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Kidney Week

Abstract: TH-PO089

Blue Kidney With Repaired Valve

Session Information

  • AKI: Mechanisms - I
    November 03, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
    Abstract Time: 10:00 AM - 12:00 PM

Category: Acute Kidney Injury

  • 103 AKI: Mechanisms

Authors

  • Haq, Kanza, Johns Hopkins University, Baltimore, Maryland, United States
  • Dasgupta, Alana, Johns Hopkins University, Baltimore, Maryland, United States
  • Bagnasco, S.M., Johns Hopkins University, Baltimore, Maryland, United States
  • Gautam, Samir Chandra, Johns Hopkins University, Baltimore, Maryland, United States
Introduction

Renal hemosiderosis has been reported in diseases characterized by chronic intravascular hemolysis but it is a relatively rare finding following cardiac valve repair

Case Description

70-year-old male with a history of CKD stage IIIBA2 presented for evaluation of worsening renal function. Pertinent past medical history includes hypertension and mitral valve annuloplasty performed 20 years prior. Serum creatinine had gradually increased from 1.6 mg/dL to 2.3 mg/dL. Urinalysis was consistently notable for hemoglobin pigment with intermittent microscopic hematuria. Serological workup was negative. Laboratory studies were also notable for anemia (hemoglobin 10.7 g/dL), elevated reticulocyte count (4.9%), elevated LDH (1174 U/L), and low haptoglobin (< 3mg/dL). Echocardiogram showed moderate to severe mitral valve regurgitation. Percutaneous renal biopsy revealed proximal tubule epithelial cells containing brown, granular pigment within the cytoplasm (Fig 1), which stains blue with the Prussian blue iron stain (Fig 2). He was ultimately referred to cardiac surgery for consideration of mitral valve replacement.

Discussion

Intravascular hemolysis is a well- recognized complication after prosthetic cardiac valve replacement or repair. Recurrent, or residual valvular regurgitation can cause serious mechanical hemolysis as regurgitant flow creates high shear stress that results in fragmentation of red blood cells. The chemically active iron in hemosiderin can cause tubular damage through various mechanisms.

Figure 1

Figure 2