Human albumin solutions in intensive care: A review

Intervention With Concentrated Albumin for Undifferentiated Sepsis in the Emergency Department (ICARUS-ED): A Pilot Randomized Controlled Trial

STUDY OBJECTIVES

Concentrated albumin early in sepsis resuscitation remains largely unexplored. Objectives were to determine 1) feasibility of early intervention with concentrated albumin in emergency department (ED) patients with suspected infection and hypoperfusion and 2) whether early albumin therapy improves outcomes.

METHODS

ED patients with suspected infection and hypoperfusion (systolic blood pressure [SBP]<90 mmHg or lactate ≥4.0 mmol/L) were randomized to receive either 400 mL 20% albumin over 4 hours or no albumin. All patients were treated with crystalloids, antibiotics, and other therapies at the treating team's discretion. Primary outcome was SBP at 24 hours; secondary outcomes included SBP at 6 hours, fluid and organ support requirements, organ dysfunction, and mortality. Quantile and logistic regressions were used to calculate differences (and 95% CI) between study groups.

RESULTS

Compliance with study protocol was more than 95%, and infection was confirmed in 95% of the 464 study patients enrolled. SBP at 24 hours did not differ between intervention (110.5 mmHg) and standard care arms (110 mmHg). In patients treated with albumin, SBP was higher at 6 hours, less total fluid was infused at 72 hours, fewer patients required vasopressor therapy at 24 and 72 hours, and organ function was improved. Mortality was not significantly different.

CONCLUSIONS

Early identification, trial enrollment, and intervention in ED patients with sepsis is feasible. In this pilot study, concentrated albumin given early in resuscitation did not improve SBP at 24 hours. Albumin was associated with less total fluid and vasopressor requirements and improved organ dysfunction. A multicenter study is indicated.

Perioperative Albumin Among Adults Undergoing Thoracic Surgery in the United States: Utilization, Associations With Clinical Outcomes, and Contribution to Hospital Costs

OBJECTIVES

To estimate the use of albumin among adults undergoing thoracic surgery in the United States, compare baseline characteristics, clinical and cost outcomes of recipients versus nonrecipients, and determine albumin's contribution to total hospital costs.

DESIGN

Retrospective cohort study.

SETTING

Nationwide sample of US hospitals.

PARTICIPANTS

Adults undergoing open and minimally invasive thoracic surgery between 2011 and 2017.

INTERVENTIONS

Albumin on the day of surgery (identified using itemized hospital billing logs).

MEASUREMENTS AND MAIN RESULTS

Albumin was used in 170 of 342 US hospitals, among 13% and 7% of 14,672 and 22,532 patients who, respectively, underwent open and minimally invasive thoracic surgery (median volume 500 mL). Baseline comorbidities and organ-supportive treatments were several-fold more prevalent among recipients (particularly vasopressors, mechanical ventilation, and red cell transfusions). In standardized mortality ratio propensity score weighted analysis, albumin use was not associated with in-hospital mortality (adjusted relative risk 1.17 [0.72, 1.92] and 1.51 [0.97, 2.34], with open and minimally invasive procedures), but was associated with morbidity and higher costs, more so with minimally invasive procedures than with open surgery. Total costs among recipients were higher by $4,744 ($3,591, $5,897) and $5,088 ($4,075, $6,100) for open and minimally invasive procedures, respectively. Albumin accounted for 2.6% of this difference (median $124 [$83-$189] per patient).

CONCLUSIONS

Albumin use varies widely across hospitals, and 9% of patients receive it (median 500 mL). Use was not associated with in-hospital mortality and was associated with more morbidity and cost. The cost of albumin accounted for a trivial portion of hospital costs. Clinical trials must examine the effects of albumin on complications and costs after thoracic surgery.

