet proven effective in COVID-19. Tocilizumab (TCZ) in patients with severe COVID-19 could be an effective treatment.

METHOD

We conducted a retrospective case-control study in the Nord Franche-Comté Hospital, France. We compared the outcome of patients treated with TCZ and patients without TCZ considering a combined primary endpoint: death and/or ICU admissions.

RESULTS

Patients with TCZ (n=20) had a higher Charlson comorbidity index (5.3 [±2.4] vs 3.4 [±2.6], P=0.014), presented with more severe forms (higher level of oxygen therapy at 13L/min vs 6L/min, P<0.001), and had poorer biological findings (severe lymphopenia: 676/mm³ vs 914/mm³, P=0.037 and higher CRP level: 158mg/L vs 105mg/L, P=0.017) than patients without TCZ (n=25). However, death and/or ICU admissions were higher in patients without TCZ than in the TCZ group (72% vs 25%, P=0.002).

CONCLUSION

Despite the small sample size and retrospective nature of the work, this result strongly suggests that TCZ may reduce the number of ICU admissions and/or mortality in patients with severe SARS-CoV-2 pneumonia.

Gemcitabine plus sorafenib versus gemcitabine alone in advanced biliary tract cancer: a double-blind placebo-controlled multicentre phase II AIO study with biomarker and serum programme

BACKGROUND

Since sorafenib has shown activity in different tumour types and gemcitabine regimens improved the outcome for biliary tract cancer (BTC) patients, we evaluated first-line gemcitabine plus sorafenib in a double-blind phase II study.

PATIENTS AND METHODS

102 unresectable or metastatic BTC patients with histologically proven adenocarcinoma of gallbladder or intrahepatic bile ducts, Eastern Cooperative Oncology Group (ECOG) 0-2 were randomised to gemcitabine (1000 mg/m2 once weekly, first 7-weeks+1-week rest followed by once 3-weeks+1-week rest) plus sorafenib (400 mg twice daily) or placebo. Treatment continued until progression or unacceptable toxicity. Tumour samples were prospectively stained for sorafenib targets and potential biomarkers. Serum samples (first two cycles) were measured for vascular endothelial growth factors (VEGFs), vascular endothelial growth factor receptor 2 (VEGFR-2) and stromal cell-derived factor 1 (SDF1)α by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Gemcitabine plus sorafenib was generally well tolerated. Four and three patients achieved partial responses in the sorafenib and placebo groups, respectively. There was no difference in the primary end-point, median progression-free survival (PFS) for gemcitabine plus sorafenib versus gemcitabine plus placebo (3.0 versus 4.9 months, P=0.859), and no difference for median overall survival (OS) (8.4 versus 11.2 months, P=0.775). Patients with liver metastasis after resection of primary BTC survived longer with sorafenib (P=0.019) compared to placebo. Patients who developed hand-foot syndrome (HFS) showed longer PFS and OS than patients without HFS. Two sorafenib targets, VEGFR-2 and c-kit, were not expressed in BTC samples. VEGFR-3 and Hif1α were associated with lymph node metastases and T stage. Absence of PDGFRβ expression correlated with longer PFS.

CONCLUSION

The addition of sorafenib to gemcitabine did not demonstrate improved efficacy in advanced BTC patients. Biomarker subgroup analysis suggested that some patients might benefit from combined treatment.

Acute Liver Failure Following Minocycline Treatment – A Case Report and Review of the Literature

We present the case of a 23-year-old female patient with acute liver failure following intake of minocycline. This patient had severe hypereosinophilia and massively increased IgE levels. Experimental studies in this case revealed elevated IFN-γ-, as well as TNF-α-producing CD4+ and CD8+ T-cells after in vitro stimulation with minocycline, indicating a type I/IgE-mediated as well as type II/cytotoxic reaction in the pathogenesis of minocycline-induced liver failure. Although mild forms of liver involvement are well known side effects of minocycline, only 8 cases with acute liver failure have been reported, and we present a review of all cases.

Case report on fatal human rabies infection in Hamburg, Germany, March 2007

In this article we describe the clinical presentation of a fatal case of rabies in a German tourist returning from Morocco. Rabies is an acute viral encephalomyelitis that is almost invariably fatal.

Rezidivierende gastrointestinale Blutungen bei Aortenklappenstenose (Heyde-Syndrom): Indikation zum Aortenklappenersatz?

Angiodysplasia are common in patients over the age of 60. Heyde syndrome describes the coincidence of aortic valve stenosis and gastrointestinal bleeding from angiodysplasia. We describe one characteristic case of aortic valve stenosis and gastrointestinal bleeding from angiodysplasia which subsided after replacement with an aortic valve bioprosthesis. We review the current literature and discuss the actual explanation approaches for this phenomenon.

