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Fulltext Association between smoking and periodontal disease: a review of the literature

Ramli J, Taiyeb Ali TB

Ann Dent, 1999;6(1):21-6.
MyJurnal

The role of smoking as a contributory factor in the progression of the periodontal disease process has long been suspected and recently a large number of studies have been published in the dental literature regarding this possible role. Much of the literature has also indicated that smokers affected with periodontitis respond less favorably to periodontal treatment be it non-surgical, surgical and regenerative. This paper will review the current literature regarding the effects of smoking on various aspects of the periodontal disease process and present an explanation for the possible association between smoking and the progression of periodontitis.
Relationship of periodontal disease to pre-term low birth weight infants in a selected population--a prospective study

Ali TB, Abidin KZ

Community Dent Health, 2012 Mar;29(1):100-5.
PMID: 22482259

To assess effect of periodontal status of antenatal mothers on pregnancy outcomes in a selected population in Malaysia.
Fulltext Outcomes of placing short implants in the posterior mandible: a preliminary randomized controlled trial

Al-Hashedi AA, Taiyeb-Ali TB, Yunus N

Aust Dent J, 2016 06;61(2):208-18.
PMID: 25966305 DOI: 10.1111/adj.12337

BACKGROUND: Short dental implants can be an alternative to bone augmentation procedures at sites of reduced alveolar bone. Most studies on short implants are retrospective or multicentre reports that lack controlled and consistent comparison between different systems. This study aimed to compare clinical and radiographic outcomes of short implants in two different systems in the posterior mandible.
METHODS: Twenty patients with two adjacent missing posterior teeth were recruited. Patients were assigned equally and randomly into two groups; Bicon(®) (6 or 8 mm) and Ankylos(®) (8 mm) implants. A two-stage surgical approach and single crowns were used for implant placement and loading. Outcomes included peri-implant clinical parameters, implant stability (Periotest values; PTVs) and peri-implant bone changes, which were assessed at baseline, 2, 6 and 12 months post-loading.
RESULTS: No implant loss was encountered up to 12 months post-loading. No significant difference in the clinical or radiographic parameters was observed except for PTVs (p < 0.05) that was lower in Ankylos(®) implants.
CONCLUSIONS: The use of short dental implants was associated with excellent 12 months clinical and radiographic outcomes. Ankylos(®) and Bicon(®) implants demonstrated similar peri-implant soft tissue and alveolar bone changes. However, Ankylos(®) implants demonstrated better implant stability at all evaluation intervals.
Bullous pemphigoid--management of a patient with oral and skin lesions

Ali TB, Zain RB, Adam BA

Singapore Dent J, 1994 Jan;19(1):18-21.
PMID: 9582679

A case of bullous pemphigoid with extra-oral and intraoral lesions in a 60-year-old female is reported. Diagnosis is based on histopathology and direct immunofluorescence, and the treatment regime described included oral prescription of prednisolone and topical application of a mixture of fluocinonide ointment and triamcinolone acetonide in Orabase on the oral lesions.
Calcifying fibroblastic granuloma. A case report

Taiyeb Ali TB, Siar CH

J N Z Soc Periodontol, 1997.
PMID: 9522721
The effect of systemic ibuprofen on gingival inflammation in humans

Taiyeb Ali TB, Waite IM

J Clin Periodontol, 1993 Nov;20(10):723-8.
PMID: 8276982

This clinical trial investigated the influence of short-term ibuprofen therapy on the early phase of the treatment of adult chronic periodontitis. The subjects were 17 patients in good general health referred for specialist periodontal treatment, having moderate chronic adult periodontitis. A series of assessments were made every 2 weeks over an 8-week period, including evaluations of oral hygiene, gingival inflammation and probing pocket depths. All participants received oral hygiene instruction, and following baseline examinations, had half the dentition, chosen at random, treated by scaling and root planing. The patients were randomly distributed into 2 groups, a test group receiving a 14-day course of 800 mg ibuprofen daily, in 4 divided doses, and a control group who did not receive any drug regime. At the 2-week assessment following the drug regime, significantly greater reduction in gingival bleeding, colour and pocketing was detected in the test compared with the control group. The beneficial effects were less evident thereafter. Although clinical application of the regime used in this study would not be justified by these results, further research into anti-inflammatory agents as an adjunct in the treatment of periodontal diseases could be considered, in the light of the beneficial effect on gingivitis in the early phase of periodontal treatment reported.
Fulltext Qat Chewing and Periodontal Pathogens in Health and Disease: Further Evidence for a Prebiotic-Like Effect

