An urgent need for community lot testing of lateral flow fentanyl test strips marketed for harm reduction in Northern America.

BACKGROUND: Fentanyl test strips (FTS) are lateral flow immunoassay strips designed for detection of ng/mL levels of fentanyl in urine. In 2021, the US Centers for Disease Control and the Substance Abuse and Mental Health Administration stated that federal funds could be used for procurement of FTS for harm reduction strategies approved by the government such as drug checking. The market for FTS has expanded rapidly in the US and Canada. However, there is no regulatory oversight by either government to ensure proper function of FTS that are being marketed for drug checking. MAIN BODY: Many brands of FTS have rapidly entered the harm reduction market, creating concerns about the reproducibility and accuracy of their performance from brand to brand and lot to lot. Some examples are provided in this Comment. Similar problems with product quality were observed in the mid 2000's when lateral flow immunoassays for malaria were funded in many countries and again in 2020, when COVID-19 tests were in huge demand. The combination of high demand and low levels of regulation and enforcement led some manufacturers to join the goldrush without adequate field testing or quality assurance. We argue that the harm reduction community urgently needs to set a lot checking program in place. A set of simple protocols for conducting the tests and communicating the results have been developed, and are described in the following Perspectives paper in this issue. CONCLUSION: In the absence of governmental regulation and enforcement, the harm reduction community should implement a FTS lot checking program. Based on previous experience with the malaria diagnostic lot checking program, this inexpensive effort could identify products that are not suitable for harm reduction applications and provide valuable feedback to manufacturers. Dissemination of the results will help harm reduction organizations to ensure that FTS they use for drug checking are fit for the purpose.

Development and application of a colloidal-gold immunochromatographic strip for detecting Getah virus antibodies.

Getah virus (GETV) is a re-emerging mosquito-borne alphavirus that is highly pathogenic, mainly to pigs and horses. There are no vaccines or treatments available for GETV in swine in China. Therefore, the development of a simple, rapid, specific, and sensitive serological assay for GETV antibodies is essential for the prevention and control of GETV. Current antibody monitoring methods are time-consuming, expensive, and dependent on specialized instrumentation, and these features are not conducive to rapid detection in clinical samples. To address these problem, we developed immunochromatographic test strips (ICTS) using eukaryotically expressed soluble recombinant p62-E1 protein of GETV as a labelled antigen, which has good detection sensitivity and no cross-reactivity with other common porcine virus-positive sera. The ICTS is highly compatible with IFA and ELISA and can be stored for 1 month at 37 °C and for at least 3 months at room temperature. Hence, p62-E1-based ICTS is a rapid, accurate, and convenient method for rapid on-site detection of GETV antibodies. KEY POINTS: • We established a rapid antibody detection method that can monitor GETV infection • We developed colloidal gold test strips with high sensitivity and specificity • The development of colloidal gold test strips will aid in the field serologic detection of GETV.

Immunochromatography Lateral Flow Strip Enhancement Based on Passive Gold Nanoparticles Conjugation to Detect Schistosma haematobium Antigens in Human Serum.

PURPOSE: This study aimed to develop and evaluate a lateral flow card for the detection of active Schistosoma haematobium infection. METHODS: In order to prepare the immunochromatography lateral flow strip (ICLFS), antibodies purified from schistosomiasis were conjugated passively with gold nanoparticles using a potassium carbonate buffer. RESULTS: The novel ICLFS was able to correctly identify 64 out of 67 samples of schistosomiasis, 6 out of 90 samples of other parasites, and 0 out of 27 control samples. Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were 95.5%, 93.3%, 90%, and 91.4% respectively. Comparatively, the sensitivity, specificity, NPV, and PPV of sandwich enzyme-linked immunosorbent assays (ELISA) conjugated with gold nanoparticles (AuNPs) were 91.1%, 88.8%, 85.9%, and 84.4% respectively. The increased sensitivity and specificity of ICLFS produced superior results to those of sandwich ELISA. CONCLUSION: In conclusion, ICLFS is more beneficial and precise than sandwich ELISA for detection of S. haematobium infection at early stage.

