Leishmania braziliensis Infection Enhances Toll-Like Receptors 2 and 4 Expression and Triggers TNF-α and IL-10 Production in Human Cutaneous Leishmaniasis.

Cutaneous leishmaniasis (CL) caused by infection with Leishmania braziliensis is characterized by an exaggerated inflammatory response that controls the parasite burden, but also contributes to pathology. While myeloid cells are required to eliminate the parasite, recent studies indicate that they may also participate in the inflammatory response driving disease progression. The innate immune response to leishmania is driven in part by the Toll-like receptors (TLRs) TLR2, TLR4, and TLR9. In this study, we used flow cytometric analysis to compare TLR2 and TLR4 expression in monocyte subsets (classical, intermediate, and non-classical) from CL patients and healthy subjects (HS). We also determined if there was an association of either the pro-inflammatory cytokine TNF or the anti-inflammatory cytokine IL-10 with TLR2 or TLR4 expression levels after L. braziliensis infection. In vitro infection with L. braziliensis caused CL monocytes to up-regulate TLR2 and TLR4 expression. We also found that intermediate monocytes expressed the highest levels of TLR2 and TLR4 and that infected monocytes produced more TNF and IL-10 than uninfected monocytes. Finally, while classical and intermediate monocytes were mainly responsible for TNF production, classical monocytes were the main source of IL-10. Collectively, our studies revealed that up-regulated TLR2/4 expression and TNF production by intermediate/inflammatory subsets of monocytes from patients correlates with detrimental outcome of cutaneous leishmaniasis.

Atypical Manifestations of Cutaneous Leishmaniasis in a Region Endemic for Leishmania braziliensis: Clinical, Immunological and Parasitological Aspects.

BACKGROUND: Atypical cutaneous leishmaniasis (ACL) has become progressively more frequent in Corte de Pedra, Northeast Brazil. Herein we characterize clinical presentation, antimony response, cytokine production and parasite strains prevailing in ACL. METHODOLOGY/PRINCIPAL FINDINGS: Between 2005 and 2012, 51 ACL (cases) and 51 temporally matched cutaneous leishmaniasis (CL) subjects (controls) were enrolled and followed over time in Corte de Pedra. Clinical and therapeutic data were recorded for all subjects. Cytokine secretion by patients' peripheral blood mononuclear cells (PBMC) stimulated with soluble parasite antigen in vitro, and genotypes in a 600 base-pair locus in chromosome 28 (CHR28/425451) of the infecting L. (V.) braziliensis were compared between the two groups. ACL presented significantly more lesions in head and neck, and higher rate of antimony failure than CL. Cytosine-Adenine substitutions at CHR28/425451 positions 254 and 321 were highly associated with ACL (p<0.0001). In vitro stimulated ACL PBMCs produced lower levels of IFN-γ (p = 0.0002) and TNF (p <0.0001), and higher levels of IL-10 (p = 0.0006) and IL-17 (p = 0.0008) than CL PBMCs. CONCLUSIONS/SIGNIFICANCE: ACL found in Northeast Brazil is caused by distinct genotypes of L. (V.) braziliensis and presents a cytokine profile that departs from that in classical CL patients. We think that differences in antigenic contents among parasites may be in part responsible for the variation in cytokine responses and possibly immunopathology between CL and ACL.

Characterization of Neutrophil Function in Human Cutaneous Leishmaniasis Caused by Leishmania braziliensis.

Infection with different Leishmania spp. protozoa can lead to a variety of clinical syndromes associated in many cases with inflammatory responses in the skin. Although macrophages harbor the majority of parasites throughout chronic infection, neutrophils are the first inflammatory cells to migrate to the site of infection. Whether neutrophils promote parasite clearance or exacerbate disease in murine models varies depending on the susceptible or resistant status of the host. Based on the hypothesis that neutrophils contribute to a systemic inflammatory state in humans with symptomatic L. braziliensis infection, we evaluated the phenotype of neutrophils from patients with cutaneous leishmaniasis (CL) during the course of L. braziliensis infection. After in vitro infection with L. braziliensis, CL patient neutrophils produced more reactive oxygen species (ROS) and higher levels of CXCL8 and CXCL9, chemokines associated with recruitment of neutrophils and Th1-type cells, than neutrophils from control healthy subjects (HS). Despite this, CL patient and HS neutrophils were equally capable of phagocytosis of L. braziliensis. There was no difference between the degree of activation of neutrophils from CL versus healthy subjects, assessed by CD66b and CD62L expression using flow cytometry. Of interest, these studies revealed that both parasite-infected and bystander neutrophils became activated during incubation with L. braziliensis. The enhanced ROS and chemokine production in neutrophils from CL patients reverted to baseline after treatment of disease. These data suggest that the circulating neutrophils during CL are not necessarily more microbicidal, but they have a more pro-inflammatory profile after parasite restimulation than neutrophils from healthy subjects.

