Absolute and relative levels of cytokines in study participants.

<p>Plasma levels of TNF-∝, IFN-γ, IL-4, IL-10, IL-12 and TGF-β for 75 samples from symptomatic malaria patients and apparently healthy controls had been previously reported <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044394#pone.0044394-Gonalves1" target="_blank">[23]</a> and here are combined with IL-6, sTNFRI and sTNFRII measurements in these same samples and a complete analysis of additional samples. Data are expressed as median (interquartile range) unless stated otherwise and compared across three or four groups with Kruskal-Wallis tests (continuous variables) or χ² tests (proportions); <i>P</i> values for this comparison across groups are presented in the right-hand column. When comparisons across groups showed statistical significance, further pairwise comparisons were made using Mann-Whitney tests (continuous variables) or χ² tests (proportions). Values with different superscripts across a row indicate pairwise comparisons with statistical significance at the 5% level. The same value may have more than one superscript. When pairs of values across a row share one superscript (either the only or one of the superscripts associated with them), no statistically significant difference was found.</p

Cytokine levels in acute-phase and convalescence blood samples from <i>P. vivax</i>-infected study participants.

<p>Levels of TNF-∝, IFN-γ, IL-4, IL-10, IL-12 and TGF-β in 22 paired samples had been reported previously <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044394#pone.0044394-Gonalves1" target="_blank">[23]</a> and were combined here with those for 17 additional pairs. Data are expressed as median (interquartile range) and were compared using Wilcoxon tests.</p

Severity of 13 malaria-associated symptoms in Amazonians with uncomplicated infection with <i>Plasmodium vivax</i> (A; n = 84), <i>P. falciparum</i> (B; n = 27) or both species (C; n = 11), diagnosed by thick-smear microscopy and confirmed by real-time PCR.

<p>Symptoms are abbreviated as follows: fever  =  Fev; chills  =  Chi; sweating  =  Swe; headache  =  Hea; myalgia  =  Mya; arthralgia  =  Art; abdominal pain  =  Abd; nausea  =  Nau; vomiting  =  Vom; dizziness  =  Diz; cough  =  Cou; dyspnea  =  Dys; diarrhea  =  Dia. Each bar segment represents the proportion of subjects reporting a given symptom as absent (no shading), mild (light gray), moderate (dark gray) or severe (black).</p

Demographic, hematologic and clinical characteristics of study participants.

<p>Clinical and laboratory data from 75 symptomatic malaria patients and apparently healthy controls had been previously reported <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044394#pone.0044394-Gonalves1" target="_blank">[23]</a> and here are combined with additional subjects living in the same areas. Data are expressed as median (interquartile range) unless stated otherwise and compared across three to five groups with Kruskal-Wallis tests (continuous variables) or χ² tests (proportions); <i>P</i> values for this comparison across groups are presented in the right-hand column. Only when comparisons across groups showed statistical significance, further pairwise comparisons were made using Mann-Whitney tests (continuous variables) or χ² tests (proportions). Values with different superscripts across a row indicate pairwise comparisons with statistical significance at the 5% level. The same value may have more than one superscript. When pairs of values across a row share one superscript (either the only or one of the superscripts associated with them), no statistically significant difference was found. Anemia was defined when hemoglobin concentration was below the following cut-off values: 120 g/l for adolescents aged 12–14 years and non-pregnant women, and 130 g/l for men aged ≥ 15 years. Thrombocytopenia was defined when the platelet count was below 150×10⁹/l.</p>*<p>Number of subjects  = 27 for hemoglobin measurements and platelet counts.</p>§<p>Number of subjects  = 11 for hemoglobin measurements and platelet counts.</p

Iron status indicators and prevalence of anemia and other nutritional and non-nutritional conditions in urban Amazonian children^a.

