Evaluation of Low-cost Techniques for Detecting Sickle Cell Disease and β-thalassemia in Nepal and Canada

Overall, the hypothesis is that an assessment of the performance and accuracies of low-cost point-of-care techniques (automated sickling test, solubility test, lateral-flow assays, Gazelle Hb variant test) against HPLC tests will provide researchers and health workers with feasible alternative options for screening and detecting SCD, SCT and β-thalassaemia in a variety of situations based on the needs of the communities and the resources available.

Objectives

Objectives specific to the current study are to:

• Determine accuracy (sensitivity and specificity) of automated sickling test to detect HbS, compared to gold standard HPLC, and to conventional solubility test
• Determine whether SCD, SCT and healthy individuals can be classified using the automated sickling test that leverages machine learning on images of blood films under hypoxia
• Validate accuracy (>95% sensitivity and specificity) of lateral- flow assays (HemoTypeSC and Sickle SCAN) to detect SCD/SCT, and of Gazelle variant test to detect SCD, SCT, and β-thalassaemia; and determine if low-cost techniques can potentially replace HPLC/electrophoresis tests in rural and remote settings

Long-term objectives of the overall project are to:

• Implement trained machine learning algorithm to classify SCD, SCT and healthy individuals during screening tests in Nepal
• Implement relevant low-cost point-of-care techniques in rural and remote communities of Nepal using insights and conclusions from current study

The plan of the study to screen the communities (e.g. in Nepalgunj, in Vancouver) using the following:

a. Low-cost screening i. Sickling test with low-cost microscope and automated screening with machine learning ii. Sickling test with traditional microscope (conventional manual screening used in Nepal) iii. HbS solubility test iv. Commercial point-of-care assays (HemoTypeSC and Sickle SCAN) v. Gazelle Hb variant test b. Gold standard test: HPLC, for determining the accuracies of low-cost screening techniques

De-identified data (images of blood films and associated documentation) will also be deposited in an online public repository, such as the Federated Research Data Repository (FRDR). FRDR is a service of the Digital Research Alliance of Canada (Alliance), a not-for-profit organization that supports digital research infrastructure in Canada. FRDR is hosted on national infrastructure, managed and administered by the Digital Research Alliance of Canada.

Inclusion criteria

Since the techniques evaluated in the study aims at detecting sickle cell disease (SCD), sickle cell trait (SCT), and β- thalassemia, the following number of participants will be included in Nepal:

• 20 individuals with SCD (HbSS)
• 20 individuals with SCT (HbAS)
• 20 individuals with sickle cell/β-thalassemia compound heterozygous form (HbS/β-thalassemia)
• 20 individuals with β-thalassemia (Hbβ/β-thalassemia)
• 20 individuals with β-thalassemia trait or carrier form (HbA/β- thalassemia)
• 20 healthy individual participants or normal participants (HbAA, participants without any known hemoglobin disorders, such as SCD, SCT or β-thalassemia)

The following number of participants will be included in Canada:

• 30 individuals with SCD (HbSS)
• 30 individuals with SCT (HbAS)
• 30 healthy individual participants or normal participants (HbAA, participants without any known hemoglobin disorders, such as SCD, SCT or β-thalassemia)

Participants older than 1 year of age at the time of drawing blood will be eligible. Signed and dated consent or assent forms will be required by the participants or their parents/guardians.

Exclusion criteria

The exclusion criteria for the study:

• Transfusion within the last 3 months
• Pregnancy Participants who wish to withdraw from the study will also be excluded.