Protective and pathological functions of CD8+ T cells in Leishmania braziliensis infection.

Cutaneous leishmaniasis (CL) caused by Leishmania braziliensis is characterized by a strong Th1 response that leads to skin lesion development. In areas where L. braziliensis transmission is endemic, up to 15% of healthy subjects have tested positive for delayed-type hypersensitivity to soluble leishmania antigen (SLA) and are considered to have subclinical (SC) infection. SC subjects produce less gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) than do CL patients, but they are able to control the infection. The aim of this study was to characterized the role of CD8(+) T cells in SC infection and in CL. Peripheral blood mononuclear cells (PBMC) were stimulated with SLA to determine the frequencies of CD4(+) IFN-γ(+) and CD8(+) IFN-γ(+) T cells. Monocytes from PBMC were infected with L. braziliensis and cocultured with CD8(+) T cells, and the frequencies of infected monocytes and levels of cytotoxicity markers, target cell apoptosis, and granzyme B were determined. The frequency of CD8(+) IFN-γ(+) cells after SLA stimulation was higher for SC individuals than for CL patients. The frequency of infected monocytes in SC cells was lower than that in CL cells. CL CD8(+) T cells induced more apoptosis of infected monocytes than did SC CD8(+) T cells. Granzyme B production in CD8(+) T cells was higher in CL than in SC cells. While the use of a granzyme B inhibitor decreased the number of apoptotic cells in the CL group, the use of z-VAD-FMK had no effect on the frequency of these cells. These results suggest that CL CD8(+) T cells are more cytotoxic and may be involved in pathology.

Tr-1-like CD4+CD25-CD127-/lowFOXP3- cells are the main source of interleukin 10 in patients with cutaneous leishmaniasis due to Leishmania braziliensis.

CD4(+)CD25(+)FOXP3(+) regulatory T cells have long been shown to mediate susceptibility to Leishmania infection, mainly via interleukin 10 production. In this work, we showed that the main sources of interleukin 10 in peripheral blood mononuclear cells (PBMCs) from patients with cutaneous leishmaniasis due to Leishmania braziliensis are CD4(+)CD25(-)CD127(-/low)FOXP3(-) cells. Compared with uninfected controls, patients with CL had increased frequencies of circulating interleukin 10-producing CD4(+)CD25(-)CD127(-/low) cells, which efficiently suppressed tumor necrosis factor α production by the total PBMC population. Also, in CL lesions, interleukin 10 was mainly produced by CD4(+)CD25(-) cells, and interleukin 10 messenger RNA expression was associated with interleukin 27, interleukin 21, and interferon γ expression, rather than with FOXP3 or transforming growth factor ß expressions. Active production of both interleukin 27 and interleukin 21, together with production of interferon γ and interleukin 10, was also detected in the lesions. Since these cytokines are associated with the differentiation and activity of Tr-1 cells, our results suggest that this cell population may play an important role in the immunomodulation of CL. Therefore, development of treatments that interfere with this pathway may lead to faster parasite elimination.

The role of inflammatory and anti-inflammatory cytokines in the pathogenesis of human tegumentary leishmaniasis.

In tegumentary leishmaniasis caused by Leishmania braziliensis, there is evidence that increased production of IFN-γ, TNF-α and absence of IL-10 is associated with strong inflammatory reaction and with tissue destruction and development of the lesions observed in cutaneous leishmaniasis (CL) and mucosal leishmaniasis (ML). We evaluate the role of regulatory cytokines and cytokine antagonists in the downregulation of immune response in L. braziliensis infection. Peripheral blood mononuclear cells from CL and ML were stimulated with soluble Leishmania antigen in the presence or absence of regulatory cytokines (IL-10, IL-27 and TGF-ß) or antagonists of cytokines (α-TNF-α and α-IFN-γ). Cytokines production (IL-10, IL-17, TNF-α and IFN-γ) was measured by ELISA. IL-10 and TGF-ß downmodulate TNF-α and IL-17 production, whereas IL-27 had no effect in the production of TNF-α, IFN-γ and IL-17 in these patients. Neutralization of TNF-α decreased IFN-γ level and the neutralization of IFN-γ decreased TNF-α level and increased IL-10 production. This study demonstrate that IL-10 and TGF-ß are cytokines that appear to be more involved in modulation of immune response in CL and ML patients. IL-10 might have a protective role, since the neutralization of IFN-γ decreases the production of TNF-α in an IL-10-dependent manner.

