Volume 51, Issue 7

Since the late 1990s, a surge in interest in the analysis of exhaled breath condensate (EBC) resulted in the American Thoracic Society and European Respiratory Society (ATS/ERS) organising a Task Force in 2001 to develop guidelines on EBC collection and measurement of biomarkers. This Task Force published their guidelines in 2005 based on literature and expert opinions at that time, and multiple shortcomings and knowledge deficits were also identified. The clinical application of EBC collection and its biomarkers are currently still limited by several of these knowledge gaps, hence further guidelines for standardisation are required to ensure external validity. Using related articles produced since the publication of the ATS/ERS Task Force report, this paper attempts to provide a comprehensive update to the original guideline and review the methodological shortcomings identified. This review can hopefully serve as a yardstick for future studies involving this emerging clinical tool.

Psoriasis is an immune-mediated, chronic, inflammatory disease that affects the skin and joints. Because of its high incidence and of its clinical symptoms it has a very strong social impact. In a genetically predisposed individual, the maintenance of the skin barrier integrity is strongly compromised in response to either environmental or self-antigenic insults. A persistent dysregulation of the skin immune system causes the typical evolutive skin lesions of psoriasis and recurrence of the disease. The most efficient laboratory approach consists of a well-defined evaluation of immune response in order to help diagnosis, to monitor evolution, and to evaluate the effects of individualized therapeutic treatments.

Since its inception in the mid-1980s of the 20th century testing for carbohydrate antigen 19-9 (CA 19-9) has raised expectation for an earlier diagnosis and accurate monitoring of several malignant diseases. After almost 30 years, the available evidences have confirmed the appropriateness and usefulness of determining CA 19-9 levels as a prognostic indicator and as a reliable tool for monitoring pancreatic and gastrointestinal cancer, but concerns have been raised about its applications in screening, which is actually not recommended, and in the diagnosis of malignancies, due to several interferences that limit the specificity and to the insufficient sensitivity of this marker. In this paper we aimed to review the basic concepts of CA 19-9 testing and its current applications, with a major focus on the most recent evidences dealing with assay interference, methods comparison and monitoring of malignant diseases. The prognostic value and monitoring recommendations for pancreatic, gastric and colorectal cancers are described in depth.

Background: Multiplexed methods permit simultaneous quantification of multiple cytokines. As several manufacturers offer reagents to quantify the same cytokines on a single instrument, comparison of the distribution should be made to determine whether these data are comparable from one assay to another. Methods: We performed the quantification of cytokines in serum samples with three commercially available assays: Cytometric Bead Array (CBA), Protein Biochip Array Technology (PBAT), and Luminex Technology analysis. Using detection limit and reference range of the three commercial multiplex technologies, we evaluated: 1) the overall distribution of cytokines; and 2) the clinical impact. Results: The three cytokines, IL-1β, IL-1α and IL-4, cannot be measured by these methods because of the high number of non-detected data (>50%). By contrast, four cytokines as IL-8, VEGF, MCP-1 and EGF exhibited a low percentage of non-detected data whatever method was used. The comparison of the percentage of samples with values higher than the respective reference range of each method reported an absence of clinical concordance (Cohen’s κ-test <0.40). Conclusions: Our results highlight the lack of transferability between the three commercially available multiplex methods evaluated (CBA, PBAT and Luminex Technology). Analytical performances are adequate for longitudinal studies using a same methodology but caution should be used for comparisons between results obtained with different methods underlying a need for standardization.

Background: Iron deficiency is a commonly encountered problem in pregnancy and a frequently observed cause of pregnancy-associated anemia. We longitudinally assessed the iron regulatory hormone hepcidin during gestation and postpartum and related hepcidin to conventional indicators of iron status and inflammation. Methods: Thirty-one healthy pregnant women were included and 81 blood samples from the three trimesters, directly and 6 weeks postpartum were analyzed for hemoglobin, the iron parameters: iron, total iron binding capacity, transferrin saturation, ferritin, soluble transferrin receptor and hepcidin, and CRP and leucocytes as markers of inflammation. Results: Hepcidin concentration decreased gradually from the first to the second and third trimester to undetectable levels (≤0.5 nmol/L) which was paralleled by decreasing hemoglobin levels and changes in iron parameters indicative for iron deficiency. During gestation hepcidin levels correlated with iron parameters, but not with inflammatory markers. Postpartum, hepcidin increased immediately to levels similar as assessed at early pregnancy. Conclusions: We conclude that hepcidin levels were suppressed during the second and third trimester of pregnancy, which was likely determined by the occurrence of iron deficiency. These data give insight in iron homeostasis during normal pregnancy.

