Use of capillary electrophoresis to quantitate carbamylated hemoglobin concentrations in dogs with renal failure

Objective - To evaluate quantification of the amount of carbamylated hemoglobin (CarbHb), using capillary electrophoresis (CE) and a new dynamic capillary coating system to separate hemoglobin derivatives, and to assess the use of CarbHb amounts to evaluate long-term urea exposure and differential diagnoses of azotemia in dogs. Animals - 8 dogs with renal failure, 2 dogs with diabetes mellitus, and 7 control dogs. Procedure - Optimal analytic conditions for separation of CarbHb and other hemoglobin derivatives in blood samples obtained from dogs were determined, using a commercial analysis system developed for the detection of glycohemoglobin Hb A1c (GlycHb) in human blood samples. Relative content of hemoglobin derivatives in blood from 10 dogs with renal failure or endocrine diseases were compared with values for 7 dogs without renal or endocrine diseases. Results - Satisfactory resolution of hemoglobin derivatives was obtained, which permitted identification and quantitation of the amount of CarbHb as a percentage of the total amount of hemoglobin. Normal or increased amounts of GlycHb did not interfere with CarbHb analysis. Dogs with chronic renal failure had considerably higher peak amounts of CarbHb than dogs with acute renal failure, a dog with chronic renal failure that was treated by use of hemodialysis, or dogs without renal disease. Conclusions and Clinical Relevance - Amounts of CarbHb in blood samples obtained from dogs can be readily quantified by use of capillary electrophoresis. Assessment of the amount of CarbHb can be used to facilitate evaluation of the cause of azotemia in dogs.