Diagnostic Marker Of Infection Research Articles

The Value of Neutrophil-to-Lymphocyte Ratio to Identify Bacterial Infection and Predict Short-Term Mortality in Patients with Acutely Decompensated Cirrhosis.

Liver cirrhosis patients are highly susceptible to infections, affecting survival, but current parameters for detecting infection are not reliable enough in this population. We investigated the ability of white blood cell (WBC), ∆WBC, neutrophil and ∆neutrophil counts, neutrophil-to-lymphocyte (NLR) and ∆NLR ratios and C-reactive protein (CRP) and procalcitonin (PCT) levels to identify infection and predict short-term mortality in liver cirrhosis patients. We recruited 233 patients with liver cirrhosis hospitalized with acute decompensation (AD) who had an outpatient visit within 1 month (baseline laboratory data) and followed them for 90 days. Difference between laboratory values at baseline and the AD episode was defined as delta (∆) values of the parameters. Delta values did not increase the diagnostic and predictive ability of investigated parameters. The CRP level was found to be the best diagnostic marker for infection in patients with cirrhosis. However, NLR seems to be superior for short-term mortality prediction, better than the WBC count. Distinguishing inflammations of different origin is a remaining clinical challenge in acutely decompensated cirrhosis. Based on our results, NLR might be more suitable for predicting short-term mortality in patients with AD than the WBC count currently included in the CLIF-C AD score.

Antibody production and characterization of the nucleoprotein of sever fever with thrombocytopenia syndrome virus (SFTSV) for effective diagnosis of SFTSV

BackgroundSevere fever with thrombocytopenia syndrome (SFTS) is an infectious disease caused by the Dabie bandavirus, [or SFTS virus (SFTSV)] that has become increasingly widespread since it was first reported in 2009. The SFTSV comprises three essential single-stranded RNA gene segments, with the S segment encoding the nucleocapsid (N) protein. Since the N protein is the most abundant and stable viral protein, it is a useful diagnostic marker of infection. Various SFTSV N-protein-based detection methods have been developed. However, given the limited research on antibodies of an SFTSV N-protein, here we report the characterization of the antibodies against SFTSV N protein especially their mapping results which is essential for more efficient and optimized detection of SFTSV.MethodsTo generate SFTSV-N-protein-specific monoclonal antibodies, recombinant full-length SFTSV N protein was expressed in E. coli, and the purified N protein was immunized to mice. The binding epitope positions of the antibodies generated were identified through binding-domain mapping. An antibody pair test using a lateral flow immunoassay (LFIA) was performed to identify effective diagnostic combinations of paired antibodies.ResultsNine monoclonal antibodies specific for the SFTSV N protein were generated. Antibodies #3(B4E2) and #5(B4D9) were specific for sequential epitopes, while the remainder were specific for conformational epitopes. Antibody #4(C2G1) showed the highest affinity for the SFTSV N protein. The binding domain mapping results indicated the binding regions of the antibodies were divided into three groups. The antibody pair test demonstrated that #3(B4E2)/#4(C2G1) and #4(C2G1)/#5(B4D9) were effective antibody pairs for SFTSV diagnosis.ConclusionsEffective virus detection requires at least two strong antibodies recognizing separate epitope binding sites of the virus antigen. Here, we generated SFTSV-N-protein-specific monoclonal antibodies and subsequently performed epitope mapping and an antibody pair test to enhance the diagnostic efficiency and accuracy of SFTSV. Confirmation of epitope mappings and their combination immune response to the N protein provide valuable information for effective detection of SFTSV as well as can respond actively to detect a variant SFTSV.

Monocyte Distribution Width as a Diagnostic Marker for Infection: A Systematic Review and Meta-analysis

