MS-0975

MS-0975

A 38-year-old male visits his primary care physician complaining of polyuria, nocturia, and chronic dry mouth that have persisted for 4 months. He has a medical history of systemic lupus erythematosus (SLE) with associated renal involvement. His recent eGFR result was:

eGFR 23ml/min/1.73m²

The physician orders a water deprivation test along with other investigations.

What is the probable diagnosis for this patient, and what can be expected from his water deprivation test?