Studying the Changes in Physical Functioning and Oxidative Stress-Related Molecules in People Living with HIV after Switching from Triple to Dual Therapy.

BACKGROUND: Physical activity could increase the production of oxidative stress biomarkers, affecting the metabolism and excretion of antiretroviral drugs and, consequently, the clinical outcome. Nowadays, people living with HIV (PLWH) are mostly switching from triple to dual therapy, but no data are available in terms of physical functioning and oxidative stress. The aim of this study was to evaluate if some antioxidant biomarkers and physical functioning tests could be different according to triple or dual antiretroviral therapy. METHODS: PLWH were evaluated at baseline (BL), while treated with three drugs, and six months after the switch to dual therapy. Physical functioning was quantified using validated tools. Mitochondrial and cytosol antioxidant molecules were evaluated through liquid chromatography. RESULTS: Twenty-five patients were analyzed. A statistically significant difference between triple and dual therapy was found for mitochondrial glutathione, but not for physical tests. Evaluating differences between physically active and inactive individuals, the following statistically significant differences were suggested, considering triple therapy (mitochondrial n-formyl-methionine p = 0.022, triglycerides p = 0.023) and double therapy (mitochondrial glycine p = 0.035, cytosol glutamic acid p = 0.007, cytosol s-adenosylmethionine p = 0.021). CONCLUSIONS: For the first time, this study suggests possible differences in terms of antioxidant molecules and physical functioning in PLWH switching from triple to dual therapy.

Cannabinoid levels description in a cohort of patients with chronic and neuropathic pain treated with Cannabis decoction: A possible role of TDM.

The phytocomplex of Cannabis is made up of approximately 500 substances: terpeno-phenols metabolites, including Δ-9-tetrahydrocannabinol and cannabidiol, exhibit pharmacological activity. Medical Cannabis has several pharmacological potential applications, in particular in the management of chronic and neuropathic pain. In the literature, a few data are available concerning cannabis pharmacokinetics, efficacy and safety. Thus, aim of the present study was the evaluation of cannabinoid pharmacokinetics in a cohort of patients, with chronic and neuropathic pain, treated with inhaled medical cannabis and decoction, as a galenic preparation. In this study, 67 patients were enrolled. Dried flower tops with different THC and CBD concentrations were used: Bedrocan® medical cannabis with THC level standardized at 19% and with a CBD level below 1%, Bediol® medical cannabis with THC and CBD level standardized at similar concentration of 6.5% and 8%, respectively. Cannabis was administered as a decoction in 47 patients and inhaled in 11 patients. The blood withdrawn was obtained before the new dose administration at the steady state and metabolites plasma concentrations were measured with an UHPLC-MS/MS method. Statistically significant differences were found in cannabinoids plasma exposure between inhaled and oral administration of medical cannabis, between male and female and cigarette smokers. For the first time, differences in cannabinoid metabolites exposures between different galenic formulations were suggested in patients. Therapeutic drug monitoring could be useful to allow for dose adjustment, but further studies in larger cohorts of patients are required in order to confirm these data.

Host single nucleotide polymorphisms and biomarkers of neuronal damage and inflammation in people living with HIV.

OBJECTIVES: Blood-brain barrier impairment is frequent in people living with human immunodeficiency virus (PLWHIV), affecting the penetration of target cells and antiretrovirals into the central nervous system, through transporters (e.g. ABCB1), leading to neuroinflammation. This study aimed to identify variants of genes encoding transporters able to predict neuroinflammation biomarker levels. METHODS: Cerebrospinal fluid (CSF) and plasma samples were obtained from PLWHIV. The CSF biomarkers were quantified by commercial assays. Genetic variants were evaluated through real-time polymerase chain reaction (PCR). RESULTS: A total of 107 PLWHIV (163 samples) were included in the study: 79% were male, median age was 48.5 years, CD4% was 25%, and HIV-associated neurocognitive disorder (HAND) was observed in 17.8%. The ABCB1 2677G>T genetic variant showed a different allelic distribution according to the clinical group (P = 0.026). In linear regression analyses, HIV-related central nervous system disorders, ABCG2 1194+928CC genotype, log viral load, CSF-to-serum albumin ratio, ß-1,42 levels, and CSF proteins were retained in the final model as factors independently associated with CSF neopterin levels; CSF proteins and integrase inhibitor use were associated with CSF tau level in the multivariate model. Phospho-tau regression analysis reported the ABCB1 2677GT/TT genotype and CSF proteins as predictors in the final model; sex, protease inhibitors, neopterin, and ABCB1 2677 GT/ TT genotype were predictors in the multivariate regression for ß-1,42. CONCLUSIONS: For the first time, pharmacogenetic and clinical features were found to be predictors of neuro-inflammation biomarkers.

