Diagnostic accuracy in field conditions of the sickle SCAN® rapid test for sickle cell disease among children and adults in two West African settings: the DREPATEST study

A multiplexed, allele-specific recombinase polymerase amplification assay with lateral flow readout for sickle cell disease detection

Isothermal nucleic acid amplification tests have the potential to improve disease diagnosis at the point of care, but it remains challenging to develop multiplexed tests that can detect ≥3 targets or to detect point mutations that may cause disease. These capabilities are critical to enabling informed clinical decision-making for many applications, such as sickle cell disease (SCD). To address this, we describe the development of a multiplexed allele-specific recombinase polymerase amplification (RPA) assay with lateral flow readout. We first characterize the specificity of RPA using primer design strategies employed in PCR to achieve point mutation detection, and demonstrate the utility of these strategies in achieving selective isothermal amplification and detection of genomic DNA encoding for the healthy βA globin allele, or genomic DNA containing point mutations encoding for pathologic βS and βC globin alleles, which are responsible for most sickle cell disorders. We then optimize reaction conditions to achieve multiplexed amplification and identification of the three alleles in a single reaction. Finally, we perform a small pilot study with 20 extracted genomic DNA samples from SCD patients and healthy volunteers - of the 13 samples with valid results, the assay demonstrated 100% sensitivity and 100% specificity for detecting pathologic alleles, and an overall accuracy of 92.3% for genotype prediction. This multiplexed assay is rapid, minimally instrumented, and when combined with point-of-care sample preparation, could enable DNA-based diagnosis of SCD in low-resource settings. The strategies reported here could be applied to other challenges, such as detection of mutations that confer drug resistance.

Determination of birth prevalence of sickle cell disease using point of care test HemotypeSC™ at Rundu Hospital, Namibia

BACKGROUND

Sickle cell disease (SCD), a noncommunicable disease, has the greatest burden in sub-Saharan Africa. The majority of children (50-90%) with SCD die before their 5th birthday, with approximately 150,000-300,000 annual SCD child deaths in Africa. In developed countries, newborn screening (NBS) has been shown to improve the survival of children with sickle cell disease, with under5 childhood mortality reduced tenfold due to interventions performed before the development of complications. Point -of-care tests have been developed for resource limited settings to expand NBS. The aim of this study was to determine the birth prevalence of sickle cell disease in Namibia using the HemoTypeSC™ point-of-care test.

METHODS

A cross-sectional descriptive study was carried out at Rundu Intermediate Hospital in the Kavango East Region. Two hundred and two (202) well newborns within 72 h of birth were recruited for the study from 22 February to the 23th March 2023. Descriptive statistics were used to compute the haemoglobin types of the study participants.

RESULTS

The majority of the participants (n = 105, 52%) were females, and (n = 97,48%) were males. The median age of the participants was 23 h (Q1, Q3; 11; 33),) with an age range of 2-98 h. Sickle cell trait was present in 9.4% of the screened newborns, no homozygous disease was detected, and 90.6% had Hb AA.

CONCLUSIONS

This study is the first to measure HbS gene carriage at birth using HemotypeSC point-of-care testing in Namibia. There was a moderate prevalence of sickle cell traits but no SCD. This baseline study may provide the foundation for larger epidemiological surveys to map HbS gene carriage in Namibia to provide evidence for policy makers to fashion appropriate SCD newborn screening services.

Transcranial Doppler ultrasound velocities in a population of unstudied African children with sickle cell anemia

The greatest burden of sickle cell anemia (SCA) globally occurs in sub-Saharan Africa, where significant morbidity and mortality occur secondary to SCA-induced vasculopathy and stroke. Transcranial Doppler ultrasound (TCD) can grade the severity of vasculopathy, with disease modifying therapy resulting in stroke reduction in high-risk children. However, TCD utilization for vasculopathy detection in African children with SCA remains understudied. The objective was to perform a prospective, observational study of TCD findings in a cohort of children with SCA from the Democratic Republic of the Congo, Zambia, and Malawi. A total of 770 children aged 2-17 years without prior stroke underwent screening TCD. A study was scored as low risk when the time-averaged maximum of the mean (TAMMX) in the middle cerebral artery or terminal internal carotid artery was <170 cm/s but >50 cm/s, conditional risk when 170-200 cm/s, and high risk when >200 cm/s. Low-risk studies were identified in 604 children (78%), conditional risk in 129 children (17%), and high risk in three children (0.4%). Additionally, 34 (4%) were scored as having an unknown risk study (TAMMX <50 cm/s). Over the course of 15 months of follow-up, 17 children (2.2%) developed new neurologic symptoms (six with low-risk studies, seven with conditional risk, and four with unknown risk). African children with SCA in this cohort had a low rate of high-risk TCD screening results, even in those who developed new neurologic symptoms. Stroke in this population may be multifactorial with vasculopathy representing only one determinant. The development of a sensitive stroke prediction bundle incorporating relevant elements may help to guide preventative therapies in high-risk children.

