Ascitic Calprotectin is a Novel and Accurate Marker for Spontaneous Bacterial Peritonitis

Systematic review of the role of calprotectin in cirrhosis

BACKGROUND

Calprotectin is a calcium-binding-S100-protein synthetized mainly in neutrophils which has been demonstrated to be an accurate biomarker of the presence of these cells. Gut barrier dysfunction in patients with advanced chronic liver disease (ACLD), in addition to the lack of noninvasive tools for diagnosis and prognosis of cirrhosis decompensations, has raised interest in this biomarker.

AIMS

Our aim is to summarize the current evidence regarding the role of calprotectin in terms of its diagnostic and prognostic utility in ACLD.

METHODS

We performed a systematic search (PROSPERO registration no. CRD42023389069) of original articles published without any restrictions on the publication date until January 2023 providing information about calprotectin for the prognosis or diagnosis of ACLD and its decompensations in adult patients.

RESULTS

A total 227 articles were identified, and 26 observational studies finally met the inclusion criteria. In 14 studies, calprotectin was measured in ascitic fluid, all of which reported higher calprotectin values in spontaneous bacterial peritonitis, while cut-off points for its diagnosis were proposed in nine studies. Three studies reported higher faecal calprotectin levels in patients with hepatic encephalopathy and portal hypertension. Four studies evaluated faecal calprotectin and one plasma calprotectin as biomarkers for gut barrier integrity and bacterial translocation.

CONCLUSIONS

Calprotectin is emerging as a promising biomarker in ACLD, particularly for the management of bacterial infections and alcohol-related liver disease. Further research with better study designs should help to determine the feasibility of calprotectin measurement in routine clinical practice.

Ascites fluid calprotectin level is highly accurate in diagnosing spontaneous bacterial peritonitis: a preliminary proof of concept prospective study

Ascites is the most common complication of liver cirrhosis. Spontaneous bacterial peritonitis (SBP) is a common complication of ascites. The diagnosis is made by an ascitic fluid polymorphonuclear (PMN) cell count of ≥ 250/mm3. However, no other diagnostic test is present for the diagnosis of SBP. The aim of the study present study is to assess the diagnostic yield of ascitic calprotectin in SBP, and to explore whether it can predict disease stage. We performed a single center proof-of-concept prospective study including all patients with cirrhosis and ascites who underwent paracentesis. Overall, 31 patients were included in the study. Eight patients had SBP vs. 23 patients without SBP. Ascitic calprotectin level was 77.4 ± 86.5 μg/mL in the SBP group, as compared to 16.1 ± 5.6 μg/mL in the non-SBP group (P = 0.001). An ascitic calprotectin cut-off value of > 21 μg/mL was associated with sensitivity and specificity of 85.7% and 89.5%, respectively, with ROC of 0.947 (95% CI 0.783 to 0.997, P < 0.0001). Notably, ascitic calprotectin did not had a prognostic value in cirrhosis stage and prognosis. Ascitic calprotectin was highly accurate in the diagnosis of SBP. It can be a serve as adjunct for indefinite cases of SBP.

Evaluation of DiaSorin Liaison® calprotectin fecal assay adapted for pleural effusion

Objectives

Calprotectin (CP) is a calcium and zinc binding protein that is widely measured on faecal samples but its determination in other biological fluids might be of interest. The aim of this work was to validate the measurement of CP in pleural fluid by chemiluminescence.

Methods

LIAISON®XL, a fully automated chemiluminescence analyzer, was used for CP quantification on pleural fluid. A validation protocol was designed using both quality control materials provided by the manufacturer and pools of pleural fluid samples. Stability, imprecision, bias, linearity, detection capability and carry over effect were evaluated.

Results

CP was stable on pleural fluid at least one week, under refrigerated conditions, and four weeks at -80 °C. The observed intra- and inter-day imprecision was between 2.2 and 6.49 %, with a negative bias under 5.51 %. The linearity of the method was verified up to 2,000 ng/mL. The LoQ for the assay was 48.52 ng/mL. A statistically significant carry-over effect was observed after measuring CP concentrations above the upper limit of linearity, but given the observed magnitude, a clinically relevant impact should not be expected.

Conclusions

DiaSorin Liaison® calprotectin assay allows reliable measurement of CP in pleural fluid.

Evaluación de la prueba fecal Liaison® Calprotectin de DiaSorin adaptada al derrame pleural

Objetivos

La calprotectina (CP) es una proteína de unión a calcio y zinc que se suele determinar en muestras fecales, aunque su cuantificación en otros fluidos biológicos podría ser de interés. El objetivo del presente estudio es validar la determinación de CP en líquido pleural mediante quimioluminiscencia.

