Evaluation of the Relationship between Selected Reticulocyte Parameters and Inflammation determined by Plasma C-reactive Protein in Dogs

Anaemia secondary to inflammatory disease is one of the main causes of anaemia in veterinary and human medicine and impairment of iron homeostasis due to the release of pro-inflammatory cytokines is one of the aetiological mechanisms involved. Because reticulocytes are recently produced cells, reticulocyte indices are early indicators of iron deficiency anaemia in man and dogs and reticulocyte indices may be affected during the course of inflammatory processes earlier than indices related to mature red blood cells. The aim of this study was to evaluate the possible influence of inflammation on reticulocyte parameters including concentration, mean reticulocyte volume, volume distribution width, percentage of microcytic reticulocytes, percentage of macrocytic reticulocytes, mean reticulocyte haemoglobin content (CHr), haemoglobin distribution width, cell haemoglobin concentration, mean percentage of hypochromic reticulocytes, percentage of reticulocytes with low CHr and immature reticulocyte factor medium and high, and on white blood cell concentration by using C-reactive protein (CRP) as an inflammatory biomarker.Samples from 175 diseased dogs and 16 healthy dogs were included in the study. The diseased dogs were grouped according to plasma CRP and ferritin concentrations, the presence and type of anaemia and different aetiopathological categories. Dogs with high plasma CRP concentrations had lower CHr (median 23.3 pg) and percentage of reticulocytes with high CHr (median 35.5%) and higher percentage of reticulocytes with low CHr (median 14.6%) compared with dogs without inflammation (median 24.9 pg, median 50.9% and median 7.8%, respectively) and healthy dogs (median 25.1 pg, median 50.0% and median 6.1%, respectively), with no differences between the last two groups. Reticulocyte parameters, particularly those related to haemoglobin concentration, are therefore affected by inflammatory conditions in anaemic and in non-anaemic dogs.