Rita Maiavacca

The steatocrit: a simple method for monitoring fat malabsorption in patients with cystic fibrosis

Steatocrit was determined through microcentrifugation of fecal homogenate from 110 pediatric controls and 107 patients with cystic fibrosis (CF). For 74 CF patients, steatocrit was determined in the same fecal material collected to determine a fat balance. In controls, steatocrit value was 0.7 +/- 1.0%, which was significantly lower than values found in CF patients with a coefficient of fat excretion less than 10% of intake (1.7 +/- 1.2%). Significantly increased values were found in CF patients with a coefficient of fat excretion ranging between 10 and 25% of intake (4.7 +/- 1.7%) and in those whose coefficient of fat excretion was greater than 25% of intake (11.3 +/- 4.3%). In the 74 CF patients, steatocrit was directly correlated to the coefficient of fat excretion (r = 0.93; P less than 0.001). We performed steatocrit several times in the course of the 1st year of life in 33 infants with CF diagnosed by means of CF screening. Values obtained at the time of diagnosis, before starting enzymatic therapy, were relatively high; they showed a progressive decrease when, using steatocrit as a guide, the dose of pancreatic enzymes had been increased. The normalization of steatocrit values was accompanied by a better growth rate in the majority of these infants, confirming the importance of an optimal early correction of pancreatic insufficiency. We propose that this simple semiquantitative test can be usefully performed for the frequent monitoring of fat absorption and for checking the response to enzymatic therapy in patients with CF.

Determination of serum holotranscobalamin concentrations with the AxSYM active B12 assay: cut-off point evaluation in the clinical laboratory

Abstract Background: A reliable early marker is required for diagnosis of cobalamin deficiency. We calculated an appropriate holotranscobalamin (HoloTC) cut-off point for identifying cobalamin deficiency using an immunoenzymatic assay. Methods: Determination of the cut-off threshold and correlation between HoloTC and the other diagnostic parameters routinely used for vitamin B12 deficiency [total vitamin B12 (tB12), folate, homocysteine] were measured in 250 routine blood specimens from 107 men (mean age 59.0±18.8 years) and 143 women (mean age 54.2±23.1 years). The inclusion criterion was serum tB12 concentration ≤221 pmol/L. Results: Analytical performance results agreed with those reported by others. A weak correlation (R=0.42) was found between HoloTC and tB12. A 40 pmol/L cut-off threshold was chosen for HoloTC and the associated sensitivity and specificity was 0.86 and 0.66, respectively. Out of 250 tested samples, 126 showed tB12 concentrations 139–221 pmol/L (gray zone, GZ) and 124 had tB12 concentrations <139 pmol/L (low, L). Values less than the cut-off for HoloTC were present in 68.2% and 37.9% of cases in the GZ and L group, respectively (p<0.01), and in 53.2% of subjects. Conclusions: Our results confirmed the analytical reliability of the AxSYM HoloTC assay. The method is adequate for routine use and a cut-off threshold of 40 pmol/L is appropriate for assessing cobalamin deficiency in populations with reduced tB12 values. Clin Chem Lab Med 2010;48:249–53.

Diagnostic role of copeptin in patients presenting with chest pain in the emergency room

BACKGROUND Chest pain is a frequent symptom leading patients to the Emergency Room. Copeptin, the C-terminal fragment of arginin-vasopressin, is a marker of stressful situations. Recent studies showed that normal levels of copeptin combined with normal troponin accurately rule out the diagnosis of acute coronary syndrome (ACS). In this observational, prospective, multicenter study we evaluated if negative levels of copeptin combined with negative troponin (Tn-T) can correctly rule out the diagnosis of ACS and also of other life-threatening causes of chest pain. RESULTS Of 472 enrolled patients (64.6% males, mean age 60.1yrs), 28 (5.9%) were diagnosed with ST-elevation myocardial infarction (STEMI), 28 (5.9%) with non ST-elevation myocardial infarction (NSTEMI), 43 (9.1%) with unstable angina (UA), 13 (2.8%) with potentially life-threatening non-ACS pathologies (aortic dissection, pulmonary embolism, pulmonary edema, sepsis), 360 (76.2%) with benign causes of chest pain. Copeptin levels were significantly higher in ACS patients with STEMI and NSTEMI than in those with other diagnoses, but not in those with UA. The combination of copeptin and troponin-T attained a negative predictive value of 86.6% for ACS, of 97.9% for other potentially life-threatening non-ACS diseases and of 85% for all potentially lethal diseases (ACS plus others). CONCLUSIONS The combined use of troponin and copeptin significantly improved the diagnostic accuracy of troponin alone both in ACS (STEMI and NSTEMI) and in other life-threatening diseases. Measurement of this marker might be therefore considered not only for a rule-out strategy but also as a warning sign of a life-threatening disease.