Potential for a large-scale newborn screening strategy for sickle cell disease in Mali: A comparative diagnostic performance study of two rapid diagnostic tests (SickleScan® and HemotypeSC®) on cord blood

Sickle cell disease (SCD) is a life-threatening disease requiring reliable early diagnosis. We assessed the acceptability and diagnostic performances of two rapid diagnostic tests (RDTs) to identify SCD (HbSS, HbSC, HbS/β-thalassaemia) or SCD carrier (HbS/HbC) in a pilot SCD newborn screening (NBS) strategy in Mali. All consenting delivering women were offered SCD NBS using cord blood sampling on two RDTs (SickleScan® and HemotypeSC®) compared to the high-performance liquid chromatography (HPLC) gold standard to detect SCD states. From April 2021 to August 2021, 4333 delivering women were eligible of whom 96.1% were offered NBS: 1.6% refused, 13.8% delivered before consenting and 84.6% consented; 3648 newborns were diagnosed by HPLC; 1.64% had SCD (0.63% HbSS, 0.85% HbSC, 0.16 HbS/β-plus-thalassaemia); 21.79% were SCD carrier. To detect accurately SCD, SickleScan® had a sensitivity of 81.67% (95% confidence interval [CI]: 71.88-91.46) and a negative predictive value (NPV) of 99.69% (95% CI: 99.51-99.87); HemotypeSC® had a sensitivity of 78.33% (95% CI: 67.91-88.76) and a NPV of 99.64% (95% CI: 99.44-99.83). To detect SCD carrier: SickleScan® sensitivity was 96.10% (95% CI: 94.75-97.45) and NPV, 98.90% (95% CI: 98.51-99.29); HemotypeSC® sensitivity was 95.22% (95% CI: 93.74-96.70) and NPV, 98.66% (95% CI: 98.24-99.03). Routine SCD NBS was acceptable. Compared with HPLC, both RDTs had reliable diagnostic performances to exclude SCD-free newborns and to identify SCD carriers to be further confirmed. This strategy could be implemented in large-scale NBS programmes.

Red blood cell alloimmunisation in sickle cell disease patients in the Democratic Republic of the Congo

OBJECTIVES

To determine the prevalence of red blood cell (RBC) alloimmunisation and alloantibody specificity in sickle cell disease (SCD) patients in Kisangani, Democratic Republic of Congo (DRC) in comparison with those followed at the Centre Hospitalier Régional (CHR) de la Citadelle of Liège (Belgium).

BACKGROUND

Data regarding RBC alloimmunisation (immune response of the organism to foreign erythrocyte antigens, antigens that lack on its own RBC) in SCD patients are scarce in sub-Saharan Africa.

METHODS

We conducted a multi-site-based cross-sectional study among 125 SCD patients at Kisangani and 136 at the CHR de la Citadelle of Liège. The diagnosis of SCD was confirmed by high-performance liquid chromatography. Alloantibodies were screened using the agglutination technique on gel cards and their specificity determined using 11 and/or 16 cell panels. Statistical analyses were carried out using SPSS.

RESULTS

The prevalence of RBC alloimmunisation was 9.6% among SCD patients in Kisangani versus 22.8% in those of Liège. At Kisangani as well as at Liège, the median age of alloimmunised patients was higher than that of non-alloimmunised patients, 15.5 years (IQR:4.8-19.8) and 24 years (IQR:14-31) versus 10 years (IQR: 6.5-17) and 17 years (IQR:12-24), respectively. The median number of blood units was higher in both Kisangani and Liège immunised patients compared to non-immunised patients, 8 (IQR:5-11) versus 5 (IQR:3-13) and 41(IQR:6-93) versus 6.5(3-37) respectively. At Kisangani (N = 14), the most frequent antibodies were anti-D (28.6%) and anti-C versus anti-E (13.6%), anti-S (13.6%) and anti-Lea (11.4%) at Liège (N = 44).