CONCLUSION

There seems to be a clear indication for valve replacement in the case of aortic valve-stenosis and gastrointestinal bleeding due to angiodysplasia.

Severe hepatic injury in interleukin 18 (IL-18) transgenic mice: a key role for IL-18 in regulating hepatocyte apoptosis in vivo

BACKGROUND

Interleukin 18 (IL-18) is a cytokine with pleiotropic activity that augments T helper 1 responses and cytotoxic activity of natural killer cells.

METHODS

To assess the function of IL-18 in vivo, we generated IL-18 transgenic (IL-18 Tg) mice under the control of a CD2 promoter/enhancer construct.

RESULTS

Macroscopically, IL-18 Tg mice showed reduced relative liver weight compared with wild-type littermates. TUNEL assays demonstrated increased hepatocyte apoptosis, and primary hepatocytes isolated from IL-18 Tg mice exhibited an increased spontaneous apoptosis rate. Furthermore, cross linking of Fas increased significantly the apoptosis rate in hepatocytes isolated from wild- type mice but to a much lesser extent in IL-18 Tg mice, suggesting spontaneous activation of the Fas pathway in the latter mice. In fact, in vivo blockade of Fas signal transduction by an adenovirus overexpressing the dominant negative form of the Fas associated death domain rescued hepatocytes from undergoing apoptosis. Finally, adoptive transfer of CD4(+) T cells from IL-18 Tg mice but not from wild-type littermates in SCID mice resulted in severe liver failure with massive periportal fibrosis due to hepatocyte apoptosis.

CONCLUSION

IL-18 plays a fundamental role in regulating hepatocyte apoptosis. Furthermore, our transgenic model provides a novel tool to study the mechanisms of IL-18 dependent liver injury in vivo.

Chemoenzymatic synthesis of isogalactofagomine

A new chemoenzymatic synthesis of optically pure isogalactofagomine 2 starting from achiral starting materials is presented. Dimethyl 4-hydroxypyridine-3,5-dicarboxylate (7) was synthesized and converted to the corresponding saturated piperidine 8. Then the key step of the synthesis was carried out: Lipase M catalyzed hydrolysis of the prochiral diester 8 to cause formation of an asymmetric monoacid with at least 98% enantiomeric excess. Reduction of the acid, saponification of the remaining ester, and radical iododecarboxylation gave an iodide that after substitution with silver trifluoroacetate and hydrolysis gave 2.

Investigation of the slow inhibition of almond beta-glucosidase and yeast isomaltase by 1-azasugar inhibitors: evidence for the 'direct binding' model

(-)-1-Azafagomine [(3R,4R,5R)-4,5-dihydroxy-3-hydroxymethylhexahydropyridazine; inhibitor 1] is a potent glycosidase inhibitor designed to mimic the transition state of a substrate undergoing glycoside cleavage. The inhibition of glycosidases by inhbitor 1 and analogues has been found to be a relatively slow process. This 'slow inhibition' process was investigated in the inhibition of almond beta-glucosidase and yeast isomaltase by inhibitor 1 and analogues. Progress-curve experiments established that the time-dependent inhibition of both enzymes by inhibitor 1 was a consequence of relatively slow dissociation and association of the inhibitor from and to the enzyme, and not a result of slow interchanges between protein conformations. A number of hydrazine-containing analogues of inhibitor 1 also inhibited beta-glucosidase and isomaltase slowly, while the amine isofagomine [(3R,4R,5R)-3,4-dihydroxy-5-hydroxymethylpiperidine; inhibitor 5] only inhibited beta-glucosidase slowly. Inhibitor 1 and related inhibitors were found to leave almond beta-glucosidase with almost identical rate constants, so that the difference in K(i) values depended almost entirely on changes in the binding rate constant, k(on). The same trend was observed for the inhibition of yeast isomaltase by inhibitor 1 and a related inhibitor. The values of the rate constants were obtained at 25 degrees C and at pH 6.8.

[Infectious osteoarthritis due to Propionibacterium acnes. Two new cases]

INTRODUCTION

Propionibacterium acnes is an anaerobic germ, usually found as a saprophyte of the skin and the mucosa. It may be responsible for iatrogenic or spontaneous osteoarhritis.

EXEGESIS

We report two new cases of septic arthritis induced by P. acnes: a case of iatrogenic spondylodiscitis and a case of spontaneous septic arthritis of the lumbar facet joints. The two patients were immunocompetent, without acne.

