Senescence-related genes are associated with the immunopathology signature of American Tegumentary Leishmaniasis lesions and may predict progression to mucosal leishmaniasis.

The American Tegumentary Leishmaniasis (ATL) is caused by protozoans of the genus Leishmania and varies from mild localized cutaneous leishmaniasis (LCL) form to more severe manifestations such as the diffuse cutaneous leishmaniasis (DCL) form and the mucosal leishmaniasis (ML) form. Previously, we demonstrated the accumulation of senescent cells in skin lesions of patients with LCL. Moreover, lesional transcriptomic analyses revealed a robust co-induction of senescence and pro-inflammatory gene signatures, highlighting the critical role of senescent T cells in orchestrating pathology. In this work we hypothesized that senescent cells might operate differently among the ATL spectrum, potentially influencing immunopathological mechanisms and clinical outcome. We analysed previously published RNA-Seq datasets of skin biopsies of healthy subjects and lesional skin from DCL patients, LCL patients and LCL patients that, after treatment, progressed to mucosal leishmaniasis (MLP). Our findings demonstrate a robust presence of a CD8 T cell signature associated with both LCL and MLP lesions. Moreover, both inflammatory and cytotoxic signatures were significantly upregulated, showing a strong increase in MLP and LCL groups, but not DCL. The senescence signature was elevated between LCL and MLP groups, representing the only distinguishable signature of immunopathology between them. Interestingly, our analyses further revealed the senescence signature's capacity to predict progression from LCL to mucosal forms, which was not observed with other signatures. Both the senescence-signature score and specific senescence-associated genes demonstrated an increased capacity to predict mucosal progression, with correct predictions exceeding 97% of cases. Collectively, our findings contribute to a comprehensive understanding of immunosenescence in ATL and suggest that senescence may represent the latest and most important signature of the immunopathogenisis. This highlights its potential value in predicting disease severity.

First report of Leishmania RNA virus 1 in Leishmania (Viannia) braziliensis clinical isolates from Rio de Janeiro State - Brazil.

BACKGROUND: Leishmania parasites carry a double-stranded RNA virus (Leishmania RNA virus - LRV) that has been divided in LRV1 and LRV2. OBJECTIVES: Leishmania (Viannia) braziliensis clinical isolates were assessed in order to determine LRV presence. METHODS: Two-round polymerase chain reaction (PCR and nested PCR) was performed to detect LRV1 or LRV2 in L. (V.) braziliensis clinical isolates (n = 12). FINDINGS: LRV1 was detected in three clinical isolates which was phylogenetically related to other sequences reported from other American tegumentary leishmaniasis (ATL) endemic areas of Brazil. Patients infected with L. (V.) braziliensis LRV-negative showed only cutaneous lesions while LRV-positive reported different manifestations. MAIN CONCLUSION: Data presented here show for the first time that LRV1 is circulating in L. (V.) braziliensis clinical isolates from Rio de Janeiro State in Brazil.

Critically Ill Coronavirus Disease 2019 Patients Exhibit Hyperactive Cytokine Responses Associated With Effector Exhausted Senescent T Cells in Acute Infection.

BACKGROUND: Coronavirus disease 2019 (COVID-19) can progress to severe pneumonia with respiratory failure and is aggravated by the deregulation of the immune system causing an excessive inflammation including the cytokine storm. METHODS: In this study, we report that severe acutely infected patients have high levels of both type-1 and type-2 cytokines. RESULTS: Our results show abnormal cytokine levels upon T-cell stimulation, in a nonpolarized profile. Furthermore, our findings indicate that this hyperactive cytokine response is associated with a significantly increased frequency of late-differentiated T cells with particular phenotype of effector exhausted/senescent CD28-CD57+ cells. Of note, we demonstrated for the first time an increased frequency of CD3+CD4+CD28-CD57+ T cells with expression of programmed death 1, one of the hallmarks of T-cell exhaustion. CONCLUSIONS: These findings reveal that COVID-19 is associated with acute immunodeficiency, especially within the CD4+ T-cell compartment, and points to possible mechanisms of loss of clonal repertoire and susceptibility to viral relapse and reinfection events.

