S6404 Autoimmune Gastroparesis and Immune Thrombocytopenia-Effective Treatment With Immunomodulation

Introduction: Immunomodulatory therapy has been shown to have positive outcomes in improving vomiting symptoms in some gastroparetic patients who have coexisting positive autoimmune profiles. Case Description/Methods: A 45-year-old woman with a past medical history of migraines, depression, Type 2 diabetes mellitus, history of Helicobacter pylori, gastroparesis was seen in our outpatient gastroenterology clinic in March of 2020 for complaints of intermittent nausea and vomiting. She developed symptoms of nausea and vomiting which occurred in the August of 2019 and resulted in hospitalization where she was noted to have severe thrombocytopenia 12 K. Work up yielded a diagnosis of immune thrombocytopenia (ITP) and was started on intravenous immunoglobulin and prednisone taper over 8 weeks with excellent response. Her thrombocytopenia recurred as her prednisone was tapered and she was given 4 days of pulsed dexamethasone 40 mg with good response. She had a similar presentation with refractory nausea and vomiting as well as thrombocytopenia in March of 2020 with effective management with dexamethasone again. She recalls her diagnosis of Type 2 Diabetes mellitus predated her diagnosis of ITP by 1 year and after weight loss of 60 lbs (199 lbs to 139 lbs ), her hemoglobin A1c normalized and she was taken off Humalog and Triseba for diabetes. An outpatient nuclear gastric emptying study showed delayed gastric emptying at 4 hrs (20% retention), workup for autoimmune and paraneoplastic causes for gastroparesis were negative, but her ANA was positive 1:320 and positive dsDNA of 11 (normal 0-4 IU/ml). Due to worsening symptoms, she underwent gastric peroral endoscopic myotomy in July of 2021 with improvement in nausea and vomiting for 24 months. Her ITP relapsed in Aug of 2023 with shorter duration of response to dexamethasone and so was started on pulse dose dexamethasone and rituximab weekly for 4 doses in October 2023 and her ITP went into remission till October 2024 when a repeat course of dexamethasone and rituxamab was administered for recurrent thrombocytopenia with good response. in early 2025, she was hospitalized with refractory vomiting and was started on pulse dose dexamethasone and mycophenolate mofetil 500 mg twice daily. On follow up at 3 months, she noted significant improvement in her nausea and her platelet count had normalized. Discussion: This case highlights the need to consider immunomodulatory therapy for autoimmune etiology of gastroparesis. This is the only reported case of ITP and gastroparesis presenting concurrently and responding to immunomodulation.