Microvascular Alterations in Infection-Associated Chronic Illnesses: Insights from Nailfold Capillaroscopy and NASA Lean Testing 2260753

Abstract Introduction Infection-associated chronic illnesses (IACI) such as Long COVID and Chronic Lyme Disease are characterized by persistent symptoms including fatigue, pain, and brain fog. The MIT MAESTRO study aims to advance knowledge of these conditions by investigating immune pathways and physiologic changes using novel methods, such as capillaroscopy. Capillaroscopy is a non-invasive imaging technique that visualizes the microcirculation at the nailfold to detect vascular abnormalities. Methods Within the MAESTRO study, capillaroscopy was performed before and after the NASA Lean Test (NLT) to investigate microvascular changes under autonomic stress. The NLT, a test to evaluate dysautonomia, requires patients to lie down for ten minutes and then remain upright against a wall for ten minutes while heart rate, blood pressure, and symptoms are monitored. Results In several participants with IACI, striking microvascular alterations after the NLT compared to baseline were observed, including enlarged capillaries, increased tortuosity, and microhemorrhages. These findings suggest dynamic microcirculatory dysfunction that becomes more evident when the autonomic system is challenged. AI-based software was employed to quantify capillary abnormalities, providing objective measures of enlargement, tortuosity, hemorrhages, and other features. In parallel, data was integrated from the Lumia STAT earpiece, a non-invasive wearable device that captures carotid blood flow variables in real time. Reductions in carotid flow time of up to 30% were observed during the NLT, aligning with patient-reported symptoms of dizziness, brain fog, and worsening fatigue during upright posture. Conclusion By combining high-resolution visualization with quantitative metrics and real-time physiologic data, the MAESTRO study establishes a framework for advancing understanding of pathophysiology while also identifying potential biomarkers for diagnosis, disease monitoring, and therapeutic responses for people living with IACI. Funding Source Fairbairn Foundation, NIH NIAID RO1 AI 178713-01, Massachusetts Life Sciences Center, Manton Foundation Topic Categories Immune Mechanisms of Human Disease (HUM)