Monocytes Loaded with Indocyanine Green as Active Homing Contrast Agents?Permit Optical Differentiation of Infectious and Non-Infectious Inflammation

Distinguishing cutaneous infection from sterile inflammation is a diagnostic challenge and currently relies upon subjective interpretation of clinical parameters, microbiological data, and nonspecific imaging. Assessing characteristic variations in leukocytic infiltration may provide more specific information. In this study, we demonstrate that homing of systemically administered monocytes tagged using indocyanine green (ICG), an FDA-approved near infrared dye, may be assessed non-invasively using clinically-applicable laser angiography systems to investigate cutaneous inflammatory processes. RAW 264.7 mouse monocytes co-incubated with ICG fluoresce brightly in the near infrared range. In vitro, the loaded cells retained the ability to chemotax toward monocyte chemotactic protein-1. Following intravascular injection of loaded cells into BALB/c mice with induced sterile inflammation (Complete Freund’s Adjuvant inoculation) or infection (Group A Streptococcus inoculation) of the hind limb, non-invasive whole animal imaging revealed local fluorescence at the inoculation site. There was significantly higher fluorescence of the inoculation site in the infection model than in the inflammation model as early as 2 hours after injection (p<0.05). Microscopic examination of bacterial inoculation site tissue revealed points of near infrared fluorescence, suggesting the presence of ICG-loaded cells. Development of a non-invasive technique to rapidly image inflammatory states without radiation may lead to new tools to distinguish infectious conditions from sterile inflammatory conditions at the bedside.     

Place de la tomographie par émission de positons dans la prise en charge des fièvres d’origine inconnue

FDG-PET has become an established diagnostic tool in oncology. Fluorodeoxyglucose is not a specific tracer for malignant lesions, as uptake depends on accumulation of FDG in cells with an increased glucose metabolism as it is also the case in inflammatory and infectious lesions. Thus, FDG-PET could be valuable in diagnosing patients with fever of unknown origin (FUO). The percentage of FDG-PET scans helpful in the diagnostic process in patients with FUO is estimated in average around 30%. However, more evaluating prospective studies should be awaited before integrating FDG-PET in clinical routine use in order to compare different techniques already validated (biology, radiology, conventional scintigraphic imaging), to evaluate its cost-effectiveness and to determine its place for the managment of FUO.     

Product limit estimation for infectious disease data when the diagnostic test for the outcome is measured with uncertainty

Low sensitivity and/or specificity of a diagnostic test for outcome results in biased estimates of the time to first event using product limit estimation. For example, if a test has low specificity, estimates of the cumulative distribution function (cdf) are biased towards time zero, while estimates of the cdf are biased away from time zero if a test has low sensitivity. In the context of discrete time survival analysis for infectious disease data, we develop self-consistent algorithms to obtain unbiased estimates of the time to first event when the sensitivity and/or specificity of the diagnostic test for the outcome is less than 100%. Two examples are presented. The first involves estimating time to first detection of HIV-1 infection in infants in a randomized clinical trial, and the second involves estimating time to first Neisseria gonorrhoeae infection in a cohort of Kenyan prostitutes.     

Cytodiagnosis of extrapleural tumors in multiple myeloma by fine needle aspiration. A report of three cases.

Cytologic and immunocytochemical studies were done on fine needle aspirates of extrapleural tumors from three patients with multiple myeloma. In the first case the cytologic findings were consistent with myeloma, but the immunochemical studies were done improperly and were not interpretable. In the second case the cytologic findings were those of acute inflammation despite the strong clinical suspicion of the thoracic lesion's malignancy. In the third case both the cytologic and immunocytochemical findings were diagnostic of plasmacytoma. Our experience with these cases suggests that an assessment of the nature of the extrapleural tumor is indicated even in patients with known myeloma, that fine needle aspiration (FNA) is the diagnostic procedure of choice under the circumstances and that immunocytochemical studies can enhance the diagnostic accuracy of FNA for plasmacytoma. The best results for assessment of the cytologic FNA findings in extrapleural tumor in myeloma can be achieved by proper execution of both the FNA procedure and immunochemical studies and by interpretation of the cytologic findings within the context of the clinical findings.     

