An increased CDT camouflaged a monoclonal light chain gammopathy: An approach for diagnosis.

INTRODUCTION: Carbohydrate-deficient transferrin (CDT) is the most reliable indicator for the detection of chronic alcohol consumption. Recently, we have investigated a clinical case in which a concomitant monoclonal light chain gammopathy mimicked an increase of this biomarker. MATERIALS AND METHODS: A patient's serum was routinely examined by capillary electrophoresis (CE) for evaluation of CDT, and it was subsequently analysed through high-performance liquid chromatography (HPLC) to confirm the referred result. Then, according to the patient's clinical history, we performed serum and urine immunofixation, together with k and λ free light chain measurement. RESULTS: The pathological CDT value obtained by CE agreed with the patient's previous data, but it was not confirmed by the HPLC. The patient's medical record revealed hypogammaglobulinaemia since 2006, which had been recently examined by a haematological visit. Serum and urine immunofixation revealed a light chain gammopathy, which had been suspected but never confirmed by laboratory assessment. The k and λ free light chain measurement completed the diagnostic process. CONCLUSION: To the best of the authors' knowledge, this is the first study of its kind to report on a perfect camouflaging of a monoclonal light chain as disialo-transferrin. The importance of the careful examination of the patient's clinical history for the correct evaluation of laboratory results, thereby preventing misinterpretations, is also highlighted.

Osteoprotegerin and bone turnover markers in heavily pretreated HIV-infected patients.

OBJECTIVES: To characterize osteoprotegerin (OPG) levels, bone remodelling and bone mineral density (BMD) in heavily pretreated HIV-infected patients on antiretroviral therapy, and to evaluate the clinical factors associated with bone density decline. METHODS: Heavily pretreated (> 5 years) HIV-positive patients were enrolled in this cross-sectional, observational study, which was based on a total body bone densitometry examination and a comprehensive evaluation of bone and mineral parameters. RESULTS: Sixty-eight patients (55 male and 13 female) with a median age of 41 years (range 25-60 years) were included in the study. Their antiretroviral treatment lasted for 82 months. On the basis of the World Health Organization criteria, nine patients (13.2%) were osteoporotic [T-score < -2.5 standard deviation (SD)] and 19 patients (27.9%) were osteopenic (T-score between -1 and -2.5). The principal outcomes associated with the presence of a low BMD were high OPG and lysylpyridinoline/creatinine ratio (Dpd) values. Most of the patients (39 of 48; 81.25%) showed vitamin D insufficiency [Vitamin D (25(OH)D) < 18 ng/mL] with secondary hyperparathyroidism (13 of 50 patients: 26%), which proved to be correlated to osteocalcin (BGP) levels [parathyroid hormone (PTH) vs. BGP: r = 0.34; P < 0.01]. There was an inverse correlation between T-scores and serum osteocalcin and alkaline phosphatase (AP) levels, on one hand, and Dpd, on the other. High AP and Dpd values were associated with relative risks of 4.1 [95% confidence interval (CI) = 1.01-17.6] and 7.2 (95% CI = 1.67-31.03), respectively, of a pathological T-score. Multivariate analysis revealed that the factors associated with the presence of osteopenia or osteoporosis were older age and lower body mass index. CONCLUSIONS: About 40% of our heavily pretreated subjects with advanced HIV infection had a low BMD, and 56% (24 of 44 patients) showed a high bone turnover rate with marked osteoclast activation. High OPG levels may protect against bone resorption.

Simultaneous determination of human plasma levels of four selective serotonin reuptake inhibitors by high-performance liquid chromatography.

