ニボルマブによる甲状腺機能低下症における好中球/リンパ球比の関与

抄録

Nivolumab has a period to determine the therapeutic effect, and the first therapeutic effect is evaluated by the sixth dose. Several studies have indicated that the neutrophil-lymphocyte ratio (NLR) is a predictor of efficacy. These studies reported that patients with low levels of NLR had shown favorable therapeutic responses. The continuous administration of levothyroxine may be essential after the development of nivolumab-induced hypothyroidism; therefore, the elucidation of predictors associated with the development of hypothyroidism will be helpful during nivolumab treatment. This study investigated whether the NLR at the sixth dose of nivolumab could be applied as a management index in the patients who received six or more doses of nivolumab to predict the occurrence of hypothyroidism. Of the 90 patients treated with nivolumab, those (36％, n = 47) who received six or more doses of nivolumab had a significantly higher incidence of hypothyroidism than those (9％, n = 42) who received less than six doses (P < 0.01). However, the incidence of hypothyroidism did not increase based on the cumulative dose. Among 47 patients who received nivolumab six or more times, the incidence of hypothyroidism (44％) in patients with NLR < 5 was significantly higher than the incidence (9％) in patients with NLR ≥ 5 (P < 0.05). The deterioration of thyroid function needs to be monitored because patients with low levels of NLR (less than 5) at the sixth dose are more prone to developing hypothyroidism.