Monocyte Distribution Width (MDW) is an emerging biomarker for infection. It is easily and quickly available as part of the complete blood count (CBC), which is routinely performed upon hospital admission. The increasing availability and promising results of MDW as biomarker in sepsis has prompted an expansion of its use to other infectious diseases. What is the diagnostic performance of MDW across multiple infectious disease outcomes and care settings? A systematic review of the diagnostic performance of MDW across multiple infectious disease outcomes was conducted by searching PubMed, EMBASE, Scopus, and Web of Science through February 4th, 2022. Meta-analysis was performed for outcomes with three or more reports identified (sepsis and COVID-19). Diagnostic performance measures were calculated for individual studies with pooled estimates created by linear mixed effects models. We identified 29 studies meeting inclusion criteria. Most examined sepsis (19 studies) and COVID-19 (6 studies). Pooled estimates of diagnostic performance for sepsis differed by reference standard (Sepsis-2 vs Sepsis-3 criteria) and tube anticoagulant used and ranged from an area under the receiver operating characteristic curve (AUC) of 0.74 to 0.94, with mean sensitivity of 0.69 to 0.79 and mean specificity of 0.57 to 0.86. For COVID-19, the pooled AUC of MDW was 0.76, mean sensitivity was 0.79, and mean specificity was 0.59. MDW exhibited good diagnostic performance for sepsis and COVID-19. Diagnostic thresholds for sepsis should be chosen with consideration of reference standard and tube type used. PROSPERO 2022 CRD42020210074.

Procalcitonin as a diagnostic marker for infection in sickle cell disease

ABSTRACT Background Patients with sickle cell disease (SCD) are at increased risks of infection. Fever often occurs with vaso-occlusive crisis (VOC), posing a diagnostic challenge in SCD. Procalcitonin (PCT) is an infectious biomarker validated in the general population but with limited data on use in SCD. Methods We performed a retrospective single-center study (n = 145) with primary objective of assessing ability of PCT to differentiate infection from VOC in SCD presenting with fever. Subgroups included confirmed bacterial infection (CBI), suspected bacterial infection, viral infection, and VOC. A secondary objective examined the association of PCT with acute chest syndrome. Clinical characteristics and data were collected and analyzed to assess the diagnostic performance of PCT and associated variables. Results Of the cohort, 16% had CBI and 8% had viral infection. PCT was able to discriminate CBI from viral infection [AUC = 0.89 (95%CI, 0.78–0.99)] and VOC [AUC = 0.87 (95%CI, 0.78–0.97)]. PCT had an association with ACS but poor diagnostic performance [AUC = 0.69 (95% CI, 0.54–0.84)]. Conclusion PCT has utility in distinguishing confirmed bacterial infection from VOC or viral infection and is a promising biomarker when investigating fever in SCD.

Обзор медицинской термометрии: от создания до современного применения

The article describes the first and modern devices for the study of temperature, their principles of operation and the prospects for the development of medical thermometry in clinical practice, along with the use of information technologies, their advantages and disadvantages. The prospects for the use of thermometry using remote methods of recording temperature, wearable devices, the Internet of medical things, telemedicine, big data for patients in rehabilitation at home as part of continuous monitoring of the state of health are considered. The article emphasizes the importance of measuring body temperature by remote thermometry as one of the main diagnostic markers of infection during the pandemic of the novel SARS-CoV-2 virus infection. Also, the importance of thermometry for the timely appointment of antipyretic therapy, control over the course of various diseases and the effectiveness of the prescribed treatment is considered.

Plasma Fibrinogen as a Diagnostic Marker of Infection in Patients with Nonunions.

BackgroundThe timely and accurate diagnosis of infected nonunion is challenging, and there is a need for more efficient biomarkers. Previous studies have shown that fibrinogen plays an important role in mediating inflammation in bacterial infections and, therefore, could be a valuable biomarker for infected nonunion. The purpose of this study was to evaluate and compare the performance of plasma fibrinogen and other traditional blood markers for the diagnosis of infected nonunion.Materials and MethodsWe retrospectively studied 146 patients who underwent surgery for primary nonunion between January 2018 and January 2020. The patients were divided into those with infected nonunion (n = 55) and those with aseptic nonunion (n = 91). The preoperatively analyzed parameters were plasma fibrinogen, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) level, and white blood cell (WBC) count. Receiver operating characteristic (ROC) curve analysis was used to assess the sensitivity and specificity of the biomarkers, and Youden’s index was calculated to determine their optimal cut-off values.ResultsThe plasma fibrinogen values were significantly higher (p < 0.001) in the patients with infected nonunion than in those with aseptic nonunion. ROC curve analysis showed that plasma fibrinogen had a high value of area under the curve (0.816), which indicated that it had good diagnostic ability. Further, at the optimal threshold value of 2.75 g/L, plasma fibrinogen had the highest sensitivity (78.2%; 95% CI = 64.6–87.8) and good specificity (82.4%; 95% CI, 72.7–89.3).ConclusionIn comparison to the traditional markers of infection, plasma fibrinogen showed good diagnostic ability for the detection of infected nonunion. It may have potential as a practical and cost-efficient biomarker for the diagnosis of infected nonunion.