Al-Alimi A, Taiyeb-Ali T, Jaafar N, Noor Al-hebshi N

Biomed Res Int, 2015;2015:291305.
PMID: 26351631 DOI: 10.1155/2015/291305

AIM: Qat chewing has been reported to induce subgingival microbial shifts suggestive of prebiotic-like properties. The objective here was to assess the effect of qat chewing on a panel of classical and new putative periopathogens in health and periodontitis.
MATERIALS AND METHODS: 40 qat chewers and 40 nonchewers, equally stratified by periodontal health status, were recruited. Taqman, real-time PCR was used to quantify total bacteria, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Parvimonas micra, Filifactor alocis, Synergistetes, and TM7s in pooled subgingival biofilm samples. Differences in microbial parameters between the study groups were analysed using ordinal regression.
RESULTS: In health, the qat chewers harboured significantly lower relative counts of P. gingivalis, T. forsythia, Synergistetes, and TM7s after adjustment for multiple comparisons (P ≤ 0.007). At nominal significance level, they also carried lower counts of TM7s and P. micra (P ≤ 0.05). In periodontitis, the chewers had lower counts of all taxa; however, only T. denticola withstood correction for multiple comparisons (P ≤ 0.0063).
CONCLUSIONS: Qat chewing is associated with lower proportions of periopathogens, particularly in subjects with healthy periodontium, which supports previous reports of its prebiotic-like properties. This potentially beneficial biological effect can be exploited by attempting to isolate the active fraction.
Prevalence of oral precancerous and cancerous lesions in elderly Malaysians

Ali TB, Jalalluddin RL, Abdul Razak I, Zain RB

Asia Pac J Public Health, 1996;9:24-7.
PMID: 10050195

A house to house survey on elderly subjects aged 60 years old and above was undertaken in a large district in Malaysia. A total of 486 subjects in randomly selected Enumeration Blocks were interviewed and examined. The prevalence of oral precancerous lesions was recorded at 3.3%, of which leukoplakia was the most common. When the ethnic distribution of these oral precancerous and cancerous (OPC) lesions was compared, 72% of those inflicted were Indians. Oral cancer was detected in two subjects (0.4%), both of whom were of Indian origin. Among subjects with OPC lesions, 4.2% were smokers, 12.7% were betelquid chewers, 11.8% had indulged in both habits, whilst one subject had not practised any of the oral habits of interest (0.4%). The findings suggest the occurrence of OPC lesions to be related to betelquid chewing.
Publication year=1996-1997
Epidemiology of clinically significant forms of alpha- and beta-thalassemia: A global map of evidence and gaps

Musallam KM, Lombard L, Kistler KD, Arregui M, Gilroy KS, Chamberlain C, et al.

