scholarly journals Adaptation of ELISA detection of Plasmodium falciparum and Plasmodium vivax circumsporozoite proteins in mosquitoes to a multiplex bead-based immunoassay

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Alice C. Sutcliffe ◽  
Seth R. Irish ◽  
Eric Rogier ◽  
Micaela Finney ◽  
Sarah Zohdy ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Plasmodium Vivax ◽  
Lower Limit ◽  
Limit Of Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Limits Of Detection ◽  
Sporozoite Rate ◽  
The Impact ◽  
Lower Limits ◽  
Multiplex Bead

Abstract Background Plasmodium spp. sporozoite rates in mosquitoes are used to better understand malaria transmission intensity, the relative importance of vector species and the impact of interventions. These rates are typically estimated using an enzyme-linked immunosorbent assay (ELISA) utilizing antibodies against the circumsporozoite protein of Plasmodium falciparum, Plasmodium vivax VK210 (P. vivax210) or P. vivax VK247 (P. vivax247), employing assays that were developed over three decades ago. The ELISA method requires a separate assay plate for each analyte tested and can be time consuming as well as requiring sample volumes not always available. The bead-based multiplex platform allows simultaneous measurement of multiple analytes and may improve the lower limit of detection for sporozoites. Methods Recombinant positive controls for P. falciparum, P. vivax210 and P. vivax247 and previously developed circumsporozoite (cs) ELISA antibodies were used to optimize conditions for the circumsporozoite multiplex bead assay (csMBA) and to determine the detection range of the csMBA. After optimizing assay conditions, known amounts of sporozoites were used to determine the lower limit of detection for the csELISA and csMBA and alternate cut-off measures were applied to demonstrate how cut-off criteria can impact lower limits of detection. Sporozoite rates from 1275 mosquitoes collected in Madagascar and 255 mosquitoes collected in Guinea were estimated and compared using the established csELISA and newly optimized csMBA. All mosquitoes were tested (initial test), and those that were positive were retested (retest). When sufficient sample volume remained, an aliquot of homogenate was boiled and retested (boiled retest), to denature any heat-unstable cross-reactive proteins. Results Following optimization of the csMBA, the lower limit of detection was 25 sporozoites per mosquito equivalent for P. falciparum, P. vivax210 and P. vivax247 whereas the lower limits of detection for csELISA were found to be 1400 sporozoites for P. falciparum, 425 for P. vivax210 and 1650 for P. vivax247. Combined sporozoite rates after re-testing of samples that initially tested positive for Madagascar mosquitoes by csELISA and csMBA were 1.4 and 10.3%, respectively, and for Guinea mosquitoes 2% by both assays. Boiling of samples followed by csMBA resulted in a decrease in the Madagascar sporozoite rate to 2.8–4.4% while the Guinea csMBA sporozoite rate remained at 2.0%. Using an alternative csMBA cut-off value of median fluorescence intensity (MFI) of 100 yielded a sporozoite rate after confirmational testing of 3.7% for Madagascar samples and 2.0% for Guinea samples. Whether using csMBA or csELISA, the following steps may help minimize false positives: specimens are appropriately stored and bisected anterior to the thorax-abdomen junction, aliquots of homogenate are boiled and retested following initial testing, and an appropriate cut-off value is determined. Conclusions The csMBA is a cost-comparable and time saving alternative to the csELISA and may help eliminate false negatives due to a lower limit of detection, thus increasing sensitivity over the csELISA. The csMBA expands the potential analyses that can be done with a small volume of sample by allowing multiplex testing where analytes in addition to P. falciparum, P. vivax210 and P. vivax247 can be added following optimization.

scholarly journals Adaptation of ELISA Detection of Plasmodium Falciparum and Plasmodium Vivax Circumsporozoite Proteins in Mosquitoes to a Multiplex Bead-Based Immunoassay

2021 ◽  
Author(s):  
Alice Sutcliffe ◽  
Seth R. Irish ◽  
Eric Rogier ◽  
Micaela Finney ◽  
Sarah Zohdy ◽  
...  
Keyword(s):  
Lower Limit ◽  
Limit Of Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Limits Of Detection ◽  
Detection Range ◽  
Cutoff Value ◽  
Sporozoite Rate ◽  
The Impact ◽  
Lower Limits ◽  
Multiplex Bead

