Sanguine Connections: The Power of Longitudinal Collections

Welcome to Sanguine Connections, exploring the process, challenges, and nuances of biospecimen procurement for translational studies.


Sanguine Connections


The Power of Longitudinal Collections: Unveiling the Complexities of Disease Dynamics

When trying to understand disease, monitoring change over time is often crucial. By collecting data at multiple points in time (i.e. longitudinal collections), researchers can track developments, establish cause-and-effect relationships, and gain deeper insights into the dynamics of their study subjects. This blog explores the significance and challenges of longitudinal collection in research studies.


What is a Longitudinal Collection?

Longitudinal collection refers to the process of gathering data from the same subjects repeatedly over a period of time. Unlike cross-sectional studies, which provide a snapshot of a single moment, longitudinal studies reveal how variables evolve. This approach can span weeks, months, or years, depending on the research goals. Conclusions can be gleaned from these studies that are not possible from single data points, such as changes in biomarker levels or signatures, dynamics of infectious diseases, and treatment responses.. 


Case Study

Goal: Identify functional and clinically relevant predictive biomarkers for symptom onset and progression of Sickle Cell Disease (SCD).

Longitudinal Study: Blood samples and monitoring of 35 people diagnosed with SCD were evaluated over the course of six months. Blood samples were collected in the donors’ homes every three weeks while the donors also self-reported vaso-occlusive crises (VOCs). The study participants also electronically shared patient-reported outcomes, and activity was monitored via a wearable device. We had 100% of participants remaining in the study, enabling the researchers to have a robust dataset to evaluate an assay’s ability in stratifying patients for evaluating SCD severity.


Maintaining Engagement with Longitudinal Collection

Although significant benefits come from monitoring changes over the time, longitudinal studies have the inherent challenge of maintaining participant engagement over extended periods of time; and without the engagement, the significance of the study can easily be lost. Participants can remove themselves from a study at any time for any reason, but often there is keen interest in better understanding the disease being studied. At Sanguine, we pride ourselves in our donor experience being positive, which is exemplified by our 95% retention rate of donors. Continued engagement is likely from the power of our direct-to-donor model. Our model  is centered around making it as easy as possible for donors to participate in research studies, including streamlining medical record access with electronic health records (EHR) and at home collections for all samples with the exception of apheresis.


Case Study

Goal: Although many people who contract hepatitis B virus (HBV) are able to clear infections; others have chronic infection that can lead to developing liver disease. To better understand the infection, and with the goal of developing a cure, a virology company sought to monitor biomarkers in people diagnosed with HBV over the course of a year. 

                     Longitudinal Study: Weekly blood draws were planned for 100 donors with HBV that when recruited to the study were free of viral coinfections and no advanced liver disease. Sanguine identified over 1,000 potential donors, and after screening, enrolled 106 who met the inclusion and exclusion criteria. Collections were performed in the homes of donors, and the samples were then analyzed for a surface and secreted antigen to provide information about the current infection state and whether the virus is actively replicating. The study continued well past its original one year timeline to over three years, with 95% of the donors participating over the course of the entire study. 


Longitudinal studies are key to providing insight into dynamics of disease. The success of these studies, however, hinges on maintaining participant engagement. High retention rates are essential for gathering robust data. At Sanguine we believe in our approach of lowering the barrier for people to participate in research by streamlining their experience from active communication with their research coordinator to in most cases a phlebotomists coming to the donors home for collection. 


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By: Eliza Small, Ph.D.

Director Content Marketing at Sanguine