Pulmonary Function Testing and Complications of Laparoscopic Bariatric Surgery

__Abstract__ __Background__: Obesity is associated with respiratory symptoms and impaired pulmonary function, which could increase the risk of complications after bariatric surgery. The purpose of this study is to assess the relationship between pulmonary function parameters before, and the risk of complications after, laparoscopic bariatric surgery. Methods: This prospective study included patients (age 18-60, BMI >35 kg/m2), who were eligible for bariatric surgery. Spirometry was performed in all patients. Complications up to 30 days after bariatric surgery were recorded. Results: Four hundred eighty-five patients were included (304 laparoscopic sleeve gastrectomy, 181 laparoscopic gastric bypass). There were 53 complications (8 pulmonary, 27 surgical, 14 infectious, 4 other) in 50 patients (10 %). There were 35 re-admissions (7.2 %), and 17 re-laparoscopies (3.5 %). Subjects with and without complications did not differ significantly with respect to demographics, weight, BMI, abdominal circumference or fat percentage. Subjects with complications had a significantly lower mean FEV1(mean 86.9 % predicted) and FVC (95.6 % predicted) compared to patients without complications (95.9 % predicted, p = 0.005, and 100.1 % predicted, p = 0.045, respectively). After adjustment for age, gender, BMI, and smoking, abnormal spirometry value remained the single predictive covariable of postoperative complications: FEV1/FVC <70 % adjusted OR 3.1 (95%CI 1.4-6.8, p = 0.006) and ΔFEV1≥12 % adjusted OR 2.9 (95 %CI 1.3-6.6, p = 0.010). Conclusions: The risk of pulmonary complications after laparoscopic bariatric surgery is low. However, subjects with abnormal spirometry test results have a threefold risk of complications after laparoscopic bariatric surgery. Preoperative pulmonary function testing might be useful to predict the risk of complications of laparoscopic bariatric surgery

Cerebrospinal-fluid-derived immunoglobulin G of different multiple sclerosis patients shares mutated sequences in complementarity determining regions

B lymphocytes play a pivotal role in multiple sclerosis pathology, possibly via both antibody-dependent and -independent pathways. Intrathecal immunoglobulin G in multiple sclerosis is produced by clonally expanded B-cell populations. Recent studies indicate that the complementarity determining regions of immunoglobulins specific for certain antigens are frequently shared between different individuals. In this study, our main objective was to identify specific proteomic profiles of mutated complementarity determining regions of immunoglobulin G present in multiple sclerosis patients but absent in healthy controls. To achieve this objective, we purified immunoglobulin G from the cerebrospinal fluid of 29 multiple sclerosis patients and 30 healthy controls and separated the corresponding heavy and light chains via SDS-PAGE. Subsequently, bands were excised, trypsinized, and measured with high-resolution mass spectrometry. We sequenced 841 heavy and 771 light chain variable region peptides. We observed 24 heavy and 26 light chain complementarity determining regions that were solely present in a number of multiple sclerosis patients. Using stringent criteria for the identification of common peptides, we found five complementarity determining regions shared in three or more patients and not in controls. Interestingly, one complementarity determining region with a single mutation was found in six patients. Additionally, one other patient carrying a similar complementarity determining region with another mutation was observed. In addition, we found a skew in the -to-λ ratio and in the usage of certain variable heavy regions that was previously observed at the transcriptome level. At the protein level, cerebrospinal fluid immunoglobulin G shares common characteristics in the antigen binding region among different multiple sclerosis patients. The indication of a shared fingerprint may indicate common antigens for B-cell activation

Quantitative proteomics and metabolomics analysis of normal human cerebrospinal fluid samples

The analysis of cerebrospinal fluid (CSF) is used in biomarker discovery studies for various neurodegenerative central nervous system (CNS) disorders. However, little is known about variation of CSF proteins and metabolites between patients without neurological disorders. A baseline for a large number of CSF compounds appears to be lacking. To analyze the variation in CSF protein and metabolite abundances in a number of well-defined individual samples of patients undergoing routine, non-neurological surgical procedures, we determined the variation of various proteins and metabolites by multiple analytical platforms. A total of 126 common proteins were assessed for biological variations between individuals by ESI-Orbitrap. A large spread in inter-individual variation was observed (relative standard deviations [RSDs] ranged from 18 to 148%) for proteins with both high abundance and low abundance. Technical variation was between 15 and 30% for all 126 proteins. Metabolomics analysis was performed by means of GC-MS and nuclear magnetic resonance (NMR) imaging and amino acids were specifically analyzed by LC-MS/MS, resulting in the detection of more than 100 metabolites. The variation in the metabolome appears to be much more limited compared with the proteome: the observed RSDs ranged from 12 to 70%. Technical variation was less than 20% for almost all metabolites. Consequently, an understanding of the biological variation of proteins and metabolites in CSF of neurologically normal individuals appears to be essential for reliable interpretation of biomarker discovery studies for CNS disorders because such results may be influenced by natural inter-individual variations. Therefore, proteins and metabolites with high variation between individuals ought to be assessed with caution as candidate biomarkers because at least part of the difference observed between the diseased individuals and the controls will not be caused by the disease, but rather by the natural biological variation between individuals