The Strange Case of Orotic Acid: The Different Expression of Pyrimidines Biosynthesis in Healthy Males and Females.

Orotic acid (OA) is an intermediate metabolite of pyrimidine nucleotide biosynthesis and represents a minor diet constituent. The measurement of urinary orotic acid is useful in confirming the diagnosis of hereditary metabolic diseases. Moreover, it could be of interest to know how the physiological concentration of this metabolite changes in relation to different conditions of clinical normality. The purpose of this study was to determine the orotic acid concentration in the urine of healthy patients, to observe normal oroticuria and to evaluate if the expression of pyrimidine intermediate biosynthesis differs between healthy males and females. The orotic acid concentration in urine was performed via the ICH M10-validated analytical method. Unexpectedly, females showed a greater oroticuria than males in pediatric age (0-10); conversely, we did not find significant differences until 70 years of age. The LC-MS/MS method was suitable for use in the differential diagnosis of hereditary metabolic disease and metabolic monitoring of anticancer drug-induced toxicity. The analytical protocol was found to be rapid and ideal, and was used in the routine analysis of a clinical chemistry laboratory. The biochemical aspects related to the expression of pyrimidine biosynthesis should be further investigated in light of the obtained results.

Stability Study of Fosfomycin in Elastomeric Pumps at 4 °C and 34 °C: Technical Bases for a Continuous Infusion Use for Outpatient Parenteral Antibiotic Therapy.

BACKGROUND: Fosfomycin acts against aerobic Gram-/+ bacteria by blocking the synthesis of peptidoglycan. Its use has been currently re-evaluated for intravenous administration for the treatment of systemic infections by multidrug-resistant bacteria. Concentration-/time-dependent activity has been suggested, with potential clinical advantages from prolonged or continuous infusion. Nevertheless, little is known about Fosfomycin stability in elastomeric pumps. The aim of the present work was stability investigation before administration at 4 °C and during administration at 34 °C. METHODS: InfectoFos® (InfectoPharm s.r.l., Milan, Italy) preparation for intravenous use in elastomeric pumps at 4 °C and 34 °C was analyzed following EMA guidelines for drug stability. Samples were analyzed with an ultra-high performance liquid chromatography coupled with tandem mass spectrometry method on a LX50® UHPLC system equipped with a QSight 220® (Perkin Elmer, Milan, Italy) tandem mass spectrometer. RESULTS: Fosfomycin in elastomeric preparation is stable for at least 5 days at a storage temperature of 4 °C and 34 °C. CONCLUSIONS: The results suggest Fosfomycin eligibility for continuous infusion even in the context of outpatient parenteral antibiotic therapy. Therefore, this approach should be tested in clinical and pharmacokinetic studies, in order to evaluate the possible gains in the pharmacokinetic profile and the clinical effectiveness.

Vitamin D impact in affecting clozapine plasma exposure: A potential contribution of seasonality.

Schizophrenia affects approximately 24 million people worldwide and clozapine is the most effective antipsychotic drug. Nevertheless, its use in therapy is limited due to adverse effects.Therapeutic drug monitoring is a clinical tool useful to reduce the clozapine toxicity. In the literature, papers showed how psychiatric disorders could be associated with low vitamin D levels, but a few studies focusing on its role in affecting clozapine exposure are available. A TDM repository was analyzed: clozapine and vitamin D levels measured with liquid chromatography were considered. 1261 samples obtained from 228 individuals were evaluated: 624 patients (49.5%) showed clozapine plasma levels in therapeutic range (350-600 ng/mL). Clozapine toxic plasma levels (>1000 ng/mL) were more present in winter (p = 0.025), compared to other seasons. Concerning vitamin D, a sub-analysis of 859 samples was performed: 326 (37.81%) were deficient ( ng/mL), 490 (57.12%) had insufficient concentrations (10-30 ng/mL), while 43 (5.02%) had sufficient (>30 ng/mL) levels. A correlation between vitamin D and clozapine plasma levels (p = 0.007, Pearson coefficient=0.093) was observed. The role of seasonal variation in clozapine plasma exposure in psychiatric patients treated with clozapine was suggested. Further studies in larger cohorts are needed in order to clarify these aspects.