Métodos

Para la cuantificación de CP en líquido pleural, se utilizó LIAISON®XL, un autoanalizador de quimioluminiscencia. Se diseñó un protocolo de validación empleando tanto materiales de control de calidad suministrados por el fabricante, como soluciones de muestras de líquido pleural. Se evaluaron la estabilidad, imprecisión, sesgo, linealidad, capacidad de detección y efecto de arrastre.

Resultados

La CP permaneció estable en líquido pleural refrigerado durante al menos una semana, y durante cuatro semanas a −80 °C. La imprecisión intradía e interdía observada fue del 2,2 % y del 6,49 %, respectivamente, con un sesgo negativo del 5,51 %. La linealidad del método se verificó hasta los 2000 ng/mL. El límite de cuantificación (LoQ) de la prueba fue de 48,52 ng/mL. Se observó un efecto de arrastre estadísticamente significativo tras medir concentraciones de CP superiores al límite máximo de linealidad. Sin embargo, dada la magnitud observada, no se debe esperar un impacto clínicamente relevante.

Conclusiones

La prueba Liaison® Calprotectin de DiaSorin es fiable para la determinación de CP en líquido pleural.

The synovial fluid calprotectin lateral flow test for the diagnosis of chronic prosthetic joint infection in failed primary and revision total hip and knee arthroplasty

PURPOSE

The diagnostic criteria of prosthetic joint infection (PJI) recommended by the most commonly used diagnostic algorithms can be obscured or distorted by other inflammatory processes or aseptic pathology. Furthermore, the most reliable diagnostic criteria are garnered during revision surgery. A robust, reliable addition to the preoperative diagnostic cascade is warranted. Calprotectin has been shown to be an excellent diagnostic marker for PJI. In this study, we aimed to evaluate a lateral flow test (LFT) in the challenging patient cohort of a national referral centre for revision arthroplasty.

METHODS

Beginning in March 2019, we prospectively included patients scheduled for arthroplasty exchange of a total hip (THA) or knee arthroplasty (TKA). Synovial fluid samples were collected intra-operatively. We used the International Consensus Meeting of 2018 (ICM) score as the gold standard. We then compared the pre-operative ICM score with the LFT result to calculate its diagnostic accuracy as a standalone pre-operative marker and in combination with the ICM score as part of an expanded diagnostic workup.

RESULTS

A total of 137 patients with a mean age of 67 (± 13) years with 53 THA and 84 TKA were included. Ninety-nine patients (72.8%) were not infected, 34 (25.0) were infected, and four (2.9%) had an inconclusive final score and could not be classified after surgery. The calprotectin LFT had a sensitivity (95% confidence interval) of 0.94 (0.80-0.99) and a specificity of 0.87 (0.79-0.93). The area under the receiver operating characteristic curve (AUC) for the calprotectin LFT was 0.94 (0.89-0.99). In nine cases with an inconclusive pre-operative ICM score, the calprotectin LFT would have led to the correct diagnosis of PJI.

CONCLUSIONS

The synovial fluid calprotectin LFT shows excellent diagnostic metrics both as a rule-in and a rule-out test, even in a challenging patient cohort with cases of severe osteolysis, wear disease, numerous preceding surgeries, and poor soft tissue conditions, which can impair the common diagnostic criteria. As it is available pre-operatively, this test might prove to be a very useful addition to the diagnostic algorithm.

An evaluation of ascitic calprotectin for diagnosis of ascitic fluid infection in children with cirrhosis

Background

The most common infection in children with the hepatic disease with or without cirrhotic ascites is spontaneous bacterial peritonitis (SBP), which occurs in the absence of an evident intra-abdominal source of infection. The present study aims to assess the value of calprotectin in ascitic fluid in the diagnosis of ascitic fluid infection in children with liver cirrhosis.

Materials and methods

In this cross-section study, 80 children with underlying liver disease who attended the Hepatology and Emergency Department in Shiraz University Hospitals were studied. All the patients were evaluated by a thorough history, clinical examination, laboratory investigations, diagnostic paracentesis with PMNLs count, and Calprotectin, which was measured in 1 mL ascitic fluid by ELISA.

Results

Thirty-five patients (43.75%) were diagnosed with ascitic fluid infection. Of these children 6 cases had positive ascitic fluid culture (SBP). Calprotectin was high in AFI patients with a statistically significant difference in AFI patients compared to non-AFI patients. The cut-off levels were 91.55 mg /L and the area under the curve was 0.971. So it can serve as a sensitive and specific diagnostic test for detection of AFI in children with underlying liver disease.

Conclusion

Elevated ascitic calprotectin levels in cirrhotic patients are a diagnostic and reliable marker for the detection of AFI and are considered a surrogate marker for PMN.

Diagnosing Periprosthetic Joint Infection: a Scoping Review

PURPOSE OF REVIEW

The goal of this review is to provide an up to date understanding of the utility and limitations of the current tests utilized in the diagnosis of periprosthetic joint infection (PJI) in total knee and hip arthroplasty.