Abstract Background: Plasmodium spp. sporozoite rates in mosquitoes are used to better understand malaria transmission intensity, the relative importance of vector species and the impact of interventions. These rates are typically estimated using an enzyme-linked immunosorbent assay (ELISA) utilizing antibodies against the circumsporozoite protein of P. falciparum (Pf), P. vivax VK210 (Pv210) or P. vivax VK247 (Pv247), employing assays that were developed over three decades ago. The ELISA method requires a separate assay plate for each analyte tested and can be time consuming as well as requiring sample volumes not always available. The bead-based multiplex platform allows simultaneous measurement of multiple analytes and may improve the lower limit of detection for sporozoites.Methods: Recombinant positive controls for Pf, Pv210 and Pv247 and previously developed circumsporozoite (cs) ELISA antibodies were used to optimize conditions for the circumsporozoite multiplex bead assay (csMBA) and to determine the detection range of the csMBA. After optimizing assay conditions, known amounts of sporozoites were used to determine the lower limit of detection for the csELISA and csMBA and alternate cutoff measures were applied to demonstrate how cutoff criteria can impact lower limits of detection. Sporozoite rates from 1275 mosquitoes collected in Madagascar and 255 mosquitoes collected in Guinea were estimated and compared using the established csELISA and newly optimized csMBA. All mosquitoes were tested (initial test), and those that were positive were retested (retest). When sufficient sample volume remained, an aliquot of homogenate was boiled and retested (boiled retest), to denature any heat-unstable cross-reactive proteins. Results: Following optimization of the csMBA, the lower limit of detection was 25 sporozoites per mosquito equivalent for Pf, Pv and Pv247 whereas the lower limits of detection for csELISA were found to be 1400 sporozoites for Pf, 425 for Pv210 and 1650 for Pv247. Combined sporozoite rates after re-testing of samples that initially tested positive for Madagascar mosquitoes by csELISA and csMBA were 1.4% and 10.3%, respectively, and for Guinea mosquitoes 2% by both assays. Boiling of samples followed by csMBA resulted in a decreased in the Madagascar sporozoite rate to 2.8-4.4% while the Guinea csMBA sporozoite rate remained at 2.0%. Using an alternative csMBA cutoff value of median fluorescence intensity (MFI) of 100 yielded a sporozoite rate after confirmational testing of 3.7% for Madagascar samples and 2.0% for Guinea samples. Whether using csMBA or csELISA, the following steps may help minimize false positives: specimens are appropriately stored and bisected anterior to the thorax-abdomen junction, aliquots of homogenate are boiled and retested following initial testing, and an appropriate cutoff value is determined.Conclusions: The csMBA is a cost-comparable and time saving alternative to the csELISA and may help eliminate false negatives due to a lower limit of detection, thus increasing sensitivity over the csELISA. The csMBA expands the potential analyses that can be done with a small volume of sample by allowing multiplex testing where analytes in addition to Pf, Pv210 and Pv247 can be added following optimization.

scholarly journals Wireless Electrochemical Detection on a Microfluidic Compact Disc (CD) and Evaluation of Redox-Amplification during Flow

Micromachines ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 31 ◽  
Author(s):  
Maria Bauer ◽  
Jaume Bartoli ◽  
Sergio Martinez-Chapa ◽  
Marc Madou
Keyword(s):  
Cyclic Voltammetry ◽  
Real Time ◽  
Lower Limit ◽  
Electrochemical Detection ◽  
Limit Of Detection ◽  
Compact Disc ◽  
Dual Mode ◽  
Novel Biomarkers ◽  
The Impact ◽  
Lower Limits

Novel biomarkers and lower limits of detection enable improved diagnostics. In this paper we analyze the influence of flow on the lower limit of electrochemical detection on a microfluidic Compact Disc (CD). Implementing wireless transfer of data reduces noise during measurements and allows for real time sensing, demonstrated with the ferri-ferroyanide redox-couple in single and dual mode cyclic voltammetry. The impact of flow on redox-amplification and electrode integration for the lowest limit of detection are discussed.

scholarly journals Widespread zoophagy and detection of Plasmodium spp. in Anopheles mosquitoes in southeastern Madagascar

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Micaela Finney ◽  
Benjamin A. McKenzie ◽  
Bernadette Rabaovola ◽  
Alice Sutcliffe ◽  
Ellen Dotson ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Vector Control ◽  
Plasmodium Vivax ◽  
Malaria Control ◽  
Feeding Behaviour ◽  
Enzyme Linked Immunosorbent Assay ◽  
Habitat Gradient ◽  
Blood Meals ◽  
Feeding Behaviours ◽  
Southeastern Madagascar