CONCLUSION

Except for patients with criteria of the SAPHO syndrome (synovitis-acne-pustulosis-hyperostosis-osteomyelitis), osteoarthritis caused by P. acnes is increasingly described. The number of these infections is probably underestimated because of the technical problems involved in isolating P. acnes in the laboratory.

Enantiospecific synthesis of 1-azafagomine

For the first time the two enantiomeric forms of the glycosidase inhibitor 1-azafagomine have been synthesised starting from D- and L-xylose. D-Xylose was converted to the 2,3,5-tribenzylfuranose, which upon reductive amination with tert-butyl carbazate gave the protected 1-hydrazino-1-deoxypentitol in high yield. N-acetylation, mesylation of the 4-OH, removal of the Boc group, cyclisation and deprotection gave (+)-1-azafagomine ((+)-1). By a similar sequence of reactions, L-xylose was converted to (-)-1-azafagomine ((-)-1). Enzymatic and other routes to optically pure 1-azafagomine were also studied. Compound (-)-1 is a potent competitive glycosidase inhibitor, while (+)-1 has no biological activity. The inhibition of almond beta-glucosidase by (-)-1 was found to be slow owing to a slow binding step of inhibitor to enzyme, with no subsequent conformational rearrangement. The rate constants for binding and release were found to be 3.3 x 10(4)M(-1)s(-1) and 0.011 s(-1), respectively, yielding Ki = 0.33 microM.

Synthesis and deconvolution of the first combinatorial library of glycosidase inhibitors

A combinatorial library of 125 compounds with a structure consisting of 1-azafagomine linked at N-1 via an acetic acid linker to a variable tripeptide was synthesised. The library was synthesised by Merrifield split and mix synthesis of the peptide, followed by capping with chloroacetate, regioselective nucleophilic substitution with 1-azafagomine and cleavage from the polymeric support. The library was screened for inhibition of beta-glucosidase, alpha-glucosidase and glycogen phosphorylase and found to display beta-glucosidase inhibition. Deconvolution of the library revealed that some inhibition was caused by all library members but the strongest inhibitor was clearly a compound having three hydroxyproline residues in the peptide fragment. This compound was a weaker but more selective inhibitor than 1-azafagomine itself.

Cellular and humoral immune responses against autoreactive T cells in multiple sclerosis patients after T cell vaccination

Myelin basic protein (MBP)-reactive T cells may play an important role in the autoimmune pathogenesis of multiple sclerosis (MS). MBP-reactive T cells can be specifically targeted by T cell vaccination, a procedure whereby MS patients are immunized with attenuated autologous MBP reactive T cells. T cell vaccination induces immune responses to the vaccine cells together with a depletion of MBP reactive T cells. Forty-nine MS patients were treated with T cell vaccination in an extended phase I trial to study the safety, immune responses and clinical effects of T cell vaccination. In the present paper the immune responses towards the vaccine cells were characterized. Substantial long-term in vitro proliferative responses were observed in all treated patients. Some patients, immunized with different clones, displayed distinct proliferative reactivity against the various vaccine clones, suggesting unequal immunogenic properties of these clones. Reactive TCRalphabeta(+), CD8(+)and CD4(+)T cells, and to a lesser extent, gammadelta T cells and NK cells were observed to in vitro stimulation with the vaccine cells. A small fraction only of CD8(+)T cells expressed cytolytic and inhibitory anti-clonotypic reactivity against the vaccine cells. Stimulation with the vaccine clones predominantly induced expression of pro-inflammatory cytokines in these mixed cultures, although one vaccine clone consistently induced production of IL-4. CD4(+)T cells are the major cytokine-producing cells in these anti-vaccine lines. We could not detect upregulated antibody responses to the vaccine cells in most patients, although a temporary antibody response was observed in one patient. In conclusion, immunization with attenuated autoreactive T cells induces a complex cellular response specifically targeted at the vaccine cells, but no antibody responses. These data provide further insights into the mechanisms of T cell vaccination and improve our understanding of the complex regulatory networks of autoreactive T cells.

Pneumococcal polyarticular septic arthritis in a patient with rheumatoid arthritis

Rheumatoid arthritis is the most commonly reported host-related risk factor for septic arthritis. This risk is highest in severe, seropositive, long-standing (mean, 10 years) rheumatoid arthritis responsible for extraarticular symptoms and treated with systemic glucocorticoids. The clinical presentation of the joint infection is often atypical, leading to diagnostic wanderings. In 25% of cases, the infection is polyarticular, with 3.5 involved joints on average. Staphylococcus aureus is the most common causative organism. Streptococcus pneumoniae causes 5% of all cases of septic arthritis and is more often responsible for polyarticular infections than other organisms. Polyarticular septic arthritis carries a poor prognosis, with a mortality rate of 50% in rheumatoid arthritis patients. Despite its low incidence, polyarticular septic arthritis should be routinely considered in the differential diagnosis of rheumatoid flares. We report a case of pneumococcal septic arthritis involving five joints in a patient with known rheumatoid arthritis. Three other cases with involvement of more than four joints have been published.

