Endemic Control Group Research Articles

Increased platelet distribution width and reduced IL-2 and IL-12 are associated with thrombocytopenia in Plasmodium vivax malaria.

BACKGROUND Thrombocytopenia in malaria involves platelet destruction and consumption; however, the cellular response underlying this phenomenon has still not been elucidated.OBJECTIVE To find associations between platelet indices and unbalanced Th1/Th2/Th17 cytokines as a response to thrombocytopenia in Plasmodium vivax infected (Pv-MAL) patients.METHODS Platelet counts and quantification of Th1/Th2/Th17 cytokine levels were compared in 77 patients with uncomplicated P. vivax malaria and 37 healthy donors from the same area (endemic control group - ENCG).FINDINGS Thrombocytopenia was the main manifestation in 55 patients, but was not associated with parasitaemia. The Pv-MAL patients showed increases in the mean platelet volume (MPV), which may be consistent with larger or megaplatelets. Contrary to the findings regarding the endemic control group, MPV and platelet distribution width (PDW) did not show an inverse correlation, due the increase in the heterogeneity of platelet width. In addition, the Pv-MAL patients presented increased IL-1β and reduced IL-12p70 and IL-2 serum concentrations. Furthermore, the reduction of these cytokines was associated with PDW values.MAIN CONCLUSIONS Our data demonstrate that an increase in MPV and the association between reductions of IL-2 and IL-12 and PDW values may be an immune response to thrombocytopenia in uncomplicated P. vivax malaria.

Serum and urine fluoride levels in populations of high environmental fluoride exposure with endemic CKDu: a case-control study from Sri Lanka.

Chronic kidney disease of uncertain etiology (CKDu) is a common health issue among farming communities in the dry zone of Sri Lanka where groundwater fluoride is known to be higher than recommended levels. Excessive environmental ingestion of fluoride is widely considered as a possible factor for the onset of CKDu. This study was carried out to evaluate the serum and urine fluoride levels in biopsy-proven, non-dialysis CKDu patients. Control subjects were selected from the same area without any deteriorated kidney functions. Serum and urine fluoride levels were determined by ion-selective electrode method. Higher content of serum and urine fluoride levels were observed in patients with chronic renal failures. In CKDu cases, the serum fluoride concentrations ranged between 0.47 and 9.58mg/L (mean 1.39 ± 1.1mg/L), while urine levels were varied between 0.45 and 6.92mg/L (mean 1.53 ± 0.8mg/L). In patients, urine fluoride levels showed a significant difference with the CKDu stage; however, no difference was obtained between genders and age. In endemic controls, serum and urine fluoride levels ranged between 0.51 and 1.92mg/L (mean = 1.07 ± 0.3mg/L) and 0.36 and 3.80mg/L (mean = 1.26 ± 0.6mg/L), respectively. Significantly higher fluoride in serum and urine was noted in CKDu patients compared to endemic control groups. Higher fluoride exposure via drinking water is possibly the reason for higher fluoride in serum, while excessive urinary excretion would be due to deterioration of the kidney, suggesting a possible nephrotoxic role of environmental fluoride exposure.

Anti-parasite therapy drives changes in human visceral leishmaniasis-associated inflammatory balance

Visceral leishmaniasis (VL) remains a major public health problem worldwide. Cytokine balance is thought to play a critical role in the development of this disease. Here, we perform a prospective exploratory study addressing whether simultaneous assessment of circulating levels of different lipid mediators and cytokines could highlight specific pathways involved with VL pathogenesis. VL patients displayed substantial increases in serum levels of Prostaglandin F2α (PGF2α), Leukotriene B4 (LTB4), Resolvin D1 (RvD1), IL-1β, IL-6, IL-8, IL-10, IL-12p70 and TNF-α compared with uninfected endemic control group, while exhibiting decreased levels of TGF-β1. Hierarchical cluster analysis of the prospective changes in the expression level of theses parameters upon anti-Leishmania treatment initiation revealed that the inflammatory profile observed in active disease gradually changed over time and was generally reversed at day 30 of therapy. Furthermore, not only the individual concentrations of most of the inflammatory biomarkers changed upon treatment, but the correlations between those and several biochemical parameters used to characterize VL disease activity were also modified over time. These results demonstrate that an inflammatory imbalance hallmarks active VL disease and open perspective for manipulation of these pathways in future studies examining a potential host-directed therapy against VL.