Assessment of procalcitonin as a diagnostic marker of infection in pediatrics with cancer complicated by fever and neutropenia

Background: Febrile neutropenia is still one of the most important complications of treatment in cancer patients. These patients become prone to infection and consequently higher mortality and morbidity. This study aimed to determine the accuracy of serum procalcitonin (PCT) level in the detection of infection in pediatric cancer patients complicated with febrile neutropenia.&#x0D; Materials and Methods: In this cross-sectional study, all pediatric patients affected by cancer and febrile neutropenia following chemotherapy (n=107) were investigated from August 2014 to August 2015. Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and serum levels of PCT, as well as blood and urine culture, were evaluated in all patients.&#x0D; Results: The mean age of the patients was 78 ± 55 months (3 - 214 months), and in terms of gender, 53 patients (49.5%) were male. Overall, 25 patients (23.4%) and 13 patients (12%) showed positive blood and urine culture, respectively. The area under the curve (AUC) receiver operating characteristic (ROC) curve was illustrated to determine how much PCT can couldpredict infection.(AUC =0.74, 95% CI: 0.61-0.87, P&lt;0.001). Considering the cut-off of serum PCT levels as 0.70ng/mL, sensitivity, specificity, and positive and negative predictive valueof PCT were 0.76, 0.744, 0.475, and 0.91, respectively. In addition, PCT showed significant correlations with CRP (rs=0.415, P&lt;0.001) and ESR (rs =0.262, P=0.009).&#x0D; Conclusion: According to the findings of this study, serum PCT levels can be used as a diagnostic test with acceptable sensitivity and specificity and high negative predictive value, but the low positive predictive value in the evaluation of infections in patients affected by cancer and complicated with fever and neutropenia.

Chitotriosidase and Neutrophil Gelatinase-Associated Lipocalin: New Methods as a Diagnostic Marker of Infection in Patients with Febrile Neutropenia?

Chitotriosidase and Neutrophil Gelatinase-Associated Lipocalin: New Methods as a Diagnostic Marker of Infection in Patients with Febrile Neutropenia?

SuPAR as a marker of infection in acute kidney injury \u2013 a prospective observational study

BackgroundSoluble urokinase-type plasminogen activator receptor (suPAR) has emerged as a new sepsis biomarker. It is not known whether suPAR has a role in critically ill patients with severe acute kidney injury (AKI).MethodsOur main aims were to describe serial serum suPAR concentrations in patients with severe AKI, to investigate a potential association between suPAR and C-reactive protein (CRP), and to compare suPAR and CRP as diagnostic markers of infection in patients with AKI. Between April 2013 – April 2014, we recruited adult patients (≥18 years) with AKI KDIGO stage 2/3 admitted to a multidisciplinary Intensive Care Unit (ICU) in a University Hospital in UK. Serial serum suPAR and CRP concentrations were measured for 6 days. We compared the characteristics and serial suPAR and CRP concentrations of patients with and without an infection using Chi-squared, Fisher’s exact, t-test and Mann-Whitney tests as appropriate, and calculated the area under the receiver operating characteristics curve (AUC).ResultsData of 55 patients with AKI stage 2/3 were analysed (62% male; mean age 60.5) of whom 43 patients received continuous renal replacement therapy. suPAR was not detectable in effluent fluid.There was no significant correlation between daily suPAR and CRP concentrations. In patients with an infection, suPAR results were significantly higher than in those without an infection across all time points; there was no significant difference in CRP levels between both groups. After exclusion of patients with an infection before or on day of admission to ICU, the AUC of suPAR for predicting an infection later was 0.62 (95% CI 0.43–0.80) compared to 0.50 (95% CI 0.29–0.71) for CRP.ConclusionsIn critically ill patients with AKI stage 2/3, suPAR is a better marker of infection than CRP.Trial registrationThe study was retrospectively registered on the ISRCTN registry on 25 November 2012 (ISRCTN88354940).