Background: Red blood cell distribution width (RDW) is increased in liver disease. Its clinical significance, however, remains largely unknown. The aim of this study was to identify whether RDW was a prognostic index for liver disease. Methods: We studied, retrospectively, 33 patients with non-cirrhotic HBV chronic hepatitis, 125 patients with liver cirrhosis after HBV infection, 81 newly diagnosed primary hepatocellular carcinoma (pHCC) patients, 17 alcoholic liver cirrhosis patients and 42 patients with primary biliary cirrhosis (PBC). Sixty-six healthy individuals represented the control cohort. We analyzed the relationship between RDW on admission and clinical features. The association between RDW and hospitalization outcome was estimated by receiver operating curve (ROC) analysis and a multivariable logistic regression model. Results: Increased RDW was observed in liver disease patients. RDW was positively correlated with serum bilirubin and creatinine levels, prothrombin time, and negatively correlated with platelet counts and serum albumin concentration. A subgroup analysis, considering the different etiologies, revealed similar findings. Among the patients with liver cirrhosis, RDW increased with worsening of Child-Pugh grade. In patients with PBC, RDW positively correlated with Mayo risk score. Increased RDW was associated with worse hospital outcome, as shown by the AUC [95% confidence interval (CI)] of 0.76 (0.67–0.84). RDW above 15.15% was independently associated with poor hospital outcome after adjustment for serum bilirubin, platelet count, prothrombin time, albumin and age, with the odds ratio (95% CI) of 13.29 (1.67–105.68). Conclusions: RDW is a potential prognostic index for liver disease.

Background: Although the assessment of α-amylase is an essential part of the diagnostic workout of several pancreatic and extra-pancreatic disorders, its enzymatic activity is significantly reduced in the presence of cell-free hemoglobin such as in samples with spurious hemolysis, due to chemical and spectrophotometric interference. We developed a new reagent that provides reliable results on hemolyzed biological specimens. Methods: All tests were performed on Beckman Coulter AU5822. Intra-assay imprecision was assessed on three serum samples with low, intermediate and high α-amylase concentration. Linearity was assessed by serially diluting two samples with low and high values of α-amylase. The comparison with commercial reagent was performed on 40 serum samples. Hemolysis studies were carried out by mechanically hemolysis of 20 lithium-heparin samples. Results: The intra-assay imprecision was comprised between 1.3% and 2.2%. The linearity was excellent (r=0.998), and highly significant agreement was observed with the commercial assay (r=1.00; mean bias −3.8%). Although a significant correlation between non-hemolyzed and hemolyzed specimens was found with both assays (p<0.001), a much greater agreement was observed with the experimental method (r=0.997 vs. 0.818). No measurement exceeded the total allowable error with the experimental assay, whereas the threshold was exceeded in 85% of samples using the commercial method. Conclusions: The clinical applications of the experimental reagent include α-amylase assessment in hemolyzed samples, in urine and other biological fluids contaminated with lysed erythrocytes, or in patients under frequent transfusions and hemoglobin-based blood substitutes therapy. The formulation of this reagent could be adapted for other clinical chemistry or immunochemistry assays.