Clinical and laboratory profiles of patients with early spontaneous healing in cutaneous localized leishmaniasis: a historical cohort study.

BACKGROUND: Skin ulcers in American cutaneous leishmaniasis (ACL) may heal spontaneously after months/years. However, few cases may present quick heal even during diagnosis procedure (early spontaneous healing- ESH). The main objective of this study was to compare ESH patients with cases requiring specific treatment [non-ESH (NESH)]. METHODS: A historical cohort study of ACL patients (n = 445) were divided into 2 groups: ESH - spontaneously healed patients (n = 13; 2.90%), and NESH- treated patients (n = 432; 97.10%). We compared clinical and laboratorial findings at diagnosis, including the lesion healing process. RESULTS: ESH patients had a higher percentage of single lesions (p = 0.027), epithelialized lesion on initial examination (p = 0.001), lesions located in the dorsal trunk (p = 0.017), besides earlier healing (p < 0.001). NESH presents higher frequency of ulcerated lesions (p = 0.002), amastigotes identified in histopathology exams (p = 0.005), positive cultures (p = 0.001), and higher positivity in ≥3 parasitological exams (p = 0.030). All ESH cases were positive in only a single exam, especially in PCR. CONCLUSIONS: ESH group apparently presented a lower parasitic load evidenced by the difficulty of parasitological confirmation and its positivity only by PCR method. The absence or deficiency of specific treatment is commonly identified as predisposing factors for recurrence and metastasis in ACL. However, due to the drugs toxicity, the treatment of cases which progress to early spontaneous healing is controversial. ESH patients were followed for up to 5 years after cure, with no evidence of recrudescence, therefore suggesting that not treating these patients is justifiable, but periodic dermatological and otorhinolaryngological examinations are advisable to detect a possible relapse.

Severe feline sporotrichosis associated with an increased population of CD8low cells and a decrease in CD4⁺ cells.

Sporotrichosis is a subcutaneous mycosis with worldwide distribution, especially in tropical and subtropical areas. Zoonotic transmission is described with cats being the main animal species involved. The occurrence of severe feline sporotrichosis with high fungal levels demonstrates the susceptibility of cats to this disease and the importance of studying its pathogenesis. This study describes the leukocytes profile in blood of cats with sporotrichosis by flow cytometry and its correlation with histopathology and fungal load. The cats with sporotrichosis were separated into groups L1, L2, and L3 (lesions at one, two, and three or more noncontiguous skin locations, respectively) and were classified as good, fair, or poor general conditions. The highest percentage of CD4+ cells was associated to L1 (P = .04) and to good general condition (P = .03). The percentage of CD8+ cells was greater in L2 and L3 (P = .01). CD8(low) expression occurred in 20 animals with sporotrichosis, mainly in L3 (P = .01) and was not observed in healthy controls. This expression was related to macrophage granulomas (P = .01) and predominated in cases with high fungal load. Altogether, the results indicated that control over feline sporotrichosis, with maintenance of a good general condition, fixed lesions, well-organized response and lower fungal load, is associated with increased CD4+ cells percentages. In contrast, a poor general condition, disseminated lesions and high fungal load were related to increased CD8+ cell percentages and increased expression of CD8(low). As conclusion these results point to an important role of the CD4:CD8 balance in determining the clinical outcome in feline sporotrichosis.

Oral and oropharyngeal mucosal lesions: clinical-epidemiological study of patients attended at a reference center for infectious diseases.

