Progressive Chronic Kidney Disease in Young Adult with Normal Urinalysis

Case at a Glance

A 38-year-old female presented with persistently elevated serum creatinine and declining estimated glomerular filtration rate (eGFR) over 12 months, with normal urinalysis and imaging studies. Despite comprehensive workup ruling out common causes of chronic kidney disease, renal function continued to deteriorate, necessitating renal biopsy for definitive diagnosis.

Patient's Story

The patient is a 38-year-old female who was found to have elevated serum creatinine of 1.17 mg/dL during routine laboratory screening in January 2024. She has a medical history significant for non-alcoholic fatty liver disease without fibrosis. The patient maintains good lifestyle habits including regular exercise, adequate hydration, and alcohol cessation since January 2023. Her current weight is 185 lbs with a height of 5'7" (BMI 29).

Initial Assessment

Initial nephrology consultation led to discontinuation of all potentially nephrotoxic medications including over-the-counter drugs. Serial monitoring over several months showed persistent elevation in serum creatinine ranging from 1.12-1.26 mg/dL with corresponding eGFR between 50-53 mL/min/1.73m². Recent laboratory studies demonstrated progression with creatinine rising to 1.4 mg/dL and eGFR declining to 47 mL/min/1.73m². Blood pressure and glucose levels remain within normal limits.

The Diagnostic Journey

Comprehensive diagnostic evaluation included renal ultrasonography showing normal kidney morphology, complete urinalysis revealing no proteinuria or hematuria, and extensive serologic testing to exclude autoimmune conditions. All inflammatory markers and autoimmune panels returned negative. The patient's clinical presentation was described as enigmatic due to the isolated decline in renal function without obvious underlying etiology.

Final Diagnosis

Pending renal biopsy results. Differential diagnosis includes various forms of glomerulonephritis, interstitial nephritis, or other primary glomerular diseases that may not be detectable through non-invasive testing.

Treatment Plan

Plan for repeat renal function assessment within one week. If creatinine remains elevated, proceed with percutaneous renal biopsy to evaluate for glomerulonephritis and other primary renal pathologies. The biopsy will help identify specific glomerular or tubulointerstitial diseases that require targeted therapy and provide prognostic information.

Outcome and Follow-up

Patient education provided regarding the necessity of renal biopsy for definitive diagnosis of glomerular diseases when non-invasive methods are inconclusive. The biopsy will evaluate glomerular architecture, identify inflammatory processes, and guide specific treatment protocols based on histopathologic findings. Close nephrology follow-up scheduled pending biopsy results.