CONCLUSIONS

These findings stated that alloimmunisation is a common complication in SCD patients in the DRC. In the resource-limited setting of this country, blood transfusion with minimal ABO, D, C and E antigen matching in addition to the use of compatibility test could significantly reduce the incidence of this complication.

Sickle Cell Disease in Children and Adolescents: A Review of the Historical, Clinical, and Public Health Perspective of Sub-Saharan Africa and Beyond

Sickle cell disease (SCD) is an umbrella term for a group of life-long debilitating autosomal recessive disorders that are caused by a single-point mutation (Glu→Val) that results in polymerization of hemoglobin (Hb) and reversible sickle-shape deformation of erythrocytes. This leads to increased hemolysis of erythrocytes and microvascular occlusion, ischemia-reperfusion injury, and tissue infarction, ultimately causing multisystem end-organ complications. Sickle cell anemia (HbSS) is the most common and most severe genotype of SCD, followed by HbSC, HbSβ 0thalassemia, HbSβ+thalassemia, and rare and benign genotypes. Clinical manifestations of SCD occur early in life, are variable, and are modified by several genetic and environmental factors. Nearly 500 children with SCD continue to die prematurely every day, due to delayed diagnosis and/or lack of access to comprehensive care in sub-Saharan Africa (SSA), a trend that needs to be urgently reversed. Despite proven efficacy in developed countries, newborn screening programs are not universal in SSA. This calls for a consolidated effort to make this possible, through the use of rapid, accurate, and cheap point-of-care test kits which require minimal training. For almost two decades, hydroxyurea (hydroxycarbamide), a century-old drug, was the only disease-modifying therapy approved by the U.S. Food and Drug Administration. Recently, the list expanded to L-glutamine, crizanlizumab, and voxelotor, with several promising novel therapies in the pipeline. Despite its several limitations, hematopoietic stem cell transplant (HSCT) remains the only curative intervention for SCD. Meanwhile, recent advances in gene therapy trials offer a glimpse of hope for the near future, although its use maybe limited to developed countries for several decades.

[HemoTypeSC screening for sickle cell disease in the Democratic Republic of Congo (DRC): a case from the city of Kindu]

Early detection of sickle cell disease is crucial to improve people's survival. Both financial and geographic accessibility to sickle cell disease tools are barriers to universal screening in developing countries. The purpose of this study was to determine the hospital prevalence of sickle cell disease and to assess the reliability of a rapid diagnostic tool, HemoTypeSC, in a resource-limited environment. We conducted a prospective cross-sectional descriptive study in the Department of Pediatrics of 5 health facilities in the city of Kindu, Maniema province, DRC, over a period of 10 months. The study consisted of HemoType SC rapid test screening for sickle cell disease and then diagnostic confirmation by hemoglobin electrophoresis. A total of 448 children less than 5 years of age were enrolled in the study. The overall hospital prevalence of patients with sickle cell disease was 31.9%, of whom 12.7% were homozygous (SS) and 19.2% trait carriers; the level of suspicion for sickle cell disease in hospitals was 6%; the clinical presumption regarding sickle cell disease was 8%; HemoType SC rapid test had good indicators of validity for the detection of hemoglobins A and S. The study shows that the hospital prevalence of major sickle cell disease is higher in children under 5 years of age with respect to clinical suspicion in the absence of laboratory tests. HemoTypeSC rapid test seems to be a reliable tool for the screening of the disease in the city of Kindu, a resource-limited environment.

The promise and role of point of care testing to reduce the global burden of sickle cell disease through early diagnosis and linkage to care

Sickle cell disease (SCD) is a devastating and under-recognised global child health issue affecting over 300,000 infants annually, with the highest prevalence in India and sub-Saharan Africa. Most affected infants born in low- and middle-income countries (LMIC) lack access to SCD testing and die from complications in the first years of life without a formal diagnosis. The majority of deaths are preventable with early diagnosis and provision of inexpensive interventions. Despite global recognition of the urgent need, expansion of SCD newborn screening (NBS) programmes beyond the pilot stage has been obstructed by a dependence on an expensive and logistically challenging centralised laboratory testing model. Recently, several point-of-care tests (POCT) for SCD have been developed with promising field validation studies. Here, we summarise the state of POCT for SCD, review barriers and unanswered questions, and discuss optimal strategies for utilising POCT to address the growing global burden of SCD. There is an urgent need to prospectively evaluate the ability of POCT to reduce the morbidity and high early mortality of SCD. To impact a sustainable reduction to this end, it is essential to link a diagnosis with comprehensive SCD care, including wide and affordable access to affordable hydroxycarbamide therapy.