Am J Hematol, 2023 Sep;98(9):1436-1451.
PMID: 37357829 DOI: 10.1002/ajh.27006

This systematic literature review assessed the global prevalence and birth prevalence of clinically significant forms of alpha- and beta-thalassemia. Embase, MEDLINE, and the Cochrane Library were searched for observational studies published January 1, 2000, to September 21, 2021. Of 2093 unique records identified, 69 studies reported across 70 publications met eligibility criteria, including 6 records identified from bibliography searches. Thalassemia prevalence estimates varied across countries and even within countries. Across 23 population-based studies reporting clinically significant alpha-thalassemia (e.g., hemoglobin H disease and hemoglobin Bart's hydrops fetalis) and/or beta-thalassemia (beta-thalassemia intermedia, major, and/or hemoglobin E/beta-thalassemia), prevalence estimates per 100 000 people ranged from 0.2 in Spain (over 2014-2017) to 27.2 in Greece (2010-2015) for combined beta- plus alpha-thalassemia; from 0.03 in Spain (2014-2017) to 4.5 in Malaysia (2007-2018) for alpha-thalassemia; and from 0.2 in Spain (2014-2017) to 35.7 to 49.6 in Iraq (2003-2018) for beta-thalassemia. Overall, the estimated prevalence of thalassemia followed the predicted pattern of being higher in the Middle East, Asia, and Mediterranean than in Europe or North America. However, population-based prevalence estimates were not found for many countries, and there was heterogeneity in case definitions, diagnostic methodology, type of thalassemia reported, and details on transfusion requirements. Limited population-based birth prevalence data were found. Twenty-seven studies reported thalassemia prevalence from non-population-based samples. Results from such studies likely do not have countrywide generalizability as they tended to be from highly specific groups. To fully understand the global prevalence of thalassemia, up-to-date, population-based epidemiological data are needed for many countries.
Fulltext New film-coated tablet formulation of deferasirox is well tolerated in patients with thalassemia or lower-risk MDS: Results of the randomized, phase II ECLIPSE study

Taher AT, Origa R, Perrotta S, Kourakli A, Ruffo GB, Kattamis A, et al.

Am J Hematol, 2017 May;92(5):420-428.
PMID: 28142202 DOI: 10.1002/ajh.24668

Once-daily deferasirox dispersible tablets (DT) have a well-defined safety and efficacy profile and, compared with parenteral deferoxamine, provide greater patient adherence, satisfaction, and quality of life. However, barriers still exist to optimal adherence, including gastrointestinal tolerability and palatability, leading to development of a new film-coated tablet (FCT) formulation that can be swallowed with a light meal, without the need to disperse into a suspension prior to consumption. The randomized, open-label, phase II ECLIPSE study evaluated the safety of deferasirox DT and FCT formulations over 24 weeks in chelation-naïve or pre-treated patients aged ≥10 years, with transfusion-dependent thalassemia or IPSS-R very-low-, low-, or intermediate-risk myelodysplastic syndromes. One hundred seventy-three patients were randomized 1:1 to DT (n = 86) or FCT (n = 87). Adverse events (overall), consistent with the known deferasirox safety profile, were reported in similar proportions of patients for each formulation (DT 89.5%; FCT 89.7%), with a lower frequency of severe events observed in patients receiving FCT (19.5% vs. 25.6% DT). Laboratory parameters (serum creatinine, creatinine clearance, alanine aminotransferase, aspartate aminotransferase and urine protein/creatinine ratio) generally remained stable throughout the study. Patient-reported outcomes showed greater adherence and satisfaction, better palatability and fewer concerns with FCT than DT. Treatment compliance by pill count was higher with FCT (92.9%) than with DT (85.3%). This analysis suggests deferasirox FCT offers an improved formulation with enhanced patient satisfaction, which may improve adherence, thereby reducing frequency and severity of iron overload-related complications.
MRI for the diagnosis of cardiac and liver iron overload in patients with transfusion-dependent thalassemia: An algorithm to guide clinical use when availability is limited

Viprakasit V, Ajlan A, Aydinok Y, Al Ebadi BAA, Dewedar H, Ibrahim AS, et al.

Am J Hematol, 2018 06;93(6):E135-E137.
PMID: 29473204 DOI: 10.1002/ajh.25075
Fulltext Patient-reported outcomes from a randomized phase II study of the deferasirox film-coated tablet in patients with transfusion-dependent anemias

Taher AT, Origa R, Perrotta S, Kouraklis A, Ruffo GB, Kattamis A, et al.