Efficacy of praziquantel drug against Schistosoma haematobium and performance of urine reagent strips among pre-and-school aged children during the high transmission season in North-Western Tanzania.

The World Health Organization calls for schistosomiasis endemic countries to regularly monitor the efficacy of Praziquantel (PZQ) drug, the only antischistosomal drug used for four decades in Tanzania. In response to that call, the current study investigated the efficacy of single dose of PZQ against Schistosoma haematobium during the high transmission season and further assessed, the sensitivity and specificity of urine reagent strips before and after treatment. The study recruited a total of 2,498 -children aged (4 -17 years old) who provided a single urine sample that was visually examined for macro-haematuria, then using urine dipstick and urine filtration technique for microhaematuria and the presence of S. haematobium eggs. The baseline prevalence of S. haematobium eggs positive based on urine filtration test was 29.2 % (95 %CI:27.5-31.0) and that of microhaematuria was 43.1 % (95 %CI:41.1-45.0). Of the infected participants, 40.9 % (95 %CI:37.4-44.6) had a heavy intensity of infection and the geometrical mean intensity (GMI) of infection was 33.7 eggs/10mls of urine. A single dose of PZQ reduced the prevalence of infection to 16.2 %, the GMI of infection to 18.8eggs/10mls of urine and that of microhaematuria to 27.9 %. Cure rate and egg reduction rates (ERR) were 83.8 % and 44.3 % respectively. At baseline, the sensitivity and specificity of the urine reagent strips were 59.7 % and 93.8 %, whereas at post-treatment they were 16.7 % and 93.6 %. When PZQ drug is administered during the high transmission season, its efficacy in term of ERR is poor. The urine reagent strips had low sensitivity but high specificity at pre-and-post PZQ treatment.

Development of immunochromatographic strip assay to detect recent infection of Japanese encephalitis virus in swine population.

Japanese Encephalitis (JE) is a mosquito borne re-emerging viral zoonotic disease. Sero-conversion in swine occurs 2-3 weeks before human infection, thus swine act as a suitable sentinel for predicting JE outbreaks in humans. The present study was undertaken with the objective of developing immunochromatographic strip (ICS) assay to detect recent infection of Japanese Encephalitis virus (JEV) in swine population. The two formats of ICS assay were standardized. In the first format, gold nanoparticles (GNP) were conjugated with goat anti-pig IgM (50 µg/ml) followed by spotting of recombinant NS1 protein (1 mg/ml) of JEV on NCM as test line and protein G (1 mg/ml) as control line. In the format-II, GNP were conjugated with rNS1 protein (50 µg/ml) followed by spotting of Goat anti-pig IgM (1 mg/ml) as test line and IgG against rNS1 (1 mg/ml) as control line. To decrease the non- specific binding, blocking of serum and nitrocellulose membrane (NCM) was done using 5% SMP in PBS-T and 1% BSA, respectively. Best reaction conditions for the assay were observed when 10 µl of GNP conjugate and 50 µl of 1:10 SMP blocked sera was reacted on BSA blocked NCM followed by reaction time of 15 mins. Samples showing both test and control line were considered positive whereas samples showing only control line were considered negative. A total of 318 field swine sera samples were screened using indirect IgM ELISA and developed ICS assay. Relative diagnostic sensitivity and specificity of format-I was 81.25% and 93.0% whereas of format-II was 87.50% and 62.93%, respectively. Out of 318 samples tested, 32 were positive through IgM ELISA with sero-positivity of 10.06% while sero-positivity with format-I of ICS was 8.1%. Owing to optimal sensitivity and higher specificity of format-I, it was validated in three different labs and the kappa agreement ranged from 0.80 to 1, which signifies excellent repeatability of the developed assay to test field swine sera samples for detecting recent JEV infection.