Macrophages participate in host protection and the disease pathology associated with Leishmania braziliensis infection.

BACKGROUND: Leishmania preferentially infects macrophages, which allow the parasite to multiply but can also kill the parasite. Although the T cell response in human leishmaniasis is well-characterized, little is known about the concomitant macrophage behavior. The aim of this study was to characterize the macrophage immune response after Leishmania braziliensis infection in cells derived from cutaneous leishmaniasis (CL) or mucosal leishmaniasis (ML) patients, subclinical individuals (SC) and healthy control subjects (HS). METHODS: Peripheral blood mononuclear cell-derived macrophages from the different groups were exposed to L. braziliensis in vitro and were evaluated for susceptibility to Leishmania infection, ability to kill Leishmania and chemokine/cytokine production. Nitric Oxide (NO) and superoxide (O2-) levels in the supernatant of infected macrophage cultures were monitored. RESULTS: After exposure to L. braziliensis, peripheral blood mononuclear cell-derived macrophages from SC individuals showed a lower infection rate and a smaller number of intracellular amastigotes compared to cells from CL and ML patients. Macrophages from CL and ML patients produced more chemokines and TNF-α than those from the SC group. Production of NO and O2- were detected but did not vary significantly among the different groups. CONCLUSIONS: Our data indicate that macrophages play a pivotal role in controlling L. braziliensis infection and in leishmaniasis pathology by secreting pro-inflammatory chemokines/cytokines that activate and recruit T cells, overwhelming the inflammatory response.

Schistosoma mansoni antigens alter the cytokine response in vitro during cutaneous leishmaniasis.

Schistosoma mansoni infection or associated products are able to down-modulate the type 1 CD4+ T cell inflammatory response characteristic of autoimmune diseases. In this study, we evaluated how S. mansoni antigens altered the immune response that was induced by the soluble Leishmania antigen (SLA) from cutaneous leishmaniasis (CL) patients. Cytokines were measured from the supernatants of peripheral blood mononuclear cell cultures stimulated with SLA. This was performed using the sandwich enzyme linked immunosorbent assay technique in the presence or absence of S. mansoni recombinant antigens Sm29, SmTSP-2 and PIII. The addition of S. mansoni antigens to the cultures resulted in the reduction of interferon gamma (IFN-γ) levels in 37-50% of patients. Although to a lesser extent, the antigens were also able to decrease the production of tumour necrosis factor-alpha (TNF-α). We compared patients that either had or did not have reduction in IFN-γ and TNF-α production in cultures stimulated with SLA in the presence of S. mansoni antigens. We found that there was no significant difference in the levels of interleukin (IL)-10 and IL-5 in response to S. mansoni antigens between the groups. The antigens used in this study down-modulated the in vitro proinflammatory response induced by SLA in a group of CL patients through a currently undefined mechanism.

Schistosoma mansoni antigens alter the cytokine response in vitro during cutaneous leishmaniasis

Schistosoma mansoni infection or associated products are able to down-modulate the type 1 CD4+ T cell inflammatory response characteristic of autoimmune diseases. In this study, we evaluated how S. mansoni antigens altered the immune response that was induced by the soluble Leishmania antigen (SLA) from cutaneous leishmaniasis (CL) patients. Cytokines were measured from the supernatants of peripheral blood mononuclear cell cultures stimulated with SLA. This was performed using the sandwich enzyme linked immunosorbent assay technique in the presence or absence of S. mansoni recombinant antigens Sm29, SmTSP-2 and PIII. The addition of S. mansoni antigens to the cultures resulted in the reduction of interferon gamma (IFN-γ) levels in 37-50 percent of patients. Although to a lesser extent, the antigens were also able to decrease the production of tumour necrosis factor-alpha (TNF-α). We compared patients that either had or did not have reduction in IFN-γ and TNF-α production in cultures stimulated with SLA in the presence of S. mansoni antigens. We found that there was no significant difference in the levels of interleukin (IL)-10 and IL-5 in response to S. mansoni antigens between the groups. The antigens used in this study down-modulated the in vitro proinflammatory response induced by SLA in a group of CL patients through a currently undefined mechanism.