RECENT FINDINGS

Despite the growth in literature surrounding PJI diagnosis, there remains challenges in establishing a diagnosis of PJI. A combination of clinical, serum, and synovial tests and microbiologic and histologic examinations can yield a diagnosis in the majority of cases. Novel molecular and imaging studies may be beneficial for indeterminant cases. A number of emerging diagnostic tests have been proposed and may be incorporated into diagnostic algorithms in the future. Recently proposed stepwise diagnostic algorithms have shown high sensitivity and specificity. The diagnosis of PJI remains challenging due to a lack of tests that can definitively rule out infection. Diagnosis and investigations should occur in a stepwise fashion. There has been a plethora of new diagnostic tests introduced in attempts to improve the accuracy of diagnostic algorithms. The definition and algorithms for the diagnoses of PJI will continue to evolve as new techniques and tests are introduced.

Diagnostic Potential of Calprotectin for Spontaneous Bacterial Peritonitis in Patients Withliver Cirrhosis and Ascites

The development of spontaneous bacterial peritonitis (SBP) is a serious and life-threatening condition in patients with cirrhosis and ascites. The aim of this study was to determine the diagnostic potential of calprotectin in ascites, for SBP in patients with liver cirrhosis and ascites before and after antibiotic treatment and to compare the mean values of calprotectin in ascites in patients with and without SBP. This prospective-observational study was comprised of 70 patients with cirrhosis and ascites, divided into two groups, the SBP and the non-SBP group. Quantitative measurements of calprotectin in ascites was completed with the Quantum Blue Calprotectin Ascites test (LF-ASC25), using the Quantum Blue Reader. The average value of calprotectin in the SBP group was 1.5 ± 0.40 μg / mL, and in the non-SBP group it was lower (0.4 ± 0.30). The difference between the mean values was statistically significant with p <0.05. The mean value of calprotectin in ascites before therapy among the SBP group was 1.5 ± 0.4, and after antibiotic therapy, the value decreased significantly to 1.0 ± 0.6; the difference between the mean values was statistically significant with p <0.05. ROC analysis indicated that calprotectin contributed to the diagnosis of SBP with a 94.3% sensitivity rating (to correctly identify positives), and the specificity was 62.5%, which corresponded to the value of 0.275. Our research confirmed that ascitic calprotectin was a good predictor, and is significantly associated with the occurrence of SBP in patients with liver cirrhosis. By monitoring the value of calprotectin in ascites on the 7th day of antibiotic treatment, the effectiveness of antibiotic treatment in patients with SBP can be determined.

Spontaneous bacterial peritonitis: update on diagnosis and treatment

Spontaneous bacterial peritonitis (SBP) is a common complication in patients with liver cirrhosis, with an increased risk of mortality. For this reason, a diagnostic paracentesis should be performed in all patients with ascites and clinical features with high diagnostic suspicion. Although literature data abound in identifying new diagnostic markers in serum or ascites, they have not yet been validated. The final diagnosis requires the analysis of ascites and the presence of > 250 mm³ neutrophil polymorphonuclear (PMN) in ascites. If previous data showed that the most common microorganisms identified were represented by gram-negative bacteria, we are currently facing an increase in gram-positive bacteria and multi-drug resistant bacteria. Although prompt and effective treatment is required to prevent outcomes, this becomes challenging as first-line therapies may become ineffective leading to worsening prognosis and increased inhospital mortality. In this paper we will make a brief review of existing data on the diagnosis and treatment of SBP.

Influence of Xuebijing injection combined with cefoperazone sodium and sulbactam sodium in treating hepatitis B-induced liver cirrhosis complicated by spontaneous bacterial peritonitis: TNF-α, IL-18, IL-6, and hepatic function

OBJECTIVE

To analyze the influences of Xuebijing injection combined with cefoperazone sodium and sulbactam sodium (CSSS) in the treatment of hepatitis B-induced liver cirrhosis (HBLC) complicated by spontaneous bacterial peritonitis (SBP) with respect to tumor necrosis factor-α (TNF-α), interleukin-18 (IL-18), interleukin-6 (IL-6), and hepatic function.

METHODS

A total of 98 patients with HBLC complicated by SBP admitted to our hospital were selected and divided into the control group (CON, n=49) and the observation group (OBG, n=49) in accordance with the therapeutic methods. The clinical data of the patients were retrospectively analyzed. The CON was treated with CSSS, while the OBG was treated with Xuebijing injection combined with CSSS. The time of symptomatic improvement and changes of serum inflammatory factors and indices of intestinal mucosal barrier damage and hepatic function were compared between the two groups before and after treatment.

RESULTS

The time of symptomatic improvement in the OBG was shorter than that in the CON (P < 0.05). After treatment, IL-6, IL-18, TNF-α, urinary L/M, D-lactic acid, DAO, total bilirubin, ALT, and AST in the OBG were lower than those in the CON (P < 0.05).