Rapid, on-site quantitative determination of mycotoxins in grains using a multiple time-resolved fluorescent microsphere immunochromatographic test strip.

The label probe plays a crucial role in enhancing the sensitivity of lateral flow immunoassays. However, conventional fluorescent microspheres (FMs) have limitations due to their short fluorescence lifetime, susceptibility to background fluorescence interference, and inability to facilitate multi-component detection. In this study, carboxylate-modified Eu(III)-chelate-doped polystyrene nanobeads were employed as label probes to construct a multiple time-resolved fluorescent microsphere-based immunochromatographic test strip (TRFM-ICTS). This novel TRFM-ICTS facilitated rapid on-site quantitative detection of three mycotoxins in grains: Aflatoxin B1 (AFB1), Zearalenone (ZEN), and Deoxynivalenol (DON). The limit of detection (LOD) for AFB1, ZEN, and DON were found to be 0.03 ng/g, 0.11 ng/g, and 0.81 ng/g, respectively. Furthermore, the TRFM-ICTS demonstrated a wide detection range for AFB1 (0.05-8.1 ng/g), ZEN (0.125-25 ng/g), and DON (1.0-234 ng/g), while maintaining excellent selectivity. Notably, the test strip exhibited remarkable stability, retaining its detection capability even after storage at 4 °C for over one year. Importantly, the detection of these mycotoxins relied solely on simple manual operations, and with a portable reader, on-site detection could be accomplished within 20 min. This TRFM-ICTS presents a promising solution for sensitive on-site mycotoxin detection, suitable for practical application in various settings due to its sensitivity, accuracy, simplicity, and portability.

A comprehensive review of aptamer screening and application for lateral flow strip: Current status and future perspectives.

The detection of biomarkers is of great significance for medical diagnosis, food safety, environmental monitoring, and agriculture. However, bio-detection technology at present often necessitates complex instruments, expensive reagents, specialized expertise, and prolonged procedures, making it challenging to fulfill the demand for rapid, sensitive, user-friendly, and economical testing. In contrast, lateral flow strip (LFS) technology offers simple, fast, and visually accessible detection modality, allowing real-time analysis of clinical specimens, thus finding widespread utility across various domains. Within the realm of LFS, the application of aptamers as molecular recognition probes presents distinct advantages over antibodies, including cost-effectiveness, smaller size, ease of synthesis, and chemical stability. In recent years, aptamer-based LFS has found extensive application in qualitative, semi-quantitative, and quantitative detection across food safety, environmental surveillance, clinical diagnostics, and other domains. This review provided a concise overview of different aptamer screening methodologies, selection strategies, underlying principles, and procedural, elucidating their respective advantages, limitations, and applications. Additionally, we summarized recent strategies and mechanisms for aptamer-based LFS, such as the sandwich and competitive methods. Furthermore, we classified LFSs constructed based on aptamers, considering the rapid advancements in this area, and discussed their applications in biological and chemical detection. Finally, we delved into the current challenges and future directions in the development of aptamer and aptamer-based LFS. Although this review was not thoroughly, it would serve as a valuable reference for understanding the research progress of aptamer-based LFS and aid in the development of new types of aptasensors.

Rational design of peptide-based fluorescent probe for sequential recognitions of Cu(II) ions and glyphosate: Smartphone, test strip, real sample and living cells applications.