Gout. Mechanisms of inflammation in gout

An acute attack of gout is a paradigm of acute sterile inflammation, as opposed to pyogenic inflammation. Recent studies suggest that the triggering of IL-1β release from leucocytes lies at the heart of a cascade of processes that involves multiple cytokines and mediators. The NLRP3 inflammasome appears to have a specific role in this regard, but the biochemical events leading to its activation are still not well understood. We review the known mechanisms that underlie the inflammatory process triggered by urate crystals and suggest areas that require further research.     

Schistosoma mansoni: a diagnostic approach to detect acute schistosomiasis infection in a murine model by PCR

Schistosomiasis represents an increasing problem in non-endemic areas, due to the growing number of immigrants and to tourists contracting this disease in "off-the-beaten-track" tourism. Acute schistosomiasis is not diagnosed early due to the lack of diagnostic tools that are sufficiently sensitive enough to detect the parasite during the first weeks of infection. We have developed a diagnostic approach based on the detection of parasite DNA by polymerase chain reaction (PCR) in urine, comparing the performance of this new approach with the two currently used schistosomiasis diagnostic tools (Kato-Katz and ELISA) and the PCR in stool samples. This comparison was done in a Schistosoma mansoni murine experimental model, which permits follow up of the parasite from the acute to the chronic stage of infection. Our results suggest that this new PCR-based approach could be useful for the detection of acute schistosomiasis in easy-to-handle clinical samples such the urine.     

Clinical utility of ICD‐11 diagnostic guidelines for high‐burden mental disorders: results from mental health settings in 13 countries

In this paper we report the clinical utility of the diagnostic guidelines for ICD‐11 mental, behavioural and neurodevelopmental disorders as assessed by 339 clinicians in 1,806 patients in 28 mental health settings in 13 countries. Clinician raters applied the guidelines for schizophrenia and other primary psychotic disorders, mood disorders (depressive and bipolar disorders), anxiety and fear‐related disorders, and disorders specifically associated with stress. Clinician ratings of the clinical utility of the proposed ICD‐11 diagnostic guidelines were very positive overall. The guidelines were perceived as easy to use, corresponding accurately to patients’ presentations (i.e., goodness of fit), clear and understandable, providing an appropriate level of detail, taking about the same or less time than clinicians’ usual practice, and providing useful guidance about distinguishing disorder from normality and from other disorders. Clinicians evaluated the guidelines as less useful for treatment selection and assessing prognosis than for communicating with other health professionals, though the former ratings were still positive overall. Field studies that assess perceived clinical utility of the proposed ICD‐11 diagnostic guidelines among their intended users have very important implications. Classification is the interface between health encounters and health information; if clinicians do not find that a new diagnostic system provides clinically useful information, they are unlikely to apply it consistently and faithfully. This would have a major impact on the validity of aggregated health encounter data used for health policy and decision making. Overall, the results of this study provide considerable reason to be optimistic about the perceived clinical utility of the ICD‐11 among global clinicians.     

腹内压值对外科急腹症患者的检测价值研究

目的:评估膀胱压力(BP)测量作为急腹症诊断工具的临床价值。方法:选取在我院外科治疗的患者,根据病情分为两组:一组为325例急腹症患者,对照组为50例进行腹腔镜手术的患者。在治疗前测量患者腹内压力。患者采用仰卧位,将50 m L无菌生理盐水缓慢注射到膀胱中,待排光后检测BP。将导管同水压计连接,以耻骨联合处为参考点。将BP值大于10 cm H2O,作为诊断急腹症的标准。结果:BP诊断急腹症的灵敏度为94.4%,特异性为79%,阳性预测值为95.9%,阴性预测值为71.7%,精确度为92.3%。结论:腹内压(IAP)升高可以作为急性腹痛的诊断工具。BP检测有助于临床医生在试验室检查或影像学检查结果有限时对患者病情进行评估。     

The capacities of autoleukocyte-labelled scintigraphy in the detection of foci of inflammation and suppuration