Health Qual Life Outcomes, 2018 Nov 19;16(1):216.
PMID: 30453981 DOI: 10.1186/s12955-018-1041-5

BACKGROUND: Adherence to long-term chelation therapy in transfusion-dependent patients is critical to prevent iron overload-related complications. Once-daily deferasirox dispersible tablets (DT) have proven long-term efficacy and safety in patients ≥2 years old with chronic transfusional iron overload. However, barriers to optimal adherence remain, including palatability, preparation time, and requirements for fasting state. A new film-coated tablet (FCT) formulation was developed, swallowed once daily (whole/crushed) with/without a light meal.
METHODS: The open-label, Phase II ECLIPSE study evaluated patient-reported outcomes (PROs) in transfusion-dependent thalassemia or lower-risk myelodysplastic syndromes patients randomized 1:1 to receive deferasirox DT or FCT over 24 weeks as a secondary outcome of the study. Three PRO questionnaires were developed to evaluate both deferasirox formulations: 1) Modified Satisfaction with Iron Chelation Therapy Questionnaire; 2) Palatability Questionnaire; 3) Gastrointestinal (GI) Symptom Diary.
RESULTS: One hundred seventy three patients were enrolled; 87 received the FCT and 86 the DT formulation. FCT recipients consistently reported better adherence (easier to take medication, less bothered by time to prepare medication and waiting time before eating), greater satisfaction/preference (general satisfaction and with administration of medicine), and fewer concerns (less worry about not swallowing enough medication, fewer limitations in daily activities, less concern about side effects). FCT recipients reported no taste or aftertaste and could swallow all their medicine with an acceptable amount of liquid. GI summary scores were low for both formulations.
CONCLUSIONS: These findings suggest a preference in favor of the deferasirox FCT formulation regardless of underlying disease or age group. Better patient satisfaction and adherence to chelation therapy may reduce iron overload-related complications.
TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02125877; registered April 26, 2014.
An epidemiological survey of oral mucosal lesions among elderly Malaysians

Taiyeb Ali TB, Razak IA, Raja Latifah RJ, Zain RB

Gerodontology, 1995 Jul;12(1):37-40.
PMID: 8626179

A house to house random survey on elderly subjects was undertaken in the District of Klang in Malaysia. The objective of this study was to investigate the prevalence of oral mucosal lesions (OML) among the elderly in this area. The primary units in the sampling frame were the Enumeration Blocks (EBs) as defined under the population census. All households of the selected EBs were considered as sampling units and members aged 60 and above were considered as respondents. There was a slight preponderance of females, with the Malays comprising the majority of the subjects. Of the 486 respondents, mean aged 69.1 +/- 7.3 yr, 111 had at least one oral mucosal lesion, a prevalence of 22.8%. A total of 145 lesions were detected. The prevalence of OML was highest among Indians and least among the Chinese. The most common finding was tongue lesions, recording a prevalence of 10.7%, followed by oral pigmentation (4.9%) and white lesions (4.3%). Denture related lesions were comparatively low at 2.5%. Two cases of oral cancer if representative would give a relatively high prevalence of 0.4%.
Fulltext DeepMoney: counterfeit money detection using generative adversarial networks

Ali T, Jan S, Alkhodre A, Nauman M, Amin M, Siddiqui MS

PeerJ Comput Sci, 2019;5:e216.
PMID: 33816869 DOI: 10.7717/peerj-cs.216

Conventional paper currency and modern electronic currency are two important modes of transactions. In several parts of the world, conventional methodology has clear precedence over its electronic counterpart. However, the identification of forged currency paper notes is now becoming an increasingly crucial problem because of the new and improved tactics employed by counterfeiters. In this paper, a machine assisted system-dubbed DeepMoney-is proposed which has been developed to discriminate fake notes from genuine ones. For this purpose, state-of-the-art models of machine learning called Generative Adversarial Networks (GANs) are employed. GANs use unsupervised learning to train a model that can then be used to perform supervised predictions. This flexibility provides the best of both worlds by allowing unlabelled data to be trained on whilst still making concrete predictions. This technique was applied to Pakistani banknotes. State-of-the-art image processing and feature recognition techniques were used to design the overall approach of a valid input. Augmented samples of images were used in the experiments which show that a high-precision machine can be developed to recognize genuine paper money. An accuracy of 80% has been achieved. The code is available as an open source to allow others to reproduce and build upon the efforts already made.
Independent determinants of periodontitis in Yemeni adults: A case-control study

