scholarly journals Antibodies to Plasmodium falciparum Glycosylphosphatidylinositols: Inverse Association with Tolerance of Parasitemia in Papua New Guinean Children and Adults

2002 ◽  
Vol 70 (9) ◽  
pp. 5052-5057 ◽  
Author(s):  
Craig S. Boutlis ◽  
D. Channe Gowda ◽  
Ramachandra S. Naik ◽  
Graeme P. Maguire ◽  
Charles S. Mgone ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Antibody Responses ◽  
Natural Immunity ◽  
Inverse Association ◽  
Age Group ◽  
Antimalarial Treatment ◽  
Vaccination Strategies ◽  
Asymptomatic Children ◽  
The Relationship ◽  
Papua New Guinean

ABSTRACT Individuals living in regions of intense malaria transmission exhibit natural immunity that facilitates persistence of parasitemia at controlled densities for much of the time without symptoms. This aspect of immunity has been referred to as malarial “tolerance” and is thought to partly involve inhibition of the chain of events initiated by a parasite toxin(s) that may otherwise result in cytokine release and symptoms such as fever. Antibodies to the candidate Plasmodium falciparum glycosylphosphatidylinositol (GPI) toxin have been viewed as likely mediators of such tolerance. In this study, the relationship between antibodies to P. falciparum GPIs, age, and parasitemia was determined in asymptomatic children and adults living in Madang, Papua New Guinea. The prevalence and intensity of antibody responses increased with age and were lowest in children 1 to 4 years old with the highest-density parasitemias. In children of this age group who were tolerant of parasitemia during the study, only 8.3% had detectable immunoglobulin G (IgG) and none had IgM antibodies to GPI. This suggests that anti-GPI antibodies are unlikely to be the sole mediator of malarial tolerance, especially in children younger than 5 years. Following antimalarial treatment, clearance of parasitemia led to a fall in anti-GPI IgG response in children and adolescents within 6 weeks. As anti-GPI antibodies potentially play a role in protecting against disease progression, our results caution against the treatment of asymptomatic parasitemia and suggest that generation of a sustained antibody response in children poses a challenge to novel antitoxic vaccination strategies.

scholarly journals Molecular characterization of Plasmodium falciparum PHISTb proteins as potential targets of naturally-acquired immunity against malaria

2020 ◽  
Vol 5 ◽  
pp. 136
Author(s):  
Tony I. Isebe ◽  
Joel L. Bargul ◽  
Bonface M. Gichuki ◽  
James M. Njunge ◽  
James Tuju ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Transmission ◽  
The Gambia ◽  
Antibody Responses ◽  
Transmission Intensity ◽  
Parasite Development ◽  
Natural Immunity ◽  
Malaria Transmission Intensity ◽  
Transmission Region ◽  
Antibody Levels

Background: Plasmodium falciparum causes the deadliest form of malaria in humans. Upon infection, the host’s infected red blood cells (iRBCs) are remodelled by exported parasite proteins in order to provide a niche for parasite development and maturation. Methods: Here we analysed the role of three PHISTb proteins Pf3D7_0532400, Pf3D7_1401600, and Pf3D7_1102500 by expressing recombinant proteins and evaluated antibody responses against these proteins using immune sera from malaria-exposed individuals from Kenya and The Gambia in Africa. Results: Our findings show that children and adults from malaria-endemic regions recognized the three PHISTb proteins. Responses against the PHISTb proteins varied with malaria transmission intensity in three different geographical sites in Kenya (Siaya and Takaungu) and The Gambia (Sukuta). Antibody responses against PHISTb antigens Pf3D7_1102500 and Pf3D7_1401600 were higher in Sukuta, a low transmission region in the Gambia, as compared to Siaya, a high transmission region in western Kenya, unlike Pf3D7_0532400. Anti-PHIST responses show a negative correlation between antibody levels and malaria transmission intensity for two PHIST antigens, Pf3D7_1102500 and Pf3D7_1401600. However, we report a correlation in antibody responses between schizont extract and Pf3D7_0532400 (p=0.00582). Acquisition of anti-PHIST antibodies was correlated with exposure to malaria for PHISTb protein Pf3D7_0532400 (p=0.009) but not the other PHIST antigens Pf3D7_1102500 and Pf3D7_1401600 (p=0.507 and p=0.15, respectively, CI=95%). Children aged below 2 years had the lowest antibody levels, but the responses do not correlate with age differences. Conclusions: Collectively, these findings provide evidence of natural immunity against PHISTb antigens that varies with level of malaria exposure and underscore potential for these parasite antigens as possible serological markers to P. falciparum infection aimed at contributing to malaria control through vaccine development.