The diagnostics of occult inflammation foci up to day remains the major and complicated problem in almost each clinical discipline. Whole-body scintigraphy and SPECT studies with 99mTc-autoleucocytes show silent foci of inflammation and infection. 68 patients (24 females and 44 males) aged 14-59 years with non-localized inflammatory diseases were evaluated. Each patient underwent routine clinical and laboratory investigation. But because of the inadequacy of other diagnostic procedures, the Tc-99m-WBC scans may be of great clinical importance. For the determining of the SPECT of thorax were performed using Tc-99m-HMPAO (hexametylpropilenaminoxime) labeled autoleucocytes. In 1, 3 and 24 hours post injection inflammatory foci were seen as the areas of pathogenic activity. In 24 patients the circumscribed activity seen in relation to heart convincingly demonstrated endo- and/or myocarditis. 16 patients showed acute inflammation in postoperative wound, empyema of pleura and mediastinitis as the consequences of cardiosurgery. In 16 patients whole-body scanning and SPECT of the head revealed chronic infection in nasopharynx and accessory nasal sinuses dental infection and the rest 7 patients had abdominal and pelvic inflammatory diseases, such as ulcerative colitis, intraabdominal and retroperitoneal septic foci, tubo-ovarial inflammatory disease. The data demonstrated that Tc-99m-leucocytes imaging is a highly sensitive and specific for the detection of inflammatory diseases of different localization.     

Utility of Intraoperative Frozen Section in the Diagnosis of Periprosthetic Joint Infection

Purpose

Intraoperative frozen section (FS) is an effective diagnostic test for periprosthetic joint infection (PJI). We evaluated the diagnostic characteristics of single- and multiplex-site intraoperative FS, and evaluated the results of single-site FS combined with those of C-reactive protein (CRP) level and erythrocyte sedimentation rate (ESR) for assessing PJI.

Methods

We studied 156 painful joint arthroplasties in 152 consecutive patients presenting for revision total joint arthroplasty due to PJI. Receiver operating characteristic analysis was used to determine the optimal cutoff values for CRP level, ESR, and intraoperative FS histopathology. Sensitivity, specificity, positive and negative predictive values, and accuracy of the diagnostic tests were assessed using a 2×2 table.

Results

We investigated the diagnostic utility of polymorphonuclear leukocyte number (PMN) per high-power field (HPF) on FS. Our data showed that 5 PMNs per HPF is a suitable diagnostic threshold, with a high accuracy in single- and multiplex-site FS. Five PMNs in any 1 of 5 sites had the highest sensitivity of 0.86 and a specificity of 0.96. Five PMNs in every 1 of 5 sites had greater diagnostic utility, with a specificity of 1; however, the sensitivity of this measure fell to 0.62. Five PMNs in single-site FS had a sensitivity of 0.70 and a specificity of 0.94. Five PMNs in single-site FS or CRP level ≥15 mg/L increased the sensitivity to 0.92; however, the specificity decreased to 0.79.

Conclusion

Compared with single-site FS, any 1 positive site on multiplex-site FS may improve sensitivity, while every 1 positive site on multiplex-site FS may improve specificity. Five PMNs in any 1 of 5 sites on FS has excellent utility for the diagnosis of PJI. Additional systematic large-scale studies are needed to verify this result.     

Toxoplasma gondii-positive human sera recognise intracellular tachyzoites and bradyzoites with diverse patterns of immunoreactivity

Antibody detection assays have long been the first line test to confirm infection with the zoonotic parasite Toxoplasma gondii. However, challenges exist with serological diagnosis, especially distinguishing between acute, latent and reactivation disease states. The sensitivity and specificity of serological tests might be improved by testing for antibodies against parasite antigens other than those typically found on the parasite surface during the acute stage. To this end, we analysed the reactivity profile of human sera, identified as positive for anti-Toxoplasma gondii IgG in traditional assays, by indirect immunofluorescence reactivity to acute stage intracellular tachyzoites and in vitro-induced latent stage bradyzoites. The majority of anti-Toxoplasma gondii IgG positive sera recognised both intracellularly replicating tachyzoites and in vitro-induced bradyzoites with varying patterns of immune-reactivity. Furthermore, anti-bradyzoite antibodies were not detected in sera that were IgM-positive/IgG-negative. These results demonstrate that anti-Toxoplasma gondii-positive sera may contain antibodies to a variety of antigens in addition to those traditionally used in serological tests, and suggest the need for further investigations into the utility of anti-bradyzoite-specific antibodies to aid in diagnosis of Toxoplasma gondii infection.     

