RESUMEN
BACKGROUND: Currently, COVID-19 is becoming one of the most common causes of viral pneumonia worldwide. In the medical literature, very few case reports describe the association between COVID-19 and the syndrome of inappropriate antidiuretic hormone secretion (SIADH) in kidney transplant patients. METHODS: A 74-year-old immunocompromised man post-kidney transplant presented with nonspecific symptoms consisting of fatigue, malaise, and anorexia. He was also found to have hyponatremia in the context of pulmonary insults. SIADH in the setting of COVID-19 pneumonia was diagnosed after exclusion of other causes of hyponatremia. He was treated for COVID-19 pneumonia with antiviral therapy, secondary bacterial infection prophylaxis, dexamethasone and ventilatory support in addition to modification of antirejection medications. RESULTS: The patient has improved and his serum sodium normalized with management of primary insult. CONCLUSIONS: SIADH should be suspected in transplant patients with COVID-19 pneumonia once they develops hyponatremia. The decision of intravenous fluid administration should be taken carefully in these settings.