scholarly journals Exposures to different SARS-CoV-2 spike variants elicit neutralizing antibody responses with differential specificity towards established and emerging strains

2021 ◽  
Author(s):  
Matthew T Laurie ◽  
Jamin Liu ◽  
Sara Sunshine ◽  
James Peng ◽  
Douglas Black ◽  
...  
Keyword(s):  
Immune Response ◽  
Wide Spectrum ◽  
Booster Vaccination ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Spike Protein ◽  
Vaccination Strategies ◽  
Cross Neutralization ◽  
The Relationship

The wide spectrum of SARS-CoV-2 variants with phenotypes impacting transmission and antibody sensitivity necessitates investigation of the immune response to different spike protein versions. Here, we compare the neutralization of variants of concern, including B.1.617.2 (Delta) in sera from individuals exposed to variant infection, vaccination, or both. We demonstrate that neutralizing antibody responses are strongest against variants sharing one or more spike mutations with the immunizing exposure. We also observe that exposure to multiple spike variants increases the breadth of variant cross-neutralization. These findings contribute to understanding the relationship between exposures and antibody responses and may inform booster vaccination strategies.

scholarly journals Plasmodium falciparum Genotypes, Low Complexity of Infection, and Resistance to Subsequent Malaria in Participants in the Asembo Bay Cohort Project

2001 ◽  
Vol 69 (12) ◽  
pp. 7783-7792 ◽  
Author(s):  
Oralee H. Branch ◽  
Shannon Takala ◽  
Simon Kariuki ◽  
Bernard L. Nahlen ◽  
Margaret Kolczak ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Protective Immunity ◽  
Low Complexity ◽  
Antigenic Determinants ◽  
Natural Immunity ◽  
Subsequent Infection ◽  
Host Diversity ◽  
The Impact ◽  
The Relationship ◽  
Complexity Of Infection

ABSTRACT To assess the relationship between the within-host diversity of malaria infections and the susceptibility of the host to subsequent infection, we genotyped 60 children's successive infections from birth through 3 years of life. MSP-1 Block2 genotypes were used to estimate the complexity of infection (COI). Malaria transmission and age were positively associated with the number of K1 and Mad20 alleles detected (COIKM) (P < 0.003). Controlling for previous parasitemia, transmission, drug treatment, parasite density, sickle cell, and age, COIKM was negatively correlated with resistance to parasitemia of >500/μl (P < 0.0001). Parasitemias with the RO-genotype were more resistant than those without this genotype (P < 0.0000). The resistance in low COIKM infections was not genotype specific. We discuss the impact of genotype-transcending immunity to conserved antigenic determinants. We also propose a diversity-driven immunomodulation hypothesis that may explain the delayed development of natural immunity in the first few years of life and suggest that interventions that decrease the COIKM could facilitate the development of protective immunity.

scholarly journals Relationships between Plasmodium falciparum infection and morbidity in a highly endemic area

Parasitology ◽  
1994 ◽  
Vol 109 (5) ◽  
pp. 539-549 ◽  
Author(s):  
T. Smith ◽  
B. Genton ◽  
K. Baea ◽  
N. Gibson ◽  
J. Taime ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Endemic Area ◽  
Health Centre ◽  
Age Groups ◽  
Reporting Rate ◽  
Age Group ◽  
Clinical Criteria ◽  
Attributable Fractions ◽  
Morbidity Risk ◽  
The Relationship

A total of 736 outpatients diagnosed as having malaria using clinical criteria at a health centre in a highly endemic area of Papua New Guinea were investigated parasitologically. Plasmodium falciparum-attributable fractions were determined using a logistic regression model to compare parasite densities in cases with those of healthy individuals in community surveys. Thirty-seven percent of presumptive cases were found to have raised P. falciparum parasitaemia. This corresponds to an average reporting rate for the population of 0·53 attributable episodes per annum. Whilst the maximum prevalence of parasitaemia in the community was in children aged 5–9 years, the maximum age-specific incidence of attributable cases at the outpatient clinic was 2 cases per annum in the 2- to 4-year-old age group. The procedure for estimating attributable fractions makes it possible to compare morbidity rates between age groups, and to examine how the relationship between morbidity risk and parasite density changes with age, without diagnosing individual episodes. The average tolerance of parasites in an age group was measured by considering the level of parasitaemia associated with a given risk of malaria-attributable morbidity. In contrast to anti-parasite immunity, tolerance of parasites declines with age since at parasite isodensity the probability of being symptomatic increases with age.

