A Simple Method for Quantification of Five Urinary Porphyrins, Porphobilinogen and 5-Aminolevulinic Acid, Using Liquid Chromatography Tandem Mass Spectrometry.

Analysis of porphyrins and 5-aminolevulinic acid (ALA), porphobilinogen (PBG) in physiological liquids is required for diagnosis and follow-up of porphyrias. High performance liquid chromatography (HPLC) and liquid chromatography tandem mass spectrometry (LC-MS) methods with higher specificity and sensitivity have been developed. The major disadvantage of those methods is that they require longer extraction times due to their matrix effects. The present study suggests a simple, fast, sensitive, and specific assay for determination of Coproporphyrin, 5-carboxylporphyrin, 6-carboxylporphyrin, 7-carboxylporphyrin, Uroporphyrin I and ALA, PBG in urine sample by direct injection without sample pre-treatment using LC-MS. For the purposes of the present study LC-MS device was set to multiple reaction monitoring (MRM) and positive ion mode. Porphyrins and ALA, porphobilinogen were characterized by their MS/MS product ion, spectra. ALA, PBG and 5 porphyrins were detected simultaneously. Limit of detection for Coproporphyrin, 5-carboxylporphyrin, 6-carboxylporphyrin, 7-carboxylporphyrin, Uroporphyrin I were 2 nmol/L, where it was 5 µmol/L for ALA and 2 µmol/L for porphobilinogen. The present study suggests that the present method is very effective compared to many other available methods for it does not require pre-treatment, provides simultaneous results of ALA, PBG and 5 porphyrins quantitatively in a shorter span of time, and has suitable sensitivity and selectivity. LC-MS technique was used clinically for the determination of urine porphyrin levels.

The Impact of Repetitive Transcranial Magnetic Stimulation on Oxidative Stress in Subjects With Medication-Resistant Depression.

OBJECTIVES: Recent studies have shown that oxidative stress is involved in the neurobiology of depression. We investigated the effects of repetitive transcranial magnetic stimulation (rTMS) on a novel oxidative stress marker, thiol-disulfide homeostasis, in subjects with medication-resistant major depression (MRD). METHODS: Twenty-six subjects with MRD underwent 15 rTMS sessions. Sociodemographic and baseline and post-rTMS Montgomery-Asberg Depression Rating Scale (MADRS) data were collected. Serum levels of native thiol, total thiol, and disulfide and their pairwise ratios were measured in baseline and post-rTMS blood samples. RESULTS: Serum levels of native and total thiol were significantly decreased after rTMS treatment (P < 0.05). Serum levels of thiol-disulfide and their ratios did not significantly differ (P > 0.05) between rTMS treatment responders (>50% reduction in MADRS score, n = 11) and rTMS treatment nonresponders (n = 15). The percentage MADRS score changes did not correlate with the changes in the levels of serum thiol-disulfide from baseline to post-rTMS treatment in any subject (P > 0.05). CONCLUSIONS: Our results showed that rTMS treatment was effective in subjects with MRD and was associated with changes in serum thiol levels regardless of improvement in depression severity. Thus, the results did not support a possible therapeutic relationship between rTMS and thiol-disulfide homeostasis in subjects with MRD.

Comparison of four automated serum vitamin B12 assays.

BACKGROUND: Diagnosis of vitamin B12 deficiency is generally based on the measurement of serum vitamin B12 levels. However, in selected cases functional indices of vitamin B12, such as methylmalonic acid (MMA) and homocysteine (HCY), are needed. Here we compare the performance of four automated total vitamin B12 assays and also investigate how these assays relate to functional indices of vitamin B12 status. METHODS: Total vitamin B12, MMA and HCY were measured in 69 serum samples from routine vitamin B12 assay requests. Serum vitamin B12 analysis was performed using four different immunoassay autoanalyzers: DxI 800 Unicel (Beckman Coulter, USA), ADVIA Centaur XP (Siemens Diagnostics, Tarrytown, NY, USA), Roche Cobas E601 (Roche Diagnostics, Germany), Architect i2000sr (Abbott Laboratories, Abbott Park, IL, USA). Serum MMA levels were determined by liquid chromatography-mass spectrometry (LC-MS) and serum homocysteine levels were determined by high pressure liquid chromatography (HPLC) methods. RESULTS: Four immunoassay methods were comparable and correlated with each other. Correlation coefficients (r) ranged from 0.898 to 0.987, p<0.001. Highest correlation was observed between Roche Cobas - Architect i2000sr and poorest correlation was observed between DxI 800 Unicel - ADVIA Centaur comparison. DxI 800 Unicel assay demonstrated high mean bias [-122 pg/mL (-616-125 pg/mL)] and a concordance correlation coefficient (CCC) of 0.9161, lower than the others. MMA and HCY were correlated with the vitamin B12 results. The correlation coefficients with their 95% CI indicated that there was no statistically significant difference between the four methods according to their relationship with MMA and HCY. CONCLUSIONS: Total B12 assays correlate very well with each other. However, results of DxI 800 Unicel were lower compared to the other three autoanalyzers. All total vitamin B12 methods show similar relationships with HCY and MMA. Standardization of serum vitamin B12 assays is still not completed and further standardization studies are needed. Laboratory professionals and clinicians should be aware of this disagreement between assay methods and they should use these tests as ancillary tests.