Reappraisal of the immunopathogenesis of disseminated leishmaniasis: in situ and systemic immune response.

Disseminated leishmaniasis (DL) is an emerging form of Leishmania braziliensis infection characterised by multiple cutaneous lesions on different parts of the body and a high rate of mucosal involvement. Systemic production of TNFα and IFNγ in DL patients is lower than in cutaneous leishmaniasis (CL) caused by L. braziliensis, which may account for parasite dissemination due to the decreased ability to control parasite growth. In this study, the systemic and in situ immune response of DL and CL patients was characterised through evaluation of chemokine and cytokine production. In situ evaluation showed similar production of IFNγ, TNFα, IL-10, transforming growth factor-beta (TGFß), chemokine (C-C motif) ligand 2 (CCL2), CCL3, CCL11 and chemokine (C-X-C motif) ligand 10 (CXCL10) in papular and ulcerative lesions from DL as well as in ulcerated lesions from CL. Serum levels of CXCL9, a chemokine that attracts T-cells, was higher in serum from DL than from CL. These data indicate that a decrease in the type 1 immune response in peripheral blood of DL patients is due to attraction of Leishmania antigen-activated T-cells to the multiple cutaneous lesions. This may account for the absence of or few parasites in the lesions and for the development of ulcers similar to those observed in CL.

Serum cytokine levels in patients with chronic low back pain due to herniated disc: analytical cross-sectional study.

CONTEXT AND OBJECTIVE: the role of immune response and proinflammatory cytokines in the pathogenesis of chronic pain has been of growing interest. In order to evaluate whether there is any association between disc herniation and elevated cytokine levels, we measured cytokine levels in patients with chronic low back pain and in healthy subjects. DESIGN AND SETTING: analytical cross-sectional study at the Pain Clinic of Universidade Federal da Bahia (UFBA). METHODS: cytokine levels were measured using the enzyme-linked immunosorbent assay (ELISA) technique on 23 patients with low back pain (G1) and on 10 healthy subjects (G2). RESULTS: the levels of tumor necrosis factor-alpha [TNF-alpha] (G1 = 5.6 ± 2.3 pg/ml; G2 = 1.6 ± 0.5 pg/ml; P = 0.01) and interleukin-6 [IL-6] (G1 = 4.1 ± 3.0 pg/ml; G2 = 0.9 ± 0.4 pg/ml; P = 0.01) were higher in G1. There were no statistically significant differences in relation to interleukin-1 [IL-1] (G1 = 0.5 ± 0.3 pg/ml; G2 = 0.5 ± 0.1 pg/ml; P = 1) or soluble tumor necrosis factor receptor [sTNF-R] (G1 = 572 pg/ml ± 36; G2 = 581 ± 50 pg/ml; P = 0.87). CONCLUSION: The patients with chronic low back pain due to disc herniation presented higher levels of TNF-alpha and IL-6, but not of IL-1 or sTNF-R.

Serum cytokine levels in patients with chronic low back pain due to herniated disc: analytical cross-sectional study / Concentrações plasmáticas de citocinas em pacientes com lombalgia crônica por hérnia de disco: estudo transversal analítico

CONTEXT AND OBJECTIVE: The role of immune response and proinflammatory cytokines in the pathogenesis of chronic pain has been of growing interest. In order to evaluate whether there is any association between disc herniation and elevated cytokine levels, we measured cytokine levels in patients with chronic low back pain and in healthy subjects. DESIGN AND SETTING: Analytical cross-sectional study at the Pain Clinic of Universidade Federal da Bahia (UFBA). METHODS: Cytokine levels were measured using the enzyme-linked immunosorbent assay (ELISA) technique on 23 patients with low back pain (G1) and on 10 healthy subjects (G2). RESULTS: The levels of tumor necrosis factor-alpha [TNF-alpha] (G1 = 5.6 ± 2.3 pg/ml; G2 = 1.6 ± 0.5 pg/ml; P = 0.01) and interleukin-6 [IL-6] (G1 = 4.1 ± 3.0 pg/ml; G2 = 0.9 ± 0.4 pg/ml; P = 0.01) were higher in G1. There were no statistically significant differences in relation to interleukin-1 [IL-1] (G1 = 0.5 ± 0.3 pg/ml; G2 = 0.5 ± 0.1 pg/ml; P = 1) or soluble tumor necrosis factor receptor [sTNF-R] (G1 = 572 pg/ml ± 36; G2 = 581 ± 50 pg/ml; P = 0.87). CONCLUSION: The patients with chronic low back pain due to disc herniation presented higher levels of TNF-alpha and IL-6, but not of IL-1 or sTNF-R.

