The value of routine laboratory screening in the neonatal intensive care unit.

BACKGROUND: Healthcare spending is expected to grow faster than the economy over the next decade, and the cost of prematurity increases annually. The aim of this study was to investigate the frequency of intervention after routine laboratory testing in preterm infants. METHODS: This was a retrospective study of preterm infants (≤34 weeks) admitted to the NYU Langone Health NICU from June 2013 to December 2014. Data collected included demographics, results of laboratory tests, and resulting interventions. Intervention after a hemogram was defined as a blood transfusion. Intervention after a hepatic panel was defined as initiation or termination of ursodiol or change in dose of vitamin D. Subjects were stratified into 3 groups based on gestation (<28 weeks, 28-31 6/7 weeks, 32-34 weeks). Chi-square analysis was used to compare the frequency of intervention between the groups. RESULTS: A total of 135 subjects were included in the study. The frequency of intervention after a hemogram was 8.4% in infants <28 weeks, 4.6% in infants 28-31 6/7 weeks, and 0% in infants 32-34 weeks; this difference was found to be statistically significant (p = 0.02). The frequency of intervention after a hepatic panel was 4.2% in infants <28 weeks, 5.7% in infants 28-31 6/7 weeks, and 0% in infants 32-34 weeks, which was not found to be a statistically significant different. CONCLUSION: No interventions were undertaken post-routine laboratory testing in any infant 32-34 weeks and routine testing in this population may be unnecessary. Further studies are needed to elucidate if routine testing affects neonatal outcomes.

Serum and Hepatic Autofluorescence as a Real-Time Diagnostic Tool for Early Cholestasis Assessment.

While it is well established that various factors can impair the production and flow of bile and lead to cholestatic disease in hepatic and extrahepatic sites, an enhanced assessment of the biomarkers of the underlying pathophysiological mechanisms is still needed to improve early diagnosis and therapeutic strategies. Hence, we investigated fluorescing endogenous biomolecules as possible intrinsic biomarkers of molecular and cellular changes in cholestasis. Spectroscopic autofluorescence (AF) analysis was performed using a fiber optic probe (366 nm excitation), under living conditions and in serum, on the livers of male Wistar rats submitted to bile duct ligation (BDL, 24, 48, and 72 h). Biomarkers of liver injury were assayed biochemically. In the serum, AF analysis distinctly detected increased bilirubin at 24 h BDL. A continuous, significant increase in red-fluorescing porphyrin derivatives indicated the subversion of heme metabolism, consistent with an almost twofold increase in the serum iron at 72 h BDL. In the liver, changes in the AF of NAD(P)H and flavins, as well as lipopigments, indicated the impairment of mitochondrial functionality, oxidative stress, and the accumulation of oxidative products. A serum/hepatic AF profile can be thus proposed as a supportive diagnostic tool for the in situ, real-time study of bio-metabolic alterations in bile duct ligation (BDL) in experimental hepatology, with the potential to eventually translate to clinical diagnosis.

Clinical Assessment of Differential Diagnostic Methods in Infants with Cholestasis due to Biliary Atresia or Non-Biliary Atresia.

The different methods in differentiating biliary atresia (BA) from non-BA-related cholestasis were evaluated in order to provide a practical basis for a rapid, early and accurate differential diagnosis of the diseases. 396 infants with cholestatic jaundice were studied prospectively during the period of May 2007 to June 2011. The liver function in all subjects was tested. All cases underwent abdominal ultrasonography and duodenal fluid examination. Most cases were subjected to hepatobiliary scintigraphy, magnetic resonance cholangiopancreatography (MRCP) and a percutaneous liver biopsy. The diagnosis of BA was finally made by cholangiography or histopathologic examination. The accuracy, sensitivity, specificity and predictive values of these various methods were compared. 178 patients (108 males and 70 females with a mean age of 58±30 days) were diagnosed as having BA. 218 patients (136 males and 82 females with a mean age of 61 ±24 days) were diagnosed as having non-BA etiologies of cholestasis jaundice during the follow-up period in which jaundice faded after treatment with medical therapy. For diagnosis of BA, clinical evaluation, hepatomegaly, stool color, serum gamma-glutamyltranspeptidase (GGT), duodenal juice color, bile acid in duodenal juice, ultrasonography (gallbladder), ultrasonography (griangular cord or strip-apparent hyperechoic foci), hepatobiliary scintigraphy, MRCP, liver biopsy had an accuracy of 76.0%, 51.8%, 84.3%, 70.0%, 92.4%, 98.0%, 90.4%, 67.2%, 85.3%, 83.2% and 96.6%, a sensitivity of 83.1%, 87.6%, 96.1%, 73.7%, 90.4%, 100%, 92.7%, 27.5%, 100%, 89.0% and 97.4%, a specificity of 70.2%, 77.5%, 74.8%, 67.0%, 94.0%, 96.3%, 88.5%, 99.5%, 73.3%, 75.4% and 94.3%, a positive predictive value of 69.0%, 72.6%, 75.7%, 64.6%, 92.5%, 95.7%, 86.8%, 98.0%, 75.4%, 82.6% and 98.0%, and a negative predictive value of 83.6%, 8.5%, 95.9%, 75.7%, 92.3%, 100%, 84.2%, 93.7%, 100%, 84.0% and 92.6%, respectively. It was concluded that all the differential diagnosis methods are useful. The test for duodenal drainage and elements is fast and accurate. It is helpful in the differential diagnosis of BA and non-BA etiologies of cholestasis. It shows good practical value clinically.