On the cytokine/chemokine network during Plasmodium vivax malaria: new insights to understand the disease

BackgroundThe clinical outcome of malaria depends on the delicate balance between pro-inflammatory and immunomodulatory cytokine responses triggered during infection. Despite the numerous reports on characterization of plasma levels of cytokines/chemokines, there is no consensus on the profile of these mediators during blood stage malaria. The identification of acute phase biomarkers might contribute to a better understanding of the disease, allowing the use of more effective therapeutic approaches to prevent the progression towards severe disease. In the present study, the plasma levels of cytokines and chemokines and their association with parasitaemia and number of previous malaria episodes were evaluated in Plasmodium vivax-infected patients during acute and convalescence phase, as well as in healthy donors.MethodsSamples of plasma were obtained from peripheral blood samples from four different groups: P. vivax-infected, P. vivax-treated, endemic control and malaria-naïve control. The cytokine (IL-6, IL-10, IL-17, IL-27, TGF-β, IFN-γ and TNF) and chemokine (MCP-1/CCL2, IP-10/CXCL10 and RANTES/CCL5) plasma levels were measured by CBA or ELISA. The network analysis was performed using Spearman correlation coefficient.ResultsPlasmodium vivax infection induced a pro-inflammatory response driven by IL-6 and IL-17 associated with an immunomodulatory profile mediated by IL-10 and TGF-β. In addition, a reduction was observed of IFN-γ plasma levels in P. vivax group. A lower level of IL-27 was observed in endemic control group in comparison to malaria-naïve control group. No significant results were found for IL-12p40 and TNF. It was also observed that P. vivax infection promoted higher levels of MCP-1/CCL2 and IP-10/CXCL10 and lower levels of RANTES/CCL5. The plasma level of IL-10 was elevated in patients with high parasitaemia and with more than five previous malaria episodes. Furthermore, association profile between cytokine and chemokine levels were observed by correlation network analysis indicating signature patterns associated with different parasitaemia levels.ConclusionsThe P. vivax infection triggers a balanced immune response mediated by IL-6 and MCP-1/CCL2, which is modulated by IL-10. In addition, the results indicated that IL-10 plasma levels are influenced by parasitaemia and number of previous malaria episodes.

Epidemiology of schistosomiasis in Gezira area Central Sudan and analysis of cytokine profiles

ObjectiveTo determine and compare anti-schistosoma IgG, interleukin-10 (IL-10) and interferon-γ(IFN-γ) levels in the serum of patients and endemic controls and to investigate the epidemiological situation of Al-Hebaika village in the northern part of Gezira Agricultural Irrigation Scheme in 2005. MethodsDuring 2005 survey, serum were collected from 118 villagers. Sixty eight were parasitological positive (patients), and 50 were negative (endemic controls). Indirect ELISA was used to measure and compare the levels of immunoglobulin G (IgG) against Schistsoma mansoni (S. mansoni) soluble worm antigen (SWA) in the patients and endemic control groups from the village and compared with 20 healthy non endemic controls. Sandwich ELISA was also used to measure and compare IL-10 and IFN-γ in the serum of the selected groups. ResultsThe overall prevalence of S. haematobium was 20.0% and 0.9% in the first and the second surveys respectively, while the intensity of infection was the same in the two surveys 1.38 [geometric mean egg count (GMFC)]. The overall prevalence of S. mansoni infection was 68.5% and 15.4%, while the intensity of infection was 2.75 (GMEC) and 1.70 (GMEC) in the two surveys respectively. IgG reactivity against SWA showed no significant difference between Schistosoma positive patients and endemic controls. However, there were high significant differences between each of these two groups and the non endemic control group (P= 0,000). Schistosoma patients and exposed controls had significantly higher IL-10 concentration compared with non endemic controls. While endemic controls showed significantly higher IFN-γ concentration than patients (P = 0.000). Also there was very significant difference between IFN-γ levels of each of patients endemic controls and that of the non endemic controls (P = 0.003). ConclusionsThe study concluded that IFN-γ has a role in the natural resistant to schistosoma mansoni infection. The prevalence and intensity of S. mansoni in the Gezira Irrigation Scheme was greatly reduced. S. haematobium has disappeared from the area.

