Marcus Miranda Lessa

Oral Pentoxifylline Combined with Pentavalent Antimony: A Randomized Trial for Mucosal Leishmaniasis

BACKGROUND Mucosal leishmaniasis is associated with intense tissue damage and high tumor necrosis factor-alpha production. Therapeutic failure occurs in up to 42% of cases; patients who experience treatment failure will require >1 pentavalent antimony (Sb(v)) course or alternative drugs to achieve a cure. We previously showed that an inhibitor of tumor necrosis factor-alpha (pentoxifylline) combined with Sb(v) cured 90% patients refractory to monotherapy with Sb(v). METHODS A double-blind, placebo-controlled trial involving 23 patients with mucosal leishmaniasis evaluated the efficacy of pentoxifylline when administered in association with Sb(v), compared with Sb(v) treatment alone. Eleven patients were randomized to receive Sb(v) plus oral pentoxifylline for 30 days, and 12 patients received Sb(v) plus oral placebo. The criterion for cure was a complete healing of lesions. RESULTS All patients in the pentoxifylline group experienced a cure with 1 course of Sb(v), whereas 5 (41.6%) of 12 patients in the placebo group required a second course of Sb(v) (P=.037). The healing time +/- standard deviation in the pentoxifylline group was 83+/-36 days, compared with 145+/-99 days in the placebo group (P=.049). No relapses were documented in either group at the 2-year follow-up visit. CONCLUSIONS The addition of pentoxifylline to Sb(v) in mucosal leishmaniasis reduces the healing time significantly and prevents the need for further courses of Sb(v).

Mucosal leishmaniasis: epidemiological and clinical aspects

UNLABELLED Leishmaniasis has been documented in several countries, with an estimated prevalence of 12 million people and an incidence at around 400,000 new cases per year. Leishmaniasis in the New World is one the major endemic diseases in Brazil and Latin America. OBJECTIVE The aim of this study was to add to the current knowledge on mucosal leishmaniasis, bringing the experience of the Immunology and Otolaryngology Departments in the Professor Edgar Santos University Hospital of the Federal University of Bahia. CONCLUSION Cutaneous leishmaniasis is the most common form of New World Leishmaniasis; mucosal legions may occur simultaneously or after years of disease. Mucosal leishmaniasis is caused mainly by L. braziliensis braziliensis; although the nasal mucosa is the most affected area, lesions may be found on the lips, mouth, pharynx and larynx. In addition to parasite-related factors, the host immune response may be involved in the pathogenicity of lesions in mucosal leishmaniasis.

IL6 −174 G/C Promoter Polymorphism Influences Susceptibility to Mucosal but Not Localized Cutaneous Leishmaniasis in Brazil

BACKGROUND Mucosal leishmaniasis (ML) is associated with exaggerated tumor necrosis factor- alpha and interferon- gamma responses and tissue destruction. ML follows localized cutaneous leishmaniasis (CL) caused by Leishmania braziliensis infection. Interleukin (IL)-6 down-regulates T helper (Th) cell type 1 differentiation and drives Th2 cell differentiation. The IL6 -174 G/C polymorphism is associated with proinflammatory diseases and IL-6 regulation. METHODS The -174 G/C polymorphism was genotyped in population samples and families with CL and ML from Brazil. Genotype frequencies were compared among patients with ML, patients with CL, and 2 control groups by logistic regression and family-based association test (FBAT) analysis. IL-6 levels were measured in macrophages. RESULTS The C allele was more common in patients with ML than in patients with CL (odds ratio [OR], 2.55 [95% confidence interval {CI}, 1.32-4.91]; P=.005), than in patients who were leishmanin skin-test positive (OR, 2.23 [95% CI, 1.23-4.05]; P=.009), and than in neighborhood control subjects (OR, 2.47 [95% CI, 1.24-4.90]; P=.01). FBAT analysis confirmed an association between allele C and ML under both additive (z=4.295; P=.000017) and dominant (z=4.325; P=.000015) models. Significantly lower levels of IL-6 were measured in unstimulated macrophages from CC individuals than from GG individuals (P=.003) as well as after stimulation with soluble leishmania antigen (P=.009). CONCLUSIONS IL-6 may regulate type 1 proinflammatory responses, putting individuals with low macrophage IL-6 levels at increased risk for ML.

