The change of systemic inflammation response index in the treatment of patients with myasthenia gravis undergoing thymectomy: A retrospective, follow-up study

Background: This study aims to investigate the role of neutrophil-tolymphocyte ratio, platelet-to-lymphocyte ratio, monocyte-to-lymphocyte ratio, and systemic inflammation response index in patients with myasthenia gravis, thymomas and thymic hyperplasia and to identify the relationship between the inflammation response and disease activity.Methods: Between January 2010 and December 2018, a total of 97 patients (71 males, 26 females; mean age: 36.7 +/- 16.3 years; range, 15 to 76 years) who underwent extended thymectomy with the diagnosis of myasthenia gravis were retrospectively analyzed. The patients were divided into two groups as the patient group (n=42) and the control group (n=55). Neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, monocyteto-lymphocyte ratio, and systemic inflammation response index were measured one day prior to and one month after surgery.Results: The patients with thymoma were older with a higher mean pre-systemic inflammation response index value. Preoperative systemic inflammation response index, neutrophil-to-lymphocyte ratio, and monocyte-to-lymphocyte ratio were significantly higher in patients with thymoma. A preoperative systemic inflammation response index value of less than 0.62 was accepted to indicate thymic hyperplasia and a postoperative systemic inflammation response index value higher than 2.94 was indicative of thymoma. In myasthenic patients whose steroid dose was increased and/or remained the same at the first month after surgery, postoperative monocyte-to-lymphocyte ratio and systemic inflammation response index values were found to be higher compared to preoperative values (p= 0.006 and p=0.032, respectively). Patients whose pyridostigmine dose was increased and/or remained the same had significantly higher systemic inflammation response index values postoperatively (p=0.029).Conclusion: The precise cut-off values of systemic inflammation response index may be helpful for the surgeon to predict the surgical outcome and post-systemic inflammation response index may be a predictive marker for estimating postoperative treatment changes.