Background: With the use of a traditional blood gas analyzer (BGA) (ABL800 Radiometer) for blood glucose monitoring, tight glucose control (TGC) reduced in-hospital mortality and morbidity of surgical intensive care unit (ICU) adult and pediatric patients. Such BGAs are now superseded by cassette-based BGAs. We assessed the analytical reliability of cassette-based BGAs to monitor patient’s metabolic status in an ICU setting. Methods: We evaluated recovery/linearity, imprecision/repeatability and relative accuracy vs. comparison methods for glucose [coupled hexokinase glucose-6-phosphate dehydrogenase (HK/G6PD) assay] and lactate (lactate dehydrogenase assay) in ICU patient samples with two cassette-based BGAs [RP500 (Siemens) and ABL90 (Radiometer)] and with the ABL800 BGA. Results: Recovery of spiked glucose up to 348 mg/dL (19.3 mmol/L) was complete for all BGAs. Repeatability of ABL800 and ABL90 was comparable with the comparison method (about 1%), but higher for RP500 (about 2.4%). All BGAs were in agreement with the comparison method, with all glucose measurements falling within preset 10% criteria suggested by Karon. Recovery of spiked lactate (up to 25 mmol/L) was incomplete at all levels. Repeatability of ABL800 and ABL90 was comparable with the comparison method (about 4%), and 5.5% for RP500. All BGAs were in agreement with the comparison method, with >98% of the lactate measurements falling within 30% biological-variation-based criteria. Conclusions: The cassette-based BGAs quantified blood glucose and lactate levels in ICU patients within the acceptable error ranges. Cassette-based BGAs can be used for monitoring patient’s metabolic status in an ICU setting.

Background: A multicenter study conducted in Southeast Asia to derive reference intervals (RIs) for 72 commonly measured analytes (general chemistry, inflammatory markers, hormones, etc.) featured centralized measurement to clearly detect regionality in test results. The results of 31 standardized analytes are reported, with the remaining analytes presented in the next report. Method: The study included 63 clinical laboratories from South Korea, China, Vietnam, Malaysia, Indonesia, and seven areas in Japan. A total of 3541 healthy individuals aged 20–65 years (Japan 2082, others 1459) were recruited mostly from hospital workers using a well-defined common protocol. All serum specimens were transported to Tokyo at –80°C and collectively measured using reagents from four manufacturers. Three-level nested ANOVA was used to quantitate variation (SD) of test results due to region, sex, and age. A ratio of SD for a given factor over residual SD (representing net between-individual variations) (SDR) exceeding 0.3 was considered significant. Traceability of RIs was ensured by recalibration using value-assigned reference materials. RIs were derived parametrically. Results: SDRs for sex and age were significant for 19 and 16 analytes, respectively. Regional difference was significant for 11 analytes, including high density lipoprotein (HDL)-cholesterol and inflammatory markers. However, when the data were limited to those from Japan, regionality was not observed in any of the analytes. Accordingly, RIs were derived with or without partition by sex and region. Conclusions: RIs applicable to a wide area in Asia were established for the majority of analytes with traceability to reference measuring systems, whereas regional partitioning was required for RIs of the other analytes.

Background: The 2009 Asian multicenter study for derivation of reference intervals (RIs) featured: 1) centralized measurements to exclude reagent-dependent variations; 2) inclusion of non-standardized analytes (hormones, tumor makers, etc.) in the target; and 3) cross-check of test results between the central and local laboratories. Transferability of centrally derived RIs for non-standardized analytes based on the cross-check was examined. Methods: Forty non-standardized analytes were centrally measured in sera from 3541 reference individuals recruited by 63 laboratories. Forty-four laboratories collaborated in the cross-check study by locally measuring aliquots of sera from 9 to 73 volunteers (average 22.2). Linear relationships were obtained by the major-axis regression. Error in converting RIs using the regression line was expressed by the coefficient of variation of slope b [CV(b)]. CV(b) <10% was set as the cut-off value allowing the conversion. The significance of factors for partitioning RIs was determined similarly as in the first report. Results: Significant sex-, age-, and region-related changes in test results were observed in 17, 15, and 11 of the 40 analytes, respectively. In the cross-comparison study, test results were not harmonized in the majority of immunologically measured analytes, but their average CV(b)s were <10% except for total protein, cystatin C, CA19-9, free thyroxine, and triiodothyronine. After conversion, 74% of centrally derived RIs were transferred to each local laboratory. Conclusions: Our results point to the feasibility of: 1) harmonizing test results across different laboratories; and 2) sharing centrally derived RIs of non-standardized analytes by means of comparative measurement of a set of commutable specimens.