Leishmaniose mucosa: aspectos clínicos e epidemiológicos

Leishmaniasis has been documented in several countries, with an estimated prevalence of 12 million people and an incidence at around 400,000 new cases per year. Leishmaniasis in the New World is one the major endemic diseases in Brazil and Latin America. OBJECTIVE: The aim of this study was to add to the current knowdlegde on mucosal leishmaniasis, bringing the experience of the Imunology and Otolaryngology Departments in the Professor Edgar Santos University Hospital of the Federal University of Bahia. CONCLUSION: Cutaneous leishmaniasis is the most common form of New World Leishmaniasis; mucosal legions may occur simultaneously or after years of disease. Mucosal leishmaniasis is caused mainly by L. braziliensis braziliensis; although the nasal mucosa is the most affected area, lesions may be found on the lips, mouth, pharynx and larynx. In addition to parasite-related factors, the host immune response may be involved in the pathogenicity of lesions in mucosal leishmaniasis.

Differential immune regulation of activated T cells between cutaneous and mucosal leishmaniasis as a model for pathogenesis

Cutaneous (CL) and mucosal leishmaniasis (ML) are characterized by a predominant type 1 immune response (IFN‐γ and TNF‐α production) and strong inflammatory response in the lesions with few parasites. This exacerbated type 1 response is more evident in ML as compared to CL. Our main hypothesis is that a differential immune regulation of T cell activation leads to over reactive T cells in ML. In the present study, we investigated immunological factors that could explain the mechanisms behind it by comparing some immune regulatory mechanisms between ML and CL patients: frequency of cells expressing co‐stimulatory molecules, apoptotic markers, T cell activation markers; and ability of neutralizing antibodies to IL‐2, IL‐12 and IL‐15 do down‐regulate IFN‐γ production in leishmania antigen‐stimulated peripheral blood mononuclear cells (PBMC). Interestingly, in CL anti‐IL‐2 and anti‐IL‐15 significantly suppressed antigen‐specific IFN‐γ production, while in ML only anti‐IL‐2 suppressed IFN‐γ production. Finally, higher frequency of CD4+ T cells expressing CD28−, CD69+ and CD62L low were observed in ML as compared to CL. These data indicate that an exacerbated type 1 response in ML is differentially regulated and not appropriately down modulated, with increased frequencies of activated effectors T cells, maintaining the persistent inflammatory response and tissue damage observed in ML.

Mucosal leishmaniasis patients display an activated inflammatory T-cell phenotype associated with a nonbalanced monocyte population.

Leishmania braziliensis is a parasite that can induce at least two clinical forms of leishmaniasis in humans: cutaneous leishmaniasis (CL) and mucosal leishmaniasis (ML). In humans, the specific mechanisms that determine which form will develop following infection are not well established. In this study, peripheral blood mononuclear cells from 17 CL and 9 ml patients were compared both ex vivo and after culture with soluble leishmania antigen (SLA). Patients with ML presented a higher frequency of activated T cells as measured by ex vivo frequencies of CD4+CD69+, CD4+CD28–, CD4+CD62L– and CD8+CD69+ than those with CL. Moreover, after stimulation with SLA, patients with ML presented a higher frequency of TNF‐α‐producing CD4+ and CD14+ cells than CL individuals. While CL patients displayed a positive correlation between the frequency of IL‐10 and TNF‐α‐producing monocytes, the ML patients did not. This lack of a positive correlation between IL‐10‐producing and TNF‐α‐producing monocytes in ML patients could lead to a less controlled inflammatory response in vivo. These results corroborate with a model of an exacerbated, unregulated, immune response in ML patients and point to key immunomodulatory leucocyte populations and cytokine networks that may be involved in the development of immunopathology in ML patients.

Geographic clustering of leishmaniasis in northeastern Brazil.

Different forms of this disease are spreading rapidly in distinct geographic clusters in this region.

Endoscopic ligation of the anterior ethmoidal artery: a cadaver dissection study

UNLABELLED Anterior ethmoidal artery (AEA) ligation may be necessary in cases of severe epistaxis not controllable with traditional therapy. Endoscopic endonasal ligation of the AEA is not used frequently; there are few studies in the literature for standardization of the endoscopic technique for this vessel. AIM To demonstrate the feasibility of periorbital AEA ligation in a transethmoidal endoscopic approach. METHODS A prospective study where 50 nasal cavities were dissected. After anterior ethmoidectomy and partial removal of lamina papyracea, the periorbital area was carefully dissected along a subperiosteal plane to identify the AEA. The vessel was exposed within the orbit and dissected. RESULTS Data on technical difficulties, complications, the learning curve and anatomical variations were gathered. CONCLUSION An endonasal endoscopic approach to the AEA within the orbit was shown to be feasible. Identifying the artery is not difficult, and this technique avoids external incisions. This approach appears to be an excellent alternative for approaching the AEA. Further clinical studies are needed to demonstarte the benefits of this technique.

