Infrared Matrix-Assisted Laser Desorption Electrospray Ionization Mass Spectrometry Imaging of Human Hair to Characterize Longitudinal Profiles of the Antiretroviral Maraviroc for Adherence Monitoring

Sample Matrices for Mass Spectrometry-Based Adherence Monitoring: A Systematic Critical Review

BACKGROUND

Analytical monitoring of adherence using mass spectrometry (MS) plays an important role in clinical toxicology. Unambiguous detection of drugs (of abuse) and/or their metabolites in body fluids is needed to monitor intake of medication as prescribed or to monitor abstinence as a follow-up to detoxification procedures. This study focused on the advantages and disadvantages of different sample matrices used for MS-based adherence monitoring.

METHODS

Relevant articles were identified through a literature search in the PubMed database. English articles published between January 01, 2017, and December 31, 2022, were selected using the keywords "adherence assess*" or "adherence monit*" or "compliance assess*" or "compliance monit*" in combination with "mass spectrom*" in the title or abstract.

RESULTS

A total of 51 articles were identified, 37 of which were within the scope of this study. MS-based monitoring was shown to improve patient adherence to prescribed drugs. However, MS analysis may not be able to assess whether treatment was rigorously followed beyond the last few days before the sampling event, except when hair is the sample matrix. For medication adherence monitoring, blood-based analyses may be preferred because reference plasma concentrations are usually available, whereas for abstinence control, urine and hair samples have the advantage of extended detection windows compared with blood. Alternative sample matrices, such as dried blood samples, oral fluid, and exhaled breath, are suitable for at-home sampling; however, little information is available regarding the pharmacokinetics and reference ranges of drug (of abuse) concentrations.

CONCLUSIONS

Each sample matrix has strengths and weaknesses, and no single sample matrix can be considered the gold standard for monitoring adherence. It is important to have sufficient information regarding the pharmacokinetics of target substances to select a sample matrix in accordance with the desired purpose.

Feasibility, Acceptability and Appropriateness of MedViewer: A Novel Hair-Based Antiretroviral Real-Time Clinical Monitoring Tool Providing Adherence Feedback to Patients and Their Providers

Antiretroviral therapy (ART) adherence is key to achieving viral load suppression and ending the HIV epidemic but monitoring and supporting adherence using current interventions is challenging. We assessed the feasibility, acceptability and appropriateness of MedViewer (MV), a novel intervention that provides real-time adherence feedback for patients and providers using infra-red matrix-assisted laser desorption electrospray ionization (IR-MALDESI) for mass spectrometry imaging of daily ART concentrations in patients' hair. We used mixed methods to feasibility test MV at a busy Infectious Diseases (ID) clinic, enrolling 16 providers and 36 patients. Providers underwent standardized training; patients and providers watched an 8-min informational video about MV. We collected patient and provider data at baseline and within 24 h of clinic visits and, with patients, approximately 1 month after clinic visits. MedViewer was feasible, liked by patients and providers, and perceived to help facilitate adherence conversations and motivate patients to improve adherence. Trial Registration: NCT04232540.

Mass spectrometry imaging of hair identifies daily maraviroc adherence in HPTN 069/ACTG A5305

Objective measures of adherence for antiretrovirals used as pre-exposure prophylaxis (PrEP) are critical for improving preventative efficacy in both clinical trials and real-world application. Current objective adherence measures either reflect only recent behavior (eg days for plasma or urine) or cumulative behavior (eg months for dried blood spots). Here, we measured the accumulation of the antiretroviral drug maraviroc (MVC) in hair strands by infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) mass spectrometry imaging (MSI) to evaluate adherence behavior longitudinally at high temporal resolution. An MSI threshold for classifying daily adherence was established using clinical samples from healthy volunteers following directly observed dosing of 1 to 7 doses MVC/week. We then used the benchmarked MSI assay to classify adherence to MVC-based PrEP regimens in hair samples collected throughout the 48-week HPTN069/ACTGA5305 study. We found that only ~32% of investigated hair samples collected during the study's active dosing period showed consistent daily PrEP adherence throughout a retrospective period of 30 days, and also found that profiles of daily individual adherence from MSI hair analysis could identify when patients were and were not taking study drug. The assessment of adherence from MSI hair strand analysis was 62% lower than adherence classified using paired plasma samples, the latter of which may be influenced by white-coat adherence. These findings demonstrate the ability of MSI hair analysis to examine daily variability of adherence behavior over a longer-term measurement and offer the potential for longitudinal comparison with risk behavior to target patient-specific adherence interventions and improve outcomes.