Al-Alimi A, Halboub E, Al-Sharabi AK, Taiyeb-Ali T, Jaafar N, Al-Hebshi NN

Int J Dent Hyg, 2018 Nov;16(4):503-511.
PMID: 29963753 DOI: 10.1111/idh.12352

OBJECTIVES: The relative importance of risk factors of periodontitis varies from one population to another. In this study, we sought to identify independent risk factors of periodontitis in a Yemeni population.
METHODS: One hundred and fifty periodontitis cases and 150 healthy controls, all Yemeni adults 30-60 years old, were recruited. Sociodemographic data and history of oral hygiene practices and oral habits were obtained. Plaque index (PI) was measured on index teeth. Periodontal health status was assessed using Community Periodontal Index (CPI) and Clinical Attachment Loss (CAL) according to WHO. Periodontitis was defined as having one or more sextants with a CPI score ≥ 3. Multiple logistic regression modelling was employed to identify distal, intermediate and proximal determinants of periodontitis, while ordinal regression was used to identify those of CAL scores.
RESULTS: In logistic regression, PI score was associated with the highest odds of periodontitis (OR = 82.9) followed by cigarette smoking (OR = 12.8), water pipe smoking (OR = 10.2), male gender (OR = 3.4) and age (OR = 1.19); on the other hand, regular visits to the dentist (OR = 0.05), higher level of education (OR = 0.37) and daily dental flossing (OR = 0.95) were associated with lower odds. Somewhat similar associations were seen for CAL scores (ordinal regression); however, qat chewing was identified as an additional determinant (OR = 4.69).
CONCLUSION: Water pipe smoking is identified as a risk factor of periodontitis in this cohort in addition to globally known risk factors. Adjusted effect of qat chewing is limited to CAL scores, suggestive of association with recession.
Fulltext Stabilization and tracking control of underactuated ball and beam system using metaheuristic optimization based TID-F and PIDD2-PI control schemes

Zafar F, Malik SA, Ali T, Daraz A, Afzal AR, Bhatti F, et al.

PLoS One, 2024;19(2):e0298624.
PMID: 38354203 DOI: 10.1371/journal.pone.0298624

In this paper, we propose two different control strategies for the position control of the ball of the ball and beam system (BBS). The first control strategy uses the proportional integral derivative-second derivative with a proportional integrator PIDD2-PI. The second control strategy uses the tilt integral derivative with filter (TID-F). The designed controllers employ two distinct metaheuristic computation techniques: grey wolf optimization (GWO) and whale optimization algorithm (WOA) for the parameter tuning. We evaluated the dynamic and steady-state performance of the proposed control strategies using four performance indices. In addition, to analyze the robustness of proposed control strategies, a comprehensive comparison has been performed with a variety of controllers, including tilt integral-derivative (TID), fractional order proportional integral derivative (FOPID), integral-proportional derivative (I-PD), proportional integral-derivative (PI-D), and proportional integral proportional derivative (PI-PD). By comparing different test cases, including the variation in the parameters of the BBS with disturbance, we examine step response, set point tracking, disturbance rejection analysis, and robustness of proposed control strategies. The comprehensive comparison of results shows that WOA-PIDD2-PI-ISE and GWO-TID-F- ISE perform superior. Moreover, the proposed control strategies yield oscillation-free, stable, and quick response, which confirms the robustness of the proposed control strategies to the disturbance, parameter variation of BBS, and tracking performance. The practical implementation of the proposed controllers can be in the field of under actuated mechanical systems (UMS), robotics and industrial automation. The proposed control strategies are successfully tested in MATLAB simulation.
Fulltext Sedation depth and long-term mortality in mechanically ventilated critically ill adults: a prospective longitudinal multicentre cohort study

Shehabi Y, Chan L, Kadiman S, Alias A, Ismail WN, Tan MA, et al.