<p>IQR, interquartile ranges.</p>a<p>Totals in brackets differ from the total number of study children by age group because of missing values.</p>b<p>Cut-offs for anemia: <110.0 and <115.0 g/L for 6–59 months and ≥60 months, respectively;</p>c<p>Cut-offs for microcytosis by age: <67, <73, <74, and <76 fl for <24 months, 24–59 months, 5–7.9 years, and 8–11.9 years, respectively;</p>d<p>PF: <12 and <15 µg/L for <59 and ≥60 months, respectively;</p>e<p>sTfR: >8.3 mg/L;</p>f<p>Cut-off for high CRP: >5 mg/L;</p>g<p>CRP index defined as (0.34+0.0043×PF – [2.7×sTfR]/PF+0.00696×CRP+0.05×sTfR);</p>h<p>Serum retinol <0.70µmol/L;</p>i<p>Serum vitamin B₁₂<150 pmol/L;</p>j<p>Serum folate <10 nmol/L;</p>k<p>According to cut-offs for PF or sTfR.</p>l<p>Geohelminths in this population included <i>Ascaris lumbricoides</i> (overall prevalence, 2.4%), <i>Strongyloides stercoralis</i> (0.5%), and <i>Trichuris trichiura</i> (0.8%) - the same subject may be co-infected with more than one species.</p

Attributable fractions (AF) of anemia according to age group in urban Amazonian children.

a<p>Prevalence (%) of cases exposed in each risk factors.</p>b<p>Adjusted prevalence ratio (aPR) estimated from multiple Poisson regression models with additional adjustment for age (in overall analysis), sex, wealth index (quartile), maternal schooling (≤4, 5–8, and ≥9 years), and maternal age (10–21, 22–35, and >35 years).</p>c<p>Attributable fraction defined as p(aPR –1)/aPR.</p

Multiple linear regression analysis of factors associated with hemoglobin in urban Amazonian children.

a<p>Total differs from total number of study children because of missing values.</p

CD39 and immune regulation in a chronic helminth infection: The puzzling case of <i>Mansonella ozzardi</i>

<div><p>Background</p><p>Chronic helminth infections typically induce an immunoregulatory environment, with markedly reduced immune responses to both parasite-specific and unrelated bystander antigens. Here we tested whether these changes are also observed in human infections with <i>Mansonella ozzardi</i>, a neglected filarial nematode widely distributed across Latin America.</p><p>Methods</p><p>CD4⁺ T cell populations from microfilaremic (Fil+) and uninfected (Fil-) inhabitants in <i>M</i>. <i>ozzardi</i>-endemic riverine communities in Brazil were characterized by flow cytometry analysis. Plasma concentrations of a wide range of cytokines and chemokines were measured. We examined whether <i>M</i>. <i>ozzardi</i> infection is associated with suppressed <i>in vitro</i> lymphoproliferative and inflammatory cytokine responses upon stimulation with filarial antigen, unrelated antigens or mitogens.</p><p>Principal findings/Conclusions</p><p>Fil+ subjects had lower plasma levels of selected inflammatory cytokines, such as TNF-α, IL-8, and IL-6, than their Fil- counterparts. However, we found no evidence for attenuated T-cell responses to filarial antigens or co-endemic pathogens, such as malaria parasites and <i>Toxoplasma gondii</i>. CD4⁺ T cells expressing CD39, an ectonucleosidase involved in the generation of the anti-inflammatory molecule adenosine, were increased in frequency in Fil+ subjects, compared to uninfected controls. Significantly, such an expansion was directly proportional to microfilarial loads. Surprisingly, CD39 blocking with a neutralizing antibody suppressed antigen-driven lymphoproliferation <i>in vitro</i>, while decreasing inflammatory cytokine responses, in Fil+ and Fil- individuals. These findings suggest that circulating CD4⁺ CD39⁺ T cells comprise subsets with both regulatory and stimulatory roles that contribute to the immune homeostasis in chronic <i>M</i>. <i>ozzardi</i> infection.</p></div

General characteristics of children aged 6 months to 10 years (N = 1111).

a<p>Totals differ from the total number of study children because of missing values.</p

Frequency of CD4⁺CD25^hiCD127^-FoxP3⁺ Treg cells expressing regulation and activation markers in microfilaremic subjects (Fil+) and uninfected controls (Fil-).

<p>Frequency of CD4⁺CD25^hiCD127^-FoxP3⁺ Treg cells expressing regulation and activation markers in microfilaremic subjects (Fil+) and uninfected controls (Fil-).</p