Comparison between a new multiplex electrochemiluminescence assay and the WHO reference enzyme-linked immunosorbent assay to measure serum antibodies against pneumococcal serotype-specific polysaccharides

Background

Two electrochemiluminescence (ECL) assays were developed which, together, can simultaneously measure serum antibodies against pneumococcal capsular polysaccharides (PnPS) for 17 serotypes. The assays were validated for the 13 PnPS included in the 13-valent pneumococcal conjugate vaccine (PCV13). As recommended by the World Health Organization (WHO), we compared the ECL assays with the WHO reference enzyme-linked immunosorbent assay (ELISA) and derived a threshold corresponding to the 0.35?µg/mL threshold established for the WHO reference ELISA for the non-inferiority comparison and licensure of new PCVs against invasive pneumococcal disease.

Method development of immunoglobulin G purification from micro-volumes of human serum for untargeted and targeted proteomics-based antibody repertoire studies

Immunoglobulins (Igs) are major serum proteins which play important roles in immunity. Both untargeted and targeted proteomic workflows can be applied to investigate antigen-binding sites and the glycosylation profiles of Igs. For a more-comprehensive picture of IgG from human serum, we developed an IgG purification process and coupled the standardized method to untargeted and targeted proteomic workflows for IgG investigations. Parameters such as the type of purification beads, volume of the bead slurry, incubation conditions, and binding capacities were evaluated in this study. Only 2 μL of human serum was required for each sample. The performance of coupling the purification process to untargeted proteomics in the IgG analysis was evaluated by comparing normalized abundances of IgG subclass-specific peptides with quantification results from an ELISA. Pearson's correlation values were all >0.82. Targeted proteomic workflow was applied to serum samples from patients with autoimmune pancreatitis and from healthy controls, and the results corresponded to clinical findings that IgG4-related peptides/glycopeptides showed higher abundances in the diseased group. The developed IgG purification process is simple and requires small sample volume, and it can be coupled to targeted and untargeted proteomic workflows for clinical investigations in the future.     

Application of disaccharides alone and in combination,for the improvement of stability and particle properties of spray-freeze dried IgG

Purpose: Spray-freeze drying (SFD) is a recently applied method to develop pharmaceutical powders. This study aimed to analyze the competence of Trehalose, Mannitol, Lactose, and Sorbitol instability and aerosolization of Immunoglobulin G (IgG) via SFD.

Methods: Induced soluble aggregates were quantified at 0 and 3?months, and 45?°C using size-exclusion chromatography. Conformation and thermogravimetric assessments were done by Fourier transform infrared spectroscopy and differential scanning calorimetry. Laser light scattering was performed to determine the particle sizes. Aerodynamic features were characterized by twin stage impinger and scanning electron microscopy.

Results: Although sugars/polyols preferably stabilized IgG following the process, storage stabilization was achieved in Trehalose, Trehalose-Lactose, Lactose, and Trehalose-Mannitol-based powders with soluble aggregates <5%. The conformation of antibody was preserved with β sheet content from 66.28% to 76.37%. Particle sizes ranged from 5.23 to 8.12?µm. Mannitol exhibited the best aerodynamic behavior, fine particle fraction (FPF: 70%) but high degree of protein aggregation during storage.

Conclusions: SFD could favorably stabilize antibody using Trehalose and its combination with Lactose and Mannitol, and also, Lactose alone. Sorbitol disturbed IgG powder recovery. Incorporation of other types of excipient is required for efficient respiratory delivery of IgG molecules.     

