Endocrine Abstracts

Introduction: Recently, Programmed cell death ligand 1 (PD-L1) inhibitors have been frequently used as promising treatment options for some advanced malignancies. Although immune-related side effects secondary to PD-1 inhibitor treatment are well defined in the literature, data on PD-L1 inhibitors are limited. Thyroid dysfunction was reported in 10% of patients in the clinical study of atezolizumab. We aimed to present a case of severe hypothyroidism-related rhabdomyolysis and acute renal failure in a patient receiving atezolizumab with the diagnosis of metastatic lung cancer.

Case report: A 63-year-old male metastatic lung cancer was admitted to the hospital with complaints of generelized weakness, myalgias, shortness of breath, difficulty in walking. He has been receiving chemotherapy (carboplatin, etoposide, cisplatin) for small cell lung cancer for 2 years. Atezolizumab (PD-L1 inhibitor) was added to this treatment regimen from 3. cycle and total of 7 doses were used. The patient was receiving atezolizumab treatment every 21 days. Last dose of atezolizumab administered two weeks before admission. In the laboratory tests of the patient who did not have a known history of thyroid and kidney disease, cr: 1.6 8 mg/dl(0.7-1.2), ALT:118 U/l(<41) AST:173U/l(<40) CK: 2422 U/l (39-308), TSH: 168Mu/l(0.27-4.2), fT4: 0.3ng/l(8.9-17.1), fT3: 1,23 ng/l(2-4.4), cortisol:12.3 mg/dl (6.02-18.4) were found. In thyroid ultrasound of the patient; The thyroid gland dimensions are normal, the echo pattern is slightly heterogeneous and the echo intensity is decreased, there is no nodul. The patient was hydrated, L-thyroxine replacement was performed (excluding adrenal insufficiency). L-thyroxine treatment was gradually increased to 125 mg. After the treatment, the patient’s complaints regressed. In laboratuary tests cr:1.09 mg/dl (0.7-1.2) CK:428 U/l (39-308) decreased, while TSH:63 mU/l (0.27-4.2) was suppressed, increased to fT3:2.2ng/l (2-4.4) and fT4:7.86ng/l (8.9-17.1). Liver function tests decreased to the normal range.

Conclusions: The fact that PD-L1 inhibitors cause severe hypothyroidism, rhabdomyolysis and acute kidney failure shows that the evaluation of thyroid function tests in patients using these drugs is very important. Therefore, we recommend that patients taking PD-L1 inhibitors have their thyroid function tests checked regularly and their creatinine kinase (CK) and creatinine levels should be measured when they show clinical signs of myositis such as myalgia and hypothyroidsm.

Kaynaklar: 1- PD-L1 Inhibitor-Induced Thyroiditis Is Associated with Better Overall Survival in Cancer Patients. Thyroid. February 2020; 30(2): 177–184.