Reliability of albumin bromocresol green colorimetric method and clinical impact

Measuring plasma albumin is a common and important laboratory test. We compared the results obtained with the bromocresol green (BCG) colorimetric, immunoturbidimetric (IT), and capillary electrophoresis (CE) methods and evaluated the clinical reliability of the colorimetric test. Samples from 320 patients including 227 patients with hypoalbuminemia (albumin levels <35 g/L) were analyzed. Results were compared between different patient groups. The BCG method indicated significantly higher plasma albumin levels than the CE and IT methods, especially in patients with elevated C-reactive protein, alpha-1 globulin (a1G), and alpha-2 globulin (a2G) values. A significant proportion of patients with mild hypoalbuminemia tested using the BCG method (albBCG) and were classified as severely hypoalbuminemic (albumin <20 g/L) when switching to the CE or IT method (albCE and albIT). These patients had elevated a1G and/or a2G levels. This change of result implied an additional indication for albumin replacement therapy. The BCG method significantly overestimates albumin levels in patients with inflammation and hypoalbuminemia, which may lead to inappropriate therapeutic decisions.

The clinical significance of hypoalbuminaemia

Albumin is a relatively small molecule with a radius of 7.5 nm and a molecular weight of 65 kDa. It is the most abundant protein in plasma, accounting for 60-75% of its oncotic pressure. Its concentration in plasma is merely one static measurement reflecting a dynamic and complex system of albumin physiology, and is the net result of several different processes, one or more of which may become deranged by disease or its treatment. It is also unsurprising that hypoalbuminaemia has proved to be an indicator of morbidity and mortality risk since the underlying conditions which cause it, including protein energy malnutrition, crystalloid overload, inflammation, and liver dysfunction are themselves risk factors. In some cases, its underlying cause may require treatment but mostly it is just a parameter to be monitored and used as one measure of clinical progress or deterioration. While malnutrition, associated with a low protein intake, may be a contributory cause of hypoalbuminaemia, in the absence of inflammation and/or dilution with crystalloid its development in response to malnutrition alone is slow compared with the rapid change caused by inflammatory redistribution or dilution with crystalloids. Other significant causes include liver dysfunction and serous losses. These causal factors may occur singly or in combination in any particular case. Treatment is that of the underlying causes and associated conditions such as a low plasma volume, not of hypoalbuminaemia per se.

Association between lactate-to-albumin ratio and 28-days all-cause mortality in patients with sepsis-associated liver injury: a retrospective cohort study

BACKGROUND

The mortality rate of sepsis-associated liver injury (SALI) is relatively high, but there is currently no authoritative prognostic criterion for the outcome of SALI. Meanwhile, lactate-to-albumin ratio (LAR) has been confirmed to be associated with mortality rates in conditions such as sepsis, heart failure, and respiratory failure. However, there is a scarcity of research reporting on the association between LAR and SALI. This study aimed to elucidate the association between LAR and the 28-day mortality rate of SALI.

METHODS

In this retrospective cohort study, data were obtained from the Medical Information Mart for Intensive Care IV (v2.2). Adult patients with SALI were admitted to the intensive care unit in this study. The LAR level at admission was included, and the primary aim was to assess the relationship between the LAR and 28-day all-cause mortality.

RESULTS

A total of 341 patients with SALI (SALI) were screened. They were divided into a survival group (241) and a non-survival group (100), and the 28-day mortality rate was 29.3%. Multivariable Cox regression analysis revealed that for every 1-unit increase in LAR, the 28-day mortality risk for SALI patients increased by 21%, with an HR of 1.21 (95% CI 1.11 ~ 1.31, p < 0.001).

CONCLUSIONS

This study indicates that in patients with SALI, a higher LAR is associated with an increased risk of all-cause mortality within 28 days of admission. This suggests that LAR may serve as an independent risk factor for adverse outcomes in SALI patients.

Cost-effectiveness of intravenous resuscitation fluids in sepsis patients: a patient-level data analysis in Jordan

AIM

Albumin role as fluid resuscitation in sepsis remains understudied in low- and middle-income countries. This study aimed to evaluate the cost-effectiveness of intravenous (IV) Albumin compared to Crystalloids in sepsis patients using patient-level data in Jordan.