Background: Carbohydrate antigen 19-9 (CA19-9) is frequently tested in cancer patients. However, elevated CA19-9 can be found in many benign diseases. We investigated the relationship between elevated CA19-9 and diseases, and presented suggestions for its utility in a health check-up cohort. Methods: From June 2008 to December 2008, we enrolled consecutive health check-up individuals with elevated CA19-9 (>37 U/mL). They were divided into three groups: group A (malignant diseases), group B (decreasing concentrations), and group C (increasing concentrations) according to the following criteria: (i) CA19-9 was rechecked monthly in the first 3 months; (ii) follow-up was completed if malignancy was found or if CA19-9 concentration dropped to normal; (iii) if CA19-9 kept increasing, it was monitored every 3 months; (4) total duration was 1 year. Results: Among 33,867 individuals, 572 (1.7%) individuals showed elevated CA19-9 concentration. A total of 509 (90.0%) individuals finished at 1-year follow-up. In total, nine (1.8%) individuals were diagnosed with malignancies. For 336 (66.0%) individuals CA19-9 concentrations dropped to normal, whereas for 164 (32.2%) individuals it kept rising. Interestingly, we did not find any differences in concentration levels between group A and group C. The main associated benign diseases included fatty liver (25.3%), cholecystolithiasis (13.9%), and chronic hepatitis B (13.9%). Conclusions: Dynamic monitoring of CA19-9 is recommended in asymptomatic populations with elevated CA19-9 concentrations.

Background: Ovarian cancer is the leading cause of death among all gynecological disorders. Aberrant glycosylation, or more specifically, increased sialylation of proteins has been observed in ovarian cancer. Several sialyltransferase genes have been shown to be up-regulated at both the mRNA and protein levels in a number of cancers, including that of the ovary. ST6GAL1 (β-galactosamide α2,6-sialyltranferase 1) gene expression has previously been shown to be upregulated in ovarian cancers of all major subtypes. Methods: We have identified the sialome (i.e., sialic acid containing glycoproteins) of biological fluids from ovarian cancer patients and ovarian cancer cell lines utilizing tandem mass spectrometry as a potential pool of novel biomarker candidates. The sialoglycopeptides from four ovarian cancer cell lines, pooled ascites (n=13) and ovarian cyst (n=14) fluids from ovarian cancer patients were enriched utilizing affinity to agarose-immobilized Elderberry lectin ( Sambucus nigra agglutinin) and magnetic hydrazide beads folowing periodate-mediated oxidation of sialic acids. Benign ovarian cyst (n=10) and peritoneal effusion (n=20) fluids were analyzed in the same fashion to serve as controls. PNGase F deglycosylated peptides were identified using electrospray ionization-LTQ Orbitrap tandem mass spectrometry. Results: In all of the samples analyzed in the glycoproteomic portion of the study, we have identified 579 glycosylation sites on 333 proteins. Of these, 13 were exclusively identified in biological fluids from ovarian cancer patients, and another eight were common to these fluids and the ovarian cancer cell line supernatants. Conclusions: The proteins identified in the present study could form the basis for future studies examining and quantifying their sialylation status as biomarkers of ovarian cancer.

Background: To prospectively evaluate the role of procalcitonin (PCT) in detecting or excluding medullary thyroid carcinoma (MTC) among patients with thyroid nodules and increased calcitonin (CT) levels. Methods: Fourteen of 1236 patients referred for thyroid nodules had increased serum CT >10 pg/mL. A stimulation test with pentagastrin was done and both CT and PCT were measured after stimulation. All patients underwent thyroid ultrasound, fine-needle cytology and, if indicated, surgery with histological and immunohistochemical examination of the surgical specimens. Results: After follow-up, two MTCs were found. These two patients had basal CT >100 pg/mL and detectable (>0.1 ng/mL) PCT, with 100% sensitivity. Pentagastrin stimulated CT achieved values above 100 pg/mL in two MTCs and in other two cases with no MTC outcome (50% PPV and 83% NPV). On the contrary, all patients with no MTC had both basal and stimulated undetectable PCT (100% PPV and 100% NPV). Conclusions: The addition of basal PCT measurement in patients with thyroid nodule(s) and increased CT may significantly improve accuracy of CT measurement without needing a PG stimulation test.