OBJECTIVE: To determine the prevalence, epidemiological profile, and clinical characteristics of Oral or Oropharyngeal Mucosal Lesions (OOPML) in patients attended at the Otorhinolaryngology Service of the Evandro Chagas National Institute of Infectious Diseases (INI-FIOCRUZ) from 2005 to 2017. METHODS: Statistical analysis of descriptive data from medical records (gender, age, education level, skin color, origin, smoking, alcoholism, HIV co-infection, time of disease evolution, first symptom, and OOPML location) was performed. RESULTS: Of 7551 patients attended at the service, 620 (8.2%) were included in the study. OOPML were classified into developmental anomalies (n = 3), infectious diseases (non-granulomatous n = 220; granulomatous n = 155), autoimmune diseases (n = 24), neoplasms (benign n = 13; malignant, n = 103), and unclassified epithelial/soft tissue diseases (n = 102). OOPML of infectious diseases (60.5%) and neoplasms (18.7%) were the most frequent. The predominant demographics of patients with OOPML were: males (63.5%), white (53.5%), and those in the fifth to sixth decades of life (43.3%). Local pain (18.1%) and odynophagia (15%) were the most reported first symptoms, and the most frequent OOPML sites were the palatine tonsil (28.5%), hard palate (22.7%), and tongue (20.3%). The median evolution time was three months. CONCLUSIONS: Infectious OOPML were the most frequent, as expected in a reference center for infectious diseases, and thus, they are likely to be less frequent in general care and/or dental services. Underreporting of OOPML is possible, as oral/oropharyngeal examination is often not included in the routine medical examination. Oral cavity/oropharynx examination should be performed by specialists, such as dentists and otorhinolaryngologists, who have the expertise in identifying OOPML, even in incipient/asymptomatic cases. Given the numerous diseases in which OOPML can present, diagnosis could be facilitated by multidisciplinary teams, potentially enabling the early treatment of diseases, and thus, reduce morbidity and improve prognosis. The use of standardized medical records for oral/oropharyngeal systematic examination could provide relevant tools for differential diagnoses and information for new clinical-epidemiological studies. LEVEL OF EVIDENCE: Level 3.

Neutrophil Oxidative Burst Profile Is Related to a Satisfactory Response to Itraconazole and Clinical Cure in Feline Sporotrichosis.

Despite the central role of cats in the transmission and amplification of Sporothrix, studies regarding immune response in feline sporotrichosis are scarce. In cats with sporotrichosis, neutrophil-rich lesions are usually associated to good general condition and lower fungal burden. However, the role of neutrophils in anti-Sporothrix immunity has been little explored in cats. Thus, the aim of this study was to evaluate the neutrophil oxidative burst in the blood of cats with sporotrichosis. Cats with sporotrichosis included in the study were treated with itraconazole (ITZ) alone or combined with potassium iodide (KI). The neutrophil oxidative burst was evaluated through a flow-cytometry-based assay using dihydrorhodamine 123 (background) and stimulation with Zymosan and heat-killed Sporothrix yeasts. The cure rate was 50.0% in cats under treatment with ITZ monotherapy and 90.9% in cats treated with ITZ + KI (p = 0.014), endorsing the combination therapy as an excellent alternative for the treatment of feline sporotrichosis. Higher percentages of Sporothrix-stimulated neutrophils were associated with good general condition (p = 0.003). Higher percentages of Sporothrix- (p = 0.05) and Zymosan-activated (p = 0.014) neutrophils before and early in the treatment were related to clinical cure in ITZ-treated cats. The correlation between oxidative burst and successful use of KI could not be properly assessed given the low number of failures (n = 2) in this treatment group. Nasal mucosa involvement, typically linked to treatment failure, was related to lower percentages of activated neutrophils in the background at the treatment outcome (p = 0.02). Our results suggest a beneficial role of neutrophils in feline sporotrichosis and a positive correlation between neutrophil activation and the cure process in ITZ-treated cats.

Balance of apoptotic and anti-apoptotic marker and perforin granule release in squamous intraepithelial lesions. HIV infection leads to a decrease in perforin degranulation.

