The global demand for specialized sample processing has grown dramatically, with an increasing number of clinical trial protocols calling for services such as PBMC isolation and DNA/RNA extraction. In oncology trials alone, the percentage is nearly 80%.1
Despite the rising need, research teams continue to struggle to obtain high-quality laboratory support services to perform sample processing. In particular, PBMC isolations are exacting procedures that demand care and training and must be performed within a very short window of time. Additionally, because samples may be collected thousands of miles from a qualified sample processing center, the risk of shipping sensitive biological specimens across long distances may be unavoidable.
This article discusses solutions to the risks inherent in global sample processing. Knowing these risks and how to mitigate them will enable the consistent processing of high-quality samples in support of global research protocols.
Risk #1: Turnaround time
A key challenge for clinical trials that require specialized sample processing, such as PBMC isolation, is the limited acceptable stability times. For optimal results, PBMC samples must be processed within 24 hours of collection. In some protocols, this time frame is as short as eight hours.
These requirements are difficult to meet even when the processing lab is close to the point of collection. However, economics and patient enrollment requirements are driving the globalization of clinical trials.2 Shipping to a central lab for processing from remote sites adds another dimension of risk and, in many cases, meeting the above time restriction is nearly impossible, especially when potential transit delays or customs clearances are considered.
An alternative to long-distance shipping is to task regional laboratories near investigator sites to process the samples. This option presents risk in that sample processing is not routine at these facilities and personnel are not typically trained in these specialized processing techniques. Therefore, results tend to be inconsistent and quality is questionable.
The risk of long-distance shipping can be avoided through a large network of pre-qualified regional labs capable of consistently performing the required processing tasks to a high standard. For example, rather than relying on two or three central lab locations, an organization offering multiple points of service across Europe, Asia, Australia, and the Americas would be a more effective strategy. A global network of qualified regional labs minimizes shipping time from site to processing lab, enabling clients to decrease turnaround times when necessary. In addition, local compliance expertise helps prevent customs delays, and logistical dry runs enable time for troubleshooting prior to patient activity.
Risk #2: Shipping conditions
Specimen logistics is a challenge in any study design, but especially in projects involving PBMC isolation and DNA/RNA extraction. The growing use of these methods, and of particularly sensitive specimen material, calls for narrow conditions within which specimens are analytically viable. Temperature, humidity, light exposure, physical shock, and other factors can negatively impact the viability of critical specimens. Many sensitive specimens require tightly controlled room temperature (CRT) or refrigerated temperature (2–8°C) during transport with no deviations permitted.
Qualified shipper solutions maintain the specimen cold chain, as defined by analytical requirements and best practices for stability and preservation. Properly qualified shippers are tested in both prescribed extreme environments and real-world logistics scenarios over long durations, data from which is essential to study design and packaging selection when sensitive specimen types are considered. Advanced packaging solutions (which are provided by LabConnect), including proprietary, validated designs and packaging solutions, are custom-designed and qualified to withstand a variety of environmental extremes, demanded by increasing logistical and analytical complexity.
Risk #3: Quality of sample preparation
When samples arrive at the lab, they must be processed promptly under strict parameters. It is critical that regional labs be equipped properly to perform sample processing consistently and reliably. Improper processing can result in lost or unreliable data.
The procedures for PBMC isolation and DNA/RNA processing must be routinely performed with precision in order to achieve consistent, high-quality results. Sponsors could potentially travel to regional laboratories to train the staff—however, long-term oversight and compliance to the training and processing procedures become difficult to guarantee, threatening the outcome of high-quality results. High levels of staff turnover are also a common challenge to these labs, which also influences the quality of the sample processing.
Uncertainty regarding the quality of cell preparation in regional labs can be offset with stringent, uniform analyst certification requirements. Ongoing implementation of standardized analyst training and qualification requirements, as well as standardized methods across labs, ensure high quality and consistent processing while diminishing the risk of unknowns at the time of downstream analysis.
To ensure analysts are qualified to run these preparation methods, they must complete a pre-defined analyst qualification procedure. Typical qualifications would entail a tiered approach of observing a trained analyst perform a processing procedure, followed by a side-by-side execution of the procedure, and then finally an independent run. The objective pass/fail criteria will vary. For PBMC isolation, cell recovery and viability would be assessed; for DNA/RNA extraction, pass/fail criteria might include the concentration and purity of the sample after extraction has occurred.
Risk #4: Storage
Short- and long-term storage are critical steps between initial processing and analysis. DNA/RNA extractions, PBMC isolates, and other sensitive specimen materials require strict storage conditions demanded by their analytical requirements, from CRT storage (20–25°C) to cryogenic storage (-190°C). Any deviation to defined storage conditions—including unplanned freeze/thaw cycles, improper storage temperature—can result in specimen loss.
Maintaining an intact specimen cold chain begins at initial specimen handling, where carefully designed processes, training, equipment, and workspaces are essential to minimizing specimen handling. Upon storage, industry best practices are critical to ensure storage units are properly validated and maintained to mitigate even the slightest risk of failure. For further risk-mitigation, redundancy is necessary across all equipment and processes to ensure operational continuity in even the most extreme events. This redundancy should include redundant power supply to the biorepository, 24/7 monitoring with redundant alarm and notification functionality, dry fire suppression, back-up storage units, and a well-trained team of experts who coordinate storage operations with project needs.
Risk #5: Systematic errors
Delayed detection of laboratory failures can lead to significant data loss. If an isolation was performed incorrectly, for example, this could impact the quality and success of downstream testing, resulting in the absence of data for specific time points or studies. The larger risk is that one systematic error may result in a widespread loss of viable data. Without vigilance, such losses may not be recognized until long after they occurred—at the time of downstream sample analysis. This delay means ongoing errors will not be rectified in time to minimize their adverse effects.
Real-time monitoring of laboratory performance data provides sponsors with additional assurance of quality sample processing. Monitoring outcomes of sample processing procedures from participating laboratories will help ensure consistency and high-quality sample generation. Qualified personnel reviewing this information can alert the labs and analysts of issues promptly, so systematic errors can be corrected before many samples are affected.
Providing this added oversight on the results of all sample processing as labs generate samples allows for connection with the lab and/or analyst to ensure steps are taken to correct any issues in short order. Sponsors benefit from more reliable sample integrity and high-quality processing—and peace of mind.
Global sample processing requirements present an ongoing dilemma for research teams. They may engage a global central lab partner with limited processing locations and subject samples to long-distance transport. Alternatively, they may attempt to use unfamiliar, local laboratories and risk subjecting their samples to poor-quality processing.
There is another option: an extensive global network of qualified regional labs close enough to their investigative sites to allow for expedient turnaround. Such a network, combined with uniform analyst certification and centralized lab performance monitoring, can help scientists increase recovery and viability of PBMCs and achieve higher DNA/RNA concentrations with greater purity to mitigate risk in global research protocols.
1.The Editors. Genetic Testing in Clinical Trials: A New Level of Patient Centricity. Applied Clinical Trials. 2018;27(9). Published September 1, 2018. Accessed May 6, 2019.
2. CenterWatch Online. High Costs and Recruitment Issues Drive the Globalization of Clinical Trials. Published online August 21, 2017. Accessed May 5, 2019.
Jeff Mayhew is chief development officer, Elizabeth Koury is vice president of scientific affairs, and Ben Booher is logistics specialist at LabConnect.