METHODS

This was a retrospective cohort study of sepsis patients aged 18 or older admitted to intensive care units (ICU) at two major tertiary hospitals during the period 2018-2019. Patients information, type of IV fluid, and clinical outcomes were retrieved from medical records, and charges were retrieved from the billing system. A 90-day partitioned survival model with two health states (alive and dead) was constructed to estimate the survival of sepsis patients receiving either Albumin or Crystalloids as IV fluids for resuscitation. Overall survival was predicted by fitting a Weibull model on the patient-level data from the current study. To further validate the results, and to support the assessment of uncertainty, time-dependent transition probabilities of death at each cycle were estimated and used to construct a state-transition patient-level simulation model with 10,000 microsimulation trials. Adopting the healthcare system perspective, incremental cost-effectiveness ratios(ICERs) of Albumin versus Crystalloids were calculated in terms of the probability to be discharged alive from the ICU. Uncertainty was explored using probabilistic sensitivity analysis.

RESULTS

In the partitioned survival model, Albumin was associated with an incremental cost of $1,007 per incremental1% in the probability of being discharged alive from the ICU. In the state-transition patient-level simulation model, ICER was $1,268 per incremental 1% in the probability of being discharged alive. Probabilistic sensitivity analysis showed that Albumin was favored at thresholds >$800 per incremental 1%in the probability of being discharged alive from the ICU.

CONCLUSION

IV Albumin use in sepsis patients might not be cost-effective from the healthcare perspective of Jordan. This has important implications for policymakers to readdress Albumin prescribing practice in sepsis patients.

Use of a Novel Buffered Hypertonic Saline Solution for Fluid Replacement and Resuscitation During Spinal Surgery in Adolescents

Background

During major orthopedic procedures, such as posterior spinal fusion (PSF), isotonic fluids, colloids, starches, or gelatins are commonly used to replace the preoperative fluid deficit and provide ongoing fluid resuscitation. Given recent concerns regarding the potential adverse physiologic effects of albumin solutions, we have modified our intraoperative practice to include the use of a novel 2% buffered hypertonic saline solution during major orthopedic procedures. We present our preliminary clinical experience with this novel fluid for intraoperative resuscitation and its impact on limiting the use of 5% albumin.

Methods

A retrospective review was performed to identify patients who received 2% buffered hypertonic saline during PSF. The intraoperative course of these patients was compared to case-matched control patients who received standard care with isotonic fluids plus 5% albumin as an adjunct for intravascular resuscitation.

Results

The study cohort included 23 patients who received 2% buffered hypertonic saline and 25 in the case-matched control group. There was no difference in the volume of intraoperative isotonic crystalloid fluids, estimated blood loss, and urine output between the two groups. In the control cohort, 19 of 25 patients (76%) received 5% albumin compared to only six of 23 patients (26%, P = 0.0005) in the 2% buffered hypertonic saline group. The final pH was higher in the patients that received 2% buffered hypertonic saline than in the control group (7.40 ± 0.03 versus 7.36 ± 0.06, P = 0.0131). Additionally, the starting and final serum sodium values were higher in the patients that received 2% buffered hypertonic saline, although no difference was noted in the mean change from the starting value (average increase of 2 mEq/L in both groups).

Conclusion

Use of a novel 2% buffered hypertonic saline solution for intraoperative resuscitation during major orthopedic procedures decreases the need for 5% albumin while avoiding the development of hyperchloremic metabolic acidosis which may occur with standard sodium chloride solutions.

The Case for Albumin as Volume Expander and beyond

This chapter discusses the importance of endogenous albumin, the most abundant plasma protein in the body. Albumin has diverse functions such as antioxidant, anti-inflammatory activities, intravascular buffering, drug metabolism, transport, distribution, and restoration of vascular endothelial integrity. It is also crucial for maintaining the endothelial glycocalyx layer in blood vessels. Critically ill patients may experience hypoalbuminemia, defined as serum albumin <35 g/L, due to reduced synthesis, malnutrition, increased loss, or increased catabolism. Observational studies show hypoalbuminemia as an independent predictor of worse outcomes, with a 10 g/L decrease in serum albumin linked to a higher risk of mortality, morbidity, longer ICU/hospital stays, and increased resource utilisation. Administering exogenous albumin targeting serum albumin >30 g/L may reduce complications, but further trials are needed. Exogenous albumin is used in the ICU for various indications, including resuscitation and deresuscitation. Evidence on its use as a plasma expander is inconclusive. Both high- (20%) and low-concentration (4 and 5%) albumin can be used for resuscitation if patients require additional fluid, despite receiving crystalloids. Albumin is safe and effective for plasma expansion in patients with sepsis and septic shock but should be avoided in traumatic brain injury. Judicious and vigilant use of albumin is recommended due to its cost and potential risks. Albumin administration should be based on clinical indications, and monitoring fluid balance and clinical parameters is critical to prevent fluid accumulation and oedema formation.

