Application of the Sampson equation to estimate LDL-C in children: Comparison with LDL direct measurement and Friedewald equation in the BLIP study.

BACKGROUND AND AIMS: In epidemiological trials and in clinical practices, it is relevant to have affordable and reliable methods to measure the main lipid cardiovascular risk factors, and in particular low-density lipoprotein cholesterol (LDL-C) plasma level. In this context, we aimed to compare the reliability of the Friedewald's (LDL-Cf) and Sampson's (LDL-Cs) equations with the LDL-value dosed by a validated dosage method (LDL-Cd) in a large cohort of children. METHODS AND RESULTS: We considered the lipid values of 145 infants, 278 preschoolers, 810 scholar children, and 1372 adolescents (Total N. 2605, 1291 males, 1314 females), with mean total cholesterol (TC) = 169.8 ± 39.7 mg/dL, HDL-Cholesterol = 50.8 ± 12.7 mg/dL, non HDL-Cholesterol = 118.9 ± 35.9 mg/dL, Triglycerides (TG) = 90.3 ± 77.9 mg/dL, LDL-Cd = 106.2 ± 29.9 mg/dL, LDL-Cf = 100.9 ± 33.8 mg/dL, and LDL-Cs = 102.2 ± 33.4 mg/dL. Comparing the distance to the LDL-Cd, Friedewald's equation mildly but significantly underestimated in infants (3.4 ± 5.3 mg/dL), preschoolers (1.5 ± 7.1 mg/dL). Children (1.2 ± 2.2 mg/dL) and adolescents (1.1 ± 5.9 mg/dL) compared to Sampson's equation (all comparisons, p < 0.001). CONCLUSIONS: Our analysis, being carried out on a large population sample, shows that Sampson's equation is more reliable than Friedewald's one at each considered age class and even for extreme TG values.

Posttranscriptional changes of serum albumin: clinical and prognostic significance in hospitalized patients with cirrhosis.

UNLABELLED: Beside the regulation of fluid distribution, human serum albumin (HSA) carries other activities, such as binding, transport, and detoxification of many molecules. In patients with cirrhosis, HSA exhibits posttranscriptional alterations that likely affect its functions. This study aimed at identifying the structural HSA alterations occurring in cirrhosis and determining their relationship with specific clinical complications and patient survival. One hundred sixty-eight patients with cirrhosis, 35 with stable conditions and 133 hospitalized for acute clinical complications, and 94 healthy controls were enrolled. Posttranscriptional HSA molecular changes were identified and quantified by using a high-performance liquid chromatography/electrospray ionization mass spectrometry technique. Clinical and biochemical parameters were also recorded and hospitalized patients were followed for up to 1 year. Seven HSA isoforms carrying one or more posttranscriptional changes were identified. Altered HSA isoforms were significantly more represented in patients than in healthy controls. Conversely, the native, unchanged HSA isoform was significantly reduced in cirrhosis. Native HSA and most altered isoforms correlated with both Child-Pugh and Model for End-Stage Liver Disease scores. In hospitalized patients, oxidized and N-terminal truncated isoforms were independently associated with ascites, renal impairment, and bacterial infection. Finally, the native HSA and cysteinylated/N-terminal truncated isoforms were predictors of 1-year survival, with greater prognostic accuracy than total serum albumin concentration. CONCLUSIONS: Extensive posttranscriptional changes of HSA, involving several molecular sites and increasing in parallel with disease severity, occur in patients with cirrhosis. Altered isoforms are independently associated with specific clinical complications, whereas the residual, native HSA isoform independently predicts patient survival. These findings support the concept of the "effective albumin concentration," which implies that the global HSA function is related not only to its serum concentration, but also to the preservation of its structural integrity.

Use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) to detect carbapenemase production in Enterobacteriaceae by a rapid meropenem degradation assay.

We evaluated the analytical performance of a liquid chromatography-tandem mass spectrometry assay to detect carbapenemase activity in a group of carbapenemase-producing Enterobacteriaceae by meropenem hydrolysis. This one-hour method showed a sensitivity of 94% and a specificity of 100%, representing a rapid and reliable option compared to conventional phenotypic assays.

Evaluation of twelve formulas for LDL-C estimation in a large, blinded, random Italian population.

BACKGROUND AND AIMS: Low-density lipoprotein-cholesterol (LDL-C) is the major determinant of cardiovascular disease (CVD) burden. Being the direct assays time consuming, expensive, not fully standardized and not worldwide available, indirect formulas represent the most used laboratory estimation of LDL-C. In this study we analyzed the accuracy of twelve formulas for LDL-C estimation in an Italian population of 114,774 individuals. METHODS: All lipid samples were analyzed using direct homogeneous assay. The population was divided into various subgroups based on triglycerides and directly dosed LDL-C (D-LDL) levels. Twelve formulas (Friedewald, DeLong, Hata, Hattori, Puavillai, Anandaraja, Ahmadi, Chen, Vujovic, de Cordova, Martin, and Sampson) were compared in terms of their mean absolute deviations and the correlation and concordance of their estimated LDL-C with the respective D-LDL values. RESULTS: LCL-C measured by Friedewald formula and direct assay differed by more than 9 mg/dL. For D-LDL>115 mg/dl, we observed a concordance rate of only 55% between Friedewald and the respective D-LDL values. For TG<250 mg/dl, the proportion of reclassification between the different formulas and D-LDL was 14.1% with Vujovic, 14.4% Sampson, 15.9% DeLong, 16.5% Puavilai, 19.9% Martin, 21.9% Friedewald, 23.5% Chen, 29% Anandaraja, 31.1% Ahmadi, 31.5% Hata, 33.2% Hattori, and 44.4% with De Cordova formula. CONCLUSIONS: Our study compared for the first time 12 different LDL-C formulas on a Southern European population of more than 100,000 people. 'Several formulas showed better accuracy compared to Friedewald. Sampson, Martin and Vujovic resulted the most accurate formulas.