CONTEXTO E OBJETIVO: A função da resposta imunológica e das citocinas pró-inflamatórias na patogênese da dor crônica tem tido interesse crescente. Para avaliar se há correlação entre hérnia de disco e aumento de citocinas, foi medida a concentração de citocinas em pacientes com lombalgia crônica e em indivíduos sadios. TIPO DE ESTUDO E LOCAL: Estudo transversal analítico realizado na Clínica de Dor da Universidade Federal da Bahia (UFBA). MÉTODO: As concentrações de citocinas foram medidas pela técnica de ELISA (enzyme linked immunosorbent assay) em 23 pacientes com lombalgia (G1) e 10 sadios (G2). RESULTADOS: As concentrações de fator-alfa de necrose tumoral [TNF-alpha] (G1 = 5.6 ± 2.3 pg/ml; G2 = 1.6 ± 0.5 pg/ml; P = 0,01) e interleucina-6 [IL-6] (G1 = 4.1 ± 3.0 pg/ml; G2 = 0.9 ± 0.4 pg/ml; P = 0,01) foram maiores no G1. Não houve diferença estatisticamente significante para interleucina-1 [IL-1] (G1 = 0.5 ± 0.3 pg/ml; G2 = 0.5 ± 0.1 pg/ml; P = 1) e receptor solúvel do factor de necrose tumoral [sTNF-R] (G1 = 572 pg/ml ± 36; G2 = 581 ± 50 pg/ml; P = 0,87). CONCLUSÃO: Os pacientes com lombalgia crônica por hérnia de disco apresentam concentrações maiores de TNF-alpha e IL-6, mas não de IL-1 ou sTNF-R.

Citocinas pró-inflamatórias em pacientes com dor neuropática submetidos a tratamento com Tramadol / Proinflammatory cytokines in patients with neuropathic pain treated with Tramadol / Interleucinas proinflamatorias en pacientes con dolor neuropático sometidos a tratamiento con Tramadol

JUSTIFICATIVA E OBJETIVOS: As citocinas pró-inflamatórias têm função importante na fisiopatologia das síndromes dolorosas neuropáticas. O objetivo desse estudo foi avaliar os níveis plasmáticos de citocinas pró-inflamatórias antes e após o tratamentocom tramadol em pacientes com hérnia discal e síndrome do túnel do carpo e compará-los com indivíduos normais.MÉTODO: Investigou-se 38 pacientes com dor neuropática por hérnia discal ou síndrome do túnel do carpo. Todos os pacientes foram tratados com tramadol de liberação controlada (100 mg em 12h) durante 10 dias. Realizaram-se coletas de sangue venoso (5 mL), no período matutino, antes do tratamento e no 11º dia e as amostras foram armazenadas até análise (-70ºC). Foram utilizados testes enzimáticos ELISA para dosagem de citocinas plasmáticas (TNF-α, IL-1, IL-6) e receptores sTNF-R1, (R & D Systems). Realizou-se dosagem de citocinas em soro de 10 voluntários sadios. RESULTADOS: A concentração de TNF-α antes (5,8 ± 2,8 pg.mL-1) foi significativamente maior que após o tramadol (4,8 ± 2,1 pg.mL-1; p = 0,04, Teste Mann-Whitney). Não houve diferença significativa de IL-1β, IL-6 e sTNF-R1 antes e após o tratamento. As concentrações plasmáticas de TNF-α (sadios: 1,4 ± 0,5; pacientes com dor: 5,8 ± 2,8 pg.mL-1; p = 0.01) e IL-6 (sadios: 1,2 ± 0,8; pacientes com dor: 3,5 ± 2,6 pg.mL-1; p = 0,01) foram significativamente maiores nos pacientes com dor neuropática que nos voluntários, Teste de Mann-Whitney. CONCLUSÕES: Nos pacientes com hérnia discal e síndrome do túnel do carpo as concentrações plasmáticas de TNF-α e IL-6 foram maiores que em voluntários sadios, não havendo diferença das concentrações de sTNF-R e IL-1β. Houve redução da concentraçãoplasmática de TNF-α após tratamento com tramadol (100 mg em 12h), mas não de IL-6, sTNF-R e IL-1β.