A reversed-phase high-performance liquid chromatography (HPLC) method with fluorimetric detection, which allows the simultaneous determination of plasma concentrations of four selective serotonin reuptake inhibitors (SSRIs) is presented. Fluvoxamine, paroxetine, sertraline, and fluoxetine were extracted from plasma with ethyl acetate and then derivatized with dansyl chloride. The analytes were separated using Hypersyl ODS C18 (5 microm) 250 x 4.6 mm column (ThermoQuest, Runcorn, UK). For continuous gradient separation, the mobile phase consists of two eluents, acetonitrile and potassium phosphate buffer (10 mmol/L, pH 7.2) at total flow rate of 1.5 mL/min. Detection was carried out at lambda exc = 366 nm and lambda em = 490 nm. The authors found recoveries of 90% to 95% for fluvoxamine, 94% to 100% for paroxetine, 88% to 95% for sertraline, 93% to 100% for fluoxetine, and 97% to 100% for internal standard (nortriptyline). Imprecision of the method ranged from 2.5% to 8.9%. The assay was linear from 10 to 1500 ng/mL for sertraline, and from 5 to 1500 ng/mL for the other drugs. The authors conclude that this method is suitable for monitoring antidepressant therapy. In addition, the authors report the effects of adding paroxetine to fluvoxamine on plasma levels in a group of patients in combined drug therapy.

Total and free deoxypyridinoline after acute osteoclast activity inhibition.

BACKGROUND: Deoxypyridinoline (Dpd) is one of the two pyridinium cross-links that provide structural rigidity to type I collagen in bone. During osteoclastic resorption, Dpd is released into circulation and is excreted in the urine in free and peptide-bound forms. Free and total Dpd are highly correlated, but whether the free-to-total cross-link ratio is constant in both normal and high bone turnover states remains controversial. To compare free and total Dpd performance in a physiological condition, urinary free and total Dpd were measured after a short-term inhibition of osteoclast activity such as that induced by an oral calcium load. METHODS: Total and free Dpd were measured by HPLC and by immunosorbent assay, respectively, in two groups of subjects, one (calcium-treated; n = 16) taking calcium and the other not (control; n = 9). RESULTS: The urinary excretion of total Dpd at 2 and 4 h after oral calcium loading was decreased compared with controls. By contrast, changes in free Dpd were similar in the calcium-treated and control groups, reflecting only circadian rhythm. CONCLUSIONS: Total and free Dpd do not show comparable sensitivity in detecting short-term inhibition of osteoclast activity. The degradation process of peptide-bound to free Dpd could render free Dpd insensitive to acute changes of osteoclast activity.

Accuracy of the plasma amino acid-consumption test in detecting pancreatic diseases is due to different methods.

The aim of this study was to evaluate the controversial specificity of the plasma amino acid (AA)-consumption test in detecting pancreatic diseases by using two different quantitative methods. A total of 55 subjects: 13 healthy subjects, 13 patients with chronic pancreatitis (three mild/moderate, eight severe), 13 patients with pancreatectomy and complete suppression of the exocrine pancreatic secretion, eight patients with chronic liver disease (five with impaired synthetic function), and eight patients with chronic renal failure. Total plasma AAs were quantified by a colorimetric method (p-benzoquinone) in all subjects, at 0, 30, 45, and 60 min during and 30 min after minute 60 of i.v. cerulein infusion (50 ng/kg/h). Either total and individual AAs were quantified by chromatography (high-performance liquid chromatography; HPLC) in 10 healthy subjects, 10 patients with pancreatectomy, and 10 with chronic pancreatitis at 0 and 60 min after the start of the cerulein infusion. For the colorimetric method, healthy subjects had maximal percentage decreases of total AA concentrations not significantly different from those of patients with pancreatectomy and significantly higher than those of patients with chronic pancreatitis (p < 0.0001) or chronic liver disease (p < 0.001). Pancreatic function, as assessed by fecal elastase-1 test, was not significantly correlated to the maximal percentage decrease in total plasma AAs. For the chromatographic method, total AA concentrations were not significantly correlated to those determined by colorimetry. The concentration of each of the individual plasma AAs varied considerably in each group. Fecal elastase-1 values were normal (> or = 200 microg/g) in all patients without pancreatic disease and in only one of 11 patients with chronic pancreatitis and exocrine insufficiency. The type of method used can explain the different results of the AA-consumption test. This test is not very specific for the pancreas.