Relationship between serum Betatrophin, GPIHBP1, and LDL subfractions in patients with gestational diabetes mellitus.

OBJECTIVES: Gestational diabetes mellitus (GDM) leads to changes in the lipid metabolism. In this study, we aimed to compare serum levels of LDL subfractions, betatrophin, and glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1 (GPIHBP1) between patients with GDM and healthy pregnant women. DESIGN AND METHODS: We designed a prospective case-control study with 41 pregnant women. Subjects were divided into two groups: GDM and control. Betatrophin and GPIHBP1 levels were measured by ELISA method. Lipoprint LDL subfraction kit was used to perform LDL subfraction analysis electrophoretically. RESULTS: Serum levels of LDL6 subfraction, betatrophin, and GPIHBP1 were found to be higher in GDM group compared to the controls (p < 0.001). The mean LDL size were also found larger in GDM group. A positive correlation was found between betatrophin and GPIHBP1 levels (rho = 0.96, p < 0.001). CONCLUSIONS: Our findings suggest that betatrophin, and GPIHBP1 levels were found to be increased in GDM. This maybe the result of adaptive mechanisms in response to insulin resistance, but also this relationship should be evaluated for their effects on impaired lipid metabolism and lipoprotein lipase metabolism. There is a need for further prospective studies with larger samples to fully elucidate the mechanisms of this relationship both in pregnant patients and the other patient groups.

Erythrocyte Autoantibody Positivity in Serological Cross-matching.

OBJECTIVE: To investigate the erythrocyte autoantibody positivity detected in the serological cross-matching (XM), and its  possible effects on salient hemogram parameters. STUDY DESIGN: A descriptive study. PLACE AND DURATION OF STUDY: Balikesir Atatürk City Hospital's Blood Transfusion Centre, Faculty of Medicine, Department of Anesthesiology and Reanimation, Balikesir University, Turkey, from 2017 to 2018. METHODOLOGY: Erythrocyte autoantibody positivity, which was detected in the traditional serological cross-matching for a pre-transfusion laboratory test were analysed retrospectively. Later, hemogram changes in the previous (no erythrocyte autoantibodies) and following (erythrocyte autoantibodies present) transfusions were investigated using statistical methods. RESULTS: Erythrocyte autoantibody positivity rate was 10.16% (342/3,365). There was no statistically significant difference in the increase of hemoglobin, hematocrit, and red blood cell between the period when erythrocyte autoantibodies were detected or not, (p = 0.27, 0.13, and 0.09, respectively). CONCLUSION: Erythrocyte autoantibodies positivity found on routine cross-match exmination, which must be considered together with parameters such as previous transfusion history, other pre-transfusion laboratory test results, and clinical presentation and management. Key Words: Transfusion, Erythrocye autoantibody, Alloantibody, Hemogram, Cross-matching.

Moxifloxacin-induced neutropenia in 26-year-old man.

Moxifloxacin is a fourth generation widely used fluoroquinolone antibiotic. There are three cases of moxifloxacin-induced neutropenia reported in the literature and we report the fourth case. A 26-year-old man with pneumonia was treated with moxifloxacin because of penicillin allergy. On the second day of therapy, leukopenia [White blood cell (WBC) count 2.7×10³/µL] and neutropenia (neutrophils 1.21×10³/µL) occurred. Rothia mucilaginosa was isolated in sputum culture. On the fourth day of hospitalization moxifloxacin treatment was stopped and clarithromycin 500 mg PO twice daily was started. Leukopenia and neutropenia resolved one day after discontinuation of moxifloxacin that WBC and neutrophil count rose 4.5×10³/µL and 1.97×10³/µL, respectively. On the sixth day of hospitalization, WBC and neutrophil count was 4.3×10³/µL and 2.29×10³/µL, respectively. The immunomodulatory effects of moxifloxacin may result in the changes of WBC count like leukopenia with neutropenia. Moxifloxacin induced neutropenia may be more common and is an important adverse effect. More observational studies about safety profiles of moxifloxacin are needed.