A Narrative Literature Review of the Established Safety of Human Serum Albumin Use as a Stabilizer in Aesthetic Botulinum Toxin Formulations Compared to Alternatives

Despite more than 80 years of use in a number of conditions, including in critically ill patients, comments have recently arisen regarding the safety and efficacy of human serum albumin (HSA) as a therapeutic product and stabilizer/excipient in botulinum neurotoxins. This review summarizes the literature on the safety of HSA. Beyond decades of safe use, the largest clinical dataset of HSA safety is a large meta-analysis of HSA supplier data, which found only an extremely remote risk of serious adverse events across millions of doses of therapeutic concentrations of HSA. There is a paucity of literature identifying HSA-specific adverse events when used as a stabilizer/excipient; however, studies of HSA-containing botulinum neurotoxins (BoNTs) suggest that adverse events are not related to HSA. Polysorbates, which are synthetically produced and not physiologically inert, are contained in pending or new-to-market BoNT formulations. In contrast to HSA, evidence exists to suggest that polysorbates (particularly PS20/PS80) can cause serious adverse events (e.g., hypersensitivity, anaphylaxis, and immunogenicity).

The effects of resuscitation with different plasma products on endothelial permeability and organ injury in a rat pneumosepsis model

BACKGROUND

Endothelial injury and permeability are a hallmark of sepsis. Initial resuscitation of septic patients with crystalloids is associated with aggravation of endothelial permeability, which may be related either to low protein content or to volume. We investigated whether initial resuscitation with different types of plasma or albumin decreases endothelial dysfunction and organ injury in a pneumosepsis rat model compared to the same volume of crystalloids.

STUDY DESIGN AND METHODS

Sprague-Dawley rats were intratracheally inoculated with Streptococcus pneumoniae. Twenty-four hours after inoculation, animals were randomized to 2 control groups and 5 intervention groups (n = 11 per group) to receive resuscitation with a fixed volume (8 mL/kg for 1 h) of either Ringer's Lactate, 5% human albumin, fresh frozen plasma derived from syngeneic donor rats (rFFP), human-derived plasma (hFFP) or human-derived solvent detergent plasma (SDP). Controls were non-resuscitated (n = 11) and healthy animals. Animals were sacrificed 5 h after start of resuscitation (T = 5). Pulmonary FITC-dextran leakage as a reflection of endothelial permeability was used as the primary outcome.

RESULTS

Inoculation with S. Pneumoniae resulted in sepsis, increased median lactate levels (1.6-2.8 mM, p < 0.01), pulmonary FITC-dextran leakage (52-134 µg mL-1, p < 0.05) and lung injury scores (0.7-6.9, p < 0.001) compared to healthy controls. Compared to animals receiving no resuscitation, animals resuscitated with rFFP had reduced pulmonary FITC leakage (134 vs 58 µg/mL, p = 0.011). However, there were no differences in any other markers of organ or endothelial injury. Resuscitation using different human plasma products or 5% albumin showed no differences in any outcome.

CONCLUSIONS

Resuscitation with plasma did not reduce endothelial and organ injury when compared to an equal resuscitation volume of crystalloids. Rat-derived FFP may decrease pulmonary leakage induced by shock.

Serum Albumin in Health and Disease: From Comparative Biochemistry to Translational Medicine

Being one of the main proteins in the human body and many animal species, albumin plays a decisive role in the transport of various ions, electrically neutral molecules and in maintaining the colloid osmotic pressure of the blood [...].

Expert perspectives for the pharmacist on facilitating and improving the use of albumin in cirrhosis

PURPOSE

Albumin, the most abundant and arguably most important protein in the human body, plays a unique role in decompensated cirrhosis because its structure and function are quantitatively and qualitatively affected. A literature review was performed to provide insights into albumin use. The manuscript was developed using a multidisciplinary approach; 2 hepatologists, a nephrologist, a hospitalist, and a pharmacist, who are all members of or work closely with the Chronic Liver Disease Foundation, collaborated to write this expert perspective review.