Background: Serum HER2 (S-HER2) was approved in 2003 by the US Food and Drug Administration (FDA) for monitoring trastuzumab treatment in tissue HER2 positive breast cancer patients. Information of the value of S-HER2 is scarce. We hypothesised that S-HER2 would reflect the clinical effect of trastuzumab. Methods: We followed 48 patients eligible for trastuzumab treatment for up to 6 years or until death. S-HER2 was measured on an ADVIA Centaur System and S-Trastuzumab was measured by an in-house developed fluorescent enzyme immunoassay system on the ImmunoCap 100. Results: A decrease in S-HER2 of ≥20% was correlated to no progression in the disease in 20 out of 21 clinical courses (p<0.0001). An increase in S-HER2 of ≥20% was correlated to progression in the disease in 40 out of 44 clinical courses (p<0.0001). Patients with no recurrence after trastuzumab treatment (n=18) had a median S-HER2 concentration of 10.5 μg/L, whereas patients alive with recurrence (n=13) had a median S-HER2 of 20.1 μg/L (p=0.002). Patients who died prompted by recurrence (n=17) had a median S-HER2 of 232.4 μg/L at latest measurement before death (p=<0.0001) compared to patients without recurrence. In two patients with S-HER2 values above 1000 μg/L the concentrations of S-trastuzumab were measured below the target trough concentration in serum of 10 mg/L. Conclusions: Decreasing values of S-HER2 predicts response to treatment whereas increasing levels predict resistance. S-HER2 above 1000 μg/L warns that standard doses of trastuzumab may be insufficient as reflected by low concentrations of S-trastuzumab.

Background: The role of tumor markers in pulmonary alveolar proteinosis (PAP) remains unclear. This study investigated the tumor markers in serum and bronchoalveolar lavage fluid (BALF) in PAP patients and explored the relationship between tumor markers and the severity of PAP. Methods: We retrospectively reviewed 38 patients with PAP. Results: Mean serum carcinoembryonic antigen (CEA) and CYFRA21-1 levels were higher than the cut-off values (12.7±17.5 ng/mL and 10±10.66 ng/mL, respectively). Significant correlations were found between levels of CEA and neuron-specific enolase (NSE) in serum and serum lactate dehydrogenase (LDH) values (r=0.60, p<0.001 and r=0.56, p<0.001, respectively). A significant correlation was also observed between levels of squamous cell carcinoma (SCC) in serum and PaO 2 and PA-aO 2 (r=−0.49 p=0.01 and r=−0.51, p=0.01, respectively). The changes of CEA, SCC and NSE levels were consistent with the changes of LDH and PaO 2 . The serum levels of CEA, NSE and SCC were significantly lower after whole lung lavage compared with those before (8.7±10.6 vs. 15.7±22, 7.9±5.2 vs. 16.6±11.8, 0.4±0.24 vs. 0.59±0.42; p<0.05, respectively). Conclusions: Elevated serum tumor marker levels were found in PAP patients. The serum levels of CEA, NSE and SCC may reflect the severity of the disease and predict the therapeutic effect of whole lung lavage.

Background: Carcinoembryonic antigen (CEA), a biomarker overexpressed in malignant tumors, exhibits increased levels in certain non-malignant conditions, including chronic inflammatory status. The elevation of CEA in chronic inflammatory conditions suggests that this marker may also be associated with non-alcoholic fatty liver disease (NAFLD). Therefore, we investigated the relationship between serum CEA concentrations and NAFLD in healthy Korean non-smokers. Methods: A total of 200 healthy Korean non-smokers were enrolled during their routine health check-ups. Biomarkers of metabolic risk factors were assessed along with the presence of NAFLD using the liver Fibroscan ® . Serum CEA levels were measured using a chemiluminescence immunoassay analyzer. Results: The prevalence of NAFLD increased significantly with increasing CEA quartiles; the mean log CEA level increased gradually according to the grade of hepatic steatosis. Multivariate logistic regression analysis adjusted for age, gender, body mass index, exercise, blood pressure, fasting glucose, insulin, total cholesterol, triglycerides, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, white blood cell counts, aspartate aminotransferase, alanine aminotransferase and γ-glutamyltransferase showed that the fourth CEA quartile was associated with NAFLD, with an odds ratio of 2.98 (95% confidence interval 1.10–8.05, p<0.01). Conclusions: Our study showed independent associations between CEA and NAFLD by analyzing data from 200 healthy Korean non-smokers, suggesting that CEA functions in the pathophysiology of fatty liver disease. Further studies are required to better understand the clinical and pathophysiological significance of our findings.