Cell-mediated cytotoxicity plays an important role in the regulation to HPV-associated cervical intraepithelial neoplasia. HIV co-infection is related to poorer prognosis and more rapid clinical progression to cancer. We evaluated the presence of cervical inflammatory cells, apoptotic (Bax, Bcl-2, FasL, NOS2, perforin) markers and the degranulating expressing cell marker (CD107a) in low and high squamous intraepithelial lesions (LSIL and HSIL, respectively) from HIV-negative and -positive women. Higher percentage of cervical CD4(+), CD8(+) T cells and macrophage were observed in LSIL and HSIL groups when compared with control, especially in epithelium and basal layer of epithelium. However, progression from LSIL to HSIL did not change the frequency of inflammatory cells. HIV-infection lead to a reduction on cervical CD4(+) T cell infiltration and an increased CD8(+) T cell distribution in LSIL groups. A balance between pro- and anti-apoptotic protein expressions was verified. Bax-expressing cells were present in all groups and were rarely expressed in keratinocytes in the epithelium in LSIL and control groups, but notably decreased in HSIL group. However, its frequency was enhanced in the basal layer of the epithelium meanly in LSIL group. Bcl2-expressing cells in the epithelium and the stroma were enhanced in HSIL group when compared with LSIL group. HIV-infection did not interfere in both expressions NOS2 expression was located on keratinocytes in both LSIL and HSIL groups when compared with control group. There were few FasL cervical expressing cells in all groups. Indeed, perforin was identified in few cervical cells. However, CD107a, a surface marker for cellular degranulation was significantly higher in epithelium, basal layer of epithelium and stroma in LSIL and HSIL, respectively, when compared with control group. These results support that HIV infection may induce reduction on inflammatory cervical cell degranulation corroborating to carcinogenesis process. This is the first description on the role of HIV in downregulation of perforin degranulation in the cervical lesions and it might be related to carcinogenesis.

Advancement in Leishmaniasis Diagnosis and Therapeutics.

Leishmaniasis is a complex of clinical manifestations that affects thousands of people in the world each year according to WHO [...].

Vaccine Development against Infectious Diseases: State of the Art, New Insights, and Future Directions.

In the 18th century, English physician Edward Jenner laid the foundation for modern vaccination by achieving protection against variola [...].

Is There Any Difference in the In Situ Immune Response in Active Localized Cutaneous Leishmaniasis That Respond Well or Poorly to Meglumine Antimoniate Treatment or Spontaneously Heal?

Localized cutaneous leishmaniasis caused by Leishmania braziliensis can either respond well or poorly to the treatment or heal spontaneously; It seems to be dependent on the parasite and/or host factors, but the mechanisms are not fully understood. We evaluated the in situ immune response in eighty-two active lesions from fifty-eight patients prior to treatment classified as early spontaneous regression (SRL-n = 14); treatment responders (GRL-n = 20); and non-responders (before first treatment/relapse, PRL1/PRL2-n = 24 each). Immunohistochemistry was used to identify cell/functional markers which were correlated with the clinical characteristics. PRL showed significant differences in lesion number/size, clinical evolution, and positive parasitological examinations when compared with the other groups. SRL presented a more efficient immune response than GRL and PRL, with higher IFN-γ/NOS2 and a lower percentage of macrophages, neutrophils, NK, B cells, and Ki-67+ cells. Compared to SRL, PRL had fewer CD4+ Tcells and more CD163+ macrophages. PRL1 had more CD68+ macrophages and Ki-67+ cells but less IFN-γ than GRL. PRL present a less efficient immune profile, which could explain the poor treatment response, while SRL had a more balanced immune response profile for lesion healing. Altogether, these evaluations suggest a differentiated profile of the organization of the inflammatory process for lesions of different tegumentary leishmaniasis evolution.

Leishmania amazonensis promastigotes induce and are killed by neutrophil extracellular traps.

Neutrophils are short-lived leukocytes that die by apoptosis, necrosis, and NETosis. Upon death by NETosis, neutrophils release fibrous traps of DNA, histones, and granule proteins named neutrophil extracellular traps (NETs), which can kill bacteria and fungi. Inoculation of the protozoan Leishmania into the mammalian skin causes local inflammation with neutrophil recruitment. Here, we investigated the release of NETs by human neutrophils upon their interaction with Leishmania parasites and NETs' ability to kill this protozoan. The NET constituents DNA, elastase, and histones were detected in traps associated to promastigotes by immunofluorescence. Electron microscopy revealed that Leishmania was ensnared by NETs released by neutrophils. Moreover, Leishmania and its surface lipophosphoglycan induced NET release by neutrophils in a parasite number- and dose-dependent manner. Disruption of NETs by DNase treatment during Leishmania-neutrophil interaction increased parasite survival, evidencing NETs' leishmanicidal effect. Leishmania killing was also elicited by NET-rich supernatants from phorbol 12-myristate 13-acetate-activated neutrophils. Immunoneutralization of histone during Leishmania-neutrophil interaction partially reverted Leishmania killing, and purified histone killed the parasites. Meshes composed of DNA and elastase were evidenced in biopsies of human cutaneous leishmaniasis. NET is an innate response that might contribute to diminish parasite burden in the Leishmania inoculation site.

