A Rare Case Report of Acquired Bartters With Positive Anti Scl70 Antibody

Abstract

Introduction: Bartter syndrome autosomal recessive renal tubular disorders usualy presents in infant age group or antenatallyCase Description64 years housewife, a known case of hypothyroidism with in emergency with generalized weakness and hypotension. She had an small adrenal nodule work up which showed that it was non functional. On evaluation at time of stress (blood pressure 70/50) her serum cortisol was 300nmol/l and she was therefore started on hydrocortisone. Her records revealed hypokalemia for last 2 years. Workup of hypokalemia showed kaliuresis, metabolic alkalosis, hypercalciuria and excess chloride excretion in the urine, suggestive of bartter’s syndrome. But this needed further confirmation as bartter’s is rare in this age group and also the test was done at the time of stress. She was started on spironolactone and oral potassium supplementation. CECT head done for evaluation of postural dizziness showed chronic cortical venous thrombosis. On follow up ACTH stimulated cortisol was done which showed normal cortisol level so steroid was stopped. She was readmitted one month later with hypokalemia(K-1.8 meq/l) while being on same dosage of spironolactone and potassium. Workup of hypokalemia showed same feature of bartter’s syndrome. Considering the chain of events, a suggestion of bartter’s and response to steroid, a diagnosis of acquired autoimmune bartter’s syndrome along with hypothyroidism was made. An autoimmune work up showed anti SCL 70 positive2+(++). Patient responded to steroid, spironolactone, indomethacin and oral potassium supplementation. Discussion: Bartter’s syndrome can rarely happen in old age too. Seek for autoimmune cause once we suspect acquired bartter’s. To best of our knowledge previously only one case has been reported of acquired Bartter with systemic sclerosis. Patient may develop systemic sclerosis in future as anti SCL70 antibody is very specific for it. It is positive in less than 1 % of general population. Anti SCL70 antibody is rarely positive in Sjogrens syndrome. Our patient did not feature of sjogren or systemic sclerosis even after 4 years follow up