Intensive Care Med, 2013 May;39(5):910-8.
PMID: 23344834 DOI: 10.1007/s00134-013-2830-2

PURPOSE: To ascertain the relationship among early (first 48 h) deep sedation, time to extubation, delirium and long-term mortality.
METHODS: We conducted a multicentre prospective longitudinal cohort study in 11 Malaysian hospitals including medical/surgical patients (n = 259) who were sedated and ventilated ≥24 h. Patients were followed from ICU admission up to 28 days in ICU with 4-hourly sedation and daily delirium assessments and 180-day mortality. Deep sedation was defined as Richmond Agitation Sedation Score (RASS) ≤-3.
RESULTS: The cohort had a mean (SD) age of 53.1 (15.9) years and APACHE II score of 21.3 (8.2) with hospital and 180-day mortality of 82 (31.7%) and 110/237 (46.4%). Patients were followed for 2,657 ICU days and underwent 13,836 RASS assessments. Midazolam prescription was predominant compared to propofol, given to 241 (93%) versus 72 (28%) patients (P < 0.0001) for 966 (39.6%) versus 183 (7.5%) study days respectively. Deep sedation occurred in (182/257) 71% patients at first assessment and in 159 (61%) patients and 1,658 (59%) of all RASS assessments at 48 h. Multivariable Cox proportional hazard regression analysis adjusting for a priori assigned covariates including sedative agents, diagnosis, age, APACHE II score, operative, elective, vasopressors and dialysis showed that early deep sedation was independently associated with longer time to extubation [hazard ratio (HR) 0.93, 95% confidence interval (CI) 0.89-0.97, P = 0.003], hospital death (HR 1.11, 95% CI 1.05-1.18, P < 0.001) and 180-day mortality (HR 1.09, 95% CI 1.04-1.15, P = 0.002), but not time to delirium (HR 0.98, P = 0.23). Delirium occurred in 114 (44%) of patients.
CONCLUSION: Irrespective of sedative choice, early deep sedation was independently associated with delayed extubation and higher mortality, and thus was a potentially modifiable risk in interventional trials.
Fulltext Dielectrophoresis of Amyloid-Beta Proteins as a Microfluidic Template for Alzheimer's Research

Al-Ahdal SA, Ahmad Kayani AB, Md Ali MA, Chan JY, Ali T, Adnan N, et al.

Int J Mol Sci, 2019 Jul 23;20(14).
PMID: 31340481 DOI: 10.3390/ijms20143595

We employed dielectrophoresis to a yeast cell suspension containing amyloid-beta proteins (Aβ) in a microfluidic environment. The Aβ was separated from the cells and characterized using the gradual dissolution of Aβ as a function of the applied dielectrophoretic parameters. We established the gradual dissolution of Aβ under specific dielectrophoretic parameters. Further, Aβ in the fibril form at the tip of the electrode dissolved at high frequency. This was perhaps due to the conductivity of the suspending medium changing according to the frequency, which resulted in a higher temperature at the tips of the electrodes, and consequently in the breakdown of the hydrogen bonds. However, those shaped as spheroidal monomers experienced a delay in the Aβ fibril transformation process. Yeast cells exposed to relatively low temperatures at the base of the electrode did not experience a positive or negative change in viability. The DEP microfluidic platform incorporating the integrated microtip electrode array was able to selectively manipulate the yeast cells and dissolve the Aβ to a controlled extent. We demonstrate suitable dielectrophoretic parameters to induce such manipulation, which is highly relevant for Aβ-related colloidal microfluidic research and could be applied to Alzheimer's research in the future.
Detection of mobile colistin-resistance gene variants (mcr-1 and mcr-2) in urinary tract pathogens in Bangladesh: the last resort of infectious disease management colistin efficacy is under threat

Ara B, Urmi UL, Haque TA, Nahar S, Rumnaz A, Ali T, et al.