CONCLUSION

Xuebijing injection combined with CSSS is conducive to improving the inflammatory responses of the body, intestinal tract barrier function, and hepatic function, showing satisfactory efficacy in the treatment of HBLC complicated by SBP.

The diagnostic accuracy of ascitic calprotectin for the early diagnosis of spontaneous bacterial peritonitis: systematic review and meta-analysis

Spontaneous bacterial peritonitis (SBP) is a common complication in patients with cirrhosis and has an incidence of up to 30% in hospitalized patients. Importantly, it may raise their mortality rate up to 30%. Hence, a delayed diagnosis is associated with poor prognosis. This systematic review aims to assess the diagnostic accuracy of ascitic fluid calprotectin for the early diagnosis of SBP in patients with ascites. This study was conducted in accordance with the PRISMA statement. A systematic literature search was conducted from inception to February 2020 in the following electronic bibliographic databases: MEDLINE, Scopus, The Cochrane Library and OpenGrey. Quality Assessment of Diagnostic Accuracy Studies tool was used to assess risk of bias. Ten studies were included in the qualitative and quantitative synthesis. Hierarchical summary receiver operating characteristic curves were plotted and the summary sensitivity of a positive ascitic fluid calprotectin assessment to detect SBP was 93% [95% confidence interval (CI) 90-95%] while the summary specificity was 89% (95% CI 80-95%), irrespectively of the method used. The positive likelihood ratio and negative likelihood ratio of the test were 8.7 (95% CI 4.4-17.1) and 0.08 (85% CI 0.06-0.12). All studies showed positive correlation between ascitic calprotectin and polymorphonuclear (PMN) leukocyte count. Ascitic calprotectin appears to be an excellent alternative to PMN leucocyte count of ≥250 cells/mm3 for the diagnosis of SBP with much faster time to diagnosis. Owing to its substantially high negative predictive value, the test can accurately exclude SBP avoiding unnecessary antibiotics in suspected patients.

Ascitic calprotectin for the diagnosis of spontaneous bacterial peritonitis: a systematic review and meta-analysis

Calprotectin is a promising diagnostic biomarker for spontaneous bacterial peritonitis (SBP) among cirrhotic patients, but published studies report a wide variation of its diagnostic accuracy. We systematically searched six databases for eligible studies (i.e., all original studies that reported ascitic calprotectin as a diagnostic marker for SBP in cirrhotic patients), and assessed their quality with the Quality Assessment of Diagnostic Accuracy Studies-2 tool. We calculated the pooled sensitivity, specificity, positive and negative likelihood ratios (PLR and NLR), and diagnostic odds ratio (DOR) using the bivariate mixed-effect model. We constructed the summary receiver operating characteristic and determined the area under the curve (AUC). We registered the study protocol in PROSPERO (CRD42019125476). Our search retrieved 102 studies, of which 10 were included in the analysis. The overall risk of bias of these studies ranged from low to moderate. There was no heterogeneity from the threshold effect (Spearman correlation coefficient = 0.100, P value = 0.770). The pooled estimates [95% confidence intervals (CIs)] for ascitic calprotectin were as follows: sensitivity 0.91 (95% CI: 0.88-0.94), specificity 0.87 (95% CI: 0.68-0.96), PLR 7.18 (95% CI: 2.52-20.43), NLR 0.10 (95% CI: 0.07-0.15), DOR 71.91 (95% CI: 19.42-266.34), and AUC 0.92 (95% CI: 0.90-0.94). The sensitivity analysis did not detect outliers, and the model had a robust goodness of fit. There was no significant publication bias detected (Deeks test of asymmetry, P value = 0.79). Ascitic calprotectin is a promising diagnostic biomarker for SBP in cirrhotic patients.

Diagnostic and prognostic role of ascitic fluid calprotectin level: six-month outcome findings in cirrhotic patients

AIM

To assess the role of ascites calprotectin in early detection of SBP in patients with cirrhosis and to investigate its prognostic value in determination of the 6-month outcome. Methods and material: In this cross-sectional study, patients with liver cirrhosis who were consecutively referred to Imam Reza hospital, tertiary referral center in the northwest of Iran, underwent abdominal paracentesis. The samples were collected for measurement of calprotectin, albumin, total protein, WBCs, and PMNs.

RESULTS

The mean age of a total of 87 included patients was 56.86 (SD 16.05) years old with over half of the subjects (55.2%) being female. About 28.7% of performed paracenteses tested positive for SBP. Ascitic calprotectin was positively correlated to the PMN counts. Patients with SBP were found to have higher levels of ascites albumin, total protein, and calprotectin. Only 51 individuals survived the 6-month follow-up period and mortality outcomes were significantly related to the levels of aforementioned biochemical markers (p-value <.05).