BACKGROUND AND METHODS: Proinflammatory cytokines play an important role in the pathophysiology of neuropathic pain syndromes. The objective of this study was to evaluate plasma levels of proinflammatory cytokines before and after treatment with tramadol in patients with herniated intervertebral disks and carpal tunnel syndrome, and to compare them with normal individuals. METHODS: Thirty-eight patients with neuropathic pain secondary to herniated intervertebral disks or carpal tunnel syndrome participated in this study. All patients were treated with controlled release tramadol (100 mg every 12 hours) for 10 days. Venous blood (5 mL) was collected in the morning, before treatment and on the 11th day, and stored (-70º C) until analysis. ELISA was used to determine the plasma levels of cytokines (TNF-α, IL-1, IL-6) andreceptors sTNF-R1 (R & D Systems). Plasma levels of cytokines of 10 healthy volunteers were also determined. RESULTS: The concentration of TNF-α before (5.8 ± 2.8 pg.mL-1) was significantly higher than after treatment with tramadol (4.8 ± 2.1 pg.mL-1; p = 0.04, Mann-Whitney test). The levels of IL-1β, IL-6, and sTNF-R1 before and after treatment with tramadol showed nosignificant differences. Plasma levels of TNF-α (healthy individuals: 1.4 ± 0.5; pain patients: 5.8 ± 2.8 pg.mL-1; p = 0.01) and IL-6 (healthy individuals: 1.2 ± 0.8; pain patients: 3.5 ± 2.6 pg.mL-1; p = 0.01) were significantly higher in patients with neuropathic pain, Mann-Whitney Test. CONCLUSIONS: In patients with herniated intervertebral disks and carpal tunnel syndrome, plasma levels of TNF-α and IL-6 werehigher than in healthy volunteers, while differences in the concentrations of sTNF-R and IL-1β were not observed. Plasma levels of TNF-α, but not of IL-6, sTNF-R, and IL-1β, decreased after treatment with tramadol (100 mg every 12 hours).

JUSTIFICATIVA Y OBJETIVOS: Las interleucinas proinflamatorias tienen una función importante en la fisiopatología de los síndromes dolorosos neuropáticos. El objetivo de este estudio, fue evaluar los niveles plasmáticos de interleucinas proinflamatorias antes y después del tratamiento con tramadol en pacientes con hernia de disco y síndromedel túnel del carpo, y compararlos con individuos normales. MÉTODO: Se investigaron 38 pacientes con dolor neuropático por hernia de disco o síndrome del túnel del carpo. Todos los pacientes fueron tratados con tramadol de liberación controlada (100 mg en 12h) durante 10 días. Se realizaron muestras de sangre venosa (5 mL), por la mañana, antes del tratamiento y en el 11º día, y las mismas se almacenaron para ser analizadas (-70ºC). Se utilizaron test enzimáticos ELISA para la dosificación de las interleucinas plasmáticas (TNF-α, IL-1, IL-6) y receptores sTNFR1, (R & D Systems). Se realizó la dosificación de interleucinasen suero de 10 voluntarios sanos. RESULTADOS: La concentración de TNF-α antes (5,8 ± 2,8 pg.mL-1) fue significativamente mayor que después del tramadol (4,8 ± 2,1 pg.mL-1; p = 0,04, Test de Mann-Whitney). No hubo diferencia significativa de IL-1β, IL-6 y sTNF-R1 antes y después del tratamiento. Las concentraciones plasmáticas de TNF-α (sanos: 1,4 ± 0,5; pacientes con dolor: 5,8 ± 2,8 pg.mL-1; p = 0.01) y IL-6 (sanos: 1,2 ± 0,8; pacientes con dolor: 3.5 ± 2,6 pg.mL-1; p = 0,01) fueron significativamente mayores en los pacientes con dolor neuropático que en los voluntarios, test de Mann-Whitney. CONCLUSIONES: En los pacientes con hernia discal y síndrome del túnel del carpo, las concentraciones plasmáticas de TNF-α yIL-6, fueron más elevadas que en los voluntarios sanos, no habiendo ninguna diferencia en las concentraciones de sTNF-R y IL-1β...

Association of treatment of American cutaneous leishmaniasis prior to ulcer development with high rate of failure in northeastern Brazil.