Potential intake of vitamins "A" and "D" through branded intravenous lipid emulsions: Liquid Chromatography-Tandem Mass Spectrometry Analysis.

No data exist for vitamin A group and vitamin D2/D3 content in branded intravenous lipid emulsions (ILEs). Our goal is to evaluate and quantify their concentrations in different ILEs to assess whether they are clinically relevant. Analyses were carried out in triplicates on six ILEs: 1) 30% soybean oil-based, 2) 20% olive-soybean oil based, 3) 10 + 10% soybean - MCT coconut oil based, 4) 20% soybean-olive-MCT-fish oil based, 5) 20% soybean-MCT-fish oil based and 6) 10% pure fish oil based, respectively. Retinol group (vitamin A) and ergo-chole-calciferol (vitamin D2/D3) were analyzed and quantified by a quali-quantitative Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) method after potassium hydroxide alkaline hydrolysis, hexane extraction, reverse phase-liquid chromatography and specific multiple-reaction-monitoring (MRM) detection. On average, measured retinol content was in the range of 200-1000 µg/L in ILEs (1,2, and 3), whereas it was higher (1000-2000 µg/L) in the ILEs containing fish-oil. Vitamin D content was in the range of 1-10 µg/L in the fish-oil based ILEs, but undetectable in those ILEs containing purely vegetable oils. This study shows that vitamin A and D contents are variably present in ILEs based on their different lipid sources. Both contents should be explicitly mentioned in the products.

Albumin Homodimers in Patients with Cirrhosis: Clinical and Prognostic Relevance of a Novel Identified Structural Alteration of the Molecule.

Decompensated cirrhosis is associated to extensive post-transcriptional changes of human albumin (HA). This study aims to characterize the occurrence of HA homodimerization in a large cohort of patients with decompensated cirrhosis and to evaluate its association with clinical features and prognosis. HA monomeric and dimeric isoforms were identified in peripheral blood by using a HPLC-ESI-MS technique in 123 cirrhotic patients hospitalized for acute decompensation and 50 age- and sex-comparable healthy controls. Clinical and biochemical parameters were recorded and patients followed up to one year. Among the monomeric isoforms identified, the N- and C-terminal truncated and the native HA underwent homodimerization. All three homodimers were significantly more abundant in patients with cirrhosis, acute-on-chronic liver failure and correlate with the prognostic scores. The homodimeric N-terminal truncated isoform was independently associated to disease complications and was able to stratify 1-year survival. As a result of all these changes, the monomeric native HA was significantly decreased in patients with cirrhosis, being also associated with a poorer prognosis. In conclusion homodimerization is a novel described structural alteration of the HA molecule in decompensated cirrhosis and contributes to the progressive reduction of the monomeric native HA, the only isoform provided of structural and functional integrity.

Standard fortification of preterm human milk fails to meet recommended protein intake: Bedside evaluation by Near-Infrared-Reflectance-Analysis.

BACKGROUND: Protein content of preterm human milk (HM) is relatively low and extremely variable among mothers: thus, recommended protein intake is rarely met. OBJECTIVES: To evaluate in a NICU setting if HM protein content after standard fortification meets the recommended intake, and also to check the effect of fortification on the osmolality of HM, as an index of feeding intolerance. METHODS: Protein content of 34 preterm HM samples was evaluated by a bedside technique (Near-Infrared-Reflectance-Analysis - NIRA); osmolality was also checked. Seventeen samples were fortified with Aptamil BMF, Milupa (Group A) and 17 with FM85, Nestlé (Group B). Fortification was performed as recommended by the manufacturer ("full fortification [FF]") and also with a lower amount of fortifier ("low-dose fortification [LF]"). After fortification, actual protein content was calculated and compared to that needed to meet recommended intake (2.33-3g/dl), and osmolality was measured. RESULTS: After FF, protein content was above 3g/dl in none of the samples, and below 2.33 g/dl in 16/34 samples (11 in Group A, 5 in Group B). After LF, protein content was above 3g/dl in none of the samples and below 2.33 g/dl in 32/34 samples (15 in Group A, 17 in Group B). Osmolality exceeded 400 mOsm/kg in 19 samples after FF (10 in Group A, 9 in Group B) and in 2/34 samples after LF (1 in each group). CONCLUSION: HM protein content after standard fortification fails to meet the recommended intake for preterm infants in approximately half of the cases.