A biomarker of oxidative stress as a nontraditional risk factor in obese subjects

BACKGROUND Oxidative stress has been postulated as an additive factor linking obesity to cardiovascular disease. MATERIALS & METHODS Derivatives of reactive oxygen species metabolites (d-ROMs) were measured in 136 obese (42 males, 94 females; mean age: 47 ± 12 years; BMI: 36 ± 5 kg/m(2)) and in 306 over- and normal-weight subjects (112 males, 194 females; age: 47 ± 12 years; BMI: 24 ± 3 kg/m(2)). RESULTS d-ROMs levels were higher in obese than in over- and normal-weight subjects (395 ± 104 vs 362 ± 102 and 351 ± 84 arbitrary units (AU); p < 0.001), in women than males (390 ± 104 vs 327 ± 68 AU; p < 0.001), in subjects with than those without hypertension (390 ± 103 vs 360 ± 95 AU; p < 0.01) and in smokers than former and nonsmokers (380 ± 97 vs 358 ± 97 AU; p < 0.05). A positive correlation was found between d-ROMs and BMI (r = 0.25; p < 0.001) and age (r = 0.13; p < 0.01). Levels of d-ROM (>75th percentile: 420 AU) remained as an independent obesity predictor (odds ratio: 2.5; p < 0.001) in women. Continuous variables are reported as mean ± standard deviation. CONCLUSION d-ROMs are a powerful obesity predictor, and could represent a reliable tool in obesity and cardiovascular risk evaluation, especially in women.

Therapeutic Potential of Immunoproteasome Inhibition in Duchenne Muscular Dystrophy

Duchenne muscular dystrophy is an inherited fatal genetic disease characterized by mutations in dystrophin gene, causing membrane fragility leading to myofiber necrosis and inflammatory cell recruitment in dystrophic muscles. The resulting environment enriched in proinflammatory cytokines, like IFN-γ and TNF-α, determines the transformation of myofiber constitutive proteasome into the immunoproteasome, a multisubunit complex involved in the activation of cell-mediate immunity. This event has a fundamental role in producing peptides for antigen presentation by MHC class I, for the immune response and also for cytokine production and T-cell differentiation. Here, we characterized for the first time the presence of T-lymphocytes activated against revertant dystrophin epitopes, in the animal model of Duchenne muscular dystrophy, the mdx mice. Moreover, we specifically blocked i-proteasome subunit LMP7, which was up-regulated in dystrophic skeletal muscles, and we demonstrated the rescue of the dystrophin expression and the amelioration of the dystrophic phenotype. The i-proteasome blocking lowered myofiber MHC class I expression and self-antigen presentation to T cells, thus reducing the specific antidystrophin T cell response, the muscular cell infiltrate, and proinflammatory cytokine production, together with muscle force recovery. We suggest that i-proteasome inhibition should be considered as new promising therapeutic approach for Duchenne muscular dystrophy pathology.

Correlation between salivary and serum oxidized LDL levels: a pilot study on overweight/obese subjects

BACKGROUND Saliva contains a variety of substances and could be functionally equivalent to serum in reflecting the physiological state of the body, including metabolic variations. Salivary samples are non-invasive, safe, and easier to handle than serum. Oxidized LDL cholesterol (oxLDL) is an additional cardiovascular risk factor playing an important role in atheromatous plaque formation; overweight/obese subjects present an increase in oxLDL concentrations. The aims of the study were to assess oxLDL salivary levels, if detectable, and to verify their possible correlation with serum in overweight/obese subjects. METHODS Thirty-five consecutive overweight/obese subjects and 10 normal weight controls were enrolled. Serum and salivary oxLDL levels were measured by a commercial enzyme-linked-immunosorbent assay (ELISA method). RESULTS oxLDL levels were detectable in salivary samples and correlated (P = 0.001) with serum levels. Overweight/obese subjects showed serum and salivary oxLDL levels higher than controls (P = 0.000 and P = 0.022, respectively). CONCLUSIONS Our study showed the presence of oxLDL in salivary samples and highlighted a correlation between salivary oxLDL levels and their counterpart in serum. Moreover, salivary oxLDL levels were higher in overweight/obese subjects than in controls. Therefore, a salivary sample could be functionally equivalent to serum in monitoring cardiovascular risk in overweight/obese subjects.

An Encapsulated Juice Powder Concentrate Improves Markers of Pulmonary Function and Cardiovascular Risk Factors in Heavy Smokers

Objective: Cigarette smoking is associated with reduced pulmonary function and increased risk factors for cardiovascular disease. This randomized placebo-controlled double-blind study evaluated the effects of two different combinations of mixed fruit and vegetable juice powder concentrate (Juice Plus+, NSA, Collierville, TN) on heavy smokers. Methods: At baseline (T 0) and after 3 months’ supplementation (T 1), pulmonary function parameters and cardiovascular risk factors—that is, plasma total homocysteine (tHcy) with related B vitamins and cysteine (tCys) concentrations—were assessed in 75 apparently healthy smokers (aged 49.2 ± 10.6 years, >20 cigarettes/d, duration ≥10 years) randomized into 3 groups: placebo (P), fruit/vegetable (FV) and fruit/vegetable/berry (FVB). Results: T 0: most smokers showed abnormalities in tHcy and tCys concentrations. T 1: respiratory function was unchanged in P and slightly, but not significantly, improved in FV, whereas FVB showed a significant improvement in forced expiratory flow at 25% (FEF25; p < 0.0001 vs P and FV) and significant improvement in CO diffusion lung/alveolar volume (DLCO/VA). FV and FVB (50%) showed significant reduction in tHcy and tCys compared to T 0 ( p < 0.0001) and P ( p < 0.0001). Conclusions: At T 1, both supplemented groups, but to a greater extent the FVB group, showed improvements in some pulmonary parameters, cardiovascular risk factors, and folate status. The beneficial effects of Juice Plus+ supplementation could potentially help smokers, even if smoking cessation is advisable.