Cure rates for American cutaneous leishmaniasis (ACL) range between 60% and 90%. Early evidence suggests lower cure rates for early ACL before the development of the ulceration. We evaluated risk factors for treatment failure in patients with early and classic ulcerative ACL. Patients (n = 136) were 13-60 years of age and had lesions with a duration of 15-90-days. Patients were treated with antimony (20 mg/kg/day for 20 days). The primary outcome was lesion cure by 90 days without recurrence. Patients with early ACL (n = 16) had papules, nodules, plaques, or superficial ulcerations with less than 30 days of illness. Patients with classic ulcerative ACL (n = 120) had ulcerated classic lesions, longer duration, larger lesions, and higher levels of interferon-gamma and tumor necrosis factor-alpha (P < or = 0.01 for all comparisons). Ulcerated lesions were associated with a lower treatment failure rate compared with early ACL (25.8% versus 75.0%; P < 0.001). Early treatment of ACL does not prevent lesion ulceration and is associated with higher rates of treatment failure.

Microbiological and immunological features of oral candidiasis.

Candida albicans(C. albicans) is the major infectious agent of oral candidiasis, and both innate immunity and cell-mediated immune response participate in the control of the fungal infections. The aim of this study was to correlate the clinical forms of oral candidiasis with the number of colony forming units (CFU) of C. albicans in saliva and to characterize T cell response in patients with oral candidiasis. Participants included 75 subjects: 36 with lesions of candidiasis and 39 without lesions of oral candidiasis. A 2-ml sample of saliva was collected from all subjects for microbiological analysis. Cytokine levels were determined by ELISA in supernatants of peripheral blood mononuclear cells of 25 patients with oral candidiasis, after in vitro stimulation with C. albicans antigens. In 48% of patients, no association was observed with denture use. C. albicans was detected in the saliva of 91.7% of patients with oral candidiasis, and there was an association between the number of CFU and the presence of oral lesions. A type Th1 immune response was observed in supernatants of peripheral blood mononuclear cells stimulated with C. albicans antigens. In contrast, IL-5 and IL-10 levels were very low or undetectable. Together, this study shows an association between clinical forms of oral candidiasis and the number of colonies of C. albicans in saliva, and that a systemic immune response characterized by the production of TNF-alpha and IFN-gamma is observed in patients with oral candidiasis.

Differential effects of antigens from L. braziliensis isolates from disseminated and cutaneous leishmaniasis on in vitro cytokine production.

BACKGROUND: Disseminated leishmaniasis is an emerging infectious disease, mostly due to L. braziliensis, which has clinical and histopathological features distinct from cutaneous leishmaniasis. METHODS: In the current study we evaluated the in vitro production of the cytokines IFN-gamma, TNF-alpha, IL-5 and IL-10 by peripheral blood mononuclear cells (PBMC) from 15 disseminated leishmaniasis and 24 cutaneous leishmaniasis patients upon stimulation with L. braziliensis antigens genotyped as disseminated leishmaniasis or cutaneous leishmaniasis isolates. RESULTS: Regardless of the source of L. braziliensis antigens, PBMC from cutaneous leishmaniasis patients produced significantly higher IFN-gamma than PBMC from disseminated leishmaniasis patients. Levels of TNF-alpha by PBMC from cutaneous leishmaniasis patients were significantly higher than disseminated leishmaniasis patients only when stimulated by genotyped cutaneous leishmaniasis antigens. The levels of IL-5 and IL-10 production by PBMC were very low and similar in PBMCs from both disseminated leishmaniasis and cutaneous leishmaniasis patients. The immune response of each patient evaluated by the two L. braziliensis antigens was assessed in a paired analysis in which we showed that L. braziliensis genotyped as disseminated leishmaniasis isolate was more potent than L. braziliensis genotyped as cutaneous leishmaniasis isolate in triggering IFN-gamma and TNF-alpha production in both diseases and IL-5 only in cutaneous leishmaniasis patients. CONCLUSION: This study provides evidence that antigens prepared from genotypically distinct strains of L. braziliensis induce different degrees of immune response. It also indicates that both parasite and host play a role in the outcome of L. braziliensis infection.

[Evaluation of cellular immune response in patients with recurrent candidiasis]. / Avaliação da resposta imune celular em pacientes com candidíase recorrente.