A new peptide-based fluorescent probe named DMDH with easy-to-synthesize, excellent stability, good water solubility and large Stokes shift (225 nm) was synthesized for highly selective sequential detections of copper ions (Cu2+) and glyphosate (Glyp). DMDH demonstrated great detection performance towards Cu2+via strong fluorescence quenching, and forming non-fluorescence DMDH-Cu2+ ensemble. As a new promising cascade probe, the fluorescence of DMDH-Cu2+ ensemble was significantly recovered based on displacement approach after glyphosate was added. Interestingly, the limit of detections (LODs) for Cu2+ and glyphosate were 40.6 nM and 10.6 nM, respectively, which were far lower than those recommended by the WHO guidelines for drinking water. More importantly, DMDH was utilized to evaluate Cu2+ and glyphosate content in three real water samples, demonstrating that its effectiveness in water quality monitoring. Additionally, it is worth noting that DMDH was also applied to analyze Cu2+ and glyphosate in living cells in view of significant cells permeability and low cytotoxicity. Moreover, DMDH soaked in filter paper was used to create qualitative test strips and visually identify Cu2+ and glyphosate through significant color changes. Furthermore, smartphone RGB color recognition provided a new method for semi-quantitative testing of Cu2+ and glyphosate in the absence of expensive instruments.

Development of a time-resolved immunochromatographic test strip for rapid and quantitative determination of GFAP in serum.

Glial fibrillary acidic protein (GFAP) in serum has been shown as a biomarker of traumatic brain injury (TBI) which is a significant global public health concern. Accurate and rapid detection of serum GFAP is critical for TBI diagnosis. In this study, a time-resolved fluorescence immunochromatographic test strip (TRFIS) was proposed for the quantitative detection of serum GFAP. This TRFIS possessed excellent linearity ranging from 0.05 to 2.5 ng/mL for the detection of serum GFAP and displayed good linearity (Y = 598723X + 797198, R2 = 0.99), with the lowest detection limit of 16 pg/mL. This TRFIS allowed for quantitative detection of serum GFAP within 15 min and showed high specificity. The intra-batch coefficient of variation (CV) and the inter-batch CV were both < 4.0%. Additionally, this TRFIS was applied to detect GFAP in the serum samples from healthy donors and patients with cerebral hemorrhage, and the results of TRFIS could efficiently discern the patients with cerebral hemorrhage from the healthy donors. Our developed TRFIS has the characteristics of high sensitivity, high accuracy, and a wide linear range and is suitable for rapid and quantitative determination of serum GFAP on-site.

Development of a time-resolved immunochromatographic test strip for rapid and quantitative determination of retinol-binding protein 4 in urine.

Urine retinol-binding protein 4 (RBP4) has recently been reported as a novel earlier biomarker of chronic kidney disease (CKD) which is a global public health problem with high morbidity and mortality. Accurate and rapid detection of urine RBP4 is essential for early monitor of impaired kidney function and prevention of CKD progression. In the present study, we developed a time-resolved fluorescence immunochromatographic test strip (TRFIS) for the quantitative and rapid detection of urine RBP4. This TRFIS possessed excellent linearity ranging from 0.024 to 12.50 ng/mL for the detection of urine RBP4, and displayed a good linearity (Y = 239,581 × X + 617,238, R2 = 0.9902), with the lowest visual detection limit of 0.049 ng/mL. This TRFIS allows for quantitative detection of urine RBP4 within 15 min and shows high specificity. The intra-batch coefficient of variation (CV) and the inter-batch CV were both < 8%, respectively. Additionally, this TRFIS was applied to detect RBP4 in the urine samples from healthy donors and patients with CKD, and the results of TRFIS could efficiently discern the patients with CKD from the healthy donors. The developed TRFIS has the characteristics of high sensitivity, high accuracy, and a wide linear range, and is suitable for rapid and quantitative determination of urine RBP4.

Development of a quantum dots based immunochromatographic strip for rapid and on-site detection of African swine fever virus.

