Towards a precise test for malaria diagnosis in the Brazilian Amazon: Comparison among field microscopy, a rapid diagnostic test, nested PCR, and a computational expert system based on artificial neural networks
Andrade B.B.,Federal University of Bahia |
Reis-Filho A.,Federal University of Bahia |
Souza-Neto S.M.,State University of Santa Cruz |
Nogueira L.L.,Federal University of Santa Catarina |
And 8 more authors.
Malaria Journal | Year: 2010
Background: Accurate malaria diagnosis is mandatory for the treatment and management of severe cases. Moreover, individuals with asymptomatic malaria are not usually screened by health care facilities, which further complicates disease control efforts. The present study compared the performances of a malaria rapid diagnosis test (RDT), the thick blood smear method and nested PCR for the diagnosis of symptomatic malaria in the Brazilian Amazon. In addition, an innovative computational approach was tested for the diagnosis of asymptomatic malaria. Methods. The study was divided in two parts. For the first part, passive case detection was performed in 311 individuals with malaria-related symptoms from a recently urbanized community in the Brazilian Amazon. A cross-sectional investigation compared the diagnostic performance of the RDT Optimal-IT, nested PCR and light microscopy. The second part of the study involved active case detection of asymptomatic malaria in 380 individuals from riverine communities in Rondônia, Brazil. The performances of microscopy, nested PCR and an expert computational system based on artificial neural networks (MalDANN) using epidemiological data were compared. Results: Nested PCR was shown to be the gold standard for diagnosis of both symptomatic and asymptomatic malaria because it detected the major number of cases and presented the maximum specificity. Surprisingly, the RDT was superior to microscopy in the diagnosis of cases with low parasitaemia. Nevertheless, RDT could not discriminate the Plasmodium species in 12 cases of mixed infections (Plasmodium vivax + Plasmodium falciparum). Moreover, the microscopy presented low performance in the detection of asymptomatic cases (61.25% of correct diagnoses). The MalDANN system using epidemiological data was worse that the light microscopy (56% of correct diagnoses). However, when information regarding plasma levels of interleukin-10 and interferon-gamma were inputted, the MalDANN performance sensibly increased (80% correct diagnoses). Conclusions: An RDT for malaria diagnosis may find a promising use in the Brazilian Amazon integrating a rational diagnostic approach. Despite the low performance of the MalDANN test using solely epidemiological data, an approach based on neural networks may be feasible in cases where simpler methods for discriminating individuals below and above threshold cytokine levels are available. © 2010 Andrade et al; licensee BioMed Central Ltd.
Andrade B.B.,Federal University of Bahia |
Andrade B.B.,National Institute of Allergy and Infectious Diseases |
Araujo-Santos T.,Federal University of Bahia |
Luz N.F.,Federal University of Bahia |
And 8 more authors.
Journal of Immunology | Year: 2010
In many hemolytic disorders, such as malaria, the release of free heme has been involved in the triggering of oxidative stress and tissue damage. Patients presenting with severe forms of malaria commonly have impaired regulatory responses. Although intriguing, there is scarce data about the involvement of heme on the regulation of immune responses. In this study, we investigated the relation of free heme and the suppression of anti-inflammatory mediators such as PGE2 and TGF-β in human vivax malaria. Patients with severe disease presented higher hemolysis and higher plasma concentrations of Cu/Zn superoxide dismutase (SOD-1) and lower concentrations of PGE2 and TGF-β than those with mild disease. In addition, there was a positive correlation between SOD-1 concentrations and plasma levels of TNF-α. During antimalaria treatment, the concentrations of plasma SOD-1 reduced whereas PGE2 and TGF-β increased in the individuals severely ill. Using an in vitro model with human mononuclear cells, we demonstrated that the heme effect on the impairment of the production of PGE2 and TGF-β partially involves heme binding to CD14 and depends on the production of SOD-1. Aside from furthering the current knowledge about the pathogenesis of vivax malaria, the present results may represent a general mechanism for hemolytic diseases and could be useful for future studies of therapeutic approaches. Copyright © 2010 by The American Association of Immunologists, Inc.