Novel Insights Into Leishmania (Viannia) braziliensis In Vitro Fitness Guided by Temperature Changes Along With Its Subtilisins and Oligopeptidase B.

Proteases are virulence factors with a recognized impact on the Leishmania spp. life cycle. This study considers a set of analyses measuring phenotypic factors of L. (V.) braziliensis clinical isolates as promastigotes growth curves, murine peritoneal macrophages infection, inflammatory mediators production, and serine proteases gene expression (subtilisin 13: S13, subtilisin 28: S28, oligopeptidase B: OPB) assessing these isolates' fitness on in vitro conditions. Parasites had different behavior during the early growth phase from day zero to day three, and all isolates reached the stationary growth phase between days four and seven. Macrophages infection showed two tendencies, one of decreased infection rate and number of parasites per macrophage (Infection Index <1000) and another with a constant infection index (≥1400). TNF-α (≥10 pg/mL) detected in infections by 75% of isolates, IL-6 (≥80 pg/mL) by 30% of isolates and low levels of NO (≥0.01µM) in almost all infections. Gene expression showed higher values of S13 (≥2RQ) in the intracellular amastigotes of all the isolates evaluated. On the contrary, S28 expression was low (≤1RQ) in all isolates. OPB expression was different between promastigotes and intracellular amastigotes, being significantly higher (≥2RQ) in the latter form of 58% of the isolates. Predictive structural assays of S13 and OPB were performed to explore temperature influence on gene expression and the encoded proteases. Gene expression data is discussed based on in silico predictions of regulatory regions that show plasticity in the linearity index of secondary structures of S13 and OPB 3'-untranslated regions of mRNA, dependent on temperature changes. While hairpin structures suggest an active region of mRNA for both genes above 26°C, pseudoknot structure found in S13 is an indication of a particular profile of this gene at mammalian host temperatures (37°C). Furthermore, the predicted 3D structures are in accordance with the influence of these temperatures on the catalytic site stability of both enzymes, favoring their action over peptide substrates. Data gathered here suggest that L. (V.) braziliensis serine proteases can be influenced by the temperature conditions affecting parasite fitness throughout its life cycle.

The in situ inflammatory profile of lymphocutaneous and fixed forms of human sporotrichosis.

The most common clinical presentations of sporotrichosis are the lymphocutaneous (LC) and fixed cutaneous (F) forms, but little is known about the immunopathologic differences between them. The aim of this study was to evaluate through immunohistochemistry the composition of the in situ inflammatory reaction so as to correlate the results with the clinical presentation of the disease. The following two groups of patients were involved in the studies, i.e., LC (n=19) and F (n=11) patients. Those with the LC form, in contrast to F patients, were found to have a larger number of lesions (P=0.001), of longer duration (P=0.026) and require a more extended course of treatment (P=0.049). LC patients also presented a greater fungal burden (LC:0-6.5; F:0-1.5; P=0.021), a higher percentage of neutrophils (median LC:24.7%; F:6.7%, P=0.002), CD4(+) cells (median LC:40.9%; F:30.0%, P=0.0024), CD22(+) cells (median LC:15.3%; F:2.9%, P=0.048), and higher intensity of NOS2 expression (P=0.009). Thus, our data identified differences in cell profile and inflammatory activity in lesions of LC and F forms of human sporotrichosis.

Characteristics of Paecilomyces lilacinus infection comparing immunocompetent with immunosuppressed murine model.

The characteristics of Paecilomyces lilacinus infection were evaluated using two murine experimental models: immunocompetent and immunosuppressed. The evaluation criteria for characteristics of infection were clinical signs, weight loss, survival rates, histopathological alterations and the number of viable fungal cells re-isolated from different organs; and those for immunological status were in vitro lymphoproliferative response, cell surface phenotyping and IFN-γ production. Morphological evaluation showed that P. lilacinus isolates presented morphological characteristics consistent with those described in the literature. The immunocompetent mice could be infected by the fungi, but they did not develop the disease, unlike the immunosuppressed mice, which showed clinical signs of mycosis in an environment of suppressed cellular immune response. The hypothesis of latent infection reactivation in mice was not confirmed. The difference observed in the infection rate of the two fungi isolates points to an intrinsic variation between strains of P. lilacinus and led us to hypothesise that even in the presence of immunosuppressed environment, the fungus virulence can play a role in the pathogenesis of hyalohyphomycosis.