Blebs produced by actin–myosin contraction during apoptosis release damage-associated molecular pattern proteins before secondary necrosis occurs

Apoptosis is a fundamental homeostatic mechanism essential for the normal growth, development and maintenance of every tissue and organ. Dying cells have been defined as apoptotic by distinguishing features, including cell contraction, nuclear fragmentation, blebbing, apoptotic body formation and maintenance of intact cellular membranes to prevent massive protein release and consequent inflammation. We now show that during early apoptosis limited membrane permeabilization occurs in blebs and apoptotic bodies, which allows release of proteins that may affect the proximal microenvironment before the catastrophic loss of membrane integrity during secondary necrosis. Blebbing, apoptotic body formation and protein release during early apoptosis are dependent on ROCK and myosin ATPase activity to drive actomyosin contraction. We identified 231 proteins released from actomyosin contraction-dependent blebs and apoptotic bodies by adapted SILAC (stable isotope labeling with amino acids in cell culture) combined with mass spectrometry analysis. The most enriched proteins released were the nucleosomal histones, which have previously been identified as damage-associated molecular pattern proteins (DAMPs) that can initiate sterile inflammatory responses. These results indicate that limited membrane permeabilization occurs in blebs and apoptotic bodies before secondary necrosis, leading to acute and localized release of immunomodulatory proteins during the early phase of active apoptotic membrane blebbing. Therefore, the shift from apoptosis to secondary necrosis is more graded than a simple binary switch, with the membrane permeabilization of apoptotic bodies and consequent limited release of DAMPs contributing to the transition between these states.     

Infection de prothèse vasculaire : TEP-FDG vs scintigraphie aux leucocytes marqués (planaires et TEMP/TDM)

Vascular prosthesis infection is an uncommon but life-threatening complication. Its diagnosis is difficult to establish especially due to the low specificity of computed tomography (CT). The aim of this preliminary study was to compare the diagnostic value of positron emission tomography with¹⁸FDG (¹⁸FDG-PET) and ^99mTc-HMPAO-labeled leukocytes scintigraphy in this indication. ¹⁸FDG-PET/CT and ^99mTc-HMPAO-labeled leukocytes scintigraphy (planar at 6th and 24th hours after injection + SPECT/CT at the 6th hour) were prospectively performed in 11 patients (total of 22 vascular prosthesis with 14 clinical suspicions of infection). Both scans were retrospectively and blindly assessed by two independent nuclear medicine physicians. Interpretation was based on visual analysis. The gold standard was bacteriology findings or clinical follow-up greater than 6 months. Eight prostheses were considered as infected. PET found eight true-positive and one false-positive. Scintigraphy found eight true-positive and no false-positive. A focal or heterogeneous FDG-uptake higher or equal than hepatic uptake was considered as positive in PET. A focal prosthetic activity, stable or increased at the 24th hour was considered as positive in labeled leukocyte scintigraphy. SPECT/CT gave accurate anatomic localization and differentiated clearly infections of soft tissues from those of prostheses. ¹⁸FDG-PET could be performed in first-line in suspicion of vascular prosthesis infection. In litigious cases, a^99mTc-HMPAO-labeled leukocytes scintigraphy in association with SPECT/CT could bring additional arguments for infection diagnosis.     

Identification of diagnostic biomarkers for infection in premature neonates

Infection is a leading cause of neonatal morbidity and mortality worldwide. Premature neonates are particularly susceptible to infection because of physiologic immaturity, comorbidity, and extraneous medical interventions. Additionally premature infants are at higher risk of progression to sepsis or severe sepsis, adverse outcomes, and antimicrobial toxicity. Currently initial diagnosis is based upon clinical suspicion accompanied by nonspecific clinical signs and is confirmed upon positive microbiologic culture results several days after institution of empiric therapy. There exists a significant need for rapid, objective, in vitro tests for diagnosis of infection in neonates who are experiencing clinical instability. We used immunoassays multiplexed on microarrays to identify differentially expressed serum proteins in clinically infected and non-infected neonates. Immunoassay arrays were effective for measurement of more than 100 cytokines in small volumes of serum available from neonates. Our analyses revealed significant alterations in levels of eight serum proteins in infected neonates that are associated with inflammation, coagulation, and fibrinolysis. Specifically P- and E-selectins, interleukin 2 soluble receptor alpha, interleukin 18, neutrophil elastase, urokinase plasminogen activator and its cognate receptor, and C-reactive protein were observed at statistically significant increased levels. Multivariate classifiers based on combinations of serum analytes exhibited better diagnostic specificity and sensitivity than single analytes. Multiplexed immunoassays of serum cytokines may have clinical utility as an adjunct for rapid diagnosis of infection and differentiation of etiologic agent in neonates with clinical decompensation.     