SUMMARY

Cirrhosis represents the potential end in the spectrum of all chronic liver diseases. Decompensated cirrhosis, defined by the overt manifestation of liver failure (eg, ascites, hepatic encephalopathy, variceal bleeding), is the inflection point associated with increased mortality. Human serum albumin (HSA) infusion serves an important role in the treatment of advanced liver disease. The benefits of HSA administration in patients with cirrhosis are widely accepted, and its use has been advocated by several professional societies. However, inappropriate HSA use can lead to significant adverse patient events. This paper discusses the rationale for the administration of HSA in the treatment of complications of cirrhosis, analyzes the data on the use of HSA in cirrhosis, and streamlines practical recommendations set forth in published guidance.

CONCLUSION

Use of HSA in clinical practice needs to be improved. The objective of this paper is to empower pharmacists to facilitate and improve the use of HSA in patients with cirrhosis at their practice sites.

Peptide derived C. striata albumin as a natural angiotensin-converting enzyme inhibitor

As one of the most popular sources for fish albumin, Channa striata has been considered as a promising substitute for human albumin. However, scientific information regarding its genomic and proteomic is very limited, making its identification rather complicated. In this study, we aimed to isolate, characterize, and examine the bioactivity of protein and peptide derivatives of C. striata albumin. Fractionation of albumin from C. striata extract was conducted using Cohn Process and the yield was evaluated. The peptides were further produced by enzymatic hydrolysis. All these proteins were studied using tricine-SDS PAGE and tested for in vitro ACE inhibition. Dry weights of the Fraction-5, where the albumin was more abundant and purer, was 3.8 ± 2.1%. Based on tricine-SDS PAGE analysis, two bands of protein, e.g., approximately 10 and 13 kDa, were detected with highest intensity found in Fraction-5, which might be albumin of C. striata. An increasing trend of ACE inhibition by the fractions was observed, ranging from 7.09 to 22.99%. The highest ACEI activity was found in peptides from alcalase hydrolysis with molecular size <3 kDa (56.65 ± 2.32%, IC₅₀ 36.93 μg/mL). This value was also statistically significant compared with the non-hydrolyzed Fraction-5 and Parental Fraction, which were 23.48 ± 3.11% (P < 0.05) and 13.02 ± 0.68% (P < 0.01), respectively. Taken together, these findings suggest a promising potential of peptide-derived C. striata albumin for natural antihypertensive agents.

Study of Albumin Oxidation in COVID-19 Pneumonia Patients: Possible Mechanisms and Consequences

Oxidative stress induced by neutrophils and hypoxia in COVID-19 pneumonia leads to albumin modification. This may result in elevated levels of advanced oxidation protein products (AOPPs) and advanced lipoxidation end-products (ALEs) that trigger oxidative bursts of neutrophils and thus participate in cytokine storms, accelerating endothelial lung cell injury, leading to respiratory distress. In this study, sixty-six hospitalized COVID-19 patients with respiratory symptoms were studied. AOPPs-HSA was produced in vitro by treating human serum albumin (HSA) with chloramine T. The interaction of malondialdehyde with HSA was studied using time-resolved fluorescence spectroscopy. The findings revealed a significantly elevated level of AOPPs in COVID-19 pneumonia patients on admission to the hospital and one week later as long as they were in the acute phase of infection when compared with values recorded for the same patients 6- and 12-months post-infection. Significant negative correlations of albumin and positive correlations of AOPPs with, e.g., procalcitonin, D-dimers, lactate dehydrogenase, aspartate transaminase, and radiological scores of computed tomography (HRCT), were observed. The AOPPs/albumin ratio was found to be strongly correlated with D-dimers. We suggest that oxidized albumin could be involved in COVID-19 pathophysiology. Some possible clinical consequences of the modification of albumin are also discussed.