The development and application of matrix assisted laser desorption electrospray ionization: The teenage years

In the past 15 years, ambient ionization techniques have witnessed a significant incursion into the field of mass spectrometry imaging, demonstrating their ability to provide complementary information to matrix-assisted laser desorption ionization. Matrix-assisted laser desorption electrospray ionization is one such technique that has evolved since its first demonstrations with ultraviolet lasers coupled to Fourier transform-ion cyclotron resonance mass spectrometers to extensive use with infrared lasers coupled to orbitrap-based mass spectrometers. Concurrently, there have been transformative developments of this imaging platform due to the high level of control the principal group has retained over the laser technology, data acquisition software (RastirX), instrument communication, and image processing software (MSiReader). This review will discuss the developments of MALDESI since its first laboratory demonstration in 2005 to the most recent advances in 2021.

Mass spectrometry imaging: new eyes on natural products for drug research and development

Natural products (NPs) and their structural analogs represent a major source of novel drug development for disease prevention and treatment. The development of new drugs from NPs includes two crucial aspects. One is the discovery of NPs from medicinal plants/microorganisms, and the other is the evaluation of the NPs in vivo at various physiological and pathological states. The heterogeneous spatial distribution of NPs in medicinal plants/microorganisms or in vivo can provide valuable information for drug development. However, few molecular imaging technologies can detect thousands of compounds simultaneously on a label-free basis. Over the last two decades, mass spectrometry imaging (MSI) methods have progressively improved and diversified, thereby allowing for the development of various applications of NPs in plants/microorganisms and in vivo NP research. Because MSI allows for the spatial mapping of the production and distribution of numerous molecules in situ without labeling, it provides a visualization tool for NP research. Therefore, we have focused this mini-review on summarizing the applications of MSI technology in discovering NPs from medicinal plants and evaluating NPs in preclinical studies from the perspective of new drug research and development (R&D). Additionally, we briefly reviewed the factors that should be carefully considered to obtain the desired MSI results. Finally, the future development of MSI in new drug R&D is proposed.

Mass Spectroscopy Imaging of Hair Strands Captures Short-Term and Long-Term Changes in Emtricitabine Adherence

Most measures of adherence to antiretroviral therapy require a blood sample, and none capture longitudinal daily adherence. A new noninvasive method for measuring daily adherence to antiretroviral regimens containing emtricitabine (FTC) was developed for intact hair strands using infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) mass spectrometry imaging (MSI). A directly observed therapy study of daily and intermittent (3, 1, and 0 doses/week) FTC dosing (n = 12) benchmarked adherence in hair, revealing distinct accumulation patterns and median FTC signal abundance (1,702, 495, 352, and 0, respectively) with each dosing frequency. A threshold value of FTC_{signal abundance} of 500 differentiated daily dosing from 3 or fewer doses/week (specificity, 100%; sensitivity, 100% over 30 days and 80% over 60 days). Using these criteria, daily FTC hair adherence was classified in young men (n = 8) who have sex with men (YMSM) engaged in or initiating preexposure prophylaxis (PrEP). Four types of adherence profiles were observed in sequential 30-day periods: consistently high, occasional missed doses, improvement following study initiation, and intermittent. Discrete days of nonadherence were identified across the 60-day window, with the average number of consecutive days classified as nonadherent increasing across the four profile types (1, 2, 19, and 58 days, respectively). Additionally, cumulative FTC response in hair (60-day average) significantly correlated with dried blood spot tenofovir diphosphate concentrations collected simultaneously (r_s = 0.79, P = 0.03). Based on these data, IR-MALDESI FTC adherence classification in hair strands can better delineate short-term changes in adherence behaviors over a long retrospective window, offering great potential for noninvasive adherence monitoring and quick supportive interventions.

Molecular imaging of humain hair with MeV-SIMS: A case study of cocaine detection and distribution in the hair of a cocaine user

Human hair absorbs numerous biomolecules from the body during its growth. This can act as a fingerprint to determine substance intake of an individual, which can be useful in forensic studies. The cocaine concentration profile along the growth axis of hair indicates the time evolution of the metabolic incorporation of cocaine usage. It could be either assessed by chemical extraction and further analysis of hair bundels, or by direct single hair fibre analysis with mass spectroscopy imaging (MSI). Within this work, we analyzed the cocaine distribution in individual hair samples using MeV-SIMS. Unlike conventional surface analysis methods, we demonstrate high yields of nonfragmented molecular ions from the surface of biological materials, resulting in high chemical sensitivity and non-destructive characterisation. Hair samples were prepared by longitudinally cutting along the axis of growth, leaving half-cylindrical shape to access the interior structure of the hair by the probing ion beam, and attached to the silicon wafer. A focused 5.8 MeV 35Cl6+ beam was scanned across the intact, chemically pristine hair structure. A non-fragmented protonated [M+ H]+ cocaine molecular peak at m/z = 304 was detected and localized along the cross-section of the hair. Its intensity exhibits strong fluctuations along the direction of the hair’s growth, with pronounced peaks as narrow as 50 micrometres, corresponding to a metabolic incorporation time of approx. three hours.