Assessment of ATP8B1 Deficiency in Pediatric Patients With Cholestasis Using Peripheral Blood Monocyte-Derived Macrophages.

Progressive familial intrahepatic cholestasis type 1 (PFIC1), a rare inherited recessive disease resulting from a genetic deficiency in ATP8B1, progresses to liver failure. Because of the difficulty of discriminating PFIC1 from other subtypes of PFIC based on its clinical and histological features and genome sequencing, an alternative method for diagnosing PFIC1 is desirable. Herein, we analyzed human peripheral blood monocyte-derived macrophages (HMDM) and found predominant expression of ATP8B1 in interleukin-10 (IL-10)-induced M2c, a subset of alternatively activated macrophages. SiRNA-mediated depletion of ATP8B1 in IL-10-treated HMDM markedly suppressed the expression of M2c-related surface markers and increased the side scatter (SSC) of M2c, likely via impairment of the IL-10/STAT3 signal transduction pathway. These phenotypic features were confirmed in IL-10-treated HMDM from four PFIC1 patients with disease-causing mutations in both alleles, but not in those from four patients with other subtypes of PFIC. This method identified three PFIC1 patients in a group of PFIC patients undiagnosed by genome sequencing, an identical diagnostic outcome to that achieved by analysis of liver specimens and in vitro mutagenesis studies. In conclusion, ATP8B1 deficiency caused incomplete polarization of HMDM into M2c. Phenotypic analysis of M2c helps to identify PFIC1 patients with no apparent disease-causing mutations in ATP8B1.

Contrast-enhanced micro-computed tomography using ExiTron nano6000 for assessment of liver injury.

AIM: To explore the potential of contrast-enhanced computed tomography (CECT) using ExiTron nano6000 for assessment of liver lesions in mouse models. METHODS: Three mouse models of liver lesions were used: bile duct ligation (BDL), lipopolysaccharide (LPS)/D-galactosamine (D-GalN), and alcohol. After injection with the contrast agent ExiTron nano6000, the mice were scanned with micro-CT. Liver lesions were evaluated using CECT images, hematoxylin and eosin staining, and serum aminotransferase levels. Macrophage distribution in the injury models was shown by immunohistochemical staining of CD68. The in vitro studies measured the densities of RAW264.7 under different conditions by CECT. RESULTS: In the in vitro studies, CECT provided specific and strong contrast enhancement of liver in mice. CECT could present heterogeneous images and densities of injured livers induced by BDL, LPS/D-GalN, and alcohol. The liver histology and immunochemistry of CD68 demonstrated that both dilated biliary tracts and necrosis in the injured livers could lead to the heterogeneous distribution of macrophages. The in vitro study showed that the RAW264.7 cell masses had higher densities after LPS activation. CONCLUSION: Micro-CT with the contrast agent ExiTron nano6000 is feasible for detecting various liver lesions by emphasizing the heterogeneous textures and densities of CECT images.

Assessment of serum total and bone alkaline phosphatase measurement in clinical practice.

