Background: Immune checkpoint inhibitors have changed the therapeutic milieu for patients with metastatic melanoma. However, their use may promote autoimmunity in virtually any organ in the body due to the blockade of intrinsic immune down regulators such as cytotoxic T-lymphocyte antigen- 4 (CTLA-4), programmed cell death 1 (PD1) or its ligand (PDL1). Immune mediated adverse neurological events are rare with these agents, however, and are seen in < 1% of treated patients. We report a patient with immune checkpoint inhibitor associated autoimmune encephalitis, with complete clinical recovery after treatment.

Case Report: A 49-year-old female with metastatic melanoma currently on nivolumab therapy but recently on ipilimumab/nivolumab combined therapy presented with a new headache. She also reported associated confusion, loss of balance, personality changes and language difficulty. Magnetic resonance imaging of the brain did not reveal any evidence of metastasis, infarct, meningitis, or encephalitis. Lumbar puncture revealed an elevated protein level and pleocytosis, with a normal glucose level. She was started on empiric glucocorticoid therapy with a presumptive diagnosis of immune checkpoint inhibitor associated autoimmune encephalitis. She improved considerably by day 3 of treatment with complete resolution of neurological symptoms by day 5.

Conclusion: Immune checkpoint inhibitors are increasingly important in cancer immunotherapy as they can cause sustained remissions in patients with metastatic melanoma and other malignancies. Because these drugs block immune-regulatory targets, they can lead to enhanced activation of immune system resulting in immune-related adverse events. Autoimmune encephalitis is a rare immune-related adverse event associated with immune checkpoint inhibitors. The incidence of autoimmune encephalitis is higher with combination or sequential CTLA-4 (ipilimumab) and PD1(nivolumab) inhibitor therapy than with monotherapy. With more widespread use of immunotherapy, it is important for clinicians to be aware of this rare and reversible cause of encephalitis. Early recognition and prompt initiation of immunosuppressive therapy with glucocorticoids is essential to enhance neurological recovery.

Primary sclerosing cholangitis (PSC) is a rare autoimmune disorder of the biliary system. PSC is fulminant in its course and leads to jaundice and biliary cirrhosis with specific radiological findings of the beading of larger ducts and pruning of smaller ducts. Though cholangiogram is the gold standard for PSC diagnosis, it may be inconclusive in patients with an early disease or small duct PSC or overlap with autoimmune hepatitis. These conditions may require a liver biopsy for confirmation of the underlying pathology. In this case report, we discuss one of these rare instances when a 24-year-old male was admitted with jaundice. During hospitalization, extensive workup, including cholangiograms, remained inconclusive, but based on a high suspicion of PSC, the patient underwent a liver biopsy, which confirmed our diagnoses

Introduction: Eosinophilic Gastritis (EG), one of the less common amongst Eosinophilic Gastrointestinal Disorders (EGID), with a prevalence of 6.3 cases/100.000, is an uncommon cause of unspecific abdominal symptoms, including epigastric pain.

Case: A 23-year-old female, was admitted with recurrent episodes of nausea, vomiting, abdominal pain and weight loss. She was discharged one week previously after being treated for similar symptoms. The patient had failed an outpatient treatment with a Proton Pump Inhibitor (PPI). During her re-admission, Esophagogastroduodenoscopy (EGD) was performed, and results were significant for gastritis without ulcers or esophagitis. While awaiting biopsy results, the patient experienced a minimal improvement in her symptoms with intravenous fluids and PPI. Extensive workup remained negative except of eosinophilia in peripheral blood. Gastric mucosal biopsy revealed eosinophilic infiltrates in Lamina Propria, confirming the diagnosis of Eosinophilic Gastritis. Helicobacter pylori on immunohistochemistry was negative. The patient was counseled regarding the Six Food Elimination Diet for the management of this condition. Her symptoms began to improve under dietary restrictions. Repeated EGD with biopsy at 12 weeks showed resolved eosinophilic infiltrates.

Discussion: EG remains a rare diagnosis, and it should be included as a differential diagnosis in every patient with refractory symptoms of nausea, vomiting, abdominal pain, and failure to thrive. Diagnosis of EGID is established after the exclusion of other causes of eosinophilia in the gastrointestinal tract.

AL amyloid cardiomyopathy is an increasingly recognized condition but arises less commonly with coexistent multiple myeloma. In this case report, we present a case of restrictive cardiomyopathy caused by AL amyloidosis and multiple myeloma, identified and treated using a multidisciplinary approach.

Hyponatremia is one of the most common electrolyte abnormalities found in hospitalized patients. The diagnosis of the underlying cause of hyponatremia could be challenging. However, common causes include the syndrome of inappropriate anti-diuretic hormone (SIADH), diuretic use, polydipsia, adrenal insufficiency, hypovolemia, heart failure, and liver cirrhosis. The ongoing pandemic of coronavirus disease 2019 (COVID-19) can present with severe hyponatremia. The association of hyponatremia and COVID-19 infection has been described, though pathophysiology is not clear. Here we describe a case of a 61-year-old male who presented with severe hyponatremia (Na+ 100 mmol/L) thought to be secondary to SIADH associated with COVID-19 pneumonia.