Variability of cytokine concentration in whole blood serum and bronchoalveolar lavage over time

Unrevealing the connection between real sample analysis and analytical method. The case of cytokines

Cytokines are compounds that belong to a special class of signaling biomolecules that are responsible for several functions in the human body, being involved in cell growth, inflammatory, and neoplastic processes. Thus, they represent valuable biomarkers for diagnosing and drug therapy monitoring certain medical conditions. Because cytokines are secreted in the human body, they can be detected in both conventional samples, such as blood or urine, but also in samples less used in medical practice such as sweat or saliva. As the importance of cytokines was identified, various analytical methods for their determination in biological fluids were reported. The gold standard in cytokine detection is considered the enzyme-linked immunosorbent assay method and the most recent ones have been considered and compared in this study. It is known that the conventional methods are accompanied by a few disadvantages that new methods of analysis, especially electrochemical sensors, are trying to overcome. Electrochemical sensors proved to be suited for the elaboration of integrated, portable, and wearable sensing devices, which could also facilitate cytokines determination in medical practice.

Gluten consumption and inflammation affect the development of celiac disease in at-risk children

Gene expression, lipidomic and growth impairment findings suggest that the natural history of celiac disease (CD) starts before the gluten-induced immune response. Gluten intake in the first years of life is a controversial risk factor. We aimed to estimate the risk of developing CD associated with the amount of gluten intake and the serum inflammatory profile in genetically predisposed infants. From an Italian cohort of children at risk for CD, we enrolled 27 children who developed CD (cases) and 56 controls matched by sex and age. A dietary interview at 9, 12, 18, 24 and 36 months was performed. Serum cytokines (INFγ, IL1β, IL2, IL4, IL6, IL10 IL12p70, IL17, and TNFα) were analysed at 4 and 36 months. Infants who developed CD by 6 years showed an increase in serum cytokines (INFγ, IL1β, IL2, IL6, IL10, IL12p70 and TNFα) at 4 months of age before gluten introduction. CD cases ate significantly more gluten in the second year of life than controls, and gluten intake in the second year of life was strongly correlated with serum cytokines (INFγ, IL2, IL4, IL12p70, IL17) at 36 months only in CD cases. The dietary pattern of infants who developed CD was characterized by high consumption of biscuits and fruit juices and low intake of milk products, legumes, vegetables and fruits. Genetically predisposed infants who developed CD showed a unique serum cytokine profile at 4 months before gluten consumption. The amount of gluten was strongly correlated with an inflammatory profile in serum cytokines at 36 months only in infants who developed CD.

Urinary neopterin: a novel biomarker of disease progression in amyotrophic lateral sclerosis

BACKGROUND

To evaluate urinary neopterin, a marker of pro-inflammatory state, as a potential biomarker of disease prognosis and progression in amyotrophic lateral sclerosis (ALS); and to compare its utility to urinary neurotrophin receptor p75 extracellular domain (p75^ECD ).

METHODS

Observational study including 21 healthy controls and 46 people with ALS, 29 of whom were sampled longitudinally. Neopterin and p75^ECD were measured using enzyme-linked immunoassays. Baseline and longitudinal changes in clinical measures, neopterin and urinary p75^ECD were examined, and prognostic utility explored by survival analysis.

RESULTS

At baseline, urinary neopterin was higher in ALS compared to controls (181.7 ± 78.9 μmol/mol creatinine vs 120.4 ± 60.8 μmol/mol creatinine, p= 0.002, Welch's t-test) and correlated with ALSFRS-R (r= -0.36, p= 0.01). Combining previously published urinary p75^ECD results from 22 ALS patients with a further 24 ALS patients, baseline urinary p75^ECD was also higher compared to healthy controls (6.0 ± 2.7 vs 3.2 ± 1.0 ng/mg creatinine p<0.0001) and correlated with ALSFRS-R (r= -0.36, p= 0.01). Urinary neopterin and p75^ECD correlated with each other at baseline (r= 0.38, p= 0.009). In longitudinal analysis, urinary neopterin increased on average (±SE) by 6.8 ± 1.1 μmol/mol creatinine per month (p<0.0001) and p75^ECD by 0.19 ± 0.02 ng/mg creatinine per month (p<0.0001) from diagnosis in 29 ALS patients.

CONCLUSION

Urinary neopterin holds promise as marker of disease progression in ALS and is worthy of future evaluation for its potential to predict response to anti-inflammatory therapies.

Analysis of cytokines in serum and bronchoalveolar lavage fluid in patients with immune-checkpoint inhibitor-associated pneumonitis: a cross-sectional case-control study

PURPOSE

Immune-checkpoint inhibitors (ICI) present a new treatment for malignancies by boosting the immune system. This has led to a variety of immune-related adverse events, including ICI-associated pneumonitis (ICIaP). Diagnosis thereof is often challenging, and its pathogenesis has not yet been fully understood. The aim of this cross-sectional case-control study was to investigate cytokines in serum and bronchoalveolar lavage fluid (BALF) expressed in patients with ICIaP compared to controls consisting of healthy individuals, patients with lung cancer and patients with interstitial lung diseases (ILD) other than ICIaP.

