Association Between IL-10 Levels With Plasmodim Falciparum Related to Age Groups and Density of Infection Among Sudanese Patients- Khartoum State- Sudan

Abstract: A complex parasite such as human Plasmodium is likely to generate a variety of substances that injure the hosts directly or cause immunopathology. In malaria, a blood concentration of anti-inflammatory cytokines, such as interleukin (IL-10) is increased. The present study was performed to analyze IL-10 levels in patients with malaria falciparum and healthy controls individuals and correlate with malaria density infection as well as age groups. It is a cross sectional study was carried out in Khartoum state /Sudan, a total of 70 febrile patients and 20 healthy volunteers as controls were included in this study. Blood samples were collected from both patients and control candidates in (EDTA) containers for parasitological and immunological tests. Immunochromatography test and microscopic examination for both thick and thin blood films were used to detect the positive samples for Plasmodium falciparum. Enzyme linked Immunosorbant Assay (ELISA), was used for the determination of IL-10 levels. The result showed that of IL-10 levels in malaria patients were 1598.50 and SD 4771.64 while the levels in healthy participants the level was 10.39 and SD was 124.33 the difference was found to be statistically significant (P= 0.007). The levels of cytokines mentioned above were observed to be raised in malaria individual compared to healthy control candidates

Multivariable regression analysis in Schistosoma mansoni-infected individuals in the Sudan reveals unique immunoepidemiological profiles in uninfected, egg+ and non-egg+ infected individuals

Background: In the Sudan, Schistosoma mansoni infections are a major cause of morbidity in schoolaged children and infection rates are associated with available clean water sources. During infection, immune responses pass through a Th1 followed by Th2 and Treg phases and patterns can relate to different stages of infection or immunity. Methodology: This retrospective study evaluated immunoepidemiological aspects in 234 individuals(range 4–85 years old) from Kassala and Khartoum states in 2011. Systemic immune profiles(cytokines and immunoglobulins) and epidemiological parameters were surveyed in n = 110 persons presenting patent S. mansoni infections (egg+), n = 63 individuals positive for S. mansoni via PCR in sera but egg negative (SmPCR+) and n = 61 people who were infection-free (Sm uninf). Immunoepidemiological findings were further investigated using two binary multivariable regression analysis. Principal Findings: Nearly all egg+ individuals had no access to latrines and over 90% obtained water via the canal stemming from the Atbara River. With regards to age, infection and an egg+ status was linked to young and adolescent groups. In terms of immunology, S. mansoni infection per se was strongly associated with increased SEA-specific IgG4 but not IgE levels. IL-6, IL-13 and IL-10 were significantly elevated in patently-infected individuals and positively correlated with egg load. In contrast, IL-2 and IL-1β were significantly lower in SmPCR+ individuals when compared to Sm uninf and egg+ groups which was further confirmed during multivariate regression analysis. Conclusions/Significance: Schistosomiasis remains an important public health problem in the Sudan with a high number of patent individuals. In addition, SmPCR diagnostics revealed another cohort of infected individuals with a unique immunological profile and provides an avenue for future studies on non-patent infection states. Future studies should investigate the downstream signalling pathways/mechanisms of IL-2 and IL-1β as potential diagnostic markers in order to distinguish patent from non-patent individuals

Summary of binary multivariable regression analysis between the different patient groups: Relation of the covariates age, exposure and individual cytokines or Igs.

<p>Summary of binary multivariable regression analysis between the different patient groups: Relation of the covariates age, exposure and individual cytokines or Igs.</p

Gender and age distribution of study participants.

<p>Study participants were grouped according to absence (<i>Sm</i> uninf = 61) or presence of <i>S</i>. <i>mansoni</i> DNA in blood (<i>Sm</i>PCR⁺ = 63) or <i>S</i>. <i>mansoni</i> eggs in stool samples (egg⁺ = 110). (A) Distribution of age within all three groups. Data shows box whiskers with median, interquartile ranges and outliers. Statistical significances between the indicated groups were obtained after Kruskal-Wallis and Mann-Whitney-U tests. (B) Correlation of age with egg number, statistical significances were tested using the Spearman correlation test.</p

Higher levels of SEA-specific IgG4 but not IgE production in infected individuals.

<p>Serum from all three groups was analyzed for the concentration of total IgE (A) and the optical density of SEA-specific IgG4 (C) and IgE (E) using ELISA. (F) depicts the ratio of antigen-specific IgG4/IgE. Graphs show box whiskers with median, interquartile ranges and outliers. Statistical significances between the indicated groups were obtained after Kruskal-Wallis and Mann-Whitney-U tests. Levels of total IgE and SEA-specific IgG4 immunoglobulins were further correlated with egg load (B and D respectively) and tested for statistical significance using the Spearman correlation test.</p

Systemic levels of IL-10 or IL-9 showed opposing profiles in patently infected individuals.

<p>Serum from all three groups was analyzed for the production of IL-9 (A) and IL-10 (C) using FlowCytomix technology. Graphs show box whiskers with median, interquartile ranges and outliers. Statistical significances between the indicated groups were obtained after Kruskal-Wallis and Mann-Whitney-U tests. Levels of IL-9 (B) and IL-10 (D) were correlated with the number of eggs and tested for statistical significance using the Spearman correlation test.</p

Systemic IL-13 is elevated in patently-infected <i>S. mansoni</i> individuals.

<p>Serum from participants (n = 234) was analyzed for the production of IFN-γ (A), IL-2 (B), IL-4 (C), IL-5 (D) and IL-13 (E) using FlowCytomix technology. Graphs show box whiskers with median, interquartile ranges and outliers. Statistical significances between the indicated groups were obtained after Kruskal-Wallis and Mann-Whitney-U tests. IL-13 levels were correlated with the number of eggs (F) and tested for statistical significance using the Spearman correlation test.</p

Lower levels of systemic IL-1β in SmPCR⁺ individuals.

<p>Individual serum samples from all three groups were analyzed for the production of IL-12p70 (A), TNF-α (B), IL-8 (C) and IL-1β (D) using FlowCytomix technology or ELISA (IL-8). Graphs show box whiskers with median, interquartile ranges and outliers. Statistical significances between the indicated groups were obtained after Kruskal-Wallis and Mann-Whitney-U tests. IL-1β levels were correlated with the number of eggs (E) and tested for statistical significance using the Spearman correlation test.</p

Map of study area.

<p>Schematic representation of the regions of Kassala and Khartoum states in the Sudan. Red circles denote villages in which study participants resided.</p

Characteristics of study population.

<p>Characteristics of study population.</p