African swine fever (ASF) is a lethal disease caused by ASF virus (ASFV), severely impacting the global swine industry. Though nuclear acid-based detection methods are reliable, they are laboratory-dependent. In this study, we developed a device-independent, user friendly and cost-effective quantum dots based immunochromatographic strip (QDs-ICS) with high specificity and sensitivity for the rapid and on-site detection of ASFV antigen. For the preparation of the QDs-ICS, we generated a monoclonal antibody (mAb) mAb-8G8 and polyclonal antibody (pAb) against ASFV-p72 protein. The pAb was labelled with QDs to be used as the detection probe and the mAb-8G8 was coated on the nitrocellulose membrane as the test line. Our results proved that the strip displayed no cross-reactivity with other swine viruses and detection limit of the QDs-ICS was down to 1 ng/mL for the ASFV-p72 protein with great reproducibility. The strip also exhibited high stability with a storage period up to 12 months under room temperature. Twenty blind samples and one hundred clinical samples were examined by the QDs-ICS, conventional PCR and real-time PCR method, respectively. Results showed that the agreement rate between the QDs-ICS and PCR method was 100%, and the agreement rate between the strip and real-time PCR was 94%. The novel QDs-ICS developed here would be an effective tool for on-site detection of ASFV.

A lateral flow strip for on-site detection of homocysteine based on a truncated aptamer.

An elevated level of homocysteine (Hcy) in serum is closely related to the development of various diseases. Therefore, homocysteine has been widely employed as a biomarker in medical diagnosis and the on-site detection of homocysteine is highly desired. In this study, a truncated highly specific aptamer for homocysteine was screened and used to design a lateral flow strip (LFS) for the detection of homocysteine. The aptamer was derived from a previously reported sequence. Based on the result of molecular docking, the original sequence was subjected to truncation, resulting in a reduction of the length from 66 nt to 55 nt. Based on the truncated aptamer, the LFS was designed for the detection of homocysteine. In the presence of homocysteine, the aptamer selectively binds to it, releasing cDNA from the aptamer/cDNA duplex. This allows cDNA to bind to the capture probe immobilized on the T zone of the strip, resulting in a red signal on the T zone from gold nanoparticles (AuNPs). The strip enables the visual detection of homocysteine in 5 min. Quantitative detection can be facilitated with the aid of ImageJ software. In this mode, the linear detection range for homocysteine is within 5-50 µM, with a detection limit of 4.18 µM. The strip has been effectively utilized for the detection of homocysteine in human serum. Consequently, the combination of the truncated aptamer and the strip offers a method that is sensitive, quick, and economical for the on-site detection of homocysteine.

Establishment and application of a gold nanoparticle-based immunochromatographic test strip for the detection of avian leukosis virus P27 antigen in egg white samples.

Avian leukemia is an infectious tumorous disease of chickens caused by subgroup A of the avian leukemia virus (ALV-A), which mainly causes long-term viremia, slow growth, immune suppression, decreased production performance, multi-tissue tumors, and even death. The infection rate of this disease is very high in chicken herds in China, causing huge economic losses to the poultry industry every year. We successfully expressed the specific antigen protein of ALV (P27) through recombinant protein technology and screened a pair of highly sensitive monoclonal antibodies (mAbs) through mouse immunity, cell fusion, and antibody pairing. Based on this pair of antibodies, we established a dual antibody sandwich ELISA and gold nanoparticle immunochromatographic strip (AuNP-ICS) detection method. In addition, the parameters of the dual antibody sandwich ELISA and AuNP-ICS were optimized under different reaction conditions, which resulted in the minimum detection limits of 0.2 ng mL-1 and 1.53 ng ml-1, respectively. Commonly available ELISA and AuNP-ICS products on the market were compared, and we found that our established immune rapid chromatography had higher sensitivity. This established AuNP-ICS had no cross-reactivity with Influenza A (H1N1), Influenza A (H9N2), respiratory syncytial virus (RSV), varicella-zoster virus (VZV), Listeria monocytogenes listeriolysin (LLO), and Staphylococcal enterotoxin SED or SEC. Finally, the established AuNP-ICS was used to analyze 35 egg samples, and the results showed 5 positive samples and 30 negative samples. The AuNP-ICS rapid detection method established by our group had good specificity, high sensitivity, and convenience, and could be applied to the clinical sample detection of ALV-A.