METHODS

From January 2018 until June 2019, 401 adult patients with various lung diseases were prospectively enrolled in a BALF- and serum biobank, called BALOTHEK. Of these, 12 patients were diagnosed with ICIaP (Pembrolizumab, Ipilimumab, or both, and Durvalumab) serving as case group. Subjects with one of three diagnosis groups from BALOTHEK, including lung cancer, ILD other than ICIaP, and healthy individuals, served as matched controls. The following 11 cytokines were simultaneously analyzed in BALF and serum of each study participant: interferon gamma, tumor necrosis factor alpha, interleukin (IL) 1b, IL-2, IL-4, IL-5, IL-6, IL-8, IL-12p70, IL-13 and IL-17A. This study was approved by the local ethic review committee (BASEC-ID 2017-02,307 and 2018-01,724).

RESULTS

Absolute number and percentage of lymphocytes in BALF of patients with ICIaP were significantly higher compared to control groups. For the investigated cytokines in BALF, a significant increase of IL-6 level was shown for patients with ICIaP compared to control groups (p = 0.031, adjusted for multiple comparisons).

CONCLUSION

Cytokine profile assessed in BALF shows promising potential for facilitating diagnosis and understanding of pathophysiology of ICIaP. IL-6 may not only contribute to better understanding of pathophysiology but also herald therapeutic implications for Tocilizumab.

Cytokines: From Clinical Significance to Quantification

Cytokines are critical mediators that oversee and regulate immune and inflammatory responses via complex networks and serve as biomarkers for many diseases. Quantification of cytokines has significant value in both clinical medicine and biology as the levels provide insights into physiological and pathological processes and can be used to aid diagnosis and treatment. Cytokines and their clinical significance are introduced from the perspective of their pro- and anti-inflammatory effects. Factors affecting cytokines quantification in biological fluids, native levels in different body fluids, sample processing and storage conditions, sensitivity to freeze-thaw, and soluble cytokine receptors are discussed. In addition, recent advances in in vitro and in vivo assays, biosensors based on different signal outputs and intracellular to extracellular protein expression are summarized. Various quantification platforms for high-sensitivity and reliable measurement of cytokines in different scenarios are discussed, and commercially available cytokine assays are compared. A discussion of challenges in the development and advancement of technologies for cytokine quantification that aim to achieve real-time multiplex cytokine analysis for point-of-care situations applicable for both biomedical research and clinical practice are discussed.

Evaluation of cytokines in the tumor microenvironment of lung cancer using bronchoalveolar lavage fluid analysis

INTRODUCTION

Lung cancer is the leading cause of death by cancer. In recent years, immunotherapy with checkpoint inhibitors (ICI) emerged as a promising new therapeutic approach. However, a deeper understanding of the immunologic responses adjacent to the tumor known as tumor microenvironment (TME) is needed. Our study investigated TME of lung cancer by analyzing cytokines in bronchoalveolar lavage fluid (BALF).

MATERIALS AND METHODS

Between January 2018 and June 2019, 119 patients were prospectively enrolled in this study. For each cancer patient, levels of 16 cytokines (fractalkine, granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), and interleukins (IL): IL-1b, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p70, IL-13, IL-17A, and IL-23) were measured in BALF and serum and compared to healthy individuals and patients with other lung diseases.

RESULTS

There were several significant differences of cytokine levels of patients with lung cancer compared to healthy individuals. However, none of them remained in the multivariate analysis compared to other lung diseases in either BALF or serum. Furthermore, there were no significant differences between the groups in cell differentiation of either BALF or serum. Cytokine levels in BALF were generally near the lower detection limit and showed almost no correlation with their respective levels measured in serum of the same individual.

CONCLUSIONS

Cytokines in BALF and serum of lung cancer patients may indicate unspecific inflammation. BAL is not recommendable as a tool to investigate TME of lung cancer. Therefore, cytokines measured in BALF are probably not appropriate as predictors in patients treated with ICIs.

Mathematical modeling of ventilator-induced lung inflammation

Despite the benefits of mechanical ventilators, prolonged or misuse of ventilators may lead to ventilation-associated/ventilation-induced lung injury (VILI). Lung insults, such as respiratory infections and lung injuries, can damage the pulmonary epithelium, with the most severe cases needing mechanical ventilation for effective breathing and survival. Damaged epithelial cells within the alveoli trigger a local immune response. A key immune cell is the macrophage, which can differentiate into a spectrum of phenotypes ranging from pro- to anti-inflammatory. To gain a greater understanding of the mechanisms of the immune response to VILI and post-ventilation outcomes, we developed a mathematical model of interactions between the immune system and site of damage while accounting for macrophage phenotype. Through Latin hypercube sampling we generated a collection of parameter sets that are associated with a numerical steady state. We then simulated ventilation-induced damage using these steady state values as the initial conditions in order to evaluate how baseline immune state and lung health affect outcomes. We used a variety of methods to analyze the resulting parameter sets, transients, and outcomes, including a random forest decision tree algorithm and parameter sensitivity with eFAST. Analysis shows that parameters and properties of transients related to epithelial repair and M1 activation are important factors. Using the results of this analysis, we hypothesized interventions and used these treatment strategies to modulate the response to ventilation for particular parameters sets.