CONCLUSION

Alongside with standard PMN counts, calprotectin measurement in the ascitic fluid could be used as an available test for early diagnosis of SBP. Calprotectin can also serve as a valuable prognostic marker in the evaluation of cirrhotic patients.

Ascitic Calprotectin as an early predictor of hepatocellular carcinoma in patients with cirrhotic ascites

BACKGROUND

Calprotectin is a heterodimer formed by S100A8 and S100A9 proteins which are enhanced during hepatic carcinogenesis and the increased expression of both proteins promotes malignant progression of hepatocellular carcinoma. The potential correlation between ascitic Calprotectin and HCC was not studied.

METHODS

100 patients were stratified into a case group which enrolled 50 patients with cirrhotic ascites and documented HCC and a control group consisted of 50 patients with cirrhotic ascites without HCC. They were evaluated by liver function tests, abdominal ultrasound and routine ascitic fluid examination including ascetic Calprotectin and results were validated in another group (n = 100).

RESULTS

Calprotectin level was significantly higher in the HCC group with insignificant difference regarding total cell count, PNLs, ascitic albumin, LDH, CEA and SAAG. It correlated with serum creatinine (r = 0.245, p = 0.014) and number of focal hepatic lesions (r = 0.309, p = 0.002). In the validation group, 28 patients had elevated ascitic Calprotectin of which 21 patients had developed HCC (75%) after a mean period of 3.8 ± 1.54 months. A cut of value 126 ng/ml was accurate to predict HCC in liver cirrhosis with ascites with a sensitivity of 93.3% specificity 94%, AUC 0.950, Youden's J value = 0.873, p = 0.0001.

CONCLUSION

Ascitic Calprotectin may offer an easy, affordable marker that can predict the early occurrence of HCC.

The value of calprotectin in synovial fluid for the diagnosis of chronic prosthetic joint infection

Aims

This study aimed to evaluate calprotectin in synovial fluid for diagnosing chronic prosthetic joint infection (PJI) .

Methods

A total of 63 patients who were suspected of PJI were enrolled. The synovial fluid calprotectin was tested by an enzyme-linked immunosorbent assay (ELISA). Laboratory test data, such as ESR, CRP, synovial fluid white blood cells (SF-WBCs), and synovial fluid polymorphonuclear cells (SF-PMNs), were documented. Chi-squared tests were used to compare the sensitivity and specificity of calprotectin and laboratory tests. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve was calculated to determine diagnostic efficacy.

Results

The median calprotectin level was 776 μg/ml (interquartile range (IQR) 536.5 to 1132) in the PJI group and 54.5 μg/ml (IQR, 38.75 to 78.25) in the aseptic failure (AF) group (p < 0.05). Using a threshold of 173 ug/ml, the sensitivity was 95.2%, with a 97.6% specificity, and the AUC was 0.993. The sensitivity of calprotectin of the antibiotic-treated PJI group was 100% versus 90.9% of the non-antibiotic-treated PJI group. Although 47.6% (ten cases) of the patients in the PJI group received antibiotics before aspiration, the diagnostic efficacy of calprotectin was not affected. The sensitivity and specificity of ESR, CRP, SF-WBCs, and SF-PMNs ranged from 76.2% to 90.5% and 64.3% to 85.7%, respectively.

Conclusion

Calprotectin in synovial fluid has great diagnostic efficacy for PJI diagnosisand outperformed ESR, CRP, SF-WBCs, and SF-PMNs.

Cite this article: Bone Joint Res 2020;9(8):450–457.

Ascitic calprotectin as a useful marker in the diagnosis of spontaneous bacterial peritonitis in adults

Background

Ascitic fluid polymorphonuclear leucocyte count (PMN) is known to be the gold standard for spontaneous bacterial peritonitis (SBP) diagnosis. The aim of this work was to assess ascitic calprotectin for SBP diagnosis. Serum C-reactive protein (CRP), high sensitivity C-reactive protein (hsCRP), nitrous oxide, ascitic PMN, ascitic leucocyte esterase and ascitic calprotectin were measured.

Results

The average age of our patients was 55.25 ± 7.89 years, mostly males (n = 51, 63.8%), anti-HCV antibodies were positive in (n = 61, 76.3%). Sixty-four patients (80%) were Child-Pugh C and their average MELD was 24.29 ± 8.06. Patients with SBP had statistically significant higher median MELD score (26.5 vs. 19) and higher average Child-Pugh score (12.18 ± 1.74 vs. 10.5 ± 1.97). Forty patients had SBP and 40 patients were without SBP. Both the serum and ascitic nitrous oxide did not differ statistically between patients with and without SBP. In contrast, patients with SBP had higher median serum CRP (49 vs. 12 mg/dL), hsCRP (58,000 vs. 23,750 ng/dL) and ascitic calprotectin (7.57 vs. 1.1 ng/mL). The ascitic leucocyte esterase test was positive in 95% of SBP patients in contrast to 2.5% patients without SBP. Ascitic calprotectin >2 ng/mL had 90% sensitivity, 92.5% specificity, 92.3% positive predictive value and 90.2% negative predictive value. MELD, CRP, hsCRP and ascitic calprotectin are independent predictors of SBP.