Method Development for Omics Analyses using Schirmer Strips.

PURPOSE: The aim of this article was to investigate whether Schirmer strips gathered during clinical dry eye examinations can be prepared for omics analyses in a standardized way, to adjust for variations in tear volume and enable two separate omics analyses from the same sample. In addition, the intention was to investigate whether fluorescein dye instillation in the eyes gave bias effects on metabolomic analysis. METHODS: Twelve samples from six individuals, with normal or reduced tear production, were collected. Half of the samples were harvested after instillation of fluorescein in the eye. Each strip was divided in half along the length and prepared with a new method for extracting tear content from the Schirmer strip. The new method was established to compensate for different dilutions of metabolites in varying Schirmer strip wetting levels when using identical extraction volume for all samples. Metabolomic data were compared in samples with and without fluorescein dye and Schirmer strips ranging from 1 to 35 mm wetting levels using a global LC-MS method. RESULTS: All samples were successfully analyzed with an average of ∼350 relevant features detected per sample after using both positive and negative electrospray ionization mode, despite low tear volumes in some samples and that only one half of the Schirmer strips were used. Principal component analysis plots and heatmaps revealed no bias effects of fluorescein dye presence or different Schirmer strip values when using the proposed method. CONCLUSION: A high number of relevant metabolomic features can be extracted from longitudinally cut halves of Schirmer strips, which may enable analyses with more than one omics modality from the same sample. With the pre-analytical method described, Schirmer strips can be used for metabolomic analyses even in cases of very low or high tear volume with or without fluorescence.

The Development of Aptamer-Based Gold Nanoparticle Lateral Flow Test Strips for the Detection of SARS-CoV-2 S Proteins on the Surface of Cold-Chain Food Packaging.

The COVID-19 pandemic over recent years has shown a great need for the rapid, low-cost, and on-site detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this study, an aptamer-based colloidal gold nanoparticle lateral flow test strip was well developed to realize the visual detection of wild-type SARS-CoV-2 spike proteins (SPs) and multiple variants. Under the optimal reaction conditions, a low detection limit of SARS-CoV-2 S proteins of 0.68 nM was acquired, and the actual detection recovery was 83.3% to 108.8% for real-world samples. This suggests a potential tool for the prompt detection of SARS-CoV-2 with good sensitivity and accuracy, and a new method for the development of alternative antibody test strips for the detection of other viral targets.

Development of a colloidal gold immunochromatographic strip for rapid detection of avian coronavirus infectious bronchitis virus.

Avian infectious bronchitis virus (IBV) still causes serious economic losses in the poultry industry. Currently, there are multiple prevalent genotypes and serotypes of IBVs. It is imperative to develop a new diagnosis method that is fast, sensitive, specific, simple, and broad-spectrum. A monoclonal hybridoma cell, N2D5, against the IBV N protein was obtained after fusion of myeloma SP2/0 cells with spleen cells isolated from the immunized Balb/c mice. The N2D5 monoclonal antibody (mAb) and the previously prepared mouse polyclonal antibody against the IBV N protein were used to target IBV as a colloidal gold-mAb conjugate and a captured antibody, respectively, in order to develop an immunochromatographic strip. The optimal pH and minimum antibody concentration in the reaction system for colloidal gold-mAb N2D5 conjugation were pH 6.5 and 30 µg/mL, respectively. Common avian pathogens were tested to evaluate the specificity of the strip and no cross-reaction was observed. The sensitivity of the strip for detecting IBV was 10-1.4522 EID50/mL. The strip showed a broad-spectrum cross-reactive capacity for detecting IBV antigens, including multiple IBV genotypes in China and all of the seven serotypes of IBV that are currently prevalent in southern China. Additionally, the result can be observed within 2 min without any equipment. The throat and cloacal swab samples of chickens that were artificially infected with three IBV strains were tested using the developed strip and the qPCR method; the strip test demonstrated a high consistency in detecting IBV via qPCR gene detection. In conclusion, the immunochromatographic strip that was established is rapid, sensitive, specific, simple, practical, and broad-spectrum; additionally, it has the potential to serve as an on-site rapid detection method of IBV and can facilitate the surveillance and control of the disease, especially in resource-limited areas.