Recurrent cutaneous or mucosal candidiasis is characterized by the occurrence of at least four candidiasis episodes within a one-year period. The factors involved in recurrence of infection are still unknown. In the present study the lymphoproliferative response and the IFN-gamma production by candidiasis patients were evaluated. The stimulation index of mononuclear cell cultures of candidiasis patients stimulated with Candida albicans antigen, PPD and TT were 6 +/- 8, 17 +/- 20 and 65 +/- 30, respectively. The addition of monoclonal antibody anti-IL-10 to Candida albicans antigen stimulated cultures raised the lymphoproliferative response from 735 +/- 415 to 4143 +/- 1746 cpm. The IFN-gamma production by cells of candidiasis patients stimulated with Candida albicans antigen was 162 +/- 345 pg/ml. Candidiasis patients have an impairment in the lymphoproliferative response specific to C. albicans antigen and on IFN-gamma production and the lymphoproliferative response can be partially restored, in vitro, by IL-10 neutralization.

Avaliaçäo da resposta imune celular em pacientes com candidíase recorrente / Evaluation of cellular immune response in patients with recurrent candidiasis

A candidíase recorrente cutânea ou mucosa é caracterizada pela ocorrência de, no mínimo, 4 episódios de candidíase no período de um ano. Näo säo conhecidos os fatores que levam à recorrência desta infecçäo. O presente estudo avaliou a resposta linfoproliferativa e a produçäo de IFN-g de pacientes com candidíase recorrente. Os índices de estimulaçäo da resposta linfoproliferativa em culturas de células de pacientes com candidíase recorrente estimuladas com antígeno de Candida albicans, PPD e TT foram respectivamente de 6±8, 17±20 e 65±30. A adiçäo de anticorpo monoclonal anti-IL-10 às culturas de células de 6 pacientes aumentou a resposta linfoproliferativa de 735±415 para 4143±1746 cpm. A produçäo de IFN-g em culturas de células estimuladas com antígeno de Candida, foi 162±345pg/ml. Pacientes com candidíase recorrente apresentam uma deficiência na resposta linfoproliferativa e na produçäo de IFN-g, podendo a resposta imune celular ao antígeno de Candida ser restaurada parcialmente através da neutralizaçäo da IL-10 in vitro

Up-regulation of Th1-type responses in mucosal leishmaniasis patients.

The cytokine profile produced by peripheral blood mononuclear cells (PBMC) in response to leishmania antigens and the ability of interleukin-10 (IL-10) and transforming growth factor beta (TGF-beta) to modulate the immune response were evaluated in 21 mucosal leishmaniasis patients. Patients with mucosal disease exhibited increased gamma interferon (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha) secretion and decreased IL-10 secretion compared to patients with classical cutaneous leishmaniasis. CD4(+) Th1 cells were the main source of IFN-gamma and TNF-alpha production in mucosal leishmaniasis patients. Evaluation of cytokine gene expression in PBMC of these patients showed that there was strong up-regulation of IFN-gamma transcripts upon stimulation with leishmania antigen, in contrast to the baseline levels of IL-10 mRNA. IL-10 suppressed IFN-gamma production by 48% in cell cultures from cutaneous leishmaniasis patients and by 86% in cell cultures from healthy subjects stimulated with purified protein derivative, whereas in similar conditions IL-10 suppressed IFN-gamma production by 19% in cell cultures from mucosal leishmaniasis patients stimulated with leishmania antigen. TGF-beta suppressed IFN-gamma levels to a greater extent in healthy subjects than in mucosal leishmaniasis and cutaneous leishmaniasis patients. These data indicate that a poorly modulated T-cell response in mucosal leishmaniasis patients leads to production of high levels of proinflammatory cytokines, such as IFN-gamma and TNF-alpha, as well as a decreased ability of IL-10 and TGF-beta to modulate this response. These abnormalities may be the basis for the pathological findings observed in this disease.

Epidemiologic and immunologic findings for the subclinical form of Leishmania braziliensis infection.

The epidemiologic and immunologic findings for 104 subjects with subclinical Leishmania braziliensis infection were compared with those for 29 patients with cutaneous leishmaniasis (CL) from the same area of endemicity. Subjects had a positive leishmania skin test result and remained asymptomatic during the next 4 years of follow-up were considered to have subclinical infection. Patients with CL were younger, had larger-diameter indurations after skin testing, and were more likely to have positive serologic markers than were those with subclinical infection (P<.05). In subjects with subclinical infection, levels of interferon-gamma and tumor necrosis factor-alpha in lymphocyte supernatants were lower than they were in patients with CL (P<.05); however, mean interleukin-5 levels were slightly higher in patients with subclinical infection than in patients with CL. These data indicate that, unlike patients with CL, individuals who do not develop disease when infected with L. braziliensis may have the ability to modulate their immune response.