A mass spectrometry assay for detection of endogenous and lentiviral engineered hemoglobin in cultured cells and sickle cell disease mice

Sickle cell disease (SCD) results from a sequence defect in the β-globin chain of adult hemoglobin (HbA) leading to expression of sickle hemoglobin (HbS). It is traditionally diagnosed by cellulose-acetate hemoglobin electrophoresis or high-performance liquid chromatography. While clinically useful, these methods have both sensitivity and specificity limitations. We developed a novel mass spectrometry (MS) method for the rapid, sensitive and highly quantitative detection of endogenous human β-globin and sickle hβ-globin, as well as lentiviral-encoded therapeutic hβAS3-globin in cultured cells and small quantities of mouse peripheral blood. The MS methods were used to phenotype homozygous HbA (AA), heterozygous HbA-HbS (AS) and homozygous HbS (SS) Townes SCD mice and detect lentiviral vector-encoded hβAS3-globin in transduced mouse erythroid cell cultures and transduced human CD34+ cells after erythroid differentiation. hβAS3-globin was also detected in peripheral blood 6 weeks post-transplant of transduced Townes SS bone marrow cells into syngeneic Townes SS mice and persisted for over 20 weeks post-transplant. As several genome-editing and gene therapy approaches for severe hemoglobin disorders are currently in clinical trials, this MS method will be useful for patient assessment before treatment and during follow-up.

Last Trends in Point-of-Care (POC) Diagnostics for the Management of Hematological Indices in Home Care Patients

Today, complete blood count (CBC) analyses are highly automated and allow for high throughput and accurate and reliable results. However, new analytical tools are in great demand to provide simple, rapid and cost-effective management of hematological indices in home care patients. Chronic disease monitoring at home has become a benefit for patients who are finding cost savings in programs designed to monitor/treat patients in offsite locations. This review reports the latest trends in point-of-care (POC) diagnostics useful for home testing of key hematological counts that may be affected during home therapy treatment.

Smartphone-Enabled Paper-Based Hemoglobin Sensor for Extreme Point-of-Care Diagnostics

We report a simple, affordable (∼0.02 US $/test), rapid (within 5 min), and quantitative paper-based sensor integrated with smartphone application for on-spot detection of hemoglobin (Hgb) concentration using approximately 10 μL of finger-pricked blood. Quantitative analytical colorimetry is achieved via an Android-based application (Sens-Hb), integrating key operational steps of image acquisition, real-time analysis, and result dissemination. Further, feedback from the machine learning algorithm for adaptation of calibration data offers consistent dynamic improvement for precise predictions of the test results. Our study reveals a successful deployment of the extreme point-of-care test in rural settings where no infrastructural facilities for diagnostics are available. The Hgb test device is validated both in the controlled laboratory environment (n = 200) and on the field experiments (n = 142) executed in four different Indian villages. Validation results are well correlated with the pathological gold standard results (r = 0.9583) with high sensitivity and specificity for the healthy (n = 136) (>11 g/dL) (specificity: 97.2%), mildly anemic (n = 55) (<11 g/dL) (sensitivity: 87.5%, specificity: 100%), and severely anemic (n = 9) (<7 g/dL) (sensitivity: 100%, specificity: 100%) samples. Results from field trials reveal that only below 5% cases of the results are interpreted erroneously by classifying mildly anemic patients as healthy ones. On-field deployment has unveiled the test kit to be extremely user friendly that can be handled by minimally trained frontline workers for catering the needs of the underserved communities.