Interleukin-6 as a diagnostic marker for infection in critically ill patients: A systematic review and meta-analysis

BackgroundThe ability of blood levels of interleukin (IL)-6 to differentiate between infection and non-infection in critically ill patients with suspected infection is unclear. We assessed the diagnostic accuracy of serum IL-6 levels for the diagnosis of infection in critically ill patients. MethodsWe systematically searched the PubMed, MEDLINE, Cochrane Resister of Controlled Trials, Cochrane Database of Systematic Reviews, CINAHL, and Igaku Chuo Zasshi databases for studies published from 1986 to August 2016 that evaluated the accuracy of IL-6 levels for the diagnosis of infection. We constructed 2 × 2 tables and calculated summary estimates of sensitivity and specificity using a bivariate random-effects model. ResultsThe literature search identified 775 articles, six of which with a total of 527 patients were included according to the predefined criteria. The pooled sensitivity, specificity, and diagnostic odds ratio were 0.73 (95% confidence interval [CI], 0.61–0.82), 0.76 (95% CI, 0.61–0.87), and 2.31 (95% CI, 1.20–3.48), respectively. The area under the curve (AUC) of the summary receiver operator characteristic (SROC) curve was 0.81 (95% CI, 0.78–0.85). In the secondary analysis of two studies with a total of 263 adult critically ill patients with organ dysfunction, the pooled sensitivity, specificity, and diagnostic odds ratio were 0.81 (95% CI, 0.75–0.86), 0.77 (95% CI, 0.67–0.84), and 2.87 (95% CI 2.15–3.60), respectively. ConclusionsBlood levels of IL-6 have a moderate diagnostic value and a potential clinical utility to differentiate infection in critically ill patients with suspected infection.

Heparin-binding protein, lysozyme, and inflammatory cytokines in bronchoalveolar lavage fluid as diagnostic tools for pulmonary infection in lung transplanted patients.

Pulmonary infection is a common complication after lung transplantation, and early detection is crucial for outcome. However, the condition can be clinically difficult to diagnose and to distinguish from rejection. The aim of this prospective study was to evaluate heparin‐binding protein (HBP), lysozyme, and the cytokines interleukin (IL)‐1β, IL‐6, IL‐8, IL‐10 and tumor necrosis factor (TNF) in bronchoalveolar lavage fluid (BALF) as potential biomarkers for pulmonary infection in lung‐transplanted patients. One hundred thirteen BALF samples from 29 lung transplant recipients were collected at routine scheduled bronchoscopies at 3 and 6 months, or on clinical indication. Samples were classified into no, possible, probable, or definite infection at the time of sampling. Rejection was defined by biopsy results. HBP, lysozyme, and cytokines were analyzed in BALF and correlated to likelihood of infection and rejection. All biomarkers were significantly increased in BALF during infection, whereas patients with rejection presented low levels that were comparable to noninfection samples. HBP, IL‐1β, and IL‐8 were the best diagnostic markers of infection with area under the receiver‐operating characteristic curve values of 0.88, 0.91, and 0.90, respectively. In conclusion, HBP, IL‐1β, and IL‐8 could be useful diagnostic markers of pulmonary infection in lung‐transplanted patients.

Interleukin-6 Levels Act as a Diagnostic Marker for Infection and a Prognostic Marker in Patients with Organ Dysfunction in Intensive Care Units.

There are significant unmet requirements for rapid differential diagnosis of infection in patients admitted to intensive care units. Serum levels of interleukin-6 (IL-6), procalcitonin (PCT), presepsin, and C-reactive protein (CRP) are measured in clinical practice; however, their clinical utility in patients with organ dysfunction has not been tested adequately. Thus, we investigated the diagnostic and prognostic value of IL-6, PCT, presepsin, and CRP in critically ill patients who had organ dysfunction with suspicion of infection. In 100 consecutive critically ill patients with organ dysfunction and suspected infection, serum levels of IL-6, PCT, presepsin, and CRP were measured upon suspicion of infection and serially every other day up to 7 days (cohort 1). The primary outcome variable was the presence of infections. The diagnostic value of IL-6 was further tested in cohort 2 (n = 72, case-control matched). The secondary outcome variables were the sequential organ failure assessment (SOFA) score, serum creatinine levels, and 28-day mortality. Among the four biomarkers, serum IL-6 levels had the highest area under the curve (AUC) value of 0.824 (95% confidence interval [CI] 0.735-0.913) for diagnosing infection in critically ill patients with organ dysfunction and suspected infection in cohort 1 (AUC [95% CI] for the other biomarkers: PCT, 0.813 [0.714-0.911]; CRP, 0.764 [0.645-0.883]; presepsin, 0.681 [0.513-0.849]). In cohort 2, the sensitivity and specificity of IL-6 for diagnosing infection were 0.861 and 0.806, respectively. The presepsin levels were significantly correlated with the SOFA score and serum creatinine levels upon suspicion of infection (r > 0.5), especially serum creatinine levels in the patients without infection (r = 0.789). Serum IL-6 levels were significant predictors of 28-day mortality. The AUC value of serum IL-6 levels for 28-day mortality increased over time; the serum IL-6 levels on Day 7 had the highest AUC value of 0.883 (95% CI, 0.788-0.978) for 28-day mortality. Among serum IL-6, PCT, presepsin, and CRP levels, serum IL-6 levels had the highest diagnostic value for infection. They were also significant predictors of 28-day mortality. Hence, they may improve diagnosis of infection and prediction of 28-day mortality in critically ill patients with organ dysfunction.