Evaluation of a point-of-care method for screening blood donors for sickle cell status

BACKGROUND

Turbidity tests are commonly used for screening blood units for the presence of sickle cell trait (SCT) before transfusion to specific patient populations, based on recommendations of the AABB. In this pilot study, we evaluate a new method for screening blood donors and blood units for the presence of sickle hemoglobin.

STUDY DESIGN AND METHODS

This study was based at King Abdulaziz University Hospital in Jeddah, Saudi Arabia. Study participants were approached consecutively between July 24, 2016, and August 8, 2016. Blood donors, control individuals, and known patients with sickle cell disease (SCD) were tested using both a point-of-care testing technology (Sickle SCAN, Biomedomics, Inc.) and hemoglobin capillary electrophoresis (HEP). Corresponding blood units were also tested using Sickle SCAN.

RESULTS

A total of 200 donors, 13 blood units, and 57 patients and controls were included. Sensitivity and specificity of Sickle SCAN for detection of SCT and SCD was 100%, when compared to HEP as the gold standard.

CONCLUSION

Sickle SCAN is a rapid test that shows high sensitivity and specificity for identification of hemoglobin S among blood donors and when used for testing blood units.

Management of sickle cell disease: current practices and challenges in a northeastern region of the Democratic Republic of the Congo

BACKGROUND

The Democratic Republic of the Congo (DRC) is the third most affected country worldwide by sickle cell disease (SCD). However, this disease is still orphaned in the country; large-scale control actions are rare, and little is known about its management.

OBJECTIVE

To assess current practices in the management of SCD in Kisangani, DRC.

METHODS

This cross-sectional study was conducted in six health facilities in Kisangani. It involved 198 presumed sickle cell patients attending the above health facilities. The study focused on the sociodemographic and clinical data of the participants, obtained through a clinical examination and their medical records. Diagnostic confirmation of SCD was made by high-performance liquid chromatography coupled to mass spectrometry. Data were analyzed using SPSS 20.0.

RESULTS

The diagnosis of SCD was confirmed in 194 (98.0%; 95% CI: 94.9-99.2) participants, while it was not confirmed in 4 (2.0%; 95% CI: 0.8-5.1) participants. The diagnosis was mainly made by the Emmel test (42.9%). 45.8% of participants had previously been transfused with the blood of their parents. Folic acid was taken by 48.5% of participants and the previous intake of hydroxyurea was reported in 5.1% of participants. The participants vaccinated against Pneumococcus were 13.6% and against Haemophilus influenzae type b 28.3%. Penicillin prophylaxis was received by only 1.5% and malaria prophylaxis by 11.6% of participants.

CONCLUSION

Standard-care practices for SCD patients in Kisangani are insufficient. The Congolese government should regard this disease as a health priority and consider actions to improve its management.

Sickle Cell Disease in the Democratic Republic of Congo: Assessing Physicians' Knowledge and Practices

Background: Sickle cell disease is a major public health issue in the Democratic Republic of Congo (DRC), but it is still poorly understood by health professionals. The objective of this study was to assess the knowledge and practices of Congolese physicians treating sickle cell disease (SCD), in order to identify the areas for improvement in clinical care. Methods: This was a descriptive observational study conducted among Congolese physicians using a questionnaire. Participants were evaluated using a pre-established answer grid. Results: A total of 460 physicians participated, including 81 women (18%), with an average age of 35 years (range 25–60 years). Most physicians were general practitioners. Although self-assessment of their level of knowledge on SCD was estimated as average to good, less than half of the participants (n = 460; 46%) reported adequate management of vaso-occlusive crises, and only 1% of them had received specific training on SCD. Most physicians reported difficulties both in terms of diagnostic (65%) and management (79%) options of SCD patients. This study also showed that 85% of these physicians did not have access to the diagnostic tools for SCD. Conclusions: Insufficient knowledge on SCD and poor diagnostic and treatment options might contribute to increased morbidity and mortality of patients living in the DRC. Interventions aiming to improve physicians’ knowledge, patient follow-up, and treatment access are needed. Specific training alongside existing programs (HIV, malaria), early diagnosis of the disease, and the creation of patient advocacy groups should be implemented to improve SCD patient care.