scholarly journals Diverse Antibody Responses to Conserved Structural Motifs in Plasmodium falciparum Circumsporozoite Protein

2020 ◽  
Vol 432 (4) ◽  
pp. 1048-1063 ◽  
Author(s):  
Tossapol Pholcharee ◽  
David Oyen ◽  
Jonathan L. Torres ◽  
Yevel Flores-Garcia ◽  
Gregory M. Martin ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Antibody Responses ◽  
Circumsporozoite Protein ◽  
Structural Motifs

scholarly journals Reliability and Validity of Facial Check Sheet (FCS): Checklist for Self-Satisfaction with Cosmetic Acupuncture

Medicines ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 18
Author(s):  
Hiroshi Kuge ◽  
Hidetoshi Mori ◽  
Tim Hideaki Tanaka ◽  
Ryouta Tsuji
Keyword(s):  
Reliability And Validity ◽  
Internet Survey ◽  
Age Group ◽  
Facial Skin ◽  
Moderate Correlation ◽  
Skin Rejuvenation ◽  
Facial Region ◽  
Practical Tool ◽  
Multiple Comparison Procedure ◽  
The Relationship

Background: In recent years, cosmetic acupuncture has gained popularity among individuals interested in improving their facial appearance. We have created an original facial check sheet (FCS) to obtain cosmetic acupuncture patients’ perspectives on treatment outcomes. This study examined the reliability and validity of FCS. Methods: We conducted an Internet survey on the appearance of the facial region among Japanese women. A reliability analysis was performed between each item of FCS. A multiple comparison procedure was used to determine the relationship between the age group, the FCS score, and the number of terms used in the open-ended question. Results: The most frequently stated concern was blotchiness and hyperpigmented spots (47.2%, n = 67). The FCS items showed reliability (Cronbach α = 0.871). The number of extracted terms and the FCS score showed a moderate correlation (r = 0.407; p < 0.001). There was a significant relationship between age and FCS score (p = 0.005, r2 = 0.255), which indicated that the FCS score increases with aging. Conclusions: The FCS can be used as a practical tool to evaluate facial appearances and assess satisfaction levels of patients who underwent cosmetic acupuncture or other facial skin rejuvenation procedures.

scholarly journals The Relationship between Adult Height and Blood Pressure

Cardiology ◽  
2021 ◽  
pp. 1-6
Author(s):  
John Michael Cochran ◽  
Vincent R. Siebert ◽  
Jeffrey Bates ◽  
Djenita Butulija ◽  
Anna Kolpakchi ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiovascular Disease ◽  
Adult Height ◽  
Augmentation Index ◽  
Epidemiological Data ◽  
Systemic Review ◽  
Inverse Association ◽  
Literature Evidence ◽  
Artery Disease ◽  
The Relationship

Background: Identification and modification of cardiovascular risk factors is paramount to reducing cardiovascular disease morbidity and mortality. Hypertension is a major risk factor for cardiovascular disease, but its association with height remains largely underrecognized. Objectives: The objective of this manuscript is to review the evidence examining the association between blood pressure and human stature and to summarize the plausible pathophysiological mechanisms behind such an association. Methods: A systematic review of adult human height and its association with hypertension and coronary artery disease was undertaken. The literature evidence is summarized and tabulated, and an overview of the pathophysiological basis for this association is presented. Results: Shorter arterial lengths found in shorter individuals may predispose to hypertension in a complex hemodynamic interplay, which is explained predominantly by summated arterial wave reflections and an elevated augmentation index. Our systemic review suggests that an inverse relationship between adult height and blood pressure exists. However, differences in the studied populations and heterogeneity in the methods applied across the various studies limit the generalizability of these findings and their clinical application. Conclusion: Physiological studies and epidemiological data suggest a potential inverse association between adult height and blood pressure. Further research is required to define the relationship more clearly between adult height and blood pressure and to assess whether antihypertensive therapeutic approaches and goals should be modified according to patients’ heights.

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