Procalcitonin as diagnostic marker of infection in solid tumors patients with fever.

In oncologic patients fever is a non-specific clinical marker of different clinical settings. Procalcitonin (PCT) seems to be the most promising infection marker. We aimed to define the potential role of PCT as an earlier diagnostic marker in patients with fever and solid tumor. This retrospective study enrolled 431 patients. All of them performed hemoculture (HE) and basal PCT assessment (reference laboratory cut-off: ≤0.5 or >0.5 ng/dL) before starting antibiotic therapy. Gram positive (G+), negative (G−) or Fungi infection were detected. A statistically significant difference in PCT levels between patients with positive and negative HE was observed (P < 0.0001). Moreover comparing PCT values in patients with positive and negative HE, we obtain in the positive HE subpopulation an AUC of 0.7 and a cut-off of 1.52 ng/dL reached high sensitivity (61.6%) and specificity (70.1%). Using this last cut-off, instead of the normal reference value, we achieve a risk reduction to overestimate an infection status of 23.4%. We support the clinic usefulness of serum PCT dosage in febrile advanced solid tumor patients. A PCT cut-off of 1.52 ng/dL could be helpful in the management of the antibiotic therapy preventing delays of oncologic treatments.

Evaluation of Two Methods for Determination of CD64 as a Diagnostic Marker of Infection in Critically Ill Adults.

Objectives. Diagnostic markers of infection have had little innovation over the last few decades. CD64, a marker expressed on the surface of neutrophils, may have utility for this purpose. Methods. This study was conducted in an adult intensive care unit (ICU) in São Paulo, Brazil, with 89 patients. We evaluated CD64 in patients with documented or clinically diagnosed infection (infection group) and controls (patients without any evidence of infection) by two different methodologies: method #1, an in house assay, and method #2, the commercial kit Leuko64 (Trillium Diagnostics). Results. CD64 displayed good discriminating power with a 91.2% sensitivity (95% CI 90.7–91.6%) for detecting infection. The commercial kit (Leuko64) demonstrated higher specificity (87.3%) compared with method #1 as well as better accuracy (88.8%). Conclusions. CD64 seems to be a promising marker of infection in the intensive care setting, with Leuko64 showing a slight advantage.

Antibody response of definitive hosts against antigens of two life stages of the neuropathogenic schistosome Trichobilharzia regenti.

BackgroundThe nasal avian schistosome Trichobilharzia regenti spends part of its intravertebrate period of life within the central nervous system. Migration of the parasites can be accompanied by neuromotor disorders or paralysis in natural definitive hosts (ducks) and even in laboratory mammals. Cercariae are also able to penetrate human skin and induce cercarial dermatitis. While the cellular and antibody responses against cercariae and migrating schistosomula have been investigated in mice, little is known about immune reactions in birds. This study first describes the dynamics of antibody response in infected ducks and identifies frequently recognized antigens that may serve as diagnostic markers of infection by T. regenti.MethodsGroups of 35 domestic ducks and 10 mallards were exposed to different doses of T. regenti cercariae. Sera were collected at predefined time intervals and tested by ELISA for the presence of specific anti-cercarial IgY and IgM. Antigens recognized by the antibodies were identified on Western blots of cercariae and schistosomula. The applicability in immunodiagnostics was statistically evaluated by expression of specificity and sensitivity values for individual antigens.ResultsIn ELISA, the levels of anti-cercarial IgM peaked on day 15 pi. Increased production of IgY associated with the later phases of infection was observed in most individuals around 20 dpi and culminated 30 dpi. The time course of antibody response did not differ among experimental groups, variations were only observed in the levels of specific IgY which depended rather on the age of ducks at the time of infection than on the infectious dose. On Western blots, 40 cercarial and 7 schistosomular antigens were recognized by IgY from infected ducks. Among them, 4 cercarial antigens of 50, 47, 32 and 19 kDa provided the most sensitive and specific reactions.ConclusionsAntigens of cercariae and schistosomula elicited distinct antibody response in ducks, which correlated positively with the age of animals at the time of infection. Several antigens originating in cercariae and fewer in schistosomula were recognized by IgY with diverse sensitivity and specificity; only a few seemed to be common to both stages. Four of them were considered as the most promising candidates for immunodiagnostics.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-015-1007-y) contains supplementary material, which is available to authorized users.

