A 54 year old women comes to doctor because of a 3 month history of persistent dry eye, dry mouth and diffuse joint pain. No prior medical history or any medicaitons. Vitals are normal. Physical exam shows: -Bilateral conjunctival redness, dry oral mucosa, mild bilateral parotid enlargement. Labs show: Na 138 K 3.1 Cl 18 HCO3 12 BUN 18 Creatinine 0.9 Urinalysis shows pH 7.0 no blood, glucose, protein or cells. 1. What is the patients most likely diagnosis? 2. What kidney pathology is associated with this condition? 3. What is reason for this?

How do you remember renal physiology?
Use the mnemonic, A WET BED: A) maintenance of ACID-base balance; W) maintenance of WATER balance; E) balance of ELECTROLYTES; T) removal of TOXINS; B) control of BLOOD pressure; E) production of ERYTHROPOIETIN; and D) metabolism of vitamin D.