Tiburcio R.,Federal University of Bahia |
Ampuero M.,Federal University of Bahia |
Brodskyn C.,Federal University of Bahia |
Brodskyn C.,Institute Investigacao em Imunologia III
Journal of Immunology Research | Year: 2016
Leishmaniasis is a group of neglected diseases whose clinical manifestations depend on factors from the host and the pathogen. It is an important public health problem worldwide caused by the protozoan parasite from the Leishmania genus. Cutaneous Leishmaniasis (CL) is the most frequent form of this disease transmitted by the bite of an infected sandfly into the host skin. The parasites can be uptook and/or recognized by macrophages, neutrophils, and/or dendritic cells (DCs). Initially, DCs were described to play a protective role in activating the immune response against Leishmania parasites. However, several reports showed a dichotomic role of DCs in modulating the host immune response to susceptibility or resistance in CL. In this review, we discuss (1) the interactions between DCs and parasites from different species of Leishmania and (2) the crosstalk of DCs and other cells during CL infection. The complexity of these interactions profoundly affects the adaptive immune response and, consequently, the disease outcome, especially from Leishmania species of the New World. © 2016 Daniel Feijó et al.
Prates D.B.,Federal University of Bahia |
Barral-Netto M.,Federal University of Bahia |
Barral-Netto M.,Institute Investigacao em Imunologia Iii |
Barral A.,Federal University of Bahia |
Barral A.,Institute Investigacao em Imunologia Iii
Scientific Reports | Year: 2013
Leishmania infantum chagasi causes visceral leishmaniasis (VL); it is transmitted by the sand fly Lutzomyia longipalpis that injects saliva and parasites into the host's skin during a blood meal. Chickens represent an important blood source for sand flies and their presence in the endemic area is often cited as a risk factor for VL transmission. However, the role of chickens in VL epidemiology has not been well defined. Here, we tested if chicken antibodies against Lu. longipalpis salivary gland sonicate (SGS) could be used as markers of exposure to sand fly bites. All naturally exposed chickens in a VL endemic area in Brazil developed anti-SGS IgY antibodies. Interestingly, Lu. longipalpis recombinant salivary proteins rLJM17 and rLJM11 were also able to detect anti-SGS IgY antibodies. Taken together, these results show that chickens can be used to monitor the presence of Lu. longipalpis in the peri-domiciliary area in VL endemic regions, when used as sentinel animals.
Oliveira L.C.,University of Sao Paulo |
Porta G.,University of Sao Paulo |
Marin M.L.C.,University of Sao Paulo |
Bittencourt P.L.,Hospital Portugues |
And 4 more authors.
Autoimmunity Reviews | Year: 2011
Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease. Characteristic liver-infiltrating immune cells in portal and periportal areas, hypergammaglobulinemia and typical autoantibodies indicate an ongoing autoimmune reaction against liver self antigens, which lead to irreversible cellular damage and ultimately to severe hepatic failure. A significant part of adult, but not pediatric AIH patients, exhibit concurrent autoimmune diseases, further strengthening the immunological etiology of the disease. Genetic susceptibility to autoimmune hepatitis is strongly associated with HLA-DRB1 alleles. In Caucasian European and North American patients, AIH-1 is associated with the presence of DRB1* 0301, DRB3* 0101 and DRB1* 0401 alleles, while AIH-2 is associated with DRB1* 0301 or DRB1 * 07. In Brazil, the primary susceptibility allele for AIH-1 is DRB1* 1301, but a secondary association with DRB1* 0301 has also been identified. We looked for additional susceptibility factors in the extended MHC region. We genotyped 107 AIH-1 children and up to 326 healthy subjects for TNFA G-308A, TNFA G-238A, LTA A. +. 252. G, LTA A. +. 80. C, NFKBIL1 T-63A, BAT1 C-348. T, BAT1 G-22. C, MICA, and HLA-B polymorphisms. The TNFA-308 A allele was significantly increased in AIH-1 when compared with healthy controls, confirming data from other studies. Linkage disequilibrium analysis was carried out. The ancestral haplotype comprising TNFA-308A, TNFA-238. G, LTA+. 252. G, LTA+. 80. C, NFKBIL1-63A, BAT1-348. C, BAT1-22. C, HLA-B* 08, MICA* 08 was more common in DRB1 * 03 positive patients than in controls (40% vs. 14%), showing a seven-fold increased risk for the disease [OR = 7.8 (95%CI 2.04-29.9.2, p= 0.0021). In contrast, the remaining patients carrying DRB1*03 exhibited varied haplotypes. Finally, a variety of class III haplotypes was also present in HLA-DRB1 * 13 patients, without a predominant pattern. The most common of the 98 haplotypes present in patients were completely absent in controls. The extended haplotype analysis in this sample of AIH-1 patients highlights not only the genetic diversity present in the Brazilian population, but is also in accordance with the previously documented microdiversity within the MHC region. The present knowledge of AIH suggests that the same or a very similar disease can be induced by yet unknown, but different, triggers followed by presentation on different HLA-DR molecules of the epitopes derived from the corresponding autoantigens, characterizing a much more complex disease than previously thought. © 2010 Elsevier B.V.