Conclusion

Ascitic calprotectin is a useful marker for SBP diagnosis.

Evaluation of a fluorescent immunochromatography test for fecal calprotectin

BACKGROUND

Fecal calprotectin (FC) is widely used to discriminate between patients with inflammatory diseases such as inflammatory bowel disease (IBD) and functional diseases such as irritable bowel syndrome (IBS). ELISA is a time-consuming method for the measurement of FC, whereas a fluorescent immunochromatography test can obtain results in around 30 minutes and thus enables a rapid response to clinical decision.

METHODS

Two methods, the Proglead^® calprotectin (FC Proglead) and the BÜHLMANN fCAL^® ELISA (FC BÜHLMANN), were used to quantitatively examine FC in 111 stool samples. The comparison and bias estimation of both assays were assessed using CLSI EP09c protocol.

RESULTS

The two methods were highly correlated (rho = .96). Deming regression was employed to calculate the regression equation, with a slope of 1.01 and an intercept of -4.98 μg/g. The estimated median bias (FC Proglead - FC BÜHLMANN) was -4.19 μg/g with the 95% limits of agreement (-55.59 to 47.21 μg/g), and the estimated median percent bias was -8.71% with the 95% limits of agreement (-50.31% to 32.90%). There was 4.50% (5/111) of values outside the 95% limits of agreement. Percent biases at the FC cutoff values of 50 and 200 μg/g between both methods evaluated by Deming regression were 8.96% and 1.49%, respectively. The biases were all less than the acceptable standard (10%). And, 99.10% of FC results were in agreement between both methods (kappa = .99, P < .001).

CONCLUSIONS

FC Proglead may be used as a suitable alternative to FC BÜHLMANN for the disease activity assessment for patients with IBD, considering its convenience and shorter turnaround time.

Laboratory testing of extravascular body fluids: National recommendations on behalf of the Croatian Society of Medical Biochemistry and Laboratory Medicine. Part I - Serous fluids

Extravascular body fluids (EBF) analysis can provide useful information in the differential diagnosis of conditions that caused their accumulation. Their unique nature and particular requirements accompanying EBF analysis need to be recognized in order to minimize possible negative implications on patient safety. This recommendation was prepared by the members of the Working group for extravascular body fluid samples (WG EBFS). It is designed to address the total testing process and clinical significance of tests used in EBF analysis. The recommendation begins with a chapter addressing validation of methods used in EBF analysis, and continues with specific recommendations for serous fluids analysis. It is organized in sections referring to the preanalytical, analytical and postanalytical phase with specific recommendations presented in boxes. Its main goal is to assist in the attainment of national harmonization of serous fluid analysis and ultimately improve patient safety and healthcare outcomes. This recommendation is intended to all laboratory professionals performing EBF analysis and healthcare professionals involved in EBF collection and processing. Cytological and microbiological evaluations of EBF are beyond the scope of this document.

Serum CD64 and ascitic fluid calprotectin and microRNA-155 as potential biomarkers of spontaneous bacterial peritonitis

AIM

Patients with ascites are at a higher risk for associated of on top bacterial infections with subsequent life-threatening complications. We aimed to evaluate CD64, calprotectin, and microRNA-155 (miR-155) levels as diagnostic markers of spontaneous bacterial peritonitis (SBP) and the effect of using more than one use on the same spot over their diagnostic efficiency.

PATIENTS AND METHODS

An observational comparative study included 103 patients with ascites admitted to the Tropical Medicine Department, Mansoura University Hospital, Egypt, divided into two groups: case group (64 patients) with ascites with SBP and control group (39 patients) with decompensated cirrhotic non-SBP ascites. Twenty milliliters of ascetic fluid was obtained from all participants for bacterial culture, and assessment of calprotectin and miR-155, in addition to 2 ml blood for the CD64 marker expression assay by a flowcytometer.

RESULTS

The sensitivity and specificity of CD64 expression assay were 95.3 and 92.3%, respectively, area under the curve (AUC)=0.93, whereas those of ascetic fluid calprotectin and miR-155 were 87.5 and 82.1%, AUC=0.90 and 95.3 and 97.4%, with AUC of 0.95. Combined blood CD64 and ascetic fluid calprotectin had a diagnostic accuracy of 0.988 for blood CD64 and ascetic fluid miR-155, AUC=0.991, and that for ascetic fluid calprotectin and miR-155 was 0.988. On using the three studied markers together, the diagnostic accuracy was the best recorded, AUC=0.994. P values were less than 0.001.

