Measurement of Glutathionylated Haemoglobin by MALDI-ToF Mass Spectrometry as a Biomarker of Oxidative Stress in Heavy Smokers and in Occupational Obese Subjects

Glutathionyl-haemoglobin (Hb-SSG) is a minor form of haemoglobin characterized by the presence of a disulfide bond between the β-93 cysteine residue and the thiol group of glutathione. Hb-SSG is naturally present in the erythrocytes at levels comparable to those of glycated haemoglobin and can be measured by MALDI mass spectrometry on very small samples of erythrocytes from peripheral blood. Since Hb-SSG has been recognized as a sensitive biomarker of oxidative stress in several degenerative diseases (diabetes, hyperlipidemia, kidney disease) and in healthy workers exposed to glutathione-depleting toxic agents such as butadiene, we have measured for the first time the levels of Hb-SSG in two groups: healthy heavy cigarette smokers and overweight-obese

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

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.Peer Reviewe

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

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.Peer Reviewe

Case Report Mycoplasma hominis Induces Mediastinitis after a Tonsillar Abscess

Mycoplasma hominis is commonly involved in genitourinary tract infections. We report a 59-year-old man who developed a M. hominis-associated mediastinitis following acute tonsillar infection

Mycoplasma hominis Induces Mediastinitis after a Tonsillar Abscess

Mycoplasma hominis is commonly involved in genitourinary tract infections. We report a 59-year-old man who developed a M. hominis-associated mediastinitis following acute tonsillar infection