Use of Albumin in the NICU: An Evidence-based Review

Albumin is the most abundant protein in human blood with distinctive functions throughout the human body. Low albumin levels are a predictor of mortality as well as disease outcome in children and adults. However, the clinical significance of hypoalbuminemia and the role of albumin infusions in NICUs remain unclear and controversial.

Comprehensive Investigations of Multiple Factors That Are Related to Refractory Outcome in Urosepsis Patients

Background

Urosepsis is an acute life-threating disease, and some cases show refractory outcome to therapy. In an aging society of developed countries, characteristics of urosepsis are becoming complicated. We performed a comprehensive investigation regarding the clinical and social aspects that are related to refractory outcomes in urosepsis patients.

Methods

The patient cohort consisted of 66 patients with urosepsis. Multiple factors from clinical and social aspects were reviewed retrospectively. Two categories of refractory outcomes were defined. One was afebrile resistance (AR); fever continued more than 7 days from the initiation of therapy. Another was discharge resistance (DR); hospitalization continued for more than 30 days. Logistic regression analyses were performed to identify significant factors that are related to the AR or DR.

Results

Univariate analysis demonstrated that high score of Eastern Cooperative Oncology Group Performance Status (ECOG PS) (≥ 2) and Age-adjusted Charlson comorbidity index (CCI) (≥ 4), high serum C-reactive protein (CRP) level (≥ 14.9 mg/dL), and low serum albumin level (≤ 2.26 g/dL) were significantly related to AR. Univariate analysis results also revealed that high score of ECOG PS (≥ 2), high serum creatinine level (≥ 1.54 mg/dL) and vasopressor administration were significantly related to DR. Multivariate analyses demonstrated that low serum albumin level (≤ 2.26g/dL) was the only significant factor that was related to AR. In contrast, high score of ECOG PS (≥ 2) and high serum creatinine level (≥ 1.54 mg/dL) were significant factors that were related to DR.

Conclusion

It is suggested that evaluating serum albumin levels is essential for the therapeutic first step because hypoalbuminemia was the significant factor that was related to obstruction to antipyresis. It is also suggested that the deterioration of patients' activities of daily living and renal dysfunction might be the refractory factors for discharge from the hospital, which was the ultimate therapeutic goal.

Human albumin solution utilization patterns prior and during COVID-19 pandemic in United Arab Emirates: Time to develop and implement national guidelines on prescription and utilization

The human albumin solution (HAS) has limited but important indications in clinical practices. However, the inappropriate use of HAS can be costly. Thus, it is imperative to establish a practical protocol to use albumin products and rationalize its usage. The aim of this study was to identify HAS utilization patterns in a multi-specialty private hospital in Dubai, United Arab Emirates (UAE), before and during the COVID-19 pandemic. In addition, the objective was to demonstrate the importance of reconsidering the prescribing strategies for HAS administration. All data on 20% HAS administration in Mediclinic Welcare Hospital (MWEL) were retrieved between January 2019 and May 2021, including the total quantities administered and data on primary diagnosis. A total of 579 patient admissions with various diagnoses were included in this study. Our data suggested that the percentage of clinically indicated 20% HAS administrations decreased from 13.0% in the pre-COVID-19 phase to 1.5% in the COVID-19 phase (p<0.001). An increase in the administration of 20% HAS not backed by agreed clinical evidence followed the increase in new number of COVID-19 cases in the UAE. Our study suggests a large proportion of administered HAS, that drastically increased during COVID-19 with lack of evidence of its benefit. This study can be helpful to refine the institutional guidelines of HAS use, and frequent audits and interactive educational interventions are recommended to tackle this issue. In turn, the refinement of HAS administration guidelines could help to reduce the unjustified cost of inappropriate HAS use.

Integrative Role of Albumin: Evolutionary, Biochemical and Pathophysiological Aspects

Being one of the main proteins in the human body and many animal species, albumin plays a crucial role in the transport of various ions, electrically neutral molecules and in maintaining the colloidal osmotic pressure of the blood. Albumin is able to bind almost all known drugs, many nutraceuticals and toxic substances, determining their pharmaco- and toxicokinetics. However, albumin is not only the passive but also the active participant of the pharmacokinetic and toxicokinetic processes possessing a number of enzymatic activities. Due to the thiol group of Cys34, albumin can serve as a trap for reactive oxygen and nitrogen species, thus participating in redox processes. The interaction of the protein with blood cells, blood vessels, and also with tissue cells outside the vascular bed is of great importance. The interaction of albumin with endothelial glycocalyx and vascular endothelial cells largely determines its integrative role. This review provides information of a historical nature, information on evolutionary changes, inflammatory and antioxidant properties of albumin, on its structural and functional modifications and their significance in the pathogenesis of some diseases.