A Novel UHPLC-MS/MS Method for the Quantification of Seven Opioids in Different Human Tissues.

BACKGROUND: Opioids are considered the cornerstone of pain management: they show good efficacy as a first-line therapy for moderate to severe cancer pain. Since pharmacokinetic/pharmacodynamic information about the tissue-specific effect and toxicity of opioids is still scarce, their quantification in post-mortem autoptic specimens could give interesting insights. METHODS: We describe an ultra-high-performance liquid chromatography coupled with tandem mass spectrometry method for the simultaneous quantification of methadone, morphine, oxycodone, hydrocodone, oxymorphone, hydromorphone and fentanyl in several tissues: liver, brain, kidney, abdominal adipose tissue, lung and blood plasma. The presented method has been applied on 28 autoptic samples from different organs obtained from four deceased PLWH who used opioids for palliative care during terminal disease. RESULTS: Sample preparation was based on tissue weighing, disruption, sonication with drug extraction medium and a protein precipitation protocol. The extracts were then dried, reconstituted and injected onto the LX50 QSight 220 (Perkin Elmer, Milan, Italy) system. Separation was obtained by a 7 min gradient run at 40 °C with a Kinetex Biphenyl 2.6 µm, 2.1 × 100 mm. Concerning the analyzed samples, higher opioids concentrations were observed in tissues than in plasma. Particularly, O-MOR and O-COD showed higher concentrations in kidney and liver than other tissues (>15-20 times greater) and blood plasma (>100 times greater). CONCLUSIONS: Results in terms of linearity, accuracy, precision, recovery and matrix effect fitted the recommendations of FDA and EMA guidelines, and the sensitivity was high enough to allow successful application on human autoptic specimens from an ethically approved clinical study, confirming its eligibility for post-mortem pharmacological/toxicological studies.

COVID-19: A Possible Contribution of the MAPK Pathway.

BACKGROUND: COVID-19 is characterized by an uncontrolled inflammatory response with high pro-inflammatory cytokine production through the activation of intracellular pathways, such as mitogen-activated protein kinase (MAPK). Viruses are able to exploit the MAPK pathway to their advantage; this pathway relevance to severe COVID-19 is poorly described. The aim of this study was to quantify biomarkers involved in the MAPK pathway and to clarify its possible role in affecting some COVID-19-related clinical features. METHODS: H-RAS, C-RAF, MAPK1, MAPK2, and ERK were quantified through ELISA, and genetic polymorphisms were evaluated through real-time PCR. RESULTS: We prospectively recruited 201 individuals (158 positive and 43 negative for SARS-CoV-2): 35 were male, and their median age was 65 years. MAPK-related biomarker levels were increased in SARS-CoV-2-positive participants (n = 89) compared to negative ones (n = 29). Dyspnea was reported by 48%; this symptom was associated with PBMC C-RAF levels in positive participants (p = 0.022) and type of ventilation (p = 0.031). The highest degree of ventilation was used by 8% for invasive ventilation and 41% for continuous positive airway pressure (CPAP). CONCLUSIONS: This is the first study that showed a possible contribution of MAPK-related biomarkers in affecting COVID-19 clinical features, and this may be relevant for identifying COVID-19 positive participants at risk of serious complications.

COVID-19: Focusing on the Link between Inflammation, Vitamin D, MAPK Pathway and Oxidative Stress Genetics.

