White blood cells (WBC), or leukocytes, are key indicators of an individual's immune system health. High or low WBC counts can signify the severity of an infection, indicate life-threatening conditions like sepsis, or assist in monitoring patient responses to therapies like chemotherapy and psychotropic drugs. Generally, the blood collected for WBC testing is sent to a central lab for analysis that sends results within hours, making it inconvenient and delaying time-sensitive diagnosis or treatment. Now, an innovative device can rapidly count a person’s WBC with a single drop of blood, similar to the way glucometers rapidly scan for blood sugar levels, enabling rapid testing and improved triaging for infections.

Called the CytoTracker Leukometer, the device developed by researchers at Rutgers startup RizLab Health Inc. (Princeton, NJ, USA) can quickly aid the detection of elevated or reduced WBC counts. The device has undergone comprehensive testing, comparing its performance with conventional lab benchtop hematology analyzers used for standard blood tests. These trials confirmed that the CytoTracker Leukometer is at least 97% accurate, thereby meeting established clinical standards. The potential applications of the device are broad and significant. In emergency room settings, it could expedite the detection of sepsis in patients more swiftly than current methods, which typically involve blood draws and lab testing.

Oncologists might use it to quickly assess whether chemotherapy patients require a WBC stimulant. Additionally, it has important implications in psychiatry, particularly for patients on clozapine, commonly prescribed for conditions like schizophrenia. These patients frequently suffer from neutropenia, a deficiency in neutrophils, and need regular testing to renew their prescriptions. The CytoTracker Leukometer's ability to rapidly measure neutrophil levels could greatly ease the process of maintaining necessary medication regimens.

“Normally, doing a blood count requires a phlebotomist taking a needle stick and collecting significant amounts of venous blood and sending the samples off to labs where they are tested, sometimes taking hours or even days,” said Mehdi Javanmard, a professor in the Department of Electrical and Computer Engineering in the Rutgers School of Engineering, and the co-founder and CEO of RizLab Health Inc. “Our handheld device enables near-patient testing, while only requiring a tiny amount of blood and returning results within minutes, allowing clinicians to make decisions almost immediately.”

“Rapid test results have revolutionized the field of medicine,” added Dr. Tanaya Bhowmick, an infectious disease physician. “The white blood count is a parameter that physicians routinely order to evaluate a patient for possible infection. Having this information rapidly can help triage patients in the outpatient setting."