IgG Autoantibody Response against Keratinocyte Cadherins in Endemic Pemphigus Foliaceus (Fogo Selvagem)

It is well established that autoantibodies against desmoglein 3 and desmoglein 1 are relevant in the pathogenesis of pemphigus vulgaris and pemphigus foliaceus, including its endemic form, Fogo Selvagem (FS). Isolated reports have shown that in certain patients with these diseases, autoantibodies against other desmosomal cadherins and E-cadherin may also be present. The goal of this investigation was to determine if FS patients and normal individuals living in endemic areas possess autoantibodies against other desmosomal cadherins and E-cadherin. Testing a large number of FS and endemic control sera by ELISA we find a consistent and specific autoantibody response against desmoglein 1 and other keratinocyte cadherins in these individuals, which is quite different from US controls. Overall, the highest correlations among the autoantibody responses tested are in the endemic controls, followed by FS patients, and lowest in the US controls. These findings suggest that multiple, perhaps cross reactive, keratinocyte cadherins are recognized by FS patients and endemic controls.

Selection of Antigens and Development of Prototype Tests for Point-of-Care Leprosy Diagnosis

Leprosy can be a devastating chronic infection that causes nerve function impairment and associated disfigurement. Despite the recent reduction in the number of registered worldwide leprosy cases as a result of the widespread use of multidrug therapy, the number of new cases detected each year remains relatively stable. The diagnosis of leprosy is currently based on the appearance of clinical signs and requires expert clinical, as well as labor-intensive and time-consuming laboratory or histological, evaluation. For the purpose of developing an effective, simple, rapid, and low-cost diagnostic alternative, we have analyzed the serologic antibody response to identify Mycobacterium leprae proteins that are recognized by leprosy patients. More than 100 recombinant antigens were analyzed in a protein array format to select those with discriminatory properties for leprosy diagnosis. As expected, multibacillary leprosy patients recognized more antigens with stronger antibody responses than paucibacillary leprosy patients. Our data indicate, however, that multibacillary patients can be distinguished from paucibacillary patients, and both of these groups can be segregated from endemic control groups. We went on to confirm the diagnostic properties of antigens ML0405 and ML2331 and the LID-1 fusion construct of these two proteins by enzyme-linked immunosorbent assay. We then demonstrated the performance of these antigens in rapid test formats with a goal of developing a point-of-care diagnostic test. A serological diagnostic test capable of identifying and allowing treatment of leprosy could reduce transmission, prevent functional disabilities and stigmatizing deformities, and facilitate leprosy eradication.

Identification of Specific Proteins and Peptides in Mycobacterium leprae Suitable for the Selective Diagnosis of Leprosy

Diagnosis of leprosy is a major obstacle to disease control and has been compromised in the past due to the lack of specific reagents. We have used comparative genome analysis to identify genes that are specific to Mycobacterium leprae and tested both recombinant proteins and synthetic peptides from a subset of these for immunological reactivity. Four unique recombinant proteins (ML0008, ML0126, ML1057, and ML2567) and a panel of 58 peptides (15 and 9 mer) were tested for IFN-gamma responses in PBMC from leprosy patients and contacts, tuberculosis patients, and endemic and nonendemic controls. The responses to the four recombinant proteins gave higher levels of IFN-gamma production, but less specificity, than the peptides. Thirty-five peptides showed IFN-gamma responses only in the paucibacillary leprosy and household contact groups, with no responses in the tuberculosis or endemic control groups. High frequencies of IFN-gamma-producing CD4+ and CD8+ T cells specific for the 15- and 9-mer peptides were observed in the blood of a paucibacillary leprosy patient. 9-mer peptides preferentially activated CD8+ T cells, while the 15-mer peptides were efficient in inducing responses in both the CD4+ and CD8+ T cell subsets. Four of the six 9-mer peptides tested showed promising specificity, indicating that CD8+ T cell epitopes may also have diagnostic potential. Those peptides that provide specific responses in leprosy patients from an endemic setting could potentially be developed into a rapid diagnostic test for the early detection of M. leprae infection and epidemiological surveys of the incidence of leprosy, of which little is known.

Assessment of eosinophil cationic protein as a possible diagnostic marker for female genital schistosomiasis in women living in a Schistosoma haematobium endemic area.