An uncontrolled inflammatory response during SARS-CoV-2 infection has been highlighted in several studies. This seems to be due to pro-inflammatory cytokines whose production could be regulated by vitamin D, ROS production or mitogen-activated protein kinase (MAPK). Several genetic studies are present in the literature concerning genetic influences on COVID-19 characteristics, but there are few data on oxidative stress, vitamin D, MAPK and inflammation-related factors, considering gender and age. Therefore, the aim of this study was to evaluate the role of single nucleotide polymorphisms in these pathways, clarifying their impact in affecting COVID-19-related clinical features. Genetic polymorphisms were evaluated through real-time PCR. We prospectively enrolled 160 individuals: 139 patients were positive for SARS-CoV-2 detection. We detected different genetic variants able to affect the symptoms and oxygenation. Furthermore, two sub-analyses were performed considering gender and age, showing a different impact of polymorphisms according to these characteristics. This is the first study highlighting a possible contribution of genetic variants of these pathways in affecting COVID-19 clinical features. This may be relevant in order to clarify the COVID-19 etiopathogenesis and to understand the possible genetic contribution for further SARS infections.

Analytical validation of a novel UHPLC-MS/MS method for 19 antibiotics quantification in plasma: Implementation in a LC-MS/MS Kit.

BACKGROUND: Therapeutic drug monitoring (TDM) for antibiotic drugs represents a consolidated practice to optimize the effectiveness and to limit the toxicity of specific drugs by guiding dosage adjustments. The comparison of TDM results with drug-specific pharmacokinetic/pharmacodynamic (PK/PD) parameters, based on killing dynamics and bacterial susceptibility, increases the probability of therapeutic success. PURPOSE: The aim of this study was the analytical validation of a new UHPLC-MS/MS assay for the quantification of 19 antibiotics divided in two different sets considering their chemical/pharmacological properties. This method has been implemented in an analytical LC-MS/MS Kit System by CoQua Lab s.r.l (Turin). METHODS: The analytical validation is developed in accordance with "ICH Harmonized Guideline M10 on bioanalytical method validation and study sample analysis" and "Guidelines for regulatory auditing of quality management system of medical device manufacturers". Method suitability in the clinical context was tested by analysing clinical samples from patients treated with antibiotic drugs. RESULTS: This method allows for simultaneous TDM of the following molecules: dalbavancin, daptomycin, linezolid, tedizolid, levofloxacin, moxifloxacin, meropenem, ertapenem, vaborbactam, avibactam, sulbactam, tazobactam, ceftazidime, ceftriaxone, ceftolozane, ceftobiprole, cefiderocol, ceftaroline and piperacillin. These drugs were quantified showing analytical performance parameters compliant with guidelines in terms of repeatability, reproducibility, robustness, bias, LOD, LOQ and linearity. The method was capable to successfully monitor drug concentrations in 65 samples from 52 patients undergoing treatment. CONCLUSION: The UHPLC-MS/MS method described in this work can be useful for TDM of the reported antimicrobial agents. The analytical protocol is rapid and suitable to be used in routine analysis.

Antiretroviral Levels in the Cerebrospinal Fluid: The Effect of Inflammation and Genetic Variants.

Neurocognitive impairments are common in people living with HIV. Some conditions, such as chronic inflammation, astrocyte infection and an impaired blood-brain barrier (BBBi), along with host genetic variants in transporter genes, may affect antiretroviral (ARV) exposure in the cerebrospinal fluid (CSF). The aim of this study was to evaluate ARV CSF penetration according to compartmental inflammation, BBB permeability and single-nucleotide polymorphisms (SNPs) in drug transporter encoding genes. CSF neopterin (ELISA), plasma and CSF ARV concentrations (HPLC) and host genetic variants in ABCC2, HNF4α, SLCO1A2 and SLC22A6 (real-time PCR) were measured. Bi- and multivariate analyses were performed for single ARV and classes. We included 259 participants providing 405 paired plasma and CSF samples. CSF/plasma ratios (CPR) showed an increase for NRTIs and nevirapine with low penetrations for the majority of ARVs. At bi-variate analysis, several associations, including the effect of BBBi (emtricitabine, raltegravir), age (zidovudine and darunavir), and high CSF neopterin (NRTIs and border-line for PIs) were suggested. An association was found between genetic variants and integrase strand transfer (ABCC2 and HNF4α), non-nucleoside reverse transcriptase inhibitors (SLCO1A2), and protease inhibitors (SLC22A6). At multivariate analysis age, gender, BMI, and altered BBB were independent predictors of nucleoside reverse transcriptase CSF concentrations; age (for protease inhibitors) and body mass index and altered BBB (integrase strand transfer inhibitors) were also associated with ARV CSF exposure. We describe factors associated with CSF concentrations, showing that demographic, BBB integrity and, partially, genetic factors may be predictors of drug passage in the central nervous system.

