"CAR T-cell therapy in liquid and solid tumors"

Abstract

CAR T cell therapy is a type of immunotherapy that utilizes synthetic, chimeric antigen receptors (CARs) to reprogram T cell antigen specificity and function. These genetically modified T cells are expanded in the lab and then infused into the patient, granting them the ability to fight certain types of diseases such as cancer. CAR T cell therapy has changed the way we view personalized cancer treatment especially in hematologic malignancies, altering the landscape of T cell-based immunotherapy. The MHC-independent CAR-mediated T cell recognition of malignant cells has led to a plethora of targets being tested for a wide variety of tumors. The targeting of CD19, a cell surface molecule expressed on normal B cells as well as in a vast majority of B cell malignancies, and BCMA, expressed on differentiated B cells and cancerous plasma cells, showed great results in the treatment of relapsed or refractory leukemia, lymphoma, and multiple myeloma, with significant clinical responses and high rates of complete remission. Despite the durable remissions in hematologic malignancies, CAR T cell therapy is limited by potentially severe toxicities. Cytokine release syndrome and neurological toxicities are still of great concern to the safety issue following CAR T cell infusion. Treatment of solid tumors using CAR T cell therapy is still a major challenge due to the heterogeneity of such tumors, their physical barriers, and the highly immunosuppressive nature of the solid tumor microenvironment. 

TOLIS Rafail

"Investigation of the pre-analytical treatment of biological fluids for the determination of biomarkers by LC-MS/MS spectrometry"

Abstract

Biomarkers are molecules whose determination in clinical laboratories has great diagnostic and clinical value. The determination of biomarkers can be performed in various biological fluids, with blood and urine being the most widely used. Liquid chromatography coupled to mass spectrometry (LC-MS/MS) is one of the most widely applied analytical techniques in biomarker analysis, due to its advantages over others, such as high specificity and sensitivity, speed, small sample volume, simultaneous determination of multiple analytes, determination of thermally unstable and non-volatile compounds, the avoidance of derivatization of the analytes, etc.

The pre-analytical processing of biological samples is a mandatory step for the determination of various biomarkers by liquid chromatography-mass spectrometry. Its importance is decisive, and ensures reliable results for the correct diagnosis, prediction, monitoring of diseases and determination of drug levels.

The purpose of this work is to review and present selected sample preparation techniques of biological fluids suitable for the analysis of biomarkers, applying the LC-MS/MS methodology.

Protein precipitation, solid phase extraction and liquid-liquid extraction are the mainly used pretreatment techniques. Moreover, new techniques or evolution of classic techniques are used today, allowing the analysis of smaller volumes of biological fluids by using smaller volumes of elution solvents. These include solid phase microextraction, salting-out assisted liquid–liquid extraction, supported liquid extraction, fabric phase sorptive extraction, stir bar sorptive extraction, microextraction by packed sorbent and monolithic spin column extraction. Additional technologies, such as phospholipid removal plates, magnetic beads, turbulent flow extraction, as well as, the use of newer materials, such as carbon nanotubes, restricted access materials, immunosorbents, molecularly imprinted polymers and aptamers, enable greater recovery of analytes and removal of interfering substances, and resulting to more specific and sensitive biomarkers identification and quantification.

In conclusion, the selection of the most suitable sample preparation technique for the determination of specific biomarker, should be based on the evaluation of the following parameters: the chemical properties of the biomarker, the cost and the time required to perform the specific analysis as well as the available laboratory equipment. Furthermore, the performance offered by each technique in terms of sensitivity and specificity is probably the most important factor that will affect the choice of the applied technique for routine laboratory analyses.

PAPACHARISIS Vasilios

"Difference on glucose profile from Continuous Glucose Monitoring in people with prediabetes vs. normoglycemic individuals: a matched-pair analysis"

Abstract

Background and aims: The glycemic profile of prediabetes, a borderline condition with blood glucose levels higher than normal but not enough to be officially diagnosed as diabetes, derived by continuous glucose monitoring (CGM) is currently unknown. We evaluate the difference of CGM profiles between individuals with prediabetes and matched normoglycemic individuals, including the response to oral glucose tolerance test (OGTT).

Materials and methods: Participants with prediabetes matched for age, sex and body mass index (BMI) with normoglycemic individuals were selected from an ongoing cohort study in Greece. Participants were ≥18 years, without known history of diabetes, no history of severe cardiovascular, liver, kidney, or pancreas diseases. Individuals with FPG levels between 100-124 mg/dL or HbA1c 5.7-6.4% were classified as prediabetes group, whereas participants with FPG <100 mg/dL and HbA1c <5.7% were categorized as normoglycemic. They were instructed to use professional CGM (Envision™ Pro, Medtronic; access to data retrospectively) for two weeks. In the morning of the 2 nd day, a 75g OGTT was performed during fasting state. The primary outcomes were percentages of glucose readings below range (TBR; <54 or <70 mg/dL), in range (TIR; 70-180 mg/dL) and above range (TAR; >180 or >250 mg/dL). Total and incremental areas under the glucose curve (AUC) were calculated between the beginning of the OGTT until two to four hours later. Glucose variability was depicted by the coefficient of variation (CV), standard deviation (SD) and mean amplitude of glucose excursions (MAGE). Wilcoxon sign-ranked test and McNemar mid p-test were employed to detect any differences between matched pairs. Multiple linear regression models were employed to investigate the differences on all outcomes between pre-diabetic and normal participants.

Results: A total of 36 participants (median age 51 years; median BMI 26.4 kg/m 2 ) formed 18 matched pairs. Statistically significant differences were observed for 24-hour TIR (median 98.5% vs. 99.9%, p = 0.013), TAR>180 mg/dl (0.4% vs. 0%, p = 0.0062), and 24-hour mean interstitial glucose (113.8 vs. 108.8 mg/dL, p = 0.0038) between individuals with prediabetes compared to normoglycemic participants. Similarly, there was a statistically significant difference both in daytime and nocturnal percentages of TIR between people with prediabetes and normoglycemic participants (p=0.0273, p=0.0087, respectively). Statistically significant differences favoring the normoglycemic group were found for glycemic variability indexes (median CV 15.2% vs. 11.9%, p = 0.0156; median MAGE 44.3 vs. 33.3 mg/dL, p = 0.0043). Only 10 participants (6 in the prediabetes and 4 in the normoglycemic group) had glucose readings below 70 mg/dL and even fewer had below 54 mg/dL (3 overall; 2 individuals with prediabetes, 1 normoglycemic). In contrast, over 60% of participants with prediabetes had glucose readings greater than 180 mg/dL. Following OGTT, the AUC was significantly lower in normoglycemic compared to the prediabetes group (median 18615.3 vs. 16370.0, p = 0.0347 for total and 4666.5 vs. 2792.7, p = 0.0429 for incremental 2-hour post OGTT).

Conclusion: Our study highlights the different glucose profiles of people with prediabetes compared to normoglycemic individuals. CGM might be helpful in individuals with borderline glucose values for a more accurate classification.

FILIS Panagiotis