Central and Effector Memory Human CD4+ and CD8+ T Cells during Cutaneous Leishmaniasis and after In Vitro Stimulation with Leishmania (Viannia) braziliensis Epitopes

Cutaneous Leishmaniasis (CL) is a Neglected Tropical Disease characterized by skin ulcers caused by Leishmania spp. protozoans and there is no safe and effective vaccine to reduce its negative consequences. In a previous work by our group, we identified T cell epitopes of Leishmania (Viannia) braziliensis which stimulated patients' T cells in vitro. In the present work, the peptides were tested as two pools for their ability to rescue memory T cells during natural infection by Leishmania. We analyzed the frequency of central memory (TCM, CD45RA-CD62L+) and effector memory (TEM, CD45RA + CD62L-) cells during active CL and post-treatment. In parallel, we investigated cell proliferation levels and the cytokines produced after stimulation. Interestingly, we observed higher frequencies (%) in CD4+ TEM during CL, and CD8+ TEM and CD8+ TCM during CL and post-treatment. Cell proliferation was increased, and a significant difference in expression was observed on T-bet and RORγT. Besides that, IFN-γ, IL-2, and IL-10 were detected in patient samples. Collectively, this dataset suggests that during CL there is an increase in the frequency of TCM and TEM, especially in the CD8 compartment. These results indicate a potentially immunogenic profile of the peptide pools, which can support the development of anti-Leishmania formulations.

Follow-up of skin lesions during the evolution of COVID-19: a case report.

The disease caused by the new coronavirus (COVID-19) has many systemic manifestations affecting the upper airways, lungs, gastrointestinal tract and inducing hematological repercussions. With the evolution of the pandemic, skin lesions were observed. However, there is little information about the evolution of the lesions at this moment. The authors report a case of a patient who had more than one exposure to the coronavirus during the evolution of the disease and manifested different types of edematous lesions. The lesions started in the prodromal period and changed their presentation and localization during the evolution of COVID-19. The lesions regressed quickly with the use of corticoid cream and antihistamine. Viral skin lesions are frequent causes of exanthema. However, viral etiology is not always investigated in acute urticarial and atypical erythematous-edematous conditions. The immunological basis of acute urticaria has points in common with COVID-19, justifying the appearance of lesions. Investigation of viral etiology should always be remembered in acute urticarial and edematous conditions.

Pemphigus Vulgaris After COVID-19: a Case of Induced Autoimmunity.

Bullae autoimmune diseases can be induced by environmental factors in a genetically susceptible individual, and viruses may be important triggers for this process. Coronavirus disease 2019 (COVID-19) is a multisystemic disease known for developing many types of skin lesions. However, little is known about post-COVID-19 manifestations. A previous healthy male patient, 43 years old, with resistant mediastinal Hodgkin's lymphoma stage II diagnosed in 2019, without treatment at the moment, developed monomorphic flaccid bullae on the trunk 40 days after testing positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although he had risk factors for IgA and paraneoplastic pemphigus, there were no elements for these diseases. The investigation confirmed a pemphigus vulgaris (PV). PV had a good response to treatment with prednisolone 1 mg/kg per day, and methotrexate 15 mg subcutaneously was added per week. The patient was discharged with oral methotrexate and prednisolone at the same dose. Prednisolone was decreased by 20 mg per day during the follow-up. Viruses such as herpesvirus, cytomegalovirus, and varicela zoster can act as triggers for PV. This process is not immediate after the infection because it depends on the change in antibodies initially produced against the virus that start to identify antigens present in the skin's anchoring structures. SARS-CoV-2 can induce autoimmunity, as seen in Guillán-Barré syndrome and in Kawasaki disease. It is a highly immunogenic virus that is the perfect agent for triggering PV. This case can be considered a cutaneous autoimmune post-COVID-19 manifestation.

TST conversions and systemic interferon-gamma increase after methotrexate introduction in psoriasis patients.

BACKGROUND: Tuberculosis screening in psoriasis patients is complex due to the immunological alterations associated with psoriasis, the presence of comorbidities, and the effect of immunosuppressive treatment. However, it is not established whether the results of screening tests are affected by these factors in psoriasis patients. OBJECTIVES: To determine whether there is a change in the results of the tuberculin skin test (TST) or the interferon-gamma release assay (IGRA) in psoriasis patients living in tuberculosis (TB)-endemic area after 12 weeks of methotrexate (MTX) treatment and to investigate the association of the test results with clinical and inflammatory markers. METHODS: Forty-five patients were selected for a prospective single-arm self-controlled study and followed for at least 18 months. The TST, IGRA, Psoriasis Area and Severity Index (PASI), and inflammatory factors (erythrocyte sedimentation rate (ESR), C-reactive protein, interferon-gamma (IFN-γ), and tumor necrosis factor-alpha levels), were determined before and after 12 weeks of oral 15 mg per week MTX administration and compared. The associations between the IGRA and TST results were verified before and after treatment according to inflammatory factors and clinical characteristics (age, blood glucose, weight, body mass index, disease duration, and PASI). RESULTS: We collected data on 25 patients who completed the full course of therapy and the follow-up. None of the patients developed TB. TST positivity was significantly elevated at week 12 (25% baseline vs 44% at week 12, P < 0.037). Three IGRAs followed the TST conversions. There was no difference between TST and IGRA pre- or posttreatment. Serum IFN-γ increased significantly in week 12 (15.95 pg/ml baseline vs 18.82 pg/ml at week 12, P < 0.005) and tended to be higher among TST-positive patients (P = 0.072). The baseline IGRA was associated with a higher ESR (P = 0.038). None of the test results were associated with clinical characteristics. CONCLUSIONS: In addition to the classic booster effect, TST conversions in patients using MTX can occur due to an increase in IFN-γ. However, it is not possible to exclude true TST conversions. Therefore, other diagnostic methods, like IGRA or chest tomography, should be used when the TST has intermediate results.