Eosinophil cationic protein (ECP) levels were measured in vaginal lavage extracts from 518 Zimbabwean reproductive women, age range 15-49 years, to assess the potential use of ECP as a diagnostic marker for female genital schistosomiasis (FGS). One hundred and fifty women had confirmed FGS status. These included 77 (cases) women who had ova in genital tissue and 73 (controls) women who had no ova in genital tissue. Participants were examined at baseline, 3 and 15 months post-treatment with praziquantel. ECP levels were determined using the enzyme linked immunosorbent assay (ECP-ELISA). ECP levels from 18 Norwegian women were used to calculate the diagnostic values of the test. FGS was diagnosed from the study population using genital biopsy and smears. Women were also diagnosed for urinary schistosomiasis using the urine filtration technique. The prevalence of urinary schistosomiasis was 39 % at baseline and this declined to 8% and 6% at 3 and 15 month post-treatment surveys, respectively. There was a higher mean ECP level in women with FGS, 889.3 ng/mL (95% CI: 457.0-1327.5) compared to the endemic control group, 359.1 ng/mL (95%, CI: 227.3-490.9), P = 0.027. Mean ECP levels declined at 3 months following treatment of infected individuals. There was no correlation between ECP levels and tissue ova density, and urine egg intensity. The sensitivity, specificity, positive and negative predictive values for the ECP-ELISA test were 35%, 80%, 65% and 53%, respectively. Our results indicate that FGS causes an inflammatory immune response that increases ECP levels in genital fluid. Treatment of schistosomiasis results in a regression of pathology and a decline in ECP levels. However, other factors such as allergy and microbial infection could also be responsible for increased ECP levels in genital mucosa. These conditions will affect the validity of the test in diagnosis of FGS.

Ivermectin-induced immunopotentiation in onchocerciasis: recognition of selected antigens following a single dose of ivermectin.

Onchocerciasis is associated with blindness and gross skin changes, believed to be a consequence of the immune response to antigens released from the offspring of the female worm of Onchocerca volvulus, the microfilariae (mf). An effective microfilaricidal drug is now available which quickly reduces the mf burden without affecting the adult worm. There exist foci in onchocerciasis endemic areas where some of the patients have many mf in their skin but relatively few clinical symptoms. This state of hyposensitivity is believed to be due to immunosuppression. The aim of this study was to address the question of the basis of, and the effect of ivermectin treatment on this immunosuppression. Female adult worms of O. volvulus were used as whole or fractionated antigens to stimulate peripheral blood mononuclear cells. Microfilariae are found in the reproduction tract of the female worms, and thus an antigen preparation of the female adult O. volvulus contains both exclusive adult antigens as well as antigens from microfilariae. Cells were obtained from onchocerciasis patients, individuals of similar socio-economic status living in the same Ghanaian village, but who showed no parasitological or clinical evidence of onchocerciasis (exposed endemic controls), healthy Ghanaians living in areas where transmission of onchocerciasis does not seem to occur (non-exposed endemic controls) and unexposed healthy Swedish donors. As a group, cells from onchocerciasis patients proliferated to a lesser degree than cells from the exposed endemic control and the non-exposed endemic control groups to the whole worm antigen, whereas the phytohaemagglutinin (PHA) response was strongest in the patients. Proliferative responses of above 1000 ct/min to fractions of the worm extract were only evident in the cells from a few individuals in each of the various groups. However, 28 days following ivermectin treatment, cells from all onchocerciasis patients were able to mount significantly enhanced proliferation to a fraction of approximately 96 kD (fraction 3), while only four of nine of this group showed an increased response to the whole worm antigen. The proportional increase in the response to the whole organism in these individuals was of a much lower magnitude than the increased response to fraction 3. The O. volvulus antigen-specific immunosuppression observed in these onchocerciasis patients appears to be due to suppressive antigens which have the capacity to mask the potential response to selected antigens of O. volvulus, and ivermectin treatment possibly modulates the immune response, allowing for stepwise recognition of such antigens. Since ivermectin treatment kills only the microfilariae and not the adult worm, the putative suppressive antigens would be expected to be from the microfilariae.

