The effect of angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use on mortality in patients with chronic kidney disease: a meta-analysis of observational studies.

PURPOSE: There has been much controversy over the use of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACEIs/ARBs) on patients with renal dysfunction. The purpose of this study was to summarize the evidence regarding the effect of ACEIs/ARBs administration on mortality in patients with nondialysis-dependent chronic kidney disease (CKD) by using a meta-analytic approach. METHODS: We searched the PubMed, Embase, and Web of Science databases for studies on the effect of ACEIs/ARBs administration on mortality in patients with nondialysis-dependent CKD published before March 2015. Summary effect estimates with 95% confidence intervals were derived using the random-effects model, no matter whether the heterogeneity between the included studies was of statistical significance or not. Subgroup analyses, sensitivity analyses, and publication bias tests were performed. RESULTS: Up to 25 March 2015, 10 cohort studies were included in this meta-analysis. The hazard risk of the association between ACEIs/ARBs administration and overall mortality was 0.83 (95% confidence interval 0.78-0.87) using a random-effects model with no heterogeneity (heterogeneity test I(2) = 43.8%, p = 0.067) and publication bias (Egger's test, p = 0.763). The subgroup was divided according to estimated glomerular filtration rate, duration of follow-up, Newcastle-Ottawa Scale star, and proportion of patients with common complications including heart failure, diabetes mellitus, and hypertension. Improved survival outcomes were observed in all subgroups analysis. Sensitivity analysis proved that overall estimated effect was robust. CONCLUSION: This meta-analysis suggested that the use of ACEIs/ARBs in patients with nondialysis-dependent CKD was associated with improved survival. However, randomized studies are needed to confirm these findings and further establish causal relationship. Copyright © 2016 John Wiley & Sons, Ltd.

Histidine as a versatile excipient in the protein-based biopharmaceutical formulations.

Adequate stabilization is essential for marketed protein-based biopharmaceutical formulations to withstand the various stresses that can be exerted during the pre- and post-manufacturing processes. Therefore, a suitable choice of excipient is a significant step in the manufacturing of such delicate products. Histidine, an essential amino acid, has been extensively used in protein-based biopharmaceutical formulations. The physicochemical properties of histidine are unique among amino acids and could afford multifaceted benefits to protein-based biopharmaceutical formulations. With a pKa of approximately 6.0 at the side chain, histidine has been primarily used as a buffering agent, especially for pH 5.5-6.5. Additionally, histidine exhibited several affirmative properties similar to those of carbohydrates (e.g., sucrose and trehalose) and could therefore be considered to be an alternative approach to established protein-based formulation strategies. The current review describes the general physicochemical properties of histidine, lists all commercial histidine-containing protein-based biopharmaceutical products, and discusses a brief outline of the existing research focused on the versatile applications of histidine, which can act as a buffering agent, stabilizer, cryo-/lyo-protectant, antioxidant, viscosity reducer, and solubilizing agent. The interaction between histidine and proteins in protein-based biopharmaceutical formulations, such as the Donnan effect during diafiltration of monoclonal antibody solutions and the degradation of polysorbates in histidine buffer, has also been discussed. As the first review of histidine in protein biopharmaceuticals, it helps to deepen our understanding of the opportunities and challenges associated with histidine as an excipient for protein-based biopharmaceutical formulations.