Characterization of Soluble and Membrane-Bound Proteins of Toxoplasma gondii as Diagnostic Markers of Infection

In the present study, we applied the combination of one-dimensional gel electrophoresis, immunoblot and nanoliquid chromatography-tandem mass spectrometry (nanoLC-MS/MS) to identify potential immunogenic proteins of Toxoplasma gondii tachyzoites that can be used for the development of reliable assays in the serodiagnosis of acquired toxoplasmosis in immunocompetent subjects. For this purpose, we developed an immunoblot using soluble and membrane extracts of GT1 Toxoplasma gondii tachyzoites and tested 194 positive and 100 negative sera obtained from pregnant women. Five bands of soluble antigens (98 kDa, 36 kDa, 33 kDa, 32 kDa and 21 kDa) and 4 bands of membrane antigens (41 kDa, 35 kDa, 32 kDa and 30 kDa) were selected as the most valuable in terms of sensitivity and specificity. Among these bands, only 2 bands of soluble antigen (33 kDa and 32 kDa) and 2 bands of membrane antigen (32 kDa and 30 kDa) showed a specificity ≥ 90%. After mass spectrometry and bioinformatics analysis, 7 proteins were identified as potential markers for serodiagnosis of toxoplasmosis. These proteins are: SRS34A, GRA7, GRA1, DG32, MIC5, ROP5 and Toxofilin. These proteins showed a 86% to 100% homology with proteins of both VEG and ME49 strains of T. gondii and a 58% to 87% homology with Hammondia hammondi; and can be considered as attractive candidates for the development of an immunochromatography test that can be used for the rapid diagnosis of toxoplasmosis and as a confirmatory test when routine techniques give equivocal results.

Proteomic characterization of Helicobacter pylori CagA antigen recognized by child serum antibodies and its epitope mapping by peptide array.

Serum antibodies against pathogenic bacteria play immunologically protective roles, and can be utilized as diagnostic markers of infection. This study focused on Japanese child serum antibodies against Helicobacter pylori, a chronically-infected gastric bacterium which causes gastric cancer in adults. Serological diagnosis for H. pylori infection is well established for adults, but it needs to be improved for children. Serum samples from 24 children, 22 H. pylori (Hp)-positive and 2 Hp-negative children, were used to catalogue antigenic proteins of a Japanese strain CPY2052 by two-dimensional electrophoresis followed by immunoblot and LC-MS/MS analysis. In total, 24 proteins were identified as candidate antigen proteins. Among these, the major virulence factor, cytotoxin-associated gene A protein (CagA) was the most reactive antigen recognized by all the Hp-positive sera even from children under the age of 3 years. The major antigenic part of CagA was identified in the middle region, and two peptides containing CagA epitopes were identified using a newly developed peptide/protein-combined array chip method, modified from our previous protein chip method. Each of the epitopes was found to contain amino acid residue(s) unique to East Asian CagA. Epitope analysis of CagA indicated importance of the regional CagA antigens for serodiagnosis of H. pylori infection in children.