The -2518 bp promoter polymorphism at CCL2/MCP1 influences susceptibility to mucosal but not localized cutaneous leishmaniasis in Brazil

Mucosal leishmaniasis (ML) follows localized cutaneous leishmaniasis (CL) caused by Leishmania braziliensis. Proinflammatory responses mediate CL self-healing but are exaggerated in ML. Proinflammatory monocyte chemoattractant protein 1 (MCP-1; encoded by CCL2) is associated with CL. We explore its role in CL/ML through analysis of the regulatory CCL2 -2518bp promoter polymorphism in CL/ML population samples and families from Brazil. Genotype frequencies were compared among ML/CL cases and control groups using logistic regression and the family-based association test (FBAT). MCP-1 was measured in plasma and macrophages. The GG recessive genotype at CCL2 -2518bp was more common in patients with ML (N=67) than in neighborhood control (NC; N=60) subjects (OR 1.78; 95% CI 1.01-3.14; P=0.045), than in NC combined with leishmanin skin-test positive (N=60) controls (OR 4.40; 95% CI 1.42-13.65; P=0.010), and than in controls combined with CL (N=60) patients (OR 2.78; 95% CI 1.13-6.85; P=0.045). No associations were observed for CL compared to any groups. FBAT (91 ML and 223 CL cases in families) confirmed recessive association of ML with allele G (Z=2.679; P=0.007). Higher levels of MCP-1 occurred in plasma (P=0.03) and macrophages (P<0.0001) from GG compared to AA individuals. These results suggest that high MCP-1 increases risk of ML.

Wound healing genes and susceptibility to cutaneous leishmaniasis in Brazil

Leishmania braziliensis causes cutaneous (CL) and mucosal (ML) leishmaniasis. In the mouse, Fli1 was identified as a gene influencing enhanced wound healing and resistance to CL caused by Leishmania major. Polymorphism at FLI1 is associated with CL caused by L. braziliensis in humans, with an inverse association observed for ML disease. Here we extend the analysis to look at other wound healing genes, including CTGF, TGFB1, TGFBR1/2, SMADS 2/3/4/7 and FLII, all functionally linked along with FLI1 in the TGF beta pathway. Haplotype tagging single nucleotide polymorphisms (tag-SNPs) were genotyped using Taqman technology in 325 nuclear families (652 CL cases; 126 ML cases) from Brazil. Robust case-pseudocontrol (CPC) conditional logistic regression analysis showed associations between CL and SNPs at CTGF (SNP rs6918698; CC genotype; OR 1.67; 95%CI 1.10-2.54; P=0.016), TGFBR2 (rs1962859; OR 1.50; 95%CI 1.12-1.99; P=0.005), SMAD2 (rs1792658; OR 1.57; 95%CI 1.04-2.38; P=0.03), SMAD7 (rs4464148; AA genotype; OR 2.80; 95%CI 1.00-7.87; P=0.05) and FLII (rs2071242; OR 1.60; 95%CI 1.14-2.24; P=0.005), and between ML and SNPs at SMAD3 (rs1465841; OR 2.15; 95%CI 1.13-4.07; P=0.018) and SMAD7 (rs2337107; TT genotype; OR 3.70; 95%CI 1.27-10.7; P=0.016). Stepwise logistic regression analysis showed that all SNPs associated with CL at FLI1, CTGF, TGFBR2, and FLII showed independent effects from each other, but SNPs at SMAD2 and SMAD7 did not add independent effects to SNPs from other genes. These results suggest that TGFβ signalling via SMAD2 is important in directing events that contribute to CL, whereas signalling via SMAD3 is important in ML. Both are modulated by the inhibitory SMAD7 that acts upstream of SMAD2 and SMAD3 in this signalling pathway. Along with the published FLI1 association, these data further contribute to the hypothesis that wound healing processes are important determinants of pathology associated with cutaneous forms of leishmaniasis.