FIGURE 5.

OcclusionChip enables detection of HbS-related RBC abnormalities under hypoxia in SCT and SCD when HbS level is low. Shown are (A) Elongation Index (EI) results by oxygen gradient ektacytometry and (B) Occlusion Index (OI) results by the OcclusionChip on clinical blood samples acquired from a healthy donor (HbAA), a subject with SCT (HbAS), a subject with homozygous SCD (HbSS) post allogeneic hematopoietic stem cell transplant (HSCT), and a subject with homozygous SCD (HbSS) who were on-hydroxyurea (HU), under normoxic (159 mmHg) and physiologic hypoxic pO₂ level (45 mmHg). EI decreased from 0.380 to 0.325 in the sample from the on-HU HbSS subject, and remained similar in the samples from the HbAS subject and the HbSS subject who received HSCT under hypoxia. However, OI increased from 0.05% to 15.89%, from 0.03% to 7.23%, and from 0.72% to 67.52% in the samples from the HbAS subject, the HbSS subject post HSCT, and the on-HU HbSS subject, respectively, under hypoxia.