The diagnostic impact of implementing a molecular-based algorithm to standard mycobacterial screening at a reference laboratory with an intermediate prevalence for non-respiratory samples

Rapid, reliable results can be given by molecular, direct detection and identification of the Mycobacterium tuberculosis (MTB/Mtb) complex from clinical samples. The Xpert MTB/RIF assay is an assay that has been availablefor more than a decade for identification of Mycobacterium tuberculosis and resistance to rifampicin. However, there is minimal evidence on its clinical usefulness in paucibacillary, non-respiratory samples. The Xpert MTB/RIF assay clinical utility index, its diagnostic characteristics and the number required to diagnose 2935 non-respiratory specimens submitted for routine mycobacterial work-up in a reference laboratory in an intermediate prevalence setting per specimen form were evaluated. The Xpert MTB/RIF assay showed a variable clinical utility index and number required to diagnose (NND) depending on the type of specimen, which was moderate in tissue biopsies (NND = 1.8) and excellent in pus and urine samples, compared to acid-fast microscopy and culture as a gold standard technique (NND = 1.1 and 1.2). Microscopy, on the other hand, consistently showed a weak to fair index of clinical usefulness in all specimen forms, with in NND of 2.3–12.5. The NND for detecting tuberculous infection in the cerebrospinal fluid by the Xpert MTB/RIF assay was noted to be 1.2, with a moderate clinical utility index of 0.8. The evidence presented indicates that the overall appropriate diagnostic utility of the Xpert MTB/RIF assay is clinically successful in most non-respiratory samples. To check the cost-effectiveness and prognostic effect of integrating this completely automated molecular-based assay into the routine testing algorithm for non-respiratory mycobacterial specimens, further data must be collected.     

Emerging role of myeloperoxidase and oxidant stress markers in cardiovascular risk assessment

PURPOSE OF REVIEW: Myeloperoxidase, an abundant leukocyte protein that generates reactive oxidant species, is present and catalytically active within atherosclerotic lesions. Numerous lines of evidence suggest mechanistic links between myeloperoxidase, inflammation and both acute and chronic manifestations of cardiovascular disease. RECENT FINDINGS: Myeloperoxidase generates reactive oxidant species as part of its function in innate host defense mechanisms. The reactive species formed, however, may also damage normal tissues, contributing to inflammatory injury. Recent studies suggest that MPO-generated oxidants participate in multiple processes relevant to cardiovascular disease development and outcomes, including induction of foam cell formation, endothelial dysfunction, development of vulnerable plaque, and ventricular remodeling following acute myocardial infarction. Of note, measurements of myeloperoxidase mass and activity may be useful in cardiac risk stratification, both for chronic disease assessment, as well as in identification of patients at risk in the acute setting. SUMMARY: The inflammatory protein myeloperoxidase is present, active and mechanistically poised to participate in the initiation and progression of cardiovascular disease. The many links between myeloperoxidase, oxidation and cardiovascular disease suggest this leukocyte protein may have clinical utility in risk stratification for cardiovascular disease status and outcomes.     

FDG-PET-CT in pyrexia of unknown origin and inflammatory diseases

FDG-PET has been used successfully over the last decade for imaging patients with fever of unknown origin. Nowadays, PET-CT has become the standard in many centres although a limited number of prospective studies is available. This article summarizes the experience in the field and the potential use of FDG-PET in other inflammatory or immune diseases, such as sarcoidosis or rheumatoid arthritis.     

Fine needle aspiration cytology in the management of male breast masses. Nineteen years of experience.