Comparison of the sensitivity of imprint and scraping techniques in the diagnosis of American tegumentary leishmaniasis in a referral centre in Rio de Janeiro, Brazil.

American tegumentary leishmaniasis (ATL) is an infectious disease that presents a wide spectrum of clinical manifestations making parasitological tests important for its diagnosis. Direct examination, although considered of low sensitivity is still employed mainly in areas with poor laboratory infrastructure. The aim of this study was to standardize the method of collecting and reading the scraping procedure and to then compare sensitivity of this procedure on two sites of the lesion (outer edge-OE and inner edge-IE) and of the imprint against the reference method (isolation in culture) in a group of 110 patients treated at a Referral Center in Rio de Janeiro, Brazil. ATL diagnosis was confirmed in 40 patients (36.4%), 39 cases were caused by L. braziliensis and 1 by L. amazonensis. Imprint was positive in 28 patients and scraping in OE in 17 and in IE in 25 patients, resulting in sensitivity of 70%, 42.5%, and 62.5% respectively. When the three direct examinations were combined, sensitivity value attained 77.5%. Aspects related to ease and quality of the collected material, pain intensity and frequency of bleeding in the scraping procedure were also broached and discussed in this study. The parameters of accuracy presented indicate that the direct methods can be safely used in ATL diagnosis, principally in IE scraping, as it is easy to produce and the examination is not costly, which allows the procedure to be repeated at different moments which, in turn, increases the possibility of finding the parasite. Despite that the direct methods are technically widespread, they are not standardized and the parameters of accuracy are unknown. If we consider the high incidence of leishmaniasis in low-income areas, the implantation of standardized and selective methods would provide advances in the diagnosis of leishmaniasis.

The Immune System Throws Its Traps: Cells and Their Extracellular Traps in Disease and Protection.

The first formal description of the microbicidal activity of extracellular traps (ETs) containing DNA occurred in neutrophils in 2004. Since then, ETs have been identified in different populations of cells involved in both innate and adaptive immune responses. Much of the knowledge has been obtained from in vitro or ex vivo studies; however, in vivo evaluations in experimental models and human biological materials have corroborated some of the results obtained. Two types of ETs have been described-suicidal and vital ETs, with or without the death of the producer cell. The studies showed that the same cell type may have more than one ETs formation mechanism and that different cells may have similar ETs formation mechanisms. ETs can act by controlling or promoting the mechanisms involved in the development and evolution of various infectious and non-infectious diseases, such as autoimmune, cardiovascular, thrombotic, and neoplastic diseases, among others. This review discusses the presence of ETs in neutrophils, macrophages, mast cells, eosinophils, basophils, plasmacytoid dendritic cells, and recent evidence of the presence of ETs in B lymphocytes, CD4+ T lymphocytes, and CD8+ T lymphocytes. Moreover, due to recently collected information, the effect of ETs on COVID-19 is also discussed.

Serine proteases profiles of Leishmania (Viannia) braziliensis clinical isolates with distinct susceptibilities to antimony.

Glucantime (SbV) is the first-line treatment against American Tegumentary Leishmaniasis. Resistance cases to this drug have been reported and related to host characteristics and parasite phenotypes. In this study, 12 Leishmania (Viannia) braziliensis isolates from patients that presented clinical cure (Responders-R) and relapse or therapeutic failure (Non-responders-NR) after treatment with antimony, were analyzed. These parasites were assessed by in vitro susceptibility to SbIII and SbV, serine proteases activity measured with substrate (z-FR-AMC) and specific inhibitors (TLCK, AEBSF and PMSF). In vitro susceptibility of axenic amastigotes to SbIII showed a significant difference between R and NR groups. The protease assays showed that TLCK inhibited almost 100% of activity in both axenic amastigotes and promastigotes while AEBSF inhibited around 70%, and PMSF showed lower inhibition of some isolates. Principal component and clustering analysis performed with these data yielded one homogeneous cluster with only NR isolates and three heterogeneous clusters with R and NR isolates. Additionally, differential expression of subtilisins (LbrM.13.0860 and LbrM.28.2570) and TXNPx (LbrM.15.1080) was evaluated in promastigotes and axenic amastigotes from both groups. The results showed a higher expression of LbrM.13.0860 and LbrM.15.1080 genes in axenic amastigotes, while LbrM.28.2570 gene had the lowest expression in all isolates, regardless of the parasite form. The data presented here show a phenotypic heterogeneity among the parasites, suggesting that exploration of in vitro phenotypes based on SbIII and serine proteases profiles can aid in the characterization of L. (V.) braziliensis clinical isolates.

