RESUMO
INTRODUCTION: Chagas disease, caused by the protozoan Trypanosoma cruzi (T. cruzi), is the fourth most important tropical disease, which affects approximately 7 million people worldwide. The mechanisms involved in the development of this disease are not completely well understood. An important protective role of regulatory T cells (Treg) in Chagas disease has been observed; however, the specific mechanisms remain unclear. We evaluated apoptosis as a possible mechanism mediated by Treg cells (CD4+CD25HighFOXP3+) to orchestrate the immune response in chronic Chagas disease. METHODS AND RESULTS: Patients with Chagas disease were grouped as the indeterminate (IND; asymptomatic patients with Chagas disease; nâ¯=â¯10) and dilated cardiomyopathy (CARD; nâ¯=â¯10). Healthy T. cruzi-negative individuals (NI; nâ¯=â¯10) were included as a control group. In order to evaluate the apoptotic cell profile, the expression of PD1, PD1L, CD39, CD95, CD95L molecules were investigated. We also evaluated the proportion of CD14+ cells expressing caspase 3. The IND group presented a substantially higher expression of CD39 by Treg cells as compared to the CARD group. On the other hand, the CARD group showed higher expression of PD-1 by Treg cells than both NI and IND groups. Significant positive correlations were observed between Treg CD95L+ cells and CD14 cells expressing caspase 3 as well as between Treg CD39 cells and CD14+ Caspase3+ cells in the IND group. CONCLUSION: Our data indicate that the expressions of different molecules that induce apoptosis are associated with suppressive mechanisms mediated by Treg cells and suggest a possible role for PD1 and PDL1 molecules in the morbidity of chronic Chagas disease.
Assuntos
Antígeno B7-H1/metabolismo , Cardiomiopatia Dilatada/sangue , Cardiomiopatia Chagásica/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Linfócitos T Reguladores/imunologia , Trypanosoma cruzi/imunologia , Adulto , Idoso , Antígenos de Protozoários/imunologia , Apoptose/imunologia , Apirase/metabolismo , Antígenos CD4/metabolismo , Feminino , Fatores de Transcrição Forkhead/metabolismo , Humanos , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Masculino , Pessoa de Meia-Idade , Testes SorológicosRESUMO
LESSONS LEARNED: Pregabalin is a medication that can decrease neuronal hyperexcitability, relieve neuropathic pain, and reach stable plasma levels after a titration period of only a few days.Its use during oxaliplatin infusions was not able to decrease the incidence of chronic, oxalipaltin-related neuropathic pain, compared with placebo. BACKGROUND: Patients with colorectal cancer (CRC) receiving oxaliplatin (OXA) develop acute and chronic painful oxaliplatin-induced peripheral neuropathy (OXAIPN). Acute and chronic OXA-related neuropathies have different pathophysiological bases, but both lead to a common phenomenon: central sensitization (CS) of nociceptive neuronal networks, leading to increased sensitivity (hyperlgesia, allodynia) in the somatosensory system, the common ground of chronic neuropathic pain. Because CS is related to increased risk of painful OXAIPN, we hypothesized that preemptive use of the anti-hyperalgesic drug pregabaline (known to decrease CS) during OXA infusions would decrease the incidence of chronic OXAIPN. METHODS: Pain-free, chemotherapy-naïve CRC patients receiving at least one cycle of modified-FLOX [5-FU(500 mg/m2)+leucovorin(20 mg/m2)/week for] 6 weeks+oxaliplatin(85 mg/m2) at weeks 1-3-5 every 8 weeks] were randomized (1:1) into the study. Patients received either pregabalin or placebo for 3 days before and 3 days after each OXA infusion and were followed for up to 6 months. Clinical assessments were performed at baseline, at the end of chemotherapy, and after the follow-up period. The main outcome was average pain at the last visit assessed by the visual analogic scale (0-10) item of the Brief Pain Inventory (BPI). Secondary endpoints were presence of neuropathic pain according to the Douleur Neuropathique-4 (DN-4), pain dimensions (short- form McGill Pain Questionnaire [MPQ]), Neuropathic Pain Symptom Inventory (NPSI), and changes in nerve conduction studies (NCS) and side effect profile. RESULTS: One hundred ninety-nine patients (57.0 ± 10.7 years old, 98 female, 101 male) were randomized. Data from 56 patients were not included in the analyses (as they did not receive at least one full cycle of modified FLOX). Data from 78 patients in the pregabalin group and 65 patients in the placebo group were retained for analyses. At the last visit, pain intensity in the pregabalin group was 1.03 (95% confidence interval [CI] = 0.79-1.26), and 0.85 (95% CI = 0.64-1.06) in the placebo group, which did not reach significance. Scores from the BPI, MPQ, DN-4, NPSI, and NCS and side-effect profiles and incidence of death did not differ between groups. Quality of life (QoL) score did not differ between groups (placebo = 76.9 ± 23.1, pregabalin group 79.4 ± 20.6). Mood scores were not significantly different between groups (placebo 9.7 [8.1-11.2]; pregabalin 6.8 [5.6-8.0]). CONCLUSION: The preemptive use of pregabalin during OXA infusions was safe, but did not decrease the incidence of chronic pain related to OXAIPN.