Within the eighteenth day after the first referral, he revisited our hospital with his family. He was 165 cm tall and weighed 46 kg, having a BMI of 16.9. Tipelukast could indicate the onset of life-threatening Feet1D induced by anti-PD-1 antibodies. Based on the medical course of this patient and the literature, Tipelukast we suggest monitoring anti-PD-1 antibody-related T1D. Learning points: Defense checkpoint inhibitors, such as anti-PD-1 antibodies, are progressively used as anticancer medicines. Anti-PD-1 antibodies can cause immune-related adverse events, including T1D. Feet1D, a novel subtype of T1D, is definitely characterized by the abrupt onset of hyperglycemia with ketoacidosis, a relatively low glycated hemoglobin level and Rabbit polyclonal to AHCYL1 depletion of C-peptide level at onset. In patients becoming treated with anti-PD-1 antibody, hyperglycemia with C-peptide level persistence should be monitored through regular blood tests. Because of C-peptide persistence and slight hyperglycemia, it is possible to miss a analysis of life-threatening Feet1D induced by anti-PD-1 antibody. In particular, in individuals who have no history of diabetes, hyperglycemia without DKA is likely to be the very beginning of anti-PD-1 antibody-induced T1D. Consequently, such patients must be regarded as for either hospitalization or frequent outpatient appointments with insulin injections and self-monitoring of blood glucose. strong class=”kwd-title” Patient Demographics: Geriatric, Male, Asian – Japanese, Japan strong class=”kwd-title” Clinical Summary: Pancreas, Diabetes, Insulin, Diabetes mellitus type 1, Iatrogenic disorder, Hyperglycaemia, Diabetic ketoacidosis strong class=”kwd-title” Analysis and Treatment: Diabetes mellitus type 1, Hyperglycaemia, Diabetic ketoacidosis, Polydipsia, Hunger reduction/loss, C-peptide (blood), Glucose (blood), Haemoglobin A1c, Tipelukast Glucose (blood, fasting), Ketones (plasma), Glucagon activation test*, Fluid repletion, Pembrolizumab*, Immune checkpoint inhibitors*, Insulin, Saline, Insulin lispro, Insulin degludec* strong class=”kwd-title” Related Disciplines: Oncology strong class=”kwd-title” Publication Details: Unusual effects of medical treatment, April, 2020 Background Immune checkpoint inhibitors, such as anti-programmed cell death-1 (anti-PD-1) antibodies, are progressively used as anticancer medicines. Cytotoxic T lymphocytes (CTLs) have an immune checkpoint function that bank checks whether they are attacking foreign substances in the body. In short, they have a brake to control the immune system. PD-1 molecules are indicated on CTLs, and anti-PD-1 antibodies launch the brake within the immune response, which enhances the anti-tumor immune response of CTLs (1). However, when the immune response to pancreatic -cells runs out of control, type 1 diabetes (T1D) will develop. According to a Japanese survey, among patients who developed anti-PD-1 antibody-related T1D, 50% met the criteria for fulminant type 1 diabetes (FT1D) (2). Anti-PD-1 antibody-related T1D often manifests as FT1D in Western countries as well (3, 4, 5, 6, 7, 8, 9). Common FT1D patients usually develop diabetic ketoacidosis (DKA) or ketosis within 1 week after the onset of hyperglycemic symptoms, and C-peptide is usually markedly depleted when they present with DKA. Although most anti-PD-1 antibody-related T1D patients also present with DKA at the first referral, it should be noted that some of them present without DKA, having C-peptide level persistence when hyperglycemia is usually first discovered. This case statement describes a case of pembrolizumab-induced FT1D in which the patient presented with asymptomatic hyperglycemia and C-peptide level persistence and developed DKA 18 days later. Case presentation A 72-year-old Japanese man who was undergoing pembrolizumab treatment for 4 months was admitted to our hospital as a result of DKA. Six years before the admission, he had undergone surgery for colon cancer. Three years previously, he also underwent two video-assisted thoracoscopic surgeries for lung metastasis. He was diagnosed with non-small-cell lung carcinoma 11 months before the present admission. 18Fluorodeoxyglucose PET/CT showed increased 18fluorodeoxyglucose accumulation in the flank subcutaneous skin, ribs, erector spinal muscles, pancreatic head and intra-abdominal lymph nodes, which were considered to be metastases. First-line carboplatin and pemetrexed were ineffective, then second-line pembrolizumab was started 4 months before the admission. Six days before initiation of pembrolizumab treatment, a blood test found that his glycated hemoglobin (HbA1c) level was 5.6% (reference range (RR): 4.6C6.2%) and his casual blood glucose was 90 mg/dL (RR: 70C110 mg/dL). He had no personal or family history of diabetes, but his child was admitted to our hospital 8 years earlier as a result of thyroid storm and Graves disease. He had smoked 30 smokes per day until the age of 70 but experienced now quit. He drank 550 mL of beer every day. Transition of blood glucose and HbA1c values were as follows: casual blood glucose: 71 mg/dL and HbA1c: 5.6%, 3 weeks after pembrolizumab induction: blood glucose was 88 mg/dL and HbA1c: 5.6%, 6 weeks later: blood glucose was 72 mg/dL and HbA1c: 6.0%, 12 weeks after. At the end of the fifth course of pembrolizumab infusion (4 months after induction), his casual blood glucose was 209 mg/dL and HbA1c 6.4%. He was referred to an endocrinologist the same day. His physical condition was unremarkable,.