**6.2 Diagnosis**

Type 1 DM is rare but when present, ketoacidosis must be investigated and treated [34]. Anti-GAD65 can be performed to look for autoimmunity.

### **6.3 Mechanism**

The most likely mechanism of developing insulin dependent diabetes mellitus is inappropriate activation of T cells which cause destruction of pancreatic islet cells [35].

#### **6.4 Treatment**

Patients with immune mediated type 1 diabetes mellitus should be referred to endocrinology and treated with basal-bolus insulin regimen.

#### **7. Conclusion**

With the widespread use of immunotherapies in cancer, the incidence of side effects of immune check point inhibitors is also increasing. Physicians should be aware of different immune related adverse events (irAE).

Hypophysitis and thyroid dysfunction are the most common endocrinological side effects of immune check point inhibitors. Patients who receive anti-CTLA-4 therapy, the pituitary hormones should be regularly monitored and if there is concern for central adrenal or thyroid dysfunction, treatment should be instituted as soon as possible, and immunotherapy should be held.

Primary thyroid dysfunction is more common in patients who receive anti-PD1 and anti-PD-L1 antibodies. Patients may develop hyper or hypothyroidism. Hyperthyroidism is mainly transient, which can lead to hypothyroidism requiring life-long thyroid hormone treatment.

Most of the endocrine side effects of immune check point inhibitors can be adequately treated, clinicians should regularly monitor hormone levels so that it can be promptly diagnosed and treated. In patients with mild to moderate endocrinopathies, immunotherapy can be continued with careful monitoring.

Physicians should be aware that irAEs can occur during and after the treatment with immunotherapies and a multidisciplinary approach should be used in managing it. Patient's education is also very important, and physicians should guide them about the symptoms and signs to look for and notify the physicians.
