Abstract Disclosure: G. Wintermyer: None. S. Gillis-Funderburk: None. COVID-19 patients face many post-recovery complications,including autoimmune disorders. Late autoimmune diabetes ofadults (LADA) is one such disorder. Studies suggest that SARS-CoV may trigger proinflammatory cytokines that damage beta cellsand impair insulin secretion. Here, we explore a case of new-onsetLADA in a patient after recovery from COVID-19. Further, asidentical twins of LADA patients have a higher risk of developingit, we discuss how we approached the patient’s identical twin.A 29-year-old female with history of obesity (BMI 32.3) presentedto our endocrinology clinic. She complained of difficulty losingweight and fatigue and reported having COVID-19 three monthsearlier. She also mentioned having polyuria. She underwent labtests, including CBC, CMP, TSH, A1C, and a lipid panel. The testresults were within normal limits, except for her A1C of 11.3%.She was started on metformin and weekly Semaglutide injections.Given her recent COVID-19 history, she was assessed for LADA.Anti-GAD-65 and ZNT8 antibodies were 120 U/mL and 150U/mL, respectively. Serum C-peptide and IA-antibodies werewithin normal ranges. The patient informed us of her twin sister’sconcurrent COVID-19 infection. Due to the risk of LADA in hertwin sister, we recommended an evaluation by our clinic. Duringthe sister’s first visit, her BMI was 37.5, and she asked for weightloss medication. Comprehensive testing, including LADAantibodies, was conducted, with results within normal ranges andA1C level of 4.9%. The sister was also started on Semaglutide forweight management.The patient had quarterly follow-up appointments at the clinic.After a year, her A1C and continuous glucose monitoring machine(CGM) readings showed improvement. Her BMI decreased to 24.She never required insulin therapy, as her diabetes was well-managed and her average monthly glucose level on GCM readings were 125, 123 and 119 mg/dL in three different periods. Antibodieswere retested. This time IA-2 antibody was also elevated.Similarly, her twin sister continued to follow-up at our clinic. Thesister achieved significant weight loss without complications. HerLADA antibodies remained negative, and her A1C remainednormal. Clinicians should be vigilant for post-COVID LADA. In this case,Semaglutide aided weight loss, which benefits diabetesmanagement. Ongoing studies explore the potential of GLP-1medications in early-stage LADA. Historically, LADA patientswere started on insulin. However, CGM has enabled close glucosemonitoring, offering management of LADA with non-insulinmedications. It is also important to remember that autoimmunedisease risk is elevated in identical twins. In this case, although thetwin sister did not develop antibodies, the risk remains. Regularevaluation of high-risk patients is crucial for early detection ofantibodies, facilitating timely treatment to prevent adverseoutcomes. Presentation: 6/3/2024