Serum levels of immunoreactive trypsin during development: Comparison with levels of lipase and amylase

In order to obtain additional information on serum pancreatic enzyme levels during development, we have measured immunoreactive trypsin (IRT), immunoreactive lipase (IRL), and total amylase in paired fetal and maternal sera. Samples were obtained during early gestation (14–21 week of gestation) and at the time of normal delivery. IRT levels were lower in maternal sera as compared to paired fetal and neonatal (p < 0.005); conversely, IRL and amylase, although present in measurable concentrations, were significantly lower in fetal and neonatal sera than in the maternal (p < 0.001). We also serially monitored serum pancreatic enzyme levels in a group of premature infants during the first 10 days of life. Concentrations of IRT showed a significant increase over time (p < 0.05) and those of IRL remained stable while amylase levels decreased sharply, suggesting possible maternal origin of this enzyme. Serum concentrations of the three pancreatic enzymes in newborns at term (second day of life) were higher than in infants aged 0.5–6 months; however, only IRT levels were above the normal range for adults. Beyond the neonatal period, IRT levels were stable and comparable to adults, whereas amylase and IRL levels were very low in infants younger than 6 months and increased significantly with age (p < 0.001). These data seem to indicate that “physiologic hypertrypsinemia” occurs early during development and may be accentuated by postnatal events. They provide an indirect indication of both early fetal production of trypsinogen and possible placental transfer of pancreatic enzymes from the maternal circulation. The overall results would suggest that only beyond the neonatal period can determination of serum pancreatic enzyme levels be used as an indirect index of their asynchronous development.

Oxidative status in treatment-naïve essential thrombocythemia: a pilot study in a single center

Oxidative stress (OS), due to pro‐oxidant species [reactive oxygen species (ROS)] excess not counterbalanced by endogenous antioxidant molecules [e.g., reduced glutathione (GSH)], is involved in the pathogenesis of human cancers, but few data are available on essential thrombocythemia (ET). This study aims to investigate OS in ET off‐therapy patients. Thirty ET treatment‐naïve patients were compared with 26 age‐matched and gender‐matched controls. Serum ROS, urinary 8‐hydroxydeoxyguanosine, full blood GSH levels, and reduced/oxidized GSH ratio (GSH/GSSG) were measured. Data were adjusted for gender, age, JAK2 mutational status, smoking, dyslipidemia, or hypercholesterolemia requiring drug therapy, antiplatelet therapy, treatment with acetylsalicylic acid, high‐sensitive C‐reactive protein levels, and absolute monocyte count. ROS and GSH levels were increased in both patients and controls. Patients showed increased GSSG (p = 0.05), reduced GSH/GSSG ratio (p = 0.08), and similar 8‐hydroxydeoxyguanosine levels when compared with controls. No differences in OS parameters were found between JAK2‐positive and JAK2‐negative patients. Confounding factors did not modify the results. Our study suggests an OS condition in a cohort of treatment‐naïve ET patients, not associated with JAK2 mutational status or with chronic inflammation situation. GSH/GSSG ratio, altered in ET patients because of increased GSSG levels, showed the presence of higher GSH levels in ET than controls as a possible compensatory mechanism of an excess of pro‐oxidant production. Copyright

The diagnostic accuracy of biomarkers for diagnosis of primary biliary cholangitis (PBC) in anti-mitochondrial antibody (AMA)-negative PBC patients: A review of literature

Abstract Primary biliary cholangitis (PBC), also known as primary biliary cirrhosis, is an autoimmune disease of the liver characterized by anti-mitochondrial antibodies (AMA) in 90%–95% of patients. The aim of this study was to evaluate the diagnostic value of several serum biomarkers in patients with PBC but negative for AMA. Some antinuclear antibodies (ANA) pattern, detected by indirect immunofluorescence (IIF), such as multiple nuclear dot (MND) and rim-like patterns are well-known to be specific for PBC. The corresponding nuclear antigens are the components of the nuclear pore complex (Gp210 for rim-like pattern) and Sp100, PML proteins (for MND pattern) detectable by immunoblotting and ELISA methods. More recently, new biomarkers have been evaluated in order to improve the diagnostic sensitivity, such as kelch-like 12 (KLHL12) and hexokinase-1. Considering these different serum biomarkers, studies evaluating their diagnostic role in AMA-negative PBC patients compared to AMA-positive ones and controls were included in this review. Pooled sensitivity and specificity were 37% and 85%, respectively. The overall PPV and NPV mean values were 45% and 83%. Even if all biomarkers are very specific for PBC, the overall sensitivity was poor and therefore is necessary to identify a marker with a greater sensitivity for PBC in AMA-negative patients.