CONCLUSION

CD64, calprotectin, and miR-155 were good diagnostic markers of SBP and on using this combination, greater efficiency in diagnosis was achieved.

Role of ascitic prostaglandin E2 in diagnosis of spontaneous bacterial peritonitis and prediction of in-hospital mortality in patients with decompensated cirrhosis

Spontaneous bacterial peritonitis (SBP) is one of the most frequent and severe complications in patients with decompensated cirrhosis. Early antibiotic therapy is extremely important for successful treatment and reducing mortality. Prostaglandin E2 (PGE2) is a regulator of the immune response and infection. This study aimed to explore whether ascitic PGE2 could be used as a marker for diagnosing SBP and predicting in-hospital mortality.Patients with cirrhosis and ascites undergoing abdominal paracentesis were enrolled in our study. Demographic, clinical, and laboratory parameters were recorded at the time of paracentesis and ascitic PGE2 levels were determined by ELISA. The correlation between ascitic PGE2 level and SBP as well as in-hospital mortality were analyzed.There were 224 patients enrolled, 29 (13%) patients diagnosed as SBP based on the current guideline criteria. The ascitic PGE2 level of patients with SBP [32.77 (26.5-39.68) pg/mL] was significantly lower than that of patients without SBP [49.72 (37.35-54.72) pg/mL]. In ROC analysis, the AUC of ascitic PGE2 for the diagnosis of SBP was 0.75, and the AUC of ascitic PGE2 combined with WBC and ascitic PGE2 combined with neutrophils were 0.90 and 0.90, respectively, which were significantly higher than that of ascitic PGE2. In multivariate analysis, ascites PGE2≤32.88 pg/mL (OR: 9.39; 95% CI: 1.41-67.44, P = .026), hepatic encephalopathy (OR: 18.39; 95% CI: 3.00-113.13, P = .002) and a higher MELD score (OR: 1.25; 95% CI: 1.05-1.40, P = .009) remained independent predictors of in-hospital mortality.Ascitic PGE2 level is likely to be a valuable marker in prediction of in-hospital mortality in patients with decompensated cirrhosis, and its value in diagnosis of SBP was not superior to other inflammatory indicators.

Accuracy of calprotectin using the Quantum Blue Reader for the diagnosis of spontaneous bacterial peritonitis in liver cirrhosis

AIM

We aimed to evaluate the accuracy of the dosage of calprotectin in ascitic fluid (AF) using the Quantum Blue assay, for the prompt diagnosis of spontaneous bacterial peritonitis (SBP).

METHODS

We prospectively collected 236 AF samples from 119 cirrhotic patients hospitalized in two French centers between May 2016 and May 2017. Bloody and chylous/cloudy AF, and secondary peritonitis were excluded. SBP was diagnosed if neutrophils in AF were >250/mm³ using standard cytology. The Quantum Blue Reader selectively measured the calprotectin antigen (MRP8/14) in 12 min within the measurable range from 0.18 to 1.80 μg/mL; values outside this range were registered as 0.17 and 1.81 μg/mL.

RESULTS

A total of 36 AF were considered as SBP (15.2%). SBP had higher median levels of calprotectin than non-SBP (1.81 vs. 0.25 μg/mL, P < 0.001). Calprotectin levels were positively correlated with neutrophils in AF (r = 0.57, P < 0.001) and C-reactive protein (r = 0.43, P < 0.001), but not with the Child-Pugh and Model for End-Stage Liver Disease scores. The optimal threshold of calprotectin to diagnose SBP was set at 1.51 μg/mL (80th percentile of calprotectin), yielding sensitivity, specificity, and positive and negative predictive values of 86.1%, 92.0%, 65.9%, and 97.3%, respectively. Only one asymptomatic patient with SBP had a low calprotectin level, but a high serum C-reactive protein level that strongly suggested an ongoing infection. We also showed that intraclass correlation coefficients for inter- and intra-observer agreement were excellent, with 0.95 and 0.89, respectively.

CONCLUSIONS

The dosage of calprotectin in AF using the Quantum Blue assay is a rapid and reliable method of ruling out SBP in hospitalized cirrhotic patients.

Predicting mortality in patients with spontaneous bacterial peritonitis using routine inflammatory and biochemical markers

OBJECTIVES

Spontaneous bacterial peritonitis (SBP) is a common and high-mortality infectious complication of patients with cirrhosis. New inflammatory markers are associated with morbidity/mortality in various diseases. The aim of our study was to find the 30-day mortality rate of SBP and their predictors.

PATIENTS AND METHODS

Seventy patients with cirrhosis complicated with SBP and 55 non-SBP controls were enrolled into the study, and patients were evaluated for mortality rate and its predictors.