Abstract Background Malaria is a top cause of mortality on the island nation of Madagascar, where many rural communities rely on subsistence agriculture and livestock production. Understanding feeding behaviours of Anopheles in this landscape is crucial for optimizing malaria control and prevention strategies. Previous studies in southeastern Madagascar have shown that Anopheles mosquitoes are more frequently captured within 50 m of livestock. However, it remains unknown whether these mosquitoes preferentially feed on livestock. Here, mosquito blood meal sources and Plasmodium sporozoite rates were determined to evaluate patterns of feeding behaviour in Anopheles spp. and malaria transmission in southeastern Madagascar. Methods Across a habitat gradient in southeastern Madagascar 7762 female Anopheles spp. mosquitoes were collected. Of the captured mosquitoes, 492 were visibly blood fed and morphologically identifiable, and a direct enzyme-linked immunosorbent assay (ELISA) was used to test for swine, cattle, chicken, human, and dog blood among these specimens. Host species identification was confirmed for multiple blood meals using PCR along with Sanger sequencing. Additionally, 1,607 Anopheles spp. were screened for the presence of Plasmodium falciparum, P. vivax-210, and P. vivax 247 circumsporozoites (cs) by ELISA. Results Cattle and swine accounted, respectively, for 51% and 41% of all blood meals, with the remaining 8% split between domesticated animals and humans. Of the 1,607 Anopheles spp. screened for Plasmodium falciparum, Plasmodium vivax 210, and Plasmodium vivax 247 cs-protein, 45 tested positive, the most prevalent being P. vivax 247, followed by P. vivax 210 and P. falciparum. Both variants of P. vivax were observed in secondary vectors, including Anopheles squamosus/cydippis, Anopheles coustani, and unknown Anopheles spp. Furthermore, evidence of coinfection of P. falciparum and P. vivax 210 in Anopheles gambiae sensu lato (s.l.) was found. Conclusions Here, feeding behaviour of Anopheles spp. mosquitoes in southeastern Madagascar was evaluated, in a livestock rich landscape. These findings suggest largely zoophagic feeding behaviors of Anopheles spp., including An. gambiae s.l. and presence of both P. vivax and P. falciparum sporozoites in Anopheles spp. A discordance between P. vivax reports in mosquitoes and humans exists, suggesting high prevalence of P. vivax circulating in vectors in the ecosystem despite low reports of clinical vivax malaria in humans in Madagascar. Vector surveillance of P. vivax may be relevant to malaria control and elimination efforts in Madagascar. At present, the high proportion of livestock blood meals in Madagascar may play a role in buffering (zooprophylaxis) or amplifying (zoopotentiation) the impacts of malaria. With malaria vector control efforts focused on indoor feeding behaviours, complementary approaches, such as endectocide-aided vector control in livestock may be an effective strategy for malaria reduction in Madagascar.

scholarly journals Evaluation of Immunoglobulin G Responses to Plasmodium falciparum and Plasmodium vivax in Malian School Children Using Multiplex Bead Assay

2016 ◽  
Vol 96 (2) ◽  
pp. 312-318 ◽  
Author(s):  
Eric Rogier ◽  
Delynn M. Moss ◽  
Anna N. Chard ◽  
Victoria Trinies ◽  
Seydou Doumbia ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Plasmodium Vivax ◽  
School Children ◽  
Immunoglobulin G ◽  
Multiplex Bead

scholarly journals Enzyme-Linked Immunosorbent Assay for Detection of Plasmodium falciparum Histidine-Rich Protein 2 in Blood, Plasma, and Serum

2008 ◽  
Vol 15 (6) ◽  
pp. 1012-1018 ◽  
Author(s):  
Carolyne M. Kifude ◽  
Halli G. Rajasekariah ◽  
David J. Sullivan ◽  
V. Ann Stewart ◽  
Evelina Angov ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Immunosorbent Assay ◽  
Whole Blood ◽  
Linear Range ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Target Concentration ◽  
Intervention Trials ◽  
Lower Limits ◽  
Asexual Cycle