Clinical Evaluation of Neutrophil CD64 as a Diagnostic Marker of Infection in a Polyvalent Intensive Care Unit

Background Infections are one of the major causes of morbidity and mortality in critically ill patients. Severe infections should be treated at earlier stages, but the diagnosis is difficult as the clinical presentation results are unspecific. Recently, the neutrophils Fc gamma receptor, recognized by monoclonal antibodies cluster of differentiation 64 (CD64), has been proposed as an infection marker. The aim of the present study was to evaluate CD64 as a marker of infection in our polyvalent intensive care unit, distinguishing early infection from noninfected inflammation. Methods We evaluated 93 consecutive patients presenting with infection signs on admission. CD64, C-reactive protein (CRP), and white blood cell count were collected. After a test for normal distribution, data were analyzed nonparametrically and reported as median and interquartile range (IQR); then, Kruskal-Wallis and Mann-Whitney tests were performed. Statistically significant difference was defined as P < 0.05. Results C-reactive protein (median, 17.4 mg/L; IQR, 11.4–27.2 mg/L vs median, 10.1 mg/L; IQR, 7.5–13.7mg/L) and CD64 (median, 3842 antibody-binding capacity [ABC]; IQR, 2799–5283 ABC vs median, 768.5 ABC; IQR, 532.3–1269.3 ABC) showed a significant difference between septic and nonseptic patients, respectively. Receiver operating characteristic curves of CD64, CRP, and white blood cell count showed the superiority of CD64: considering a cutoff of 2000 antibody-binding capacity for infection, sensitivity was 90.2% and specificity was 96.9% in comparison with CRP (sensitivity, 85.2%; and specificity, 46.9% for cutoff of 10 mg/L). CD64 expression, but not CRP, was able to differentiate the septic stages (P < 0.001). Conclusions Neutrophil CD64 represents a sensitive and specific marker for the early diagnosis of systemic infections in adult patients admitted to intensive care unit, superior to traditional hematological parameters and CRP.

A multicentre evaluation of the accuracy and performance of IP-10 for the diagnosis of infection with M. tuberculosis

IP-10 has potential as a diagnostic marker for infection with Mycobacterium tuberculosis, with comparable accuracy to QuantiFERON-TB Gold In-Tube test (QFT-IT). The aims were to assess the sensitivity and specificity of IP-10, and to evaluate the impact of co-morbidity on IP-10 and QFT-IT. 168 cases with active TB, 101 healthy controls and 175 non-TB patients were included. IP-10 and IFN-γ were measured in plasma of QFT-IT stimulated whole blood and analyzed using previously determined algorithms. A subgroup of 48 patients and 70 healthy controls was tested in parallel with T-SPOT.TB IP-10 and QFT-IT had comparable accuracy. Sensitivity was 81% and 84% with a specificity of 97% and 100%, respectively. Combining IP-10 and QFT-IT improved sensitivity to 87% (p < 0.0005), with a specificity of 97%. T-SPOT.TB was more sensitive than QFT-IT, but not IP-10. Among non-TB patients IP-10 had a higher rate of positive responders (35% vs 27%, p < 0.02) and for both tests a positive response was associated with relevant risk factors. IFN-γ but not IP-10 responses to mitogen stimulation were reduced in patients with TB and non-TB infection. This study confirms and validates previous findings and adds substance to IP-10 as a novel diagnostic marker for infection with M. tuberculosis. IP-10 appeared less influenced by infections other than TB; further studies are needed to test the clinical impact of these findings.

Serum ovotransferrin as a biomarker of inflammatory diseases in chickens

Infectious and metabolic disorders are common in poultry and cause stress, poor performance, and mortality that results in considerable economic loss. Identifying the nature of stress in chickens will assist the development of appropriate measures to improve health and welfare. Acute phase proteins are hepatic proteins, the blood concentrations of which change significantly in the event of many health problems including inflammation and physical injuries. Thus, acute phase proteins are used as nonspecific diagnostic markers for various health disorders. Our previous studies showed that serum ovotransferrin (OVT) is an acute phase protein in chickens. Therefore, in the present study, we investigated whether OVT concentration can be a marker of physiological stress using sera from chickens with different infectious and metabolic disorders. A competitive enzyme immunoassay was developed to measure serum OVT concentrations. The results show that with experimentally induced pulmonary hypertension syndrome and tibial dyschondroplasia, there were no significant changes in OVT levels compared with matched controls. In contrast, when chickens were infected with microbes such as the bacterium Escherichia coli, or protozoan parasites such as Eimeria maxima and Eimeria tenella, there was a significant increase in the levels of OVT in the serum. Chickens with spontaneous autoimmune vitiligo also showed a significant increase in blood OVT levels. These studies suggest that blood OVT concentration is modulated under inflammatory and microbial stress and can therefore be used as a diagnostic marker of infection and inflammation in chickens.