Serum Albumin in Health and Disease: Esterase, Antioxidant, Transporting and Signaling Properties

Being one of the main proteins in the human body and many animal species, albumin plays a decisive role in the transport of various ions-electrically neutral and charged molecules-and in maintaining the colloidal osmotic pressure of the blood. Albumin is able to bind to almost all known drugs, as well as many nutraceuticals and toxic substances, largely determining their pharmaco- and toxicokinetics. Albumin of humans and respective representatives in cattle and rodents have their own structural features that determine species differences in functional properties. However, albumin is not only passive, but also an active participant of pharmacokinetic and toxicokinetic processes, possessing a number of enzymatic activities. Numerous experiments have shown esterase or pseudoesterase activity of albumin towards a number of endogeneous and exogeneous esters. Due to the free thiol group of Cys34, albumin can serve as a trap for reactive oxygen and nitrogen species, thus participating in redox processes. Glycated albumin makes a significant contribution to the pathogenesis of diabetes and other diseases. The interaction of albumin with blood cells, blood vessels and tissue cells outside the vascular bed is of great importance. Interactions with endothelial glycocalyx and vascular endothelial cells largely determine the integrative role of albumin. This review considers the esterase, antioxidant, transporting and signaling properties of albumin, as well as its structural and functional modifications and their significance in the pathogenesis of certain diseases.

Hypothesis of using albumin to improve drug efficacy in cancers accompanied by hypoalbuminemia

A common problem in many cancers is the resistance of some patients to common drugs or relapse. Hypoalbuminemia has been reported in some of resistant cancer patients.This article evaluates the usefulness of albumin in the treatment of drug-resistant cancers with hypoalbuminemia based on available evidences.Rapid metabolism and drug excretion from the body is one of the causes of drug resistance. Albumin is the major plasma protein to which almost all drugs are bound. There is some evidence that increasing drug binding to albumin has beneficial effects on drug efficacy in some cancers and cancer cells. On the other hand, some reports have shown that cancer cells can use albumin as the energy and amino acid source.We have hypothesized that in this particular group of cancers, adding albumin to a treatment regimen could have a beneficial effect on drug efficacy and dosage. In fact, excess albumin can prevent rapid metabolism of drug by increasing the fraction of albumin-bound drug, and can increase drug delivery to cancer cells due to the absorption of drug-albumin complex by cancer cells.

Hypoalbuminemia as Surrogate and Culprit of Infections

Hypoalbuminemia is associated with the acquisition and severity of infectious diseases, and intact innate and adaptive immune responses depend on albumin. Albumin oxidation and breakdown affect interactions with bioactive lipid mediators that play important roles in antimicrobial defense and repair. There is bio-mechanistic plausibility for a causal link between hypoalbuminemia and increased risks of primary and secondary infections. Serum albumin levels have prognostic value for complications in viral, bacterial and fungal infections, and for infectious complications of non-infective chronic conditions. Hypoalbuminemia predicts the development of healthcare-associated infections, particularly with Clostridium difficile. In coronavirus disease 2019, hypoalbuminemia correlates with viral load and degree of acute lung injury and organ dysfunction. Non-oncotic properties of albumin affect the pharmacokinetics and pharmacodynamics of antimicrobials. Low serum albumin is associated with inadequate antimicrobial treatment. Infusion of human albumin solution (HAS) supplements endogenous albumin in patients with cirrhosis of the liver and effectively supported antimicrobial therapy in randomized controlled trials (RCTs). Evidence of the beneficial effects of HAS on infections in hypoalbuminemic patients without cirrhosis is largely observational. Prospective RCTs are underway and, if hypotheses are confirmed, could lead to changes in clinical practice for the management of hypoalbuminemic patients with infections or at risk of infectious complications.