ABSTRACT Microscopy, the gold standard for the detection and quantification of malaria parasites in blood, is in many aspects deficient for this purpose. The method is poorly reproducible and can be inaccurate because Plasmodium falciparum parasites sequester for a portion of each asexual cycle. Due to these deficiencies, biomarkers such as P. falciparum histidine-rich protein 2 (PfHRP2) are increasingly being used. In this study, we evaluated the use of a commercial PfHRP2 enzyme-linked immunosorbent assay (ELISA) kit with some procedural modifications. We determined the linear range of the assay, including the lower limits of detection and quantitation, using recombinant PfHRP2 (rPfHRP2). In 10 repeat experiments, the linear range of optical densities (ODs) at 450 to 650 nm was from 0.05 ± 0.002 to 2.28 ± 0.042, corresponding to 3.91 to 250 ng/ml of rPfHRP2. The coefficient of variation (CV) at each target concentration ranged from 1.93 to 8.07%. Using cultured parasites, we confirmed the linear range of ODs as well as the association between the PfHRP2 ELISA results and the microscopic parasite densities. For whole-blood samples spiked with cultured, washed, ring-stage-infected red blood cells (iRBCs), the linear range was 11.7 to 750 iRBCs/μl, with CVs of 0.29 to 7.56%. The same spiked samples evaluated by microscopists had similar sensitivities, but the CVs were unacceptably high (20.7 to 161.6%). Stock rPfHRP2 was stable through four freeze-thaw cycles (P < 0.05; paired t test). When different patient sample types at different concentrations within the linear range of the assay are compared, the recoveries of PfHRP2 from blood and serum were within ±20%, whereas the recoveries from plasma ranged between +35 and −41%. We conclude that PfHRP2 ELISA using whole-blood and serum samples is a suitable adjunct to microscopy and could ultimately benefit malaria intervention trials.

scholarly journals Implications of Limits of Detection of Various Methods for Bacillus anthracis in Computing Risks to Human Health

2009 ◽  
Vol 75 (19) ◽  
pp. 6331-6339 ◽  
Author(s):  
Amanda B. Herzog ◽  
S. Devin McLennan ◽  
Alok K. Pandey ◽  
Charles P. Gerba ◽  
Charles N. Haas ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Bacillus Anthracis ◽  
Real Time ◽  
Real Time Pcr ◽  
Limit Of Detection ◽  
Quantitative Risk Assessment ◽  
Detection Methods ◽  
Enzyme Linked Immunosorbent Assay ◽  
Environmental Matrices ◽  
Limits Of Detection

ABSTRACT Used for decades for biological warfare, Bacillus anthracis (category A agent) has proven to be highly stable and lethal. Quantitative risk assessment modeling requires descriptive statistics of the limit of detection to assist in defining the exposure. Furthermore, the sensitivities of various detection methods in environmental matrices are vital information for first responders. A literature review of peer-reviewed journal articles related to methods for detection of B. anthracis was undertaken. Articles focused on the development or evaluation of various detection approaches, such as PCR, real-time PCR, immunoassay, etc. Real-time PCR and PCR were the most sensitive methods for the detection of B. anthracis, with median instrument limits of detection of 430 and 440 cells/ml, respectively. There were very few peer-reviewed articles on the detection methods for B. anthracis in the environment. The most sensitive limits of detection for the environmental samples were 0.1 CFU/g for soil using PCR-enzyme-linked immunosorbent assay (ELISA), 17 CFU/liter for air using an ELISA-biochip system, 1 CFU/liter for water using cultivation, and 1 CFU/cm2 for stainless steel fomites using cultivation. An exponential dose-response model for the inhalation of B. anthracis estimates of risk at concentrations equal to the environmental limit of detection determined the probability of death if untreated to be as high as 0.520. Though more data on the environmental limit of detection would improve the assumptions made for the risk assessment, this study's quantification of the risk posed by current limitations in the knowledge of detection methods should be considered when employing those methods in environmental monitoring and cleanup strategies.

LC-MS-MS vs ELISA: Validation of a Comprehensive Urine Toxicology Screen by LC-MS-MS and a Comparison of 100 Forensic Specimens

2019 ◽  
Vol 43 (9) ◽  
pp. 734-745 ◽  
Author(s):  
Kristin W Kahl ◽  
Joshua Z Seither ◽  
Lisa J Reidy
Keyword(s):  
Mass Spectrometry ◽  
Limit Of Detection ◽  
Screening Method ◽  
Driving Under The Influence ◽  
Cost Comparison ◽  
Enzyme Linked Immunosorbent Assay ◽  
Screening Methods ◽  
Limits Of Detection ◽  
The Cost ◽  
Urine Specimens