Background: DNA methylation represents one of the most common epigenetic changes in human cancer providing important information regarding carcinogenesis. A possible role as a prognostic indicator has also been proposed. The aim of our study was to evaluate the prognostic significance of SOX17 promoter methylation status in patients with operable gastric cancer. Methods: Using methylation-specific PCR (MSP) we examined the incidence and prognostic significance of SOX17 methylation status in cell free circulating DNA in the serum of 73 patients with operable gastric cancer. Fifty-one patients were male (69.9%), their median age was 65 years, 43 patients (58.9%) had regional lymph node involvement and all had a Performance Status (WHO) of 0–1. Results: SOX17 promoter was found to be methylated in 43 out of 73 gastric cancer serum samples examined (58.9%). All 20 control serum samples from healthy individuals were negative. Overall survival (OS) was found to be significantly associated with SOX17 methylation (p=0.049). A significant correlation between methylation status and differentiation (p=0.031) was also observed. No other significant associations between different tumor parameters examined and SOX17 methylation status were observed. Conclusions: SOX17 promoter methylation in cell free DNA of patients with operable gastric cancer is a frequent event and may provide important information regarding prognosis in this group of patients.

Background: The aim of this project was to investigate the sensitivity of CA 15-3, CEA and HER2 in the early diagnosis of metastatic breast cancer. Methods: Serial serum values of CA 15-3, CEA and HER2 were determined in 107 patients with recurrence after breast cancer. Fifteen of the patients had primary disseminated disease, nine patients only developed local recurrence during the follow-up period and the remaining 83 developed distant metastases. Results: In the group of patients with distant metastatic disease (n=83), elevated serum levels of CA 15-3 (>32.4 U/mL), CEA (>2.5 µg/L for non-smokers and >10 µg/L for smokers) and HER2 (>15 µg/L) were found in 49.4%, 38.6% and 32.5%, respectively, at the time of diagnosis of recurrence. CA 15-3 was significantly better than HER2 (p=0.027). The most sensitive combination was obtained using CA 15-3/CEA (60.2%) or CA 15-3/HER2 (57.8%). Combining all three tumour markers raised the sensitivity to 63.9%. In the subgroup of patients with tissue HER2+ tumours, the sensitivity of HER2 increased to 55.6%. The best combination in this group was CEA/HER2 (66.7%). In the subgroup of patients with tissue HER2− tumours, CA 15-3 was significantly better. The best combination was CA 15-3/HER2 or CA 15-3/CEA with a sensitivity of 55.8% and 59.6%, respectively. Conclusions: The combination of several tumour markers enhances the sensitivity for detection of metastatic breast cancer. We recommend HER2 or the combination of CEA and HER2 in tissue HER2+ and CA 15-3 or the combination of CA 15-3 and CEA in tissue HER2−.

