The Limits of Small Fluid Samples in Diagnosing Illnesses

The promise of diagnosing illnesses with small amounts of blood, saliva, or urine has gained significant attention in recent years, particularly with the emergence of companies like Haemanthus. However, the science behind this claim is a far cry from the revolutionary promise of Theranos, a biotech company that was valued at over $9 billion in 2015 but was eventually shut down due to its fraudulent technology.

Currently, clinicians and lab technicians can detect various conditions using blood tests, but these tests require significant volumes of blood, often several milliliters. Blood tests can check for signs of infection, monitor organ function, or show how a person is responding to treatment. While urine tests are non-invasive and easy to administer, factors like fluid intake and diet can influence test results, potentially affecting accuracy.

Saliva testing is another non-invasive diagnostic tool, already used in clinical settings to detect HIV antibodies and monitor cortisol levels. However, saliva production varies between individuals, and its composition can be impacted by food, drink, stress, or the time of day, limiting its reliability as a diagnostic tool.

The promise of companies like Haemanthus is that their technology can detect and diagnose illnesses using tiny amounts of blood, urine, or saliva. While this may be appealing, the physical limitations of small samples mean that many diagnostic markers are only present in very low amounts, making it harder to detect them reliably.

Key Takeaways:

• Most human diseases are complicated, and comprehensive testing approaches are usually required to diagnose them accurately.
• Relying solely on small fluid samples could lead to misdiagnosis, delayed treatments, or unnecessary interventions.
• Innovations in biosensor technology, machine learning algorithms, and biomarker discovery continue to advance the field, but more research and regulatory approvals are necessary to ensure patient safety and diagnostic accuracy.
• The promise of companies like Haemanthus is not without its challenges, including the need for reliable detection of multiple biomarkers in small sample volumes.
• Current diagnostic tests, such as finger-prick blood samples for blood glucose levels and small urine samples for urinary tract infections, can only detect specific conditions and are not applicable to all types of infections.
• The company's claims of needing only small amounts of fluid for multiple tests are not supported by the existing science, and more research is needed to develop reliable and accurate diagnostic tools using small fluid samples.

Statistics:

• Theranos was valued at over $9 billion in 2015, but its technology was eventually shut down due to fraud.
• Blood tests require significant volumes of blood, often several milliliters.
• Saliva production varies between individuals, and its composition can be impacted by food, drink, stress, or the time of day.
• The physical limitations of small samples mean that many diagnostic markers are only present in very low amounts, making it harder to detect them reliably.
• Innovations in biosensor technology, machine learning algorithms, and biomarker discovery continue to advance the field, but more research and regulatory approvals are necessary to ensure patient safety and diagnostic accuracy.

Sources:

• The Conversation (Au and NZ) -- By Amali Cooray, PhD Candidate in Genetic Engineering and Cancer, WEHI (Walter and Eliza Hall Institute of Medical Research)
• https://theconversation.com/you-usually-need-more-than-a-few-drops-of-blood-saliva-or-urine-to-detect-illnesses-heres-why-256562