Mapping the Chemistry of Hair Strands by Mass Spectrometry Imaging-A Review

Hair can record chemical information reflecting our living conditions, and, therefore, strands of hair have become a potent analytical target within the biological and forensic sciences. While early efforts focused on analyzing complete hair strands in bulk, high spatial resolution mass spectrometry imaging (MSI) has recently come to the forefront of chemical hair-strand analysis. MSI techniques offer a localized analysis, requiring fewer de-contamination procedures per default and making it possible to map the distribution of analytes on and within individual hair strands. Applying the techniques to hair samples has proven particularly useful in investigations quantifying the exposure to, and uptake of, toxins or drugs. Overall, MSI, combined with optimized sample preparation protocols, has improved precision and accuracy for identifying several elemental and molecular species in single strands of hair. Here, we review different sample preparation protocols and use cases with a view to make the methodology more accessible to researchers outside of the field of forensic science. We conclude that—although some challenges remain, including contamination issues and matrix effects—MSI offers unique opportunities for obtaining highly resolved spatial information of several compounds simultaneously across hair surfaces.

LASER DESORPTION/ABLATION POSTIONIZATION MASS SPECTROMETRY: RECENT PROGRESS IN BIOANALYTICAL APPLICATIONS

Lasers have long been used in the field of mass spectrometric analysis for characterization of condensed matter. However, emission of neutrals upon laser irradiation surpasses the number of ions. Typically, only one in about one million analytes ejected by laser desorption/ablation is ionized, which has fueled the quest for postionization methods enabling ionization of desorbed neutrals to enhance mass spectrometric detection schemes. The development of postionization techniques can be an endeavor that integrates multiple disciplines involving photon energy transfer, electrochemistry, gas discharge, etc. The combination of lasers of different parameters and diverse ion sources has made laser desorption/ablation postionization (LD/API) a growing and lively research community, including two-step laser mass spectrometry, laser ablation atmospheric pressure photoionization mass spectrometry, and those coupled to ambient mass spectrometry. These hyphenated techniques have shown potentials in bioanalytical applications, with major inroads to be made in simultaneous location and quantification of pharmaceuticals, toxins, and metabolites in complex biomatrixes. This review is intended to provide a timely comprehensive view of the broadening bioanalytical applications of disparate LD/API techniques. We also have attempted to discuss these applications according to the classifications based on the postionization methods and to encapsulate the latest achievements in the field of LD/API by highlighting some of the very best reports in the 21st century. © 2020 John Wiley & Sons Ltd.

Point-of-care and Near Real-time Testing for Antiretroviral Adherence Monitoring to HIV Treatment and Prevention

PURPOSE OF REVIEW

In this report, we review the need for point-of-care (POC) or near real-time testing for antiretrovirals, progress in the field, evidence for guiding implementation of these tests globally, and future directions in objective antiretroviral therapy (ART) or pre-exposure prophylaxis (PrEP) adherence monitoring.

RECENT FINDINGS

Two cornerstones to end the HIV/AIDS pandemic are ART, which provides individual clinical benefits and eliminates forward transmission, and PrEP, which prevents HIV acquisition with high effectiveness. Maximizing the individual and public health benefits of these powerful biomedical tools requires high and sustained antiretroviral adherence. Routine monitoring of medication adherence in individuals receiving ART and PrEP may be an important component in interpreting outcomes and supporting optimal adherence. Existing practices and subjective metrics for adherence monitoring are often inaccurate or unreliable and, therefore, are generally ineffective for improving adherence. Laboratory measures of antiretroviral concentrations using liquid chromatography tandem mass spectrometry have been utilized in research settings to assess medication adherence, although these are too costly and resource-intensive for routine use. Newer, less costly technologies such as antibody-based methods can provide objective drug-level measurement and may allow for POC or near-patient adherence monitoring in clinical settings. When coupled with timely and targeted counseling, POC drug-level measures can support adherence clinic-based interventions to ART or PrEP in near real time.

Adherence predictor variables in AIDS patients: an empirical study using the data mining-based RFM model

Background

Highly active antiretroviral therapy (ART) is still the only effective method to stop the disease progression in acquired immunodeficiency syndrome (AIDS) patients. However, poor adherence to the therapy makes it ineffective. In this work, we construct an adherence prediction model of AIDS patients using the classical recency, frequency and monetary value (RFM) model in the data mining-based customer relationship management model to obtain adherence predictor variables.