Pharmacokinetic of Cefiderocol in Critically Ill Patients Receiving Renal Replacement Therapy: A Case Series.

Background: Cefiderocol is a novel parenteral siderophore cephalosporin, demonstrating enhanced activity against multidrug-resistant (MDR) Gram-negative bacteria and difficult-to-treat Acinetobacter baumannii (DTR-AB). Plasma-free trough concentration (fCtrough) over the minimum inhibitory concentration (MIC) was reported as the best pharmacokinetic parameter to describe the microbiological efficacy of cefiderocol. Materials and methods: We retrospectively described the pharmacokinetic and pharmacodynamic profile of three critically ill patients admitted to the intensive care unit, receiving cefiderocol under compassionate use to treat severe DTR-AB infections while undergoing continuous venovenous haemofiltration. Cefiderocol was administrated at a dosage of 2 g every 8 h infused over 3 h. Therapeutic drug monitoring (TDM) was assessed at the steady state. Cthrough was evaluated by assuming a plasma protein binding of 58.0%. The fCmin/MIC was calculated assuming a cefiderocol MIC equal to the PK-PD breakpoint of susceptibility ≤ 2. The association between the PK/PD parameters and microbiological outcome was assessed. Results: fCtrough/MIC were >12 in 2 patients and 2.9 in the 1 who rapidly recovered from renal failure. Microbiological cure occurred in 3/3 of patients. None of the 3 patients died within 30 days. Conclusions: A cefiderocol dosage of 2 g q8 h in critically ill patients with AKI undergoing CVVH may bring about a very high plasma concentration, corresponding to essentially 100% free time over the MIC for DTR-AB.

A new UHPLC-MS/MS method for cannabinoids determination in human plasma: A clinical tool for therapeutic drug monitoring.

Cannabinoid derivates have been largely used for different medical purpose. In the literature, several methods capable of separating THC and its principles metabolites are described, although Δ8- and Δ9-THC separation has not been completely achieved. THC metabolism has not been fully understood and metabolites plasma distribution in healthy and pathological patients remains to further deepen. The aim of this study was the validation of UHPLC-MS/MS method for the quantification of 10 cannabinoids in human plasma, as important tool for improving clinical efficacy of cannabis administration. Obtained results were in accordance with recommendations of ICH Harmonised Guideline for bioanalytical method validation, showing a good linearity, optimal accuracy as well as satisfactory results in terms of intra-day and inter-day precision and matrix effect. Furthermore, blood sampling study was performed to investigate the better collection method. Optimal separation of Δ-9-tetrahydrocannabinol (Δ9-THC), Δ8-tetrahydrocannabinol (Δ8-THC) was obtained. The present method showed optimal linearity and satisfactory results in terms of specificity and selectivity. Recovery was between 92.0% and 96.5% for all analytes. The matrix-effect showed good performance; no carry over was observed. Cannabinoid metabolites present in higher plasma concentrations were: 11-Hydroxy-Δ9-tetrahydrocannabinol, 11-Nor-9carboxy-Δ9-tetrahydrocannabinol and THC-COOH-glucuronide. Method performance makes it suitable for routine purposes and a potential tool for therapeutic ranges definition. The present work will be used to test several samples in a long-term clinical study, paving the way for further future works.

Clinical Effectiveness and Pharmacokinetics of Dalbavancin in Treatment-Experienced Patients with Skin, Osteoarticular, or Vascular Infections.

Dalbavancin (DBV) is a lipoglycopeptide approved for the treatment of Gram-positive infections of the skin and skin-associated structures (ABSSSIs). Currently, its off-label use at different dosages for other infections deserves attention. This work aimed to study the clinical effectiveness and tolerability of DBV in outpatients with ABSSSIs, osteoarticular (OA), or other infections, treated with either one or two 1500 mg doses of dalbavancin, for different scheduled periods. A liquid chromatography-tandem mass spectrometry method was used to measure total DBV concentrations. PK/PD parameters and the clinical and microbiological features of this cohort were evaluated in order to investigate the best predictors of treatment success in real-life settings. Of the 76 screened patients, 41 completed the PK study. Long-term PK was comparable to previous studies and showed significant differences between genders and dosing schedules. Few adverse events were observed, and treatment success was achieved in the vast majority of patients. Failure was associated with lower PK parameters, particularly Cmax. Concluding, we were able to describe DBV PK and predictors of treatment success in selected infections in this cohort, finding DBV Cmax as a possible candidate for therapeutic drug-monitoring purposes, as well as highlighting the dual-dose one-week-apart treatment as the optimal choice for OA infections.