Diagnostic tests for human Schistosoma mansoni and Schistosoma haematobium infection: a systematic review and meta-analysis.

BACKGROUND: Accurate diagnosis is pivotal for implementing strategies for surveillance, control, and elimination of schistosomiasis. Despite their low sensitivity in low-endemicity areas, microscopy-based urine filtration and the Kato-Katz technique are considered as reference diagnostic tests for Schistosoma haematobium and Schistosoma mansoni infections, respectively. We aimed to collate all available evidence on the accuracy of other proposed diagnostic techniques. METHODS: In this systematic review and meta-analysis, we searched PubMed, Embase, the Cochrane Library, and LILACS for studies published from database inception to Dec 31, 2022, investigating the sensitivity and specificity of diagnostic tests for S haematobium and S mansoni infections against Kato-Katz thick smears or urine microscopy (reference tests) involving adults (aged ≥18 years), school-aged children (aged 7 to 18 years), or preschool-aged children (aged 1 month to 7 years). We extracted raw data on true positives, true negatives, false positives, and false negatives for the diagnostic tests and data on the number of participants, study authors, publication year, journal, study design, participants' age and sex, prevalence of Schistosoma infection, and treatment status. To account for imperfect reference tests, we used a hierarchical Bayesian latent class meta-analysis to model test accuracy. FINDINGS: Overall, we included 121 studies, assessing 28 different diagnostic techniques. Most studies (103 [85%] of 121) were done in Africa, 14 (12%) in South America, one (1%) in Asia, and one (1%) in an unknown country. Compared with the reference test, Kato-Katz thick smears, circulating cathodic antigen urine cassette assay version 1 (CCA1, 36 test comparisons) had excellent sensitivity (95% [95% credible interval 88-99]) and reasonable specificity (74% [63-83]) for S mansoni. ELISA-based tests had a performance comparable to circulating cathodic antigen, but there were few available test comparisons. For S haematobium, proteinuria (42 test comparisons, sensitivity 73% [62-82]; specificity 94% [89-98]) and haematuria (75 test comparisons, sensitivity 85% [80-90]; specificity 96% [92-99]) reagent strips showed high specificity, with haematuria reagent strips having better sensitivity. Despite limited data, nucleic acid amplification tests (NAATs; eg, PCR or loop-mediated isothermal amplification [LAMP]) showed promising results with sensitivity estimates above 90%. We found an unclear risk of bias of about 70% in the use of the reference or index tests and of 50% in patient selection. All analyses showed substantial heterogeneity (I2>80%). INTERPRETATION: Although NAATs and immunological diagnostics show promise, the limited information available precludes drawing definitive conclusions. Additional research on diagnostic accuracy and cost-effectiveness is needed before the replacement of conventional tests can be considered. FUNDING: WHO and Luxembourg Institute of Health.

Construction of test strips for lung cancer detection based on aptamers.

Lung cancer is the most common malignancy worldwide. Early diagnosis helps to reduce mortality and improve survival. Aptamers are widely used in cancer screening because of their high specificity, good stability and low cost. In this study, using the specific aptamer of lung cancer serum, the sandwich method colloidal gold test strip was prepared by isothermal amplification technique and the principle of nucleic acid hybridisation for the early diagnosis of lung cancer. The results showed that the test strip was positive in 8 patients with lung cancer, which was consistent with the actual cases. The test strip can accurately identify lung cancer patients. The concentration range of nucleic acid detection is 1 × 10-4 - 7 × 10-4 mol/L, and the detection limit is 0.67 mM. The test strip detection method has low cost and simple operation, and provides a reference for the development of home portable tumor early detection.