An old drug and different ways to treat cutaneous leishmaniasis: Intralesional and intramuscular meglumine antimoniate in a reference center, Rio de Janeiro, Brazil.

BACKGROUND: Treatment of cutaneous leishmaniasis (CL) remains challenging since the drugs currently used are quite toxic, thus contributing to lethality unrelated to the disease itself but to adverse events (AE). The main objective was to evaluate different treatment regimens with meglumine antimoniate (MA), in a reference center in Rio de Janeiro, Brazil. METHODOLOGY: A historical cohort of 592 patients that underwent physical and laboratory examination were enrolled between 2000 and 2017. The outcome measures of effectiveness were epithelialization and complete healing of cutaneous lesions. AE were graded using a standardized scale. Three groups were evaluated: Standard regimen (SR): intramuscular (IM) MA 10-20 mg Sb5+/kg/day during 20 days (n = 46); Alternative regimen (AR): IM MA 5 mg Sb5+/kg/day during 30 days (n = 456); Intralesional route (IL): MA infiltration in the lesion(s) through subcutaneous injections (n = 90). Statistical analysis was performed through Fisher exact and Pearson Chi-square tests, Kruskal-Wallis, Kaplan-Meier and log-rank tests. RESULTS: SR, AR and IL showed efficacy of 95.3%, 84.3% and 75.9%, with abandonment rate of 6.5%, 2.4% and 3.4%, respectively. IL patients had more comorbidities (58.9%; p = 0.001), were mostly over 50 years of age (55.6%), and had an evolution time longer than 2 months (65.6%; p = 0.02). Time for epithelialization and complete healing were similar in IL and IM MA groups (p = 0.9 and p = 0.5; respectively). Total AE and moderate to severe AE that frequently led to treatment interruption were more common in SR group, while AR and IL showed less toxicity. CONCLUSIONS/SIGNIFICANCE: AR and IL showed less toxicity and may be good options especially in CL cases with comorbidities, although SR treatment was more effective. IL treatment was an effective and safe strategy, and it may be used as first therapy option as well as a rescue scheme in patients initially treated with other drugs.

The emerging role of neutrophil extracellular traps in severe acute respiratory syndrome coronavirus 2 (COVID-19).

The novel coronavirus SARS-CoV-2 causes COVID-19, a highly pathogenic viral infection threatening millions. The majority of the individuals infected are asymptomatic or mildly symptomatic showing typical clinical signs of common cold. However, approximately 20% of the patients can progress to acute respiratory distress syndrome (ARDS), evolving to death in about 5% of cases. Recently, angiotensin-converting enzyme 2 (ACE2) has been shown to be a functional receptor for virus entry into host target cells. The upregulation of ACE2 in patients with comorbidities may represent a propensity for increased viral load and spreading of infection to extrapulmonary tissues. This systemic infection is associated with higher neutrophil to lymphocyte ratio in infected tissues and high levels of pro-inflammatory cytokines leading to an extensive microthrombus formation with multiorgan failure. Herein we investigated whether SARS-CoV-2 can stimulate extracellular neutrophils traps (NETs) in a process called NETosis. We demonstrated for the first time that SARS-CoV-2 in fact is able to activate NETosis in human neutrophils. Our findings indicated that this process is associated with increased levels of intracellular Reactive Oxygen Species (ROS) in neutrophils. The ROS-NET pathway plays a role in thrombosis formation and our study suggest the importance of this target for therapy approaches against disease.