Kidney Week

Abstract: FR-PO0416

Role of Cystatin C-Based eGFR in Integrase Strand Transfer Inhibitor-Associated Elevation in Serum Creatinine

Session Information

• AKI: Biomarkers, Diagnostics, and Risk Prediction
  October 23, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Acute Kidney Injury

• 102 AKI: Clinical, Outcomes, and Trials

Authors

• Joy, Justin, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, New York, United States

Justin Joy, MD

• Kashfi, Simon Adam, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, New York, United States

Simon Adam Kashfi, MD

• Dey, Mayukh, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, New York, United States

Mayukh Dey, MD

• Shah, Hitesh H., Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, New York, United States

Hitesh H. Shah, MD, FASN

Group or Team Name

• Northwell Health

Introduction

Integrase strand transfer inhibitors (INSTIs) are highly effective antiretroviral therapies for HIV. However, several INSTIs are known to increase serum creatinine (SCr) by inhibiting its active tubular secretion. We review the use of cystatin C to differentiate benign SCr elevations from true kidney injury in a patient treated consecutively with the integrase inhibitors bictegravir and dolutegravir.

Case Description

A 35-year-old male with HIV was referred for evaluation of an apparent acute kidney injury (AKI), with serum creatinine (SCr) rising from a baseline of 1.18 mg/dL to 1.46 mg/dL (eGFR 64 mL/min/1.73m²) after starting bictegravir/emtricitabine/tenofovir alafenamide. Despite the rise in SCr, the HIV viral load was undetectable, and an extensive workup—including urinalysis, UPCR (0.1), complements (C3/C4), hepatitis serologies, and serum immunofixation—was unremarkable. Kidney sonogram was normal. Notably, a concurrent cystatin C was 0.88 mg/L, yielding a normal eGFR of 102 mL/min/1.73m². Following a switch to dolutegravir/rilpivirine, the SCr remained elevated at 1.57 mg/dL (eGFR 59), while repeat cystatin C remained normal (0.80 mg/L; eGFR 116).

Discussion

While various antiretrovirals are linked to true AKI, the SCr elevations observed with INSTIs are often benign—representing an inhibition of the renal tubular transporters OCT2 and MATE-1/2K rather than kidney injury. When SCr rises in patients on INSTI therapy, we recommend utilizing cystatin C-based eGFR to accurately assess kidney function and avoid unnecessary drug discontinuation.