Faculty Bibliography

Sickle cell disease (SCD) is a disorder with repetitive vaso-occlusive crises resulting in microvascular obstruction and tissue ischemia that may lead to multi-organ ischemia and dysfunction. Nailfold videocapillaroscopy (NFC) is an imaging technique utilized in clinical rheumatology to visualize capillaries located near the fingertip. To characterize NFC abnormalities in the setting of pediatric SCD, we performed NFC using a video capillaroscope on 8 digits in 44 stable SCD patients and 65 age matched healthy controls. Mean capillary number was lower (6.4 ± 1.3 vs 7.5 ± 1.8, p = 0.001) in the SCD group compared to controls. The percentage of dilated capillaries was similar (7.1 ± 8.3 vs. 5.9 ± 8.2, p = 0.4). The large majority of capillaries visualized in the SCD and control groups were normal capillary types per the EULAR definition, with a similar percentage of normal, nonspecific capillary morphologies and abnormal types. Regarding normal capillary sub-types, the SCD group and controls exhibited similar percentages of stereotype hairpin shapes, and tortuous or once or twice crossing type capillaries. On multivariate analyses, mean capillary number was independently associated with SCD after adjusting for age, body mass index, systolic blood pressure and gender. In conclusion, pediatric SCD is associated with lower capillary number but similar percentage of dilated capillaries and morphology on NFC. In our SCD cohort, capillary number was unrelated to our available markers of disease severity, including history of sickle crises, previous hospitalization for crises or Hemoglobin F levels.

Sickle cell disease (SCD) is a disorder characterized by repetitive vaso-occlusive crises causing microvascular obstruction, tissue ischemia and pain that may lead to chronic multi-organ ischemic sequelae. Nailfold videocapillaroscopy (NFC) is a non-invasive imaging technique used in clinical rheumatology to directly visualize capillaries located near the fingertip. To characterize NFC abnormalities in the setting of SCD, we performed NFC on 71 SCD patients and 70 age matched controls using a video capillaroscope on 8 digits. As compared to controls, mean capillary number was lower and the final capillary score (measure of capillary dropout inversely related to capillary density) was higher in the SCD group. The SCD group had a lower percentage of stereotype hairpin shapes and a higher percentage of crossing type capillaries. On multivariate linear analyses, both mean capillary number and final capillary score were independently associated with SCD after adjusting for age, body mass index, and gender. SCD was associated with more dilated capillaries but similar numbers of hemorrhages. In conclusion, SCD is associated with lower capillary density and more dilated capillaries on NFC. These changes appear unrelated to markers of disease severity including frequency of sickle crises, number of transfusions, and HbS levels. The relation between NFC and target organ involvement merits further study.

INTRODUCTION/BACKGROUND:BioMEMS relates to the implementation of Micro-Electro-Mechanical Systems (MEMS), in the biological and medical sphere. BioMEMS sensors are being utilized for many clinical applications, including a wireless urinary pressure system, right heart pressure sensor, and measurements on shearing force on the vascular system An important application of BioMEMS is on Heart failure (HF), a common disease, with a prevalence of 10% or more in persons 70 years of age or older, associated with high morbidity and mortality. HF affects over 5 million people and contributes to over 200,000 deaths a year in the United States alone. AREAS COVERED/METHODS:The purpose of this paper is to provide a short overview on the successful implementation of BioMEMS sensors in heart failure and vascular medicine. Expert commentary: BioMEMS devices have overcome current limitations in pharmacotherapies for resistant hypertension by electrical modulation of the baroreceeptors. This represents a step towards the development of biomedical micro-devices for those conditions in which pharmacotherapies result poorly effective or elicit unacceptable toxicity.