OBJECTIVE: To determine the utility and accuracy of fine needle aspiration cytology (FNAC) as well as its sensitivity, specificity and predictive value in the diagnosis of male breast masses. STUDY DESIGN: Data on male breast FNAC done between 1978 and 1997 were retrieved from the records of the cytopathology laboratory. FNAC diagnoses were categorized as positive, negative, inconclusive or unsatisfactory. Cytohistologic correlation was done with data from histopathology records. Sensitivity, specificity, diagnostic accuracy and predictive values of FNAC were calculated using standard statistical methods. RESULTS: Five hundred seven of 13,175 patients undergoing breast FNAC were males. Of them, 393/507 had satisfactory aspirates. Of these, 70 were positive (13.8%), 295 were negative (58%), and 29 were inconclusive (5.7%). A total of 114 FNACs (22.5%) were unsatisfactory. Histopathology was available in 97/507 cases. There were no false positive or false negative diagnoses. FNAC had a sensitivity, specificity and diagnostic accuracy of 100% for male breast lesions. CONCLUSION: This large study shows that FNAC is a very accurate tool for diagnosis of male breast lesions. It is highly sensitive and specific, with good cytohistologic correlation. FNAC should therefore be an integral part of the primary assessment of breast lumps in males.     

When is pneumonia not pneumonia: a clinicopathologic study of the utility of lung tissue biopsies in determining the suitability of cadaveric tissue for donation

Healthcare-associated pneumonia (HCAP) represents a major diagnostic challenge because of the relatively low sensitivity and specificity of clinical criteria, radiological findings, and microbiologic culture results. It is often difficult to distinguish between pneumonia, underlying pulmonary disease, or conditions with pulmonary complications; this is compounded by the often-subjective clinical diagnosis of pneumonia. We conducted this study to determine the utility of post-mortem lung biopsies for diagnosing pneumonia in tissue donors diagnosed with pneumonia prior to death. Subjects were deceased patients who had been hospitalized at death and diagnosed with pneumonia. Post-mortem lung biopsies were obtained from the anatomic portion of the cadaveric lung corresponding to chest radiograph abnormalities. Specimens were fixed, stained with hematoxylin and eosin, and read by a single board-certified pathologist. Histological criteria for acute pneumonia included intense neutrophilic infiltration, fibrinous exudates, cellular debris, necrosis, or bacteria in the interstitium and intra-alveolar spaces. Of 143 subjects with a diagnosis of pneumonia at time of death, 14 (9.8 %) had histological evidence consistent with acute pneumonia. The most common histological diagnoses were emphysema (53 %), interstitial fibrosis (40 %), chronic atelectasis (36 %), acute and chronic passive congestion consistent with underlying cardiomyopathy (25 %), fibro-bullous disease (12 %), and acute bronchitis (11 %). HCAP represents a major diagnostic challenge because of the relatively low sensitivity and specificity of clinical criteria, radiological findings, and microbiologic testing. We found that attending physician-diagnosed pneumonia did not correlate with post-mortem pathological diagnosis. We conclude that histological examination of cadaveric lung tissue biopsies enables ascertainment or rule out of underlying pneumonia and prevents erroneous donor deferrals.     

Évaluation de la TEP au 18F-FDG dans l’exploration de la récidive des carcinomes colorectaux

PurposeThe aim of the study was to evaluate the diagnostic performance, the prognosis factors and the therapeutic impact of 18F-FDG positron emission tomography (FDG-PET) in the detection of recurrent colorectal cancers.MethodsSixty PET/CT with 18F-FDG and CT were performed in 52 patients, at the Paul Papin cancer center between 2003 and 2005, following suspicion of colorectal cancer relapse. The FDG-PET impact on the clinical management was studied by examination of multidisciplinary concertations results. Survival analysis were realized with a mean follow up of 2.2 years.ResultsRecurrence was confirmed for 50 explorations by histologic (n = 32), radiologic (n = 14) or clinical (n = 4) findings. Twenty patients died during the time of the study. On a patient based analysis, FDG-PET sensitivity, specificity and overall accuracy were 90, 90, 90% respectively compared with 74, 50 and 70% for CT. FDG-PET changed the clinical management in 18 cases (30%). A positive FDG-PET signal, more than one hepatic lesion, more than two lymph node lesions detected on FDG-PET and more than two hepatic lesions on CT were characterized as bad prognostic factors for survival. Multivariate analysis showed that the only independent bad prognostic factor was the FDG-PET detection of more than two liver lesions.ConclusionThese results confirmed the important impact of FDG-PET in the clinical management of patients with a suspected recurrence of colorectal cancer.