A description of Cannabinoid levels in Cannabis oil by high-performance liquid chromatography-mass spectrometry in a reference laboratory of North-Italy.

BACKGROUND: Cannabis oils from FM2®, Bedica®, Bediol®, Bedrocan®, Bedrolite® and Pedanios 22/1® are largely used for medical purposes such as spasticity, chronic pain and appetite stimulating. Several studies showed cannabinoids action on CB1 and CB2 receptors reduces the hyperalgesic phase in inflammatory pain, leading to an improvement of conditions. The active compounds of these galenic preparations show a high variability making titration mandatory. For this reason, the exact oil composition knowledge is fundamental for personalizing therapy. This amis at adapting the correct dose to the patient, improving safety and efficacy of the galenic formulation, choosing the best preparation for each patient. PURPOSE: The aim of this study was to investigate oil preparations variability among different galenic laboratories in order to highlight the importance of titration activity. METHODS: Cannabis pharmacological active compounds titration has been performed in a large cohort of galenic laboratories in Italy. CBD, CBN, THC, THCA and CBDA quantification was carried out by a previous validated method in UHPLC-MS/MS. RESULTS: A number of 4318 samples of Cannabis oil from 83 pharmacies between January 2021 and February 2022 were evaluated. All galenic preparation specialities showed statistically significant differences among galenic laboratories (p-value < 0.001). THCA and CBDA concentrations were investigated as percentage of the extration yelds for total THC and CBD: these compounds had different values in the same specialities among distinct galenic laboratories. Moreover, seasonal variability in analytes concentrations was observed. CONCLUSION: This study described a wide range of oily samples from a large number of galenic laboratories, compared to published papers. In conclusion, knowledge of the exact oil composition is fundamental in the perspective of personalized therapy. Further studies aiming at the correlation between galenic composition and cannabinoids pharmacokinetics, clinical outcomes and toxic effects could be useful to improve our knowledge.

Antifungal Drug Plasma Exposures: A Possible Contribution of Vitamin D-Related Gene Variants.

Vitamin D (VD) seems to influence drug clearance and outcome. Antifungal drugs (AFU) are the most used azoles in clinical practice. In the literature, no data are available concerning VD's impact on AFU therapy. The aim of this study was to analyze if VD pathway-related polymorphisms may influence voriconazole (VRC), itraconazole (ITC), and posaconazole (PSC) drug concentrations in order to identify patients with the highest probability of response and toxicity. Allelic discrimination was performed through real-time PCR, whereas drug concentrations were through liquid chromatography. A total of 636 samples of AFU-treated patients were included in the analysis. Concerning VRC, concentrations higher than the 1000 ng/mL efficacy cut-off value were predicted by Caucasian ethnicity, CYP24A1 3999, and CYP27B1 + 2838 polymorphisms, whereas levels higher than the 5000 ng/mL toxicity value by Caucasian, female sex, e.v. administration, and GC 1296. Considering PSC, concentrations higher than the 700 ng/mL efficacy cut-off value were predicted by VDR Cdx2, CYP27B1 - 1260, and GC 1296. Finally, for ITC, VDR BsmI was the only predictor of drug exposure higher than the 500 ng/mL efficacy cut-off value, whereas female sex, CYP27B1 - 1260, and VDR TaqI remained in the final regression model related to concentrations higher than the 1000 ng/mL toxicity-associated cut-off value. This is the first study reporting the influence of VD pathway-related gene SNPs on AFU exposures, efficacy, and toxicity.

Factors Influencing the Intracellular Concentrations of the Sofosbuvir Metabolite GS-331007 (in PBMCs) at 30 Days of Therapy.