Abstract Toxicology laboratories commonly employ immunoassay methodologies to perform an initial drug screen on urine specimens to direct confirmatory testing. Due to limitations of immunoassay testing and the need to screen for a broader range of drugs with lower limits of detection at a lower cost, mass spectrometry screening techniques have gained favor in the toxicology field. A liquid chromatography–tandem mass spectrometry (LC-MS-MS) urine screening panel was developed and validated for 52 drugs and metabolites. A simple dilute-and-shoot with enzymatic hydrolysis technique was utilized to prepare the urine specimens for analysis. Limit of detection, interference, ionization suppression/enhancement, carryover and stability of processed specimens were assessed during validation. To evaluate the toxicological results obtained from utilizing the LC-MS-MS in comparison with the laboratory’s current enzyme-linked immunosorbent assay (ELISA) panel, 100 authentic urine specimens from suspected driving under the influence and drug-facilitated crime cases were analyzed using both methodologies and the results were compared. In addition, the cost of each methodology was evaluated and compared. The validated LC-MS-MS method had limits of detection that were equal to or lower than the concentrations validated for ELISA cutoffs, had fewer exogenous interferences, and the cost of screening per specimen was reduced by ~70% when compared to ELISA. Comparing the toxicology results of forensic urine specimens demonstrated that by only using ELISA, the laboratory was unable to detect benzoylecgonine in 26%, lorazepam in 33% and oxymorphone in 60% of the positive specimens. Additional analytes detected using the LC-MS-MS method were zolpidem and/or metabolite, gabapentin, tramadol and metabolite, methadone and metabolite, meprobamate and phentermine. The results of the validation, the toxicological result comparison and the cost comparison showed that the LC-MS-MS screening method is a simple, sensitive and cost-effective alternative to ELISA screening methods for urine specimens.

scholarly journals Field Performance of Mass PCR Screening and Targeted Treatment in an Amazonian Low Malaria Transmission Setting

2021 ◽  
Author(s):  
Emilie Mosnier ◽  
Yassamine Lazrek ◽  
Aurel Carbunar ◽  
Rodolphe Priam ◽  
Jordi Landier ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Plasmodium Vivax ◽  
Health Center ◽  
French Guiana ◽  
Malaria Incidence ◽  
Local Health ◽  
Asymptomatic Malaria ◽  
Surveillance Period ◽  
Pcr Screening ◽  
The Impact

Abstract The three main obstacles to the elimination of malaria in French Guiana are asymptomatic carriers of Plasmodium vivax, relapses and, to a lesser extent, Plasmodium falciparum. This study aims to assess the impact of PCR-based mass screening and treatment (MSAT) interventions in this malaria-endemic area.Two MSAT interventions were conducted twelve months apart in inhabitants of Saint Georges de l’Oyapock village, which has the highest malaria burden in French Guiana. Symptomatic malaria incidence was also passively monitored through the local health center from 12 months before the first intervention until the end of the second intervention.At the time of the first intervention, malaria prevalence was 6.7% [CI95 5.4-7.9%], including 90% of Plasmodium vivax cases and 10% Plasmodium falciparum (n=1,501 participants). Twelve months later, it had decreased by 53.7% to a value of 2.5% [CI95 2.0-3.9%] (p<0.05; n=1,271 inhabitants), of which 83% and 17% of cases showed Plasmodium vivax and Plasmodium falciparum carriage, respectively. Similarly, the passive malaria detection carried out by the health center during the 12-month surveillance period that followed the first MSAT noted a decrease in symptomatic Plasmodium spp..This study suggests that the implementation of mass PCR testing and the subsequent malaria treatment of positive cases could reduce the prevalence of both symptomatic and asymptomatic malaria infections in the Amazonian context.

scholarly journals Development of Two-Tube Loop-Mediated Isothermal Amplification Assay for Differential Diagnosis of Plasmodium falciparum and Plasmodium vivax and Its Comparison with Loopamp™ Malaria

Diagnostics ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1689
Author(s):  
Mudsser Azam ◽  
Kirti Upmanyu ◽  
Ratan Gupta ◽  
Karugatharayil Sasi Sruthy ◽  
Monika Matlani ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Plasmodium Vivax ◽  
Sensitivity And Specificity ◽  
Limit Of Detection ◽  
Lamp Assay ◽  
Repeat Sequence ◽  
Isothermal Amplification ◽  
Malaria Surveillance ◽  
Loop Mediated Isothermal Amplification ◽  
Closed Tube