Methods

We cleaned 257,305 diagnostic data elements of AIDS outpatients in Shanghai from August 2009 to December 2019 to obtain 16,440 elements. We tested the RFM and RFm (R: recent consultation month, F: consultation frequency, M/m: total/average medical costs per visit) models, three clustering methods (K-means, Kohonen and two-step clustering) and four decision algorithms (C5.0, the classification and regression tree, Chi-square Automatic Interaction Detector and Quick, Unbiased, Efficient, Statistical Tree) to select the optimal combination. The optimal model and clustering analysis were used to divide the patients into two groups (good and poor adherence), then the optimal decision algorithm was used to construct the prediction model of adherence and obtain its predictor variables.

Results

The results revealed that the RFm model, K-means clustering analysis and C5.0 algorithm were optimal. After three rounds of k-means clustering analysis, the optimal RFm clustering model quality was 0.8, 10,614 elements were obtained, including 9803 and 811 from patients with good or poor adherence, respectively, and five types of patients were identified. The prediction model had an accuracy of 100% with the recent consultation month as an important adherence predictor variable.

Conclusions

This work presented a prediction model for medication adherence in AIDS patients at the designated AIDS center in Shanghai, using the RFm model and the k-means and C5.0 algorithms. The model can be expanded to include patients from other centers in China and worldwide.

Is there any Hope for Monitoring Adherence in an Efficient and Feasible Way for Resistant Hypertension Diagnosis and Follow-Up?

PURPOSE OF REVIEW

Non-adherence to antihypertensive treatment is highly prevalent and represents a major factor affecting their effectiveness in hypertensive patients, thus contributing to apparent treatment resistance. It is however often overlooked because the methods to assess non-adherence are mainly subjective, limiting their usefulness in clinical practice. Non-adherence to treatment affects daily patient management, resulting in inappropriate, costly, and potentially harmful treatments and loss of the expected benefits from antihypertensive drugs.

RECENT FINDINGS

Specialized centers now use a combination of objective screening tools. Firstly, snapshots of adherence levels can be provided by analytical drug detection in various biological matrixes using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and secondly electronic monitoring systems of drug delivery which provide longitudinal data on adherence. Routine utilization of those tools allows the detection of non-adherence in patients with resistant hypertension, thus enabling implementation of appropriate interventions to improve drug adherence and avoid unnecessary treatment intensification. Other complementary techniques, such as digital health feedback system with ingestible sensors, are currently evaluated. In the context of an increasing burden of uncontrolled and apparent treatment-resistant hypertension, detecting non-adherence to antihypertensive therapy is, as acknowledged by the latest guidelines, a top priority to implement in clinical practice but still faces medical conservatism and disbelief.

Influence of hair treatments on detection of antiretrovirals by mass spectrometry imaging

Analysis of drugs in hair by mass spectrometry imaging (MSI) has great potential as an objective, long-term measure of medication adherence. However, the fidelity of the chemical record in hair may be compromised by any cosmetic hair treatments. Here, we investigate infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) MSI response to multiple antiretrovirals (ARVs) in cosmetically treated hair. Hair strands from patients on different ARV regimens were mechanically treated with dye, bleach, and relaxer. The treatments had little or no effect relative to untreated controls for cobicistat, abacavir, dolutegravir, maraviroc, efavirenz, and darunavir, but all three treatments removed emtricitabine (FTC) to undetectable levels from patient hair strands. We also evaluated hair strands by IR-MALDESI MSI from 8 patients on FTC-based regimens who reported a range of hair treatments at varying recency prior to hair collection. While FTC was undetectable in the treated portion of these hair strands, ARVs coadministered with FTC remained detectable in hair strands after treatment. We conclude that IR-MALDESI MSI can be used when measuring adherence to ARV therapy, provided that ARVs other than FTC are targeted in people using hair treatments.

Coupling IR-MALDESI with Drift Tube Ion Mobility-Mass Spectrometry for High-Throughput Screening and Imaging Applications

Because of its high degree of selectivity and chemical resolution, mass spectrometry (MS) is rapidly becoming the analytical method of choice for high-throughput evaluations and clinical diagnostics. While advances in MS resolving power have increased by an order of magnitude over the past decade, advances in sample introduction are still needed for high-throughput screening applications where the time frame of chromatographic separation would limit the duty cycle. Infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) is an ambient ionization source that has been shown to be applicable for direct analyses and mass spectrometry imaging (MSI) of complex biological samples in a high-throughput manner. To increase a range of detectable features in IR-MALDESI experiments, we integrated the home-built ion source with a commercially available drift tube ion mobility spectrometer-mass spectrometer (IMS-MS) and analyzed small polar molecules, lipids, carbohydrates, and intact proteins. We also describe in detail how the pulsed ionization source was synchronized with IMS-MS.