Synthesis of substituted chiral piperazones resembling aza-sugars

(6R)-6-(Hydroxymethyl)piperazin-2-one (1), (6S)-6-(hydroxymethyl)piperazin-2-one (2) and (6S)-6-[(1R, 2S, 3R)-1,2,3,4-tetrahydroxybutyl]piperazin-2-one (3) have been prepared in optically pure forms starting from D-glucosamine hydrochloride (4). The compounds (1-3) were tested for glycosidase inhibition.

[Hepatitis C virus and autoimmune hepatitis: coincidence or causal relationship?]

HCV has been implicated in a variety of immune disorders as Sjogren's Syndrome, thyroiditis, glomerulonephritis, panarteritis nodosa and AIH. Soon after its discovery HCV has been causative associated with AIH due to a high incidence of antibodies against the virus tested by first generation assays. However applying more specific systems and by direct demonstration of the HCV RNA we have found only 2% of patients with confirmed AIH to harbour the virus. About 19% of patients with virus Hepatitis C may present with autoantibodies in the serum as RNA, SNA and only 2% have antibodies against LKM Type 1. Liver biopsies from patients with chronic Hepatitis C and autoantibodies display features typical for chronic hepatitis C as described in the literature and not those of the autoimmune type. Furthermore immunohistological findings show a predominance of CD8 lymphocytes and only a weak expression of ASGPR, parameters that are easily found in autoimmune hepatitis. On the basis of serological, histopathological and immunohistological studies it seems very unlikely that HCV can be regarded as a causative agent for the induction of autoimmune Hepatitis.

Parenchymal and nonparenchymal liver cells and their interaction in the local immune response

Nonparenchymal liver cells (Kupffer cells, sinusoidal endothelial cells, Ito-cells and liver-associated lymphocytes) interact with hepatocytes and with each other by soluble mediators and direct cell-cell contact. The acute phase response is a nonspecific reaction of the organism to trauma, injury or infection and its main constituents the acute phase proteins are produced by hepatocytes. The profile of acute phase protein production is influenced by the local presence of cytokines with IL-6 as the principal regulator. Nonparenchymal cells (Kupffer cells, sinusoidal endothelial cells and Ito-cells) are a source of IL-6 and therefore participate in the generation of acute phase response. The release of IL-10 by Kupffer cells with consecutive down-regulation of IL-6 production may be a mechanism by which resolution of acute phase response is achieved. Still, the mechanisms underlying chronic inflammation remain unclear. Concerning the antigen-specific immune response nonparenchymal liver cells have a number of important functions. They can act as antigen-presenting cells (Kupffer cells) or mediate effector functions (liver associated lymphocytes). Local interaction of nonparenchymal cells with hepatocytes can be mediated by cytokines and/or adhesion molecule expression which again may lead to mutual influence of immunological functions, e.g. TNF-alpha release by Kupffer cells may enhance MHC-II expression on hepatocytes and consequently augment antigen-presenting capacity leading to an improved antigen-specific immune response. Leukocytes are attracted and home to the liver by mechanisms poorly defined because the initial contact between leukocytes and macrovascular endothelium.(ABSTRACT TRUNCATED AT 250 WORDS)

Strategy for the characterization of autoantigens in autoimmune diseases. Investigation of the target antigens of antimitochondrial antibodies by radioimmunoassay, immunoblotting, monoclonal antibodies and affinity chromatography

We present a strategy to characterize specific antigen/autoantibody systems using polyclonal sera from patients as a probe and crude antigenic preparations such as mitoplasts. Sera from patients with primary biliary cirrhosis (PBC) are characterized by at least one of two specific subtypes of antimitochondrial antibodies (AMA), anti-p48 or anti-p62. Immunoblotting of such sera with mitoplast preparations derived from human, rat and rabbit livers revealed three proteins of approximately 27, 48 and 68 kDa as target antigens. On the basis of the molecular weight of these antigens we were able to purify them by elution from preparative SDS gels. Immunization of NZB mice with the high molecular weight component (the 68 kDa antigen from human liver mitoplasts) elicited a monoclonal antibody. The 68 kDa protein was then isolated by affinity chromatography and may well represent the prime target antigen of anti-p62 antimitochondrial antibodies. This experimental approach could be applied to protein target antigens of other autoantibodies.