The aim of the study was to measure serum levels of the bone-specific isoenzyme of alkaline phosphatase in normal subjects and patients with metabolic bone disease by using an immunoadsorption assay. We studied 140 healthy adults, 122 patients affected by metabolic bone disease and 15 patients with cholestatic liver disease. Mean values of the bone-specific isoenzyme of alkaline phosphatase in healthy men were significantly higher than those found in premenopausal women (17.8 +/- 4.2 U/l vs 15.6 +/- 4.6 U/l, p < 0.02); postmenopausal women had significantly higher levels of bone-specific isoenzyme of alkaline phosphatase (22.6 +/- 6.4 U/l) than premenopausal women (p < 0.0001). After the menopause total alkaline phosphatase increased by 46%, while the increase in bone-specific isoenzyme of alkaline phosphatase was 39%. No significant correlations were found between bone-specific isoenzyme of alkaline phosphatase and either age or years since menopause, in postmenopausal subjects. In patients with bone-specific isoenzyme of alkaline phosphatase above the upper limit of normal, the assay had a sensitivity of 100% only in patients with Paget's disease of bone. In patients with cholestatic liver disease we found no correlation between bone-specific isoenzyme of alkaline phosphatase and either total alkaline phosphatase and gamma-glutamyl transpeptidase, while a positive correlation was found between total alkaline phosphatase and gamma-glutamyl transpeptidase. Our results confirm the role of bone-specific isoenzyme of alkaline phosphatase assay in clinical research; however, its usefulness in clinical practice is unclear once liver involvement has been excluded.

Improved scintigraphic assessment of severe cholestasis with the hepatic extraction fraction.

In previous studies, we found that biliary scintigraphy with technetium-99m-labeled iminodiacetic acid ([99mTc]IDA) provided excellent discrimination between intrahepatic and extrahepatic cholestasis, except in patients with profound cholestasis who had poor visualization of the biliary tree. In this study, we have used deconvolution analysis to determine the hepatic extraction fraction (HEF) of a hypothetical single circulatory pass of [99mTc]IDA. Our hypothesis was that extraction of radionuclide from the blood would be normal in patients with extrahepatic obstruction alone, but would be impaired in patients with intrahepatic disease (IHD). The purpose of this study was to compare the HEF in patients with profound cholestasis (bilirubin greater than or equal to 3.0 mg/dl) due to either IHD or common bile duct obstruction (CBDO). Normal subjects (N = 13) had an HEF of 100%. Patients with CBDO (N = 13) had slightly reduced HEF values (92.8 +/- 3.2%) despite profound hyperbilirubinemia (6.1 +/- 1.0 mg/dl). Patients with IHD (N = 23) had a markedly reduced HEF (43.1 +/- 4.1%) which was significantly lower than patients with CBDO and normal subjects (P less than 0.001). We conclude that the determination of the HEF during biliary scintigraphy is helpful in distinguishing between intrahepatic and extrahepatic disease in patients with hyperbilirubinemia (bilirubin greater than or equal to 3.0 mg/dl).

Assessing diagnostic tests once an optimal cutoff point has been selected.

The specificity and sensitivity of a quantitative diagnostic test depends on the chosen cutoff point. The common practice of selecting a cutoff point that maximizes the specificity plus the sensitivity, as judged from the observed test results, is studied here by simulation. Test performance is on average assessed too optimistically by this procedure--a phenomenon of importance when sample sizes are small. For example, the average positive bias is up to 15% of the test performance for sample sizes of 25. Furthermore, binomial calculated standard errors of specificity and sensitivity estimates are incorrect. A Monte Carlo statistical method--the "bootstrap procedure"--is applied to correct for bias and to estimate standard errors, including the standard error of the optimal cutoff point. Independent and paired comparisons of two diagnostic tests are also considered when optimal cutoff points have been selected. For this purpose, binomial statistical tests behave satisfactorily. Examples of power functions are presented.

Evaluation of the diagnostic value of serum bile acid in the detection and functional assessment of liver diseases.

The diagnostic usefulness of fasting total serum bile acids (SBA/F) in the detection of liver diseases and assessment of different aspects of hepatic function alteration was evaluated in 61 healthy subjects and 186 patients with liver disease. The value of SBA/F was compared with other routine tests. In 49 healthy subjects and 92 patients, serum bile acids were also measured after the im administration of Ceruletide as a cholecystokinetic agent (SBA/C). The diagnostic efficacy for the detection of disease states was better with aspartate-aminotransferase (EC 2.6.1.1) and alanine-aminotransferase (EC 2.6.1.2) than with SBA/F. When SBA/C was also determined the diagnostic efficacy was not substantially better than the SBA/F test. In the assessment of hepatocellular necrosis SBA/F showed a higher rate of misclassification errors compared to alanine-aminotransferase (mean error 45% vs 17%), whereas SBA/F gave similar results with direct bilirubin and pseudocholinesterase (EC 3.1.1.8) in the evaluation of cholestasis (mean error 40% vs 41%) and impaired biosynthesis (mean error 39% vs 40%), respectively. Serum bile acid determination did not show any significant diagnostic advantage with respect to the other routine liver tests.