Is Magnetic Resonance Imaging Detection of Kidney Iron Deposition Increased in Haptoglobin 2-2 Genotype Carriers with Type 1 Diabetes?A version of the abstract was previously presented at the 77th Scientific Sessions of the American Diabetes Association, San Diego, CA, June 9–13, 2017

Haptoglobin's (Hp) main role is to bind free hemoglobin (Hb), reducing its oxidative potential. The Hp–Hb complex formed is cleared from the circulation by macrophage receptor CD163. In diabetes, impaired Hp 2-2–Hb CD163 clearance and abnormal glomerular permeability allow the large Hp 2-2–Hb complex to cross the barrier, where its redox active iron leads to cellular toxicity. Although Hp 2-2 predicts renal function decline, whether renal iron deposition differs by Hp is unknown. We used renal quantitative T2* magnetic resonance imaging to estimate iron level in the cortex and medullar of type 1 diabetes (T1D) adults [15 Hp 1-1 and 15 Hp 2-2 carriers of similar age (53 years), duration (45 years), and gender]. Total kidney iron level was estimated as the sum of the cortex and medullar iron. Albuminuria was defined as urinary albumin to creatinine ratio >30 mg/g in two of three samples. Total kidney iron did not differ by gender or Hp but was higher in those with albuminuria (p = 0.05), an associa...