To strengthen malaria surveillance, field-appropriate diagnostics requiring limited technical resources are of critical significance. Loop-mediated isothermal amplification (LAMP) based malaria diagnostic assays are potential point-of-care tests with high sensitivity and specificity and have been used in low-resource settings. Plasmodium vivax–specific consensus repeat sequence (CRS)-based and Plasmodium falciparum–specific 18S rRNA primers were designed, and a two-tube LAMP assay was developed. The diagnostic performance of a closed-tube LAMP assay and Loopamp™ Malaria Detection (Pan/Pf, Pv) kit was investigated using nested PCR confirmed mono- and co-infections of P. vivax and P. falciparum positive (n = 149) and negative (n = 67) samples. The closed-tube Pv LAMP assay showed positive amplification in 40 min (limit of detection, LOD 0.7 parasites/µL) and Pf LAMP assay in 30 min (LOD 2 parasites/µL). Pv LAMP and Pf LAMP demonstrated a sensitivity and specificity of 100% (95% CI, 95.96–100% and 89.85–100%, respectively). The LoopampTM Pan/Pf Malaria Detection kit demonstrated a sensitivity and specificity of 100%, whereas LoopampTM Pv showed a sensitivity of 98.36% (95% CI, 91.28–99.71%) and specificity of 100% (95% CI, 87.54–100%). The developed two-tube LAMP assay is highly sensitive (LOD ≤ 2 parasite/µL), demonstrating comparable results with the commercial Loopamp™ Malaria Detection (Pf/pan) kit, and was superior in detecting the P. vivax co-infection that remained undetected by the Loopamp™ Pv kit. The developed indigenous two-tube Pf/Pv malaria detection can reliably be used for mass screening in resource-limited areas endemic for both P. falciparum and P. vivax malaria.

scholarly journals Significant differences in FcγRIIa, FcγRIIIa and FcγRIIIb genes polymorphism and anti-malarial IgG subclass pattern are associated with severe Plasmodium falciparum malaria in Saudi children

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Amre Nasr ◽  
Ahmad Aljada ◽  
Osama Hamid ◽  
Hatim A. Elsheikh ◽  
Emad Masuadi ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Severe Malaria ◽  
Malaria Infection ◽  
Pcr Amplification ◽  
Plasmodium Falciparum Malaria ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Subclass ◽  
Elisa Technique ◽  
Cellular And Humoral Immunity ◽  
The Impact

Abstract Background The FcγRs genotypes have been reported to play a key role in the defence against malaria parasites through both cellular and humoral immunity. This study aimed to investigate the possible correlation between FcγR (IIa, IIIa, and IIIb) genes polymorphism and the clinical outcome for anti‐malarial antibody response of Plasmodium falciparum infection among Saudi children. Methods A total of 600 volunteers were enrolled in this study, including 200 malaria-free control (MFC) subjects, 218 patients with uncomplicated malaria (UM) and 182 patients with severe malaria (SM). The FcγR genotypes were analysed using PCR amplification methods, and measurements of immunoglobulin were determined using enzyme-linked immunosorbent assay (ELISA) technique. Results The data revealed that the FcγRIIa-R/R131 showed a statistically significant association with SM patients when compared to UM patients. Furthermore, higher levels of IgG1, IgG2, and IgG4 were associated with the FcγRIIa-H/H131 genotype among UM patients. Although the FcγRIIa-F/V176 genotype was not associated with UM, it showed a significant association with severe malaria. Interestingly, the FcγRIIIa-V/V176 genotype offered protection against SM. Moreover, SM patients carrying the FcγRIIIa-F/F genotype showed higher levels of AMA-1-specific IgG2 and IgG4 antibodies. The FcγRIIIb-NA1/NA1 and FcγRIIIb-NA2/NA2 genotypes did not show significant differences between the UM and the MFC groups. However, the genotype FcγRIIIb-NA2/NA2 was statistically significantly associated with SM patients. Conclusions The data presented in this study suggest that the influence of the FcγRIIa-R/R131, FcγRIIIa-F/F176 and FcγRIIIb-NA2/NA2 genotypes are statistically significantly associated with SM patients. However, the FcγRIIa-H/H13 and FcγRIIIa-V/V176 genotypes have demonstrated a protective effect against SM when compared to UM patients. The impact of the FcyR (IIa, IIIa and IIIb) gene variants and anti-malaria IgG subclasses play an important role in susceptibility to malaria infection and disease outcome in Saudi children.

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