Apostolico J.D.S.,Federal University of São Paulo |
Lunardelli V.A.S.,Federal University of São Paulo |
Coirada F.C.,Federal University of São Paulo |
Boscardin S.B.,University of Sao Paulo |
And 2 more authors.
Journal of Immunology Research | Year: 2016
Vaccination is one of the most efficient strategies for the prevention of infectious diseases. Although safer, subunit vaccines are poorly immunogenic and for this reason the use of adjuvants is strongly recommended. Since their discovery in the beginning of the 20th century, adjuvants have been used to improve immune responses that ultimately lead to protection against disease. The choice of the adjuvant is of utmost importance as it can stimulate protective immunity. Their mechanisms of action have now been revealed. Our increasing understanding of the immune system, and of correlates of protection, is helping in the development of new vaccine formulations for global infections. Nevertheless, few adjuvants are licensed for human vaccines and several formulations are now being evaluated in clinical trials. In this review, we briefly describe the most well known adjuvants used in experimental and clinical settings based on their main mechanisms of action and also highlight the requirements for licensing new vaccine formulations. © 2016 Juliana de Souza Apostólico et al.
Faria A.M.C.,Federal University of Minas Gerais |
Faria A.M.C.,Institute Investigacao em Imunologia iii |
Gomes-Santos A.C.,Federal University of Minas Gerais |
Gomes-Santos A.C.,Institute Investigacao em Imunologia iii |
And 10 more authors.
Frontiers in Immunology | Year: 2013
The intestinal mucosa is the major site of contact with antigens, and it houses the largest lymphoid tissue in the body. In physiological conditions, microbiota and dietary antigens are the natural sources of stimulation for the gut-associated lymphoid tissues (GALT) and for the immune system as a whole. Germ-free models have provided some insights on the immunological role of gut antigens. However, most of the GALT is not located in the large intestine, where gut microbiota is prominent. It is concentrated in the small intestine where protein absorption takes place. In this review, we will address the involvement of food components in the development and the function of the immune system. Studies in mice have already shown that dietary proteins are critical elements for the developmental shift of the immature neonatal immune profile into a fully developed immune system. The immunological effects of other food components (such as vitamins and lipids) will also be addressed. Most of the cells in the GALT are activated and local pro-inflammatory mediators are abundant. Regulatory elements are known to provide a delicate yet robust balance that maintains gut homeostasis. Usually antigenic contact in the gut induces two major immune responses, oral tolerance and production of secretory IgA. However, under pathological conditions mucosal homeostasis is disturbed resulting in inflammatory reactions such as food hypersensitivity. Food allergy development depends on many factors such as genetic predisposition, biochemical features of allergens, and a growing array of environmental elements. Neuroimmune interactions are also implicated in food allergy and they are examples of the high complexity of the phenomenon. Recent findings on the gut circuits triggered by food components will be reviewed to show that, far beyond their role as nutrients, they are critical players in the operation of the immune system in health and disease. © 2013 Faria, Gomes-Santos, Gonçalves, Moreira, Medeiros, Dourado and Cara.