Expert Rev Clin Pharmacol, 2021 Apr;14(4):513-522.
PMID: 33691556 DOI: 10.1080/17512433.2021.1901577

Background: Currently, colistin-resistant pathogens emerged has become a global health concern. This study assessed the distribution of mcr-1 to mcr-5 variants with the phenotypic colistin-resistance in bacterial isolates from urinary tract infection (UTI) patients in Bangladesh.Methods: A cross-sectional study was conducted between April 2017 and March 2018 to enroll uncomplicated UTI patients, and 142 urine samples were analyzed. Uropathogens were identified using the API-20E biochemical panel and 16s rRNA gene sequencing. Polymerase chain reactions detected the mcr gene variants in the UTI isolates. The phenotypic colistin-susceptibility was determined by the Kirby-Bauer disc-diffusion method and the minimal inhibitory concentration (MIC) measurement.Results: The combined carriage of mcr-1 and mcr-2 genes in 11.4% (14/123) of urinary tract pathogens. The mcr-positive pathogens include five Escherichia coli, three Klebsiella pneumoniae, three Pseudomonas putida, two Enterobacter cloacae, and one Enterobacter hormaechei. The mcr-positive variant showed significantly higher phenotypic colistin resistance with MIC between >16 µg/mL and >128 µg/mL (p
Fulltext AuNP Coupled Rapid Flow-Through Dot-Blot Immuno-Assay for Enhanced Detection of SARS-CoV-2 Specific Nucleocapsid and Receptor Binding Domain IgG

Sil BK, Jamiruddin MR, Haq MA, Khondoker MU, Jahan N, Khandker SS, et al.

Int J Nanomedicine, 2021;16:4739-4753.
PMID: 34267520 DOI: 10.2147/IJN.S313140

BACKGROUND: Serological tests detecting severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) are widely used in seroprevalence studies and evaluating the efficacy of the vaccination program. Some of the widely used serological testing techniques are enzyme-linked immune-sorbent assay (ELISA), chemiluminescence immunoassay (CLIA), and lateral flow immunoassay (LFIA). However, these tests are plagued with low sensitivity or specificity, time-consuming, labor-intensive, and expensive. We developed a serological test implementing flow-through dot-blot assay (FT-DBA) for SARS-CoV-2 specific IgG detection, which provides enhanced sensitivity and specificity while being quick to perform and easy to use.
METHODS: SARS-CoV-2 antigens were immobilized on nitrocellulose membrane to capture human IgG, which was then detected with anti-human IgG conjugated gold nanoparticle (hIgG-AuNP). A total of 181 samples were analyzed in-house. Within which 35 were further evaluated in US FDA-approved CLIA Elecsys SARS-CoV-2 assay. The positive panel consisted of RT-qPCR positive samples from patients with both <14 days and >14 days from the onset of clinical symptoms. The negative panel contained samples collected from the pre-pandemic era dengue patients and healthy donors during the pandemic. Moreover, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of FT-DBA were evaluated against RT-qPCR positive sera. However, the overall efficacies were assessed with sera that seroconverted against either nucleocapsid (NCP) or receptor-binding domain (RBD).
RESULTS: In-house ELISA selected a total of 81 true seropositive and 100 seronegative samples. The sensitivity of samples with <14 days using FT-DBA was 94.7%, increasing to 100% for samples >14 days. The overall detection sensitivity and specificity were 98.8% and 98%, respectively, whereas the overall PPV and NPV were 99.6% and 99%. Moreover, comparative analysis between in-house ELISA assays and FT-DBA revealed clinical agreement of Cohen's Kappa value of 0.944. The FT-DBA showed sensitivity and specificity of 100% when compared with commercial CLIA kits.
CONCLUSION: The assay can confirm past SARS-CoV-2 infection with high accuracy within 2 minutes compared to commercial CLIA or in-house ELISA. It can help track SARS-CoV-2 disease progression, population screening, and vaccination response. The ease of use of the assay without requiring any instruments while being semi-quantitative provides the avenue of its implementation in remote areas around the globe, where conventional serodiagnosis is not feasible.

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