Association of Bartter Syndrome in a Filipino Patient with Overlap Syndrome

Introduction: Bartter Syndrome is a genetic tubulopathy resulting in hypokalemia and hypochloremic alkalosis. It has been reported to exist with autoimmune diseases. We describe, possibly the first case of an acquired Bartter Syndrome in a patient with Overlap syndrome. Case Description: We present a 34-year old Filipino woman with two-month history of generalized weakness. Work-up revealed hypokalemia, urine potassium wasting, metabolic alkalosis consistent with Bartter Syndrome. Oral and intravenous potassium were given with return of potassium to normal. However, weakness persisted. EMG-NCV done showed findings of demyelinating polyneuropathy consistent with Guillain-Barre Syndrome. She was treated with Intravenous Immunoglobulin with resolution of the weakness. The patient had recurrence of weakness two months later, this time with dysphagia. Physical exam revealed diffuse skin thickening with sclerodactyly with an mRSS score of 18 for Systemic sclerosis. ANA was at 1:160. Complements were low with high Anti-dsDNA pointing to lupus. Repeat EMG-NCV showed diffuse distal and proximal sensory-motor polyradiculoneuropathy suggestive of myositis. Rheumatoid factor was positive though she had no joint pains. Serum potassium was low at 3.4. Management included oral potassium with Spironolactone and Methylprednisolone Pulse Therapy which led to significant improvement. Discussion: We presented a case of an acquired Bartter Syndrome with Overlap Syndrome (Systemic Sclerosis, SLE, pre-clinical Rheumatoid Arthritis and Myositis). This case highlighted the temporal evolution of autoimmune disease and its association with a renal tubular disorder. Management involved potassium supplementation and treatment of the underlying disorder.Flexion contracture and Sclerodactyly of the hand foot. Skin thickening of the legs and feet