Background: The nucleotide-binding oligomerization domain-like receptor 3 (NLRP3) inflammasome is a multiprotein complex consisting of NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) and caspase-1. In peripheral blood mononuclear cells (PBMCs), NLRP3 can activate interleukin-1β (IL-1β), important in the chronic inflammatory process of idiopathic dilated cardiomyopathy (IDCM). Therefore, the NLRP3 inflammasome in PBMCs may be involved in the pathogenesis of IDCM. We evaluated the association of circulating levels of NLRP3 inflammasome and cardiac function in patients with IDCM and 6-month rehospitalization. Methods: We enrolled 54 patients with IDCM and 20 healthy volunteers and analyzed left ventricle ejection fraction (LVEF), electrocardiography findings and circulating levels of NLRP3, ASC, caspase-1, IL-1β, N terminal-pro type B natriuretic peptide (NT-pro BNP) and blood values. Patients were followed up for 6 months. Results: On admission and discharge, the circulating levels of NLRP3, ASC, caspase-1 and IL-1β were higher in IDCM patients than healthy controls (all p<0.05). In patients, NLRP3 mRNA level was associated with LVEF, NT-pro BNP level and monocyte count (all p<0.05). LVEF at admission and mRNA levels of NLRP3 and IL-1β at discharge were independent risk factors of 6-month rehospitalization for patients. High NLRP3 mRNA level was associated with cumulative rehospitalization rate (p<0.05). Conclusions: NLRP3 level in PBMCs may be associated with cardiac function and rehospitalization in IDCM patients.

Background: Statins can cause tubular proteinuria by inhibiting tubular reabsorption of urinary proteins. To distinguish between microalbuminuria originating from glomerular leakage of albumin and tubular microalbuminuria due to statin therapy, the α 1 -microglobulin/albumin ratio is evaluated in patients taking statins and compared to untreated patients. Methods: Ten apparently healthy subjects were given 40 mg of simvastatin and tested for urinary α 1 -microglobulin, albumin, creatinine and cystatin C, up to 24 h after administration. Additionally, urine samples of 76 statin-treated and 456 untreated patients presenting with micro-albuminuria (albuminuria range between 20 and 200 mg/L) were tested for α 1 -microglobulin and albumin. α 1 -Microglobulin/albumin ratios were compared. Total cholesterol was measured in 50 patients on statin therapy. Results: In the 10 apparently healthy subjects, a significant temporary increase of α 1 -microglobulin, albumin and α 1 -microglobulin/albumin ratio was observed after statin intake. In the group of 532 patients showing micro-albuminuria, those treated with statins showed a significantly higher mean urinary α 1 -microglobulin/albumin ratio then untreated patients. Urinary albumin concentrations were significantly higher in patients taking simvastatin than in patients on rosuvastatin treatment and they were also higher in patients on statin therapy with a total serum cholesterol concentration below 3.88 mmol/L than in patients with a total serum cholesterol concentration above 5.17 mmol/L. Conclusions : Tubular proteinuria, caused by the use of statins, can be distinguished from glomerular proteinuria by a higher urinary α 1 -microglobulin/albumin ratio.

Background: The aim was to evaluate the clinical usefulness of a single plasma and bronchoalveolar lavage fluid (BALF) PCT and IL-6 measurement in discriminating septic from non-septic causes of acute respiratory distress syndrome (ARDS) and forecasting clinical outcomes. Methods: One hundred patients were enrolled within 48 h of ALI/ARDS recognition. Demographic, clinical data, severity indices were recorded and PCT and IL-6 concentrations were measured in plasma and BALF. Results: Plasma PCT and IL-6 values were significantly higher in septic compared to non-septic individuals (p=0.001 and 0.0005, respectively), while there were no differences in their respective BALF values. As far as identification of septic vs. non-septic ARDS is concerned, the comparison of the areas under the curves favored PCT vs. IL-6 [0.88, (95% CI 0.81–0.95) vs. 0.71, (95% CI 0.60–0.81); χ 2 =9.04, p=0.003]. A plasma PCT level of 0.815 ng/mL was associated with 74.1% sensitivity and 97.6% specificity in identifying septic ARDS cases; this corresponded to a diagnostic odds ratio value of 116. Linear regression multivariable analysis disclosed a significant relation of plasma PCT with SOFA score in septic ARDS patients (p<0.001), while neither BALF PCT nor IL-6 levels were associated with clinical outcome. Conclusions: Early plasma – but not BALF – PCT concentrations can discriminate between septic and non-septic ARDS causes and are associated with the severity of multiple organ dysfunction syndrome in septic ARDS patients. However, neither plasma or BALF IL-6 levels nor BALF PCT levels carry any prognostic potential. A single plasma PCT value higher than 0.815 ng/mL makes a non-septic cause of ARDS highly unlikely.