Acute and subsequent continuation electroconvulsive therapy elevates serum BDNF levels in patients with major depression

IntroductionThe induction of brain-derived neurotrophic factor (BDNF) release and subsequent restoration of neuroplastic homeostasis may underlie the effects of electroconvulsive therapy (ECT).ObjectivesWe aimed to assess serum and plasma BDNF levels during the course of acute ECT, as well as before and after subsequent continuation ECT, in patients with depression.MethodsWe included 24 patients with major depressive disorder (mean age ± SD: 54.5 ± 13.7; f/m: 17/7; baseline 17-item Hamilton Depression Rating Scale score of 26.79 ± 4.01). Serum and plasma BDNF (sBDNF, pBDNF) levels were assessed at nine time-points before, during, and after acute ECT series. Data were analysed using linear regression and linear mixed models, which were adjusted for multiple comparisons via Bonferroni correction. Five patients received continuation ECT subsequent to the acute ECT series. In these patients, BDNF levels were assessed before and after each two continuation ECT sessions using Wilcoxon signed-rank tests.ResultsRelative to baseline (mean ng/ml ±SD: 24.68 ± 14.40), sBDNF levels were significantly higher 1 day (33.04 ± 14.11, p = 0.013, corrected), 1 week (37.03 ± 10.29, p < 0.001, corrected), and 1 month (41.05 ± 10.67, p = 0.008, corrected) after the final ECT session, while pBDNF levels did not significantly differ (p > 0.1). Furthermore, our results indicated that sBDNF levels increased after each continuation ECT session. There was no significant association between sBDNF levels and clinical parameters or treatment response.ConclusionThe absence of an association between changes in sBDNF levels and depressive symptoms challenges the proposed concept of sBDNF/pBDNF as key markers of the effects of ECT.     

Influence of Glass Forming Ability on the Physical Stability of Supersaturated Amorphous Solid Dispersions

In this study, the influence of the glass-forming ability (GFA) of a drug on its physical stability in a supersaturated solid dispersion was investigated. Nine drugs were classified according to their GFA using their respective critical cooling rate. Their respective solubility in poly(vinylpyrrolidone-co-vinyl acetate) 6:4 (PVPVA64) was predicted using the melting point depression method based on the Flory-Huggins lattice theory. Supersaturated amorphous solid dispersions at a level of 25% w/w drug above saturation solubility in the polymer were prepared by film-casting, and their respective physical stability at temperatures of 10°C or 20°C above or below their respective T_g (dry conditions) was monitored by the use of polarized light microscopy. This study showed that drugs with good GFA (class 3) on average have higher physical stability in supersaturated amorphous solid dispersion compared to drug with modest GFA (class 2), which in turn have higher physical stability in supersaturated amorphous solid dispersion than drugs with poor GFA (class 1). These results indicate that the GFA of a drug and its physical stability in a supersaturated amorphous solid dispersion stored at a temperature above or below its T_g are correlated.     

血清NSE下降幅度与晚期小细胞肺癌化疗疗效相关性分析

目的：分析晚期小细胞肺癌患者血清神经元特异性烯醇化酶（NSE）变化与肿瘤影像学改变的关系，探讨血清NSE与晚期小细胞肺癌化疗疗效的相关性。方法：选取在南京市脑科医院胸科院区呼吸内科和江苏省肿瘤医院肿瘤内科住院治疗的70例广泛期小细胞肺癌患者，均经病理学或细胞学确诊。入选患者检测血清NSE均在化疗前一周，疗效评价均为化疗2周期后按照实体瘤的疗效评价标准（RECIST）标准进行评估，探讨血清NSE下降幅度及下降率与晚期小细胞肺癌疗效评价的相关性。结果：血清NSE与小细胞肺癌患者在患者年龄、性别、TNM分期方面均无统计学差异（P>0.05），血清NSE在化疗近期疗效上有统计学显著性差异（P<0.05）。部分缓解（PR）组、疾病稳定（SD）组患者所测得的血清NSE中位数分别为：3.55 ng·mL^-1，2.39 ng·mL^-1；临床获益组患者（PR＋SD）所测血清NSE中位数为3.40 ng·mL^-1；PD组患者所测血清NSE中位数为-5.31 ng·mL^-1，PR患者的血清NSE下降幅度、下降率均高于SD及疾病进展（PD）的患者。临床获益组（PR＋SD）患者血清NSE下降幅度、下降率均高于获得PD组的血清肿瘤标志物趋势。结论：血清NSE与晚期小细胞肺癌化疗疗效具有一定的相关性，NSE下降幅度及下降率可以辅助及时评价晚期小细胞肺癌化疗疗效。