Cytokine profiles using whole-blood assays can discriminate between tuberculosis patients and healthy endemic controls in a BCG-vaccinated population

Whole-blood assays (WB) provide a simple tool for assessing immune cytokine profiles which may be useful laboratory predictors of early disease, aiding the evaluation of new tuberculosis (TB) vaccines and offering insights into disease pathogenesis. Although BCG does not provide protection against pulmonary disease in TB endemic areas, it does modulate immune responses to mycobacterial antigens. It is important, therefore, to evaluate any new tool in an endemic setting in both BCG vaccinees and patients with tuberculosis. We have assessed the optimal conditions in terms of dose and kinetics of those cytokines which are released early (TNF-α, IL6 and TGF-β, IL10) or (interferon [IFN]-γ and IL5) in WB cultures stimulated with mitogens and mycobacterial antigens. Responses were studied in parallel in untreated TB patients and endemic control groups. Optimal responses to LPS (predominantly monocyte-derived) occurred on days 1–2, whereas for PHA (predominantly T-cell-derived), they were on days 3–5. Secreted Mycobacterium tuberculosis culture filtrate proteins (CFP) provided a stronger stimulus for monocyte-derived cytokines compared to PPD, but both antigens were comparable for induction of T-cell cytokines. Using unpaired Student's t-tests, pulmonary tuberculosis patients (P.TB; n=11), in response to CFP, showed higher monocyte-derived IL6 ( p=0.023) and IL10 ( p=0.042) compared to endemic controls (EC; n=13), and significantly suppressed T-cell-derived IFN-γ ( p=0.028) and IL5 ( p=0.012) secretion but increased IL10 ( p=0.047) on day 5, indicating that CFP is a strong stimulus for IL10 secretion in pulmonary TB patients. Extrapulmonary TB patients (E.TB; n=6) showed no elevation of early monocyte-derived cytokines to either PPD or CFP, but showed a marked suppression of the T-cell-derived cytokines IFN-γ (PPD, p=0.015; CFP, p=0.05) and IL5 (PPD, p=0.05; CFP, p=0.015). Cytokine analysis in WB cultures is, therefore, able to discriminate between active tuberculosis infection and nondiseased healthy controls.

EVALUACION DE LA INTRADERMORREACCIÓN CON ANTÍGENOS DE Leishmania (Viannia) peruviana y Leishmania (Viannia) braziliensis EN ÁREAS ENDÉMICAS DE LEISHMANIASIS EN EL PERÚ

Extracts of Leishmania soluble antigens (leishmanina) were made from Leishmania (Viannia) peruviana and Leishmania (Viannia) braziliensis promastigotes. Antigens were evaluated for sensitivity, specificity and side effects. Assays were perfomed in transmission areas for uta (andean leishmaniasis), espundia (sylvatic leishmaniasis), and also in patients seen in Lima. Leishmania (Viannia) peruviana antigen, 25 µg/ml, was adequate to detect late skin hypersensitivity reaction among patients with active cutaneous and/or mucocutaneous lesions, with an average sensitivity of 95,9%. The same sensitivity, but with more intense (potency) reactions were observed with the homologous 30 µg/ml antigen. Antigens of Leishmania (Viannia) braziliensis, 25 and 30 µg/ml, showed similar sensitivity and potency to the equivalent doses of Leishmania (Viannia) peruviana. The reaction's sensitivity and potency increase minimally with increased protein concentration. No side effects, such as vesiculation and ulceration on the site of the innoculation, were observed. Antigens showed high specificity. Specificity in the control group reached 100,0% whereas in the endemic control group, it was 95,7%.

Intraocular Pressure Decrease in Household Contacts of Patients With Hansen's Disease and Endemic Control Subjects

We compared the intraocular pressure in 150 urban household contacts of patients with Hansen's disease and 132 endemic control subjects from an urban population in Karachi, Pakistan, who were matched in regard to race, age, gender, and socioeconomic status. The mean intraocular pressure in the upright position was 12.6 mm Hg in the right eye and 12.9 mm Hg in the left eye in household contacts of patients with Hansen's disease and 15.3 mm Hg in the right eye and 15.4 mm Hg in the left eye in the endemic control population (P < .0005). The postural change in intraocular pressure from the upright to supine position was 1.7 mm Hg in the right eye and 2.1 mm Hg in the left eye in the household contacts group and 1.3 mm Hg in the right eye and 1.5 mm Hg in the left eye in the endemic control group (P < .0006). Our findings, especially in view of past observations in intraocular pressure changes in patients with Hansen's disease, raise serious questions about possible early ocular susceptibility to Mycobacterium leprae infection and about public health issues, including possible early indication of disease.