Implementing newborn screening for sickle cell disease as part of immunisation programmes in Nigeria: a feasibility study

BACKGROUND

Sickle cell disease is highly prevalent in sub-Saharan Africa, where it accounts for substantial morbidity and mortality. Newborn screening is paramount for early diagnosis and enrolment of affected children into a comprehensive care programme. Up to now, this strategy has been greatly impaired in resource-poor countries, because screening methods are technologically and financially intensive; affordable, reliable, and accurate methods are needed. We aimed to test the feasibility of implementing a sickle cell disease screening programme using innovative point-of-care test devices into existing immunisation programmes in primary health-care settings.

METHODS

Building on a routine immunisation programme and using existing facilities and staff, we did a prospective feasibility study at five primary health-care centres within Gwagwalada Area Council, Abuja, Nigeria. We systematically screened for sickle cell disease consecutive newborn babies and infants younger than 9 months who presented to immunisation clinics at these five centres, using an ELISA-based point-of care test (HemoTypeSC). A subgroup of consecutive babies who presented to immunisation clinics at the primary health-care centres, whose mothers gave consent, were tested by the HemoTypeSC point-of-care test alongside a different immunoassay-based point-of-care test (SickleSCAN) and the gold standard test, high-performance liquid chromatography (HPLC).

FINDINGS

Between July 14, 2017, and Sept 3, 2019, 3603 newborn babies and infants who presented for immunisation were screened for sickle cell disease at five primary health-care centres using the ELISA-based point-of-care test. We identified 51 (1%) children with sickle cell anaemia (HbSS), four (<1%) heterozygous for HbS and HbC (HbSC), 740 (21%) with sickle cell trait (HbAS), 34 (1%) heterozygous for HbA and HbC (HbAC), and 2774 (77%) with normal haemoglobin (HbAA). Of the 55 babies and infants with confirmed sickle cell disease, 41 (75%) were enrolled into a programme for free folic acid and penicillin, of whom 36 (88%) completed three visits over 9 months (median follow-up 226 days [IQR 198-357]). The head-to-head comparison between the two point-of-care tests and HPLC showed concordance between the three testing methods in screening 313 newborn babies, with a specificity of 100% with HemoTypeSC, 100% with SickleSCAN, and 100% by HPLC, and a sensitivity of 100% with HemoTypeSC, 100% with SickleSCAN, and 100% by HPLC.

INTERPRETATION

Our pilot study shows that the integration of newborn screening into existing primary health-care immunisation programmes is feasible and can rapidly be implemented with limited resources. Point-of-care tests are reliable and accurate in newborn screening for sickle cell disease. This feasibility study bodes well for the care of patients with sickle cell disease in resource-poor countries.

FUNDING

Doris Duke Charitable Foundation, Imperial College London Wellcome Trust Centre for Global Health Research, and Richard and Susan Kiphart Family Foundation.

Caring for Africa's sickle cell children: will we rise to the challenge?

BACKGROUND

Most of the world's sickle cell disease (SCD) burden is in Africa, where it is a major contributor to child morbidity and mortality. Despite the low cost of many preventive SCD interventions, insufficient resources have been allocated, and progress in alleviating the SCD burden has lagged behind other public-health efforts in Africa. The recent announcement of massive new funding for research into curative SCD therapies is encouraging in the long term, but over the next few decades, it is unlikely to help Africa's SCD children substantially.

MAIN DISCUSSION

A major barrier to progress has been the absence of large-scale early-life screening. Most SCD deaths in Africa probably occur before cases are even diagnosed. In the last few years, novel inexpensive SCD point-of-care test kits have become widely available and have been deployed successfully in African field settings. These kits could potentially enable universal early SCD screening. Other recent developments are the expansion of the pneumococcal conjugate vaccine towards near-universal coverage, and the demonstrated safety, efficacy, and increasing availability and affordability of hydroxyurea across the continent. Most elements of standard healthcare for SCD children that are already proven to work in the West, could and should now be implemented at scale in Africa. National and continental SCD research and care networks in Africa have also made substantial progress, assembling care guidelines and enabling the deployment and scale-up of SCD public-health systems. Substantial logistical, cultural, and awareness barriers remain, but with sufficient financial and political will, similar barriers have already been overcome in efforts to control other diseases in Africa.

