Analysis of Antiretrovirals in Single Hair Strands for Evaluation of Drug Adherence with Infrared-Matrix-Assisted Laser Desorption Electrospray Ionization Mass Spectrometry Imaging

Abstract

Adherence to a drug regimen can be a strong predictor of health outcomes, and validated measures of adherence are necessary at all stages of therapy from drug development to prescription. Many of the existing metrics of drug adherence (e.g., self-report, pill counts, blood monitoring) have limitations, and analysis of hair strands has recently emerged as an objective alternative. Traditional methods of hair analysis based on LC–MS/MS (segmenting strands at ≥1 cm length) are not capable of preserving a temporal record of drug intake at higher resolution than approximately 1 month. Here, we evaluated the detectability of HIV antiretrovirals (ARVs) in hair from a range of drug classes using infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) mass spectrometry imaging (MSI) with 100 µm resolution. Infrared laser desorption of hair strands was shown to penetrate into the strand cortex, allowing direct measurement by MSI without analyte extraction. Using optimized desorption conditions, a linear correlation between IR-MALDESI ion abundance and LC–MS/MS response was observed for six common ARVs with estimated limits of detection less than or equal to 1.6 ng/mg hair. The distribution of efavirenz (EFV) was then monitored in a series of hair strands collected from HIV infected, virologically suppressed patients. Because of the role hair melanin plays in accumulation of basic drugs (like most ARVs), an MSI method to quantify the melanin biomarker pyrrole-2,3,5-tricarboxylic acid (PTCA) was evaluated as a means of normalizing drug response between patients to develop broadly applicable adherence criteria.

Testing the Efficacy of a Social Networking Gamification App to Improve Pre-Exposure Prophylaxis Adherence (P3: Prepared, Protected, emPowered): Protocol for a Randomized Controlled Trial (Preprint)

“…Furthermore, the results represent only a short-term measure of drug taking behavior. Given the rapid processing time of the hair sampling procedures proposed (MALDESI [40] requires minimal sample processing, and the sample can be analyzed within 1 hour), this technique could be used to provide real-time adherence monitoring in future studies.…”

“…Youth confirmed as eligible will complete the informed consent/assent process, provide baseline dried blood spots (DBS) to test for TFV-DP/ emtricitabine-triphosphate (FTC-TP) levels, provide hair samples to test for tenofovir (TFV) and emtricitabine (FTC) levels, [40] and complete a CASI survey.…”

Infrared matrix-assisted laser desorption electrospray ionization mass spectrometry imaging analysis of biospecimens

“…Aqueous solutions can be analyzed by placing the liquid surface at the focal point of the laser or creating a dried droplet of the solution and deposition of an ice matrix on the surface prior to analysis. Other samples that are roughly planar can be analysed without the need for sectioning, such as fabric 26 , fibers 27 and hair 28 . Tissues are the most commonly analyzed biomaterial to date and tissue sample preparation steps will be discussed in detail.…”

“…However, this is typically performed using a thatch of hair which will represent the average incorporation over a long period of time. IR-MALDESI MSI was used to analyse single hair strands at a spatial resolution of 100 μm, which based on an average growth rate of 1 cm/month, gives a temporal resolution of approximately 7 hours 28 . This analysis is of particular interest to HIV research in patients receiving pre-exposure prophylaxis where consistent dosing is vital to the programs efficacy.…”

Ion Beam, Synchrotron Radiation, and Related Techniques in Biomedicine: Elemental Profiling of Hair

“…Hair has become a popular tool for screening and quantifying for example elemental changes within the body [14,24]. Alternatively, hair testing may find important applications in clinical medicine such as to (1) determine medicinal or chronic doping, (2) confirm gestational drug use, or (3) assess exposure to toxins and pollutants in the workplace or environment [25,26].…”