Evaluation of RETIC-HGB (reticulocyte haemoglobin content) in the diagnosis of iron-limited erythropoiesis (ILE) in cats
17 February 2020 (online)
Background Reticulocyte haemoglobin content (CHr, ADVIA® 2120) is a diagnostic marker of iron-limited erythropoiesis (ILE) in humans and dogs. RETIC-HGB (ProCyte Dx®) has recently been introduced for analysis of ILE for veterinary use.
Objectives Aim of this prospective study was to evaluate the clinical and diagnostic utility of RETIC-HGB compared to CHr in the diagnosis of feline ILE.
Methods First, reference intervals (RIs) for RETIC-HGB and CHr were established analysing 59 healthy cats. Second, 275 cats were classified as having ILE or not. Low plasma iron or low transferrin saturation in combination with either anaemia and/or altered red blood cell (RBC) indices was required for diagnosis of ILE. Haematologic variables, parameters of iron metabolism as well as serum amyloid A (SAA) were compared between both groups and correlation between RETIC-HGB and CHr was assessed.
Results RIs for RETIC-HGB and CHr were 12.5–18.0 pg and 14.0–19.9 pg, respectively. In respect of iron and haematologic variables, 20/275 cats (7.3%) were classified as ILE cats. Compared to non-ILE cats, ILE cats had significantly lower median (RETIC-HGB) and mean (CHr) values of reticulocyte haemoglobin content. Not unexpectedly, HCT, HGB, MCH, and RBC were significantly decreased in ILE cats. Additionally, ILE cats had significantly increased median SAA values. Correlation between RETIC-HGB and CHr was moderate (rs = 0.59) with a small bias of –1.2 pg.
Conclusion CHr and RETIC-HGB may be suitable early indicators of ILE, especially when used in addition to parameters of iron metabolism. The moderate correlation between RETIC-HGB and CHr is likely due to species and different methodology.