RESULTS

The 30-day and 3-month mortality rates in the SBP group were 26.1 and 50.7%, respectively. Mortality rates were higher in the SBP group than in the controls. Symptoms at hospital admission and cell counts in ascitic fluid made no difference in predicting 30-day mortality. Patients with SBP with high serum neutrophil counts, high neutrophil-lymphocyte ratio, high C reactive protein (CRP)/albumin ratio, and high model for end-stage liver disease (MELD) score had higher 30-day mortality rates. We determined optimal cutoff values of MELD scores and serum neutrophil counts for predicting 30-day mortality as 20.5 and 6850/mm, respectively. The sensitivity and specificity for the MELD cutoff value were 83.3 and 80.4%, respectively. We also followed up patients for 60 months after SBP; the patients with high inflammatory markers and MELD scores at the time of SBP diagnosis had worse survival compared with the group with lower levels.

CONCLUSION

Our results suggest that SBP has high 30-day mortality. MELD scores and inflammatory markers (CRP, CRP albumin ratio, neutrophil-lymphocyte ratio) may be used to predict mortality in patients with SBP.

Synovial Calprotectin: An Inexpensive Biomarker to Exclude a Chronic Prosthetic Joint Infection

BACKGROUND

To diagnose or exclude a chronic prosthetic joint infection (PJI) can be a clinical challenge. Therefore, sensitive and specific biomarkers are needed in the diagnostic work-up. Calprotectin is a protein with antimicrobial properties and is released by activated neutrophils, making it a specific marker for infection. Because of its low costs and ability to obtain a quantitative value as a point of care test, it is an attractive marker to use in clinical practice. In addition, the test is already used in routine care in most hospitals for other indications and therefore easy to implement.

METHODS

Between June 2015 and June 2017 we collected synovial fluid of all consecutive patients who underwent revision surgery of a prosthetic joint because of chronic pain with or without prosthetic loosening. Synovial calprotectin was measured using a lateral flow immunoassay. A PJI was defined by the diagnostic criteria described by the Musculoskeletal Infection Society.

RESULTS

Fifty-two patients with chronic pain were included. A PJI was diagnosed in 15 of 52 (29%) patients. The median calprotectin in the PJI group was 859 mg/L (interquartile range 86-1707) vs 7 mg/L (interquartile range 3-25) in the control group (P < .001). With a cut-off value of 50 mg/L, synovial calprotectin showed a sensitivity, specificity, positive predictive value, and negative predictive value of 86.7%, 91.7%, 81.3%, and 94.4%, respectively.

CONCLUSION

Synovial calprotectin is a useful and cheap biomarker to use in the diagnostic work-up of patients with chronic pain, especially to exclude a PJI prior to revision surgery.

Spontaneous peritonitis in critically ill cirrhotic patients: a diagnostic algorithm for clinicians and future perspectives

Spontaneous peritonitis (SP) is the most common infection among decompensated end-stage liver disease patients. SP is the infection of ascitic fluid (neutrophil ascitic count ≥250/mL) without an alternative focus of abdominal infection. According to the causative agent, clinicians can make the diagnosis of spontaneous bacterial peritonitis or spontaneous fungal peritonitis. The mortality rate is very high, ranging from one-fifth of the patients with spontaneous bacterial peritonitis to four-fifths of the patients with spontaneous fungal peritonitis. An immediate and accurate diagnosis can improve the outcome in end-stage liver disease patients. The aim of this work is to provide physicians with a practical diagnostic guidance for SP diagnosis according to current evidence, in order to improve the management of cirrhotic patients with infected ascitic fluid.

A novel turbidimetric immunoassay for fecal calprotectin optimized for routine chemistry analyzers

BACKGROUND

Fecal calprotectin assays are widely used to exclude inflammatory bowel disease (IBD) in patients with suspected IBD. A problem with the fecal calprotectin assays is the rather long test-turnaround times. A particle enhanced turbidimetric immunoassays (PETIA) for fecal calprotectin would reduce test-turnaround times and would permit more laboratories to perform the measurements. The aim of this study was to evaluate a new feces calprotectin PETIA.

METHOD

Using routine fecal samples the feces calprotectin PETIA was validated on two chemistry analyzers, Mindray BS-380 and Cobas 501.

RESULTS

The assay is linear in the range 11-2000 μg/g, with a limit of quantitation of approximately 10 μg/g. No antigen excess hook effect was observed up to 10 000-15 000 μg/g depending on the instrument used. The turbidimetric method showed a good agreement with the Bühlmann ELISA. The total coefficient of variation was 3%-8% in the 50-100 μg/g range.

CONCLUSION

The fecal calprotectin PETIA, fCal Turbo, is well suited for rapid analysis of fecal calprotectin on Mindray BS-380 or Cobas 501 clinical chemistry analyzers. The test results are commutable with Bühlmann fecal MRP8/14 ELISA.