CONCLUSION AND RECOMMENDATIONS

Despite remaining challenges, several high-SCD-burden African countries have the political will and infrastructure for the rapid implementation and scale-up of comprehensive SCD childcare programs. A globally funded effort starting with these countries and expanding elsewhere in Africa and to other high-burden countries, including India, could transform the lives of SCD children worldwide and help countries to attain their Sustainable Development Goals. This endeavor would also require ongoing research focused on the unique needs and challenges of SCD patients, and children in particular, in regions of high prevalence.

Newborn Screening for Sickle Cell Disease Using Point-of-Care Testing in Low-Income Setting

BACKGROUND

Newborn screening provides early diagnosis for children with sickle cell disease (SCD), reducing disease-related mortality. We hypothesized that rapid point-of-care (POC) Sickle SCAN would be reliable in Haiti and would assist newborn screening.

METHODS

Dried blood specimens were obtained from infant heel sticks and analyzed by isoelectric focusing (IEF) at a public hospital in Cap-Haïtien during a 1-year period. A total of 360 Guthrie cards were also analyzed for quality assurance by high-performance liquid chromatography at the Florida Newborn Screening Laboratory. In addition, two-thirds of the infants were also screened by the POC to assess differences with the IEF. The hemoglobinopathy incidence and the specificity and sensitivity of the POC scan were assessed.

RESULTS

Overall, 1.48% of the children screened positive for SCD. The specificity and the sensitivity of POC Sickle SCAN were 0.97 (confidence interval 0.95-0.99) and 0.90 (confidence interval 0.55-1.00), respectively, relative to high-performance liquid chromatography gold standard. The confirmatory testing rate was 75% before POC and improved to 87% after POC was added for dual screening. Confirmatory testing revealed that 0.83% of children screened had SCD. Children who screened positive for SCD by POC started penicillin earlier, had their first pediatric follow-up a median of 38 days earlier, and received antipneumococcal vaccination on time when compared with those who screened positive for SCD by IEF alone.

CONCLUSIONS

The observational study revealed a high incidence of SCD among Haitian newborns. Sickle SCAN had excellent specificity and sensitivity to detect SCD during newborn screening and shortened health care access for children positive for SCD.

Sickle cell disease in anaemic children in a Sierra Leonean district hospital: a case series

Sickle cell disease (SCD) is the most common inherited haemoglobinopathy wordwide, with the highest prevalence in sub-Saharan Africa. Due to the lack of national strategies and scarcity of diagnostic tools in resource-limited settings, the disease may be significantly underdiagnosed. We carried out a 6-month retrospective review of paediatric admissions in a district hospital in northern Sierra Leone. Our aim was to identify patients with severe anaemia, defined as Hb < 7 g/dl, and further analyse the records of those tested for SCD. Of the 273 patients identified, only 24.5% had had an Emmel test, among which 34.3% were positive. Furthermore, only 17% of patients with a positive Emmel test were discharged on prophylactic antibiotics. Our study shows that increased awareness of SCD symptoms is required in high-burden areas without established screening programmes. In addition, the creation or strengthening of follow-up programmes for SCD patients is essential for disease control.

Overreliance on Cost Reduction as a Featured Element of Sensor Design

In this Perspective, we examine the role of cost in sensor design, its meaning within the context of converting academic prototypes into commercial products, and the importance of these issues to clear scientific communication. The possible motivations to consider the cost of a technology, sensor, or assay are both numerous and apparent. However, the idea that the cost of reagents and materials at the laboratory scale will directly translate to the purchase price for a user is inaccurate. While calculating the bill of materials is easy, there are many business considerations that make commercial products entirely different from academic prototypes. With these critical aspects of commercialization considered, academics are often not equipped to predict what the final price of an assay, sensor, or instrument will be to the end user. When used without proper context and accuracy, an overreliance on the phrase "low cost" in the absence of a sufficient discussion of cost weakens the meaning of this popular term and precludes practical scientific advancements. To demonstrate how the relationship between a bill of materials and "expected purchase price" breaks down when considering academic innovations, we discuss pregnancy tests as a case study where an academic bill of materials can lead to both overestimations and underestimations of pricing.