Background Skin lesions from patients infected with Leishmania braziliensis has been associated with inflammation induced by cytotoxic CD8+ T cells. In addition, CD8+ T cell-mediated cytotoxicity has not been linked to parasite killing. Meanwhile, the cytotoxic role played by natural killer (NK) cells in cutaneous leishmaniasis (CL) remains poorly understood. Methods In this study, we observed higher frequencies of NK cells in the peripheral blood of CL patients compared with healthy subjects, and that NK cells expressed more interferon-γ, tumor necrosis factor (TNF), granzyme B, and perforin than CD8+ T cells. Results We also found that most of the cytotoxic activity in CL lesions was triggered by NK cells, and that the high levels of granzyme B produced in CL lesions was associated with larger lesion size. Furthermore, an in vitro blockade of granzyme B was observed to decrease TNF production. Concclusions Our data, taken together, suggest an important role by NK cells in inducing inflammation in CL, thereby contributing to disease immunopathology.

Background Cutaneous leishmaniasis (CL) caused by L. braziliensis is characterized by one or multiple well limited ulcerated lesions. Diabetes mellitus (DM) impair neutrophil and monocyte function and there is a report of a vegetative lesions in a patient with both diseases in Morocco. Here we evaluate the influence of DM on clinical manifestations, immune response and in the treatment of CL. Methods Participants were 36 DM patients with CL and 36 patients with CL without DM matched by age and gender. The diagnosis of CL was performed by documentation of DNA of L. braziliensis by PCR in the lesion biopsy and histopathologic findings. All patients were treated with Glucantime (Sanofi-Aventis) 20mg/Kg of weight/day for 20 days. Results There was no difference in the majority of the clinic variables between the groups and the cure rate in patients with CL and DM (67%) was similar to that observed in CL patients (56%) (P˃.05). The most important finding was the documentation that 36% of the patients with DM and CL had atypical cutaneous lesions characterized by large superficial ulcers without defined borders. High levels of IFN-γ, TNF and IL-1β were detected in supernatants of mononuclear cells stimulated with leishmania antigen in patients with DM and atypical CL. Moreover, while cure was observed in only 33% of the patients with DM and atypical CL lesions it was 85% in patients with typical lesions (P<0.05). Conclusions DM modify the clinical presentation of CL, enhances pro-inflammatory cytokine production and impair response to antimony therapy.

INTRODUCTION: The multisystemic inflammatory syndrome in pediatrics is a new entity with acute and severe presentation, which association with SARS-CoV-2 infection virus from COVID-19 has been questioned. The criteria to define a case of such syndrome were determined and published by Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO). One form of presentation of this entity is Kawasaki disease, either in the classic or incomplete forms, and/or associated with toxic shock. OBJECTIVES: Report a case of a SARS-CoV-2 seropositive patient, who developed Multisystemic Inflammatory Syndrome, Kawasaki-like disease. CASE REPORT: Preschooler, 4-years-old, male, arrives at the pediatric consultation with a history of 12-hours fever without other associated symptoms, but previously infected by SARS-CoV-2. On physical examination, he was feverish 38.3ºC, active, eupneic, with mild oropharyngeal hyperemia. In the subsequent 24 hours, fever persisted, and complaints of abdominal pain started, thus he was taken to a pediatric emergency room for diagnostic investigation. A worsening of the pain and significant reduction in activity were observed, with prostration, decreased food acceptance and diuresis. Four days after the onset of the fever, he developed signs of cardiac decompensation (shock), liver lowering, tachycardia with the presence of third sound, HR 186bpm, being taken to the pediatric ICU and a laboratory investigation was started to confirm a post-COVID-19 multisystemic inflammatory syndrome pediatric. CONCLUSION: Improving knowledge about the COVID-19 infection manifestations in children and its complications is necessary, since it is believed that there is a relationship between multisystemic inflammatory syndrome and SARS-CoV-2 infection in children.