Potential predictive value of change in inflammatory cytokines levels subsequent to initiation of immune checkpoint inhibitor in patients with advanced non-small cell lung cancer

For a definite indication for immunotherapy, finding appropriate biomarkers that are predictive of treatment responses is necessary. Inflammatory cytokines which play critical roles in immunity against infectious sources or cancer cells are suggested to activate immune cells after initiation of immune checkpoint inhibitors (ICI). Through activation of immune cells such as T cells, natural killer cells, macrophages, or tumor infiltrating dendritic cells, inflammatory cytokines usually increase after programmed death (PD)-1/PD-L1 axis blockade. There have been several studies evaluating the predictive value of early changes in inflammatory cytokines in non-small cell lung cancer (NSCLC) patients undergoing immunotherapy. In this mini-review, we went through recent articles on potential blood level values of inflammatory cytokines in NSCLC patients receiving ICI and their early change around commencement of ICIs in predicting response to treatment and disease progression. The studies evaluated cytokines including interleukin (IL)-2, 6, 8, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α for predictability for responses to ICI. A combination cytokine panel can help predict the response and prognosis of patients with NSCLC who are receiving ICI treatment. Furthermore, a more individualized ICI treatment will be available if responses and change in tumor burden can be predicted. However, most of the studies on cytokines in NSCLC patients receiving ICIs had a small number of patients, and the heterogeneous measurement time points. Nevertheless, cytokines such as IL-8 and IFN- γ have considerable potential predictive value for immunotherapy response, which is worthy of further studies. To utilize blood cytokines levels as biomarkers for immunotherapy, a larger study with uniform measurement protocol is necessary.

Diagnostic methods for the measurement of human TNF-alpha in clinical laboratory

Measurement of Tumour Necrosis Factor alpha (TNF-α) in peripheral blood is a useful tool to assess inflammatory responses in a large range of diseases. One of the major challenges for cytokine analysis is the availability of a proper analytical tool with high specificity, accuracy, linearity, precision, stability, and analytical sensitivity. Although available immunoassays are usually robust and reproducible, it is also true that they are not interchangeable. Two ELISA, four flow cytometric bead array (CBA) and four Luminex immunoassays were compared. Correlation between different techniques was almost absent, while some immunoassays based on the same technique showed significant correlation. Among the ten different assays evaluated, just few of them complied with the pre-established acceptance validation criteria. Interestingly, sera and plasma collected from the same healthy donor had significant different reference values. Samples stability was maintained in serum up to one week at four degrees, while plasma was stable only when it was frozen. Since several anti-inflammatory treatments are based on biologics targeting TNF-α (anti-TNF-α antibodies), potential interference with the immunoassays was tested and resulted relevant. This study shows that although each immunoassay presents benefits and drawbacks, just few assays are suitable for the measurement of TNF-α in clinical laboratories, demonstrating that, so far, the measurement of TNF-α in human blood is still not yet harmonised. In addition, we found that false negative results caused by anti-TNF-α treatments should be carefully considered for results interpretation.

A Systematic Safety Evaluation of Nanoporous Mannitol Material as a Dry-Powder Inhalation Carrier System

For carrier-based dry-powder inhaler (DPI) formulations, the adhesion between carrier particles and active pharmaceutical ingredients (API) particles have a significant influence on the aerosolization performance of the API-carrier complexes and the desired detachment of the API for efficient pulmonary delivery. In our previous study, nanoporous mannitol material was successfully fabricated as carriers by a one-step nonorganic solvent spray drying method with the thermal degradation of ammonium carbonate. These carriers were shown to achieve excellent aerosolization performance. In addition, no residue of ammonium carbonate was detected on the powder surface. However, the safety of nanoporous mannitol carriers (Nano-PMCs) during pulmonary administration/delivery was still unknown because the lung is vulnerable to the inhaled particles. To address this question, the present study was conducted to construct a systematic safety evaluation for DPIs carriers to investigate the safety of Nano-PMCs in the whole inhalation, which would make up for the lack of detailed and standardized method in this field. In vitro safety evaluation was carried out using respiratory and pulmonary cytotoxicity tests, hemolysis assay, and ciliotoxicity test. In vivo safety evaluation was studied by measuring inflammatory indicators in the bronchoalveolar lavage fluid, assessing the pulmonary function and observing pulmonary pathological changes. Nano-PMCs showed satisfactory biocompatibility on respiratory tracts and lungs in vitro and in vivo. It was suggested that Nano-PMCs were safe for intrapulmonary delivery and potential as DPI carriers.