Sofosbuvir (SOF) is an HCV NS5B polymerase inhibitor, and GS-331007 is its major metabolite. The aim of this study was to investigate whether clinical and pharmacological factors could influence GS-331007 intracellular (IC) concentrations in peripheral blood mononuclear cells (PBMCs) associated with a sustained virological response in patients treated with SOF and ribavirin (RBV). Drug levels were analyzed using liquid chromatography at different days of therapy, whereas variants in genes encoding transporters and nuclear factors were investigated using real-time PCR. This study enrolled 245 patients treated with SOF; 245 samples were analyzed for pharmacogenetics and 50 were analyzed for IC pharmacokinetics. The GS-331007 IC concentration at 30 days was associated with its plasma concentration determinate at 30, 60 and 90 days of SOF-therapy and with daclatasvir concentrations at 7 days of therapy. No genetic polymorphism affected IC exposure. In linear multivariate analysis, ledipasvir treatment, baseline albumin and estimated glomerular filtration rate were significant predictors of IC exposure. This study presents data on an IC evaluation in a cohort of patients treated with SOF, also considering pharmacogenetics. These results could be useful for regions where SOF-RBV treatment is considered the standard of care; moreover, they could further deepen the knowledge of IC exposure for similar drugs in the future.

Vitamin D-Related Genetics as Predictive Biomarker of Clinical Remission in Adalimumab-Treated Patients Affected by Crohn's Disease: A Pilot Study.

Adalimumab (ADA) is a human anti-tumor necrosis factor (TNF-α) monoclonal antibody used in inflammatory bowel diseases, such as Crohn's disease (CD). Vitamin-D (VD) is important for biological functions, such as the modulation of expression of genes encoding enzymes and transporters involved in drug metabolism and transport. ADA trough levels were associated with VD concentrations in patients with IBD, but no data are present in the literature concerning VD pathway-related gene single-nucleotide polymorphisms (SNPs) in affecting clinical outcomes. For this reason, the aim of this study was to evaluate the ability of VD-related genetics to predict clinical remission at 3 and 12 months in patients affected by CD treated with ADA. Patients affected by CD were included in this study. SNPs in CYP27B1, CYP24A1, GC, and VDR genes were analyzed through real-time PCR. A total of 63 patients were enrolled. Calprotectin, hemoglobin, and C-reactive protein levels were influenced by SNPs in VDR, CYP27B1, and GC genes. After 3 months of therapy, clinical remission was predicted by smoke, systemic steroids, and VDR BsmI, whereas at 12 months by GC 1296AA/AC and VD supplementation. This study reports the association between VD pathway-related genetics and ADA treatment. Further studies are needed to confirm these promising data.

Monitoring Tacrolimus Concentrations in Whole Blood and Peripheral Blood Mononuclear Cells: Inter- and Intra-Patient Variability in a Cohort of Pediatric Patients.

Tacrolimus (TAC) is a first-choice immunosuppressant for solid organ transplantation, characterized by high potential for drug-drug interactions, significant inter- and intra-patient variability, and narrow therapeutic index. Therapeutic drug monitoring (TDM) of TAC concentrations in whole blood (WB) is capable of reducing the incidence of adverse events. Since TAC acts within lymphocytes, its monitoring in peripheral blood mononuclear cells (PBMC) may represent a valid future alternative for TDM. Nevertheless, TAC intracellular concentrations and their variability are poorly described, particularly in the pediatric context. Therefore, our aim was describing TAC concentrations in WB and PBMC and their variability in a cohort of pediatric patients undergoing constant immunosuppressive maintenance therapy, after liver transplantation. TAC intra-PBMCs quantification was performed through a validated UHPLC-MS/MS assay over a period of 2-3 months. There were 27 patients included in this study. No significant TAC changes in intracellular concentrations were observed (p = 0.710), with a median percent change of -0.1% (IQR -22.4%-+46.9%) between timings: this intra-individual variability was similar to the one in WB, -2.9% (IQR -29.4-+42.1; p = 0.902). Among different patients, TAC weight-adjusted dose and age appeared to be significant predictors of TAC concentrations in WB and PBMC. Intra-individual seasonal variation of TAC concentrations in WB, but not in PBMC, have been observed. These data show that the intra-individual variability in TAC intracellular exposure is comparable to the one observed in WB. This opens the way for further studies aiming at the identification of therapeutic ranges for TAC intra-PBMC concentrations.