Diagnosis of Disorders of Iron Metabolism in Dogs and Cats.

Iron is an essential element and is used by every cell in the body. This article summarizes iron metabolism and disorders associated with iron metabolism in dogs and cats. The diagnostic tests currently in use for assessing iron status are discussed.

Clinical utility of reticulocyte parameters.

The reticulocyte count reflects the erythropoietic activity of bone marrow and is thus useful in both diagnosing anemias and monitoring bone marrow response to therapy. Automated flow-cytometric analysis has led to a significant advance in reticulocyte counting, by simultaneously providing additional parameters and indices such as the reticulocyte immature reticulocyte fraction (IRF), the reticulocyte volume, and the hemoglobin content and concentration. IRF has been proposed as an early marker of engraftment. Reticulocyte hemoglobin content is useful in assessing the functional iron available for erythropoiesis, and reticulocyte volume is a useful indicator when monitoring the therapeutic response of anemias.

Low reticulocyte hemoglobin content is associated with a higher blood transfusion rate in critically ill patients: a cohort study.

BACKGROUND: Intensive care unit (ICU) patients often need blood transfusion, but no reliable predictors of transfusion requirements are available at ICU admission. The authors hypothesized that ICU patients with functional iron deficiency may be at higher risk for developing anemia, requiring blood transfusion. Their objective was to determine whether low reticulocyte hemoglobin content (CHr) was associated with transfusion requirements in ICU patients. METHODS: This is a prospective cohort study in a general ICU. The authors studied 62 patients, after excluding those transfused on or before ICU admission. The authors recorded age, diagnosis, severity score, presence of sepsis, ICU complications, ICU treatments, and transfusion-free interval. Threshold for low CHr was 29 pg. The authors also recorded ICU and hospital outcome. The statistical analysis included Cox proportional hazard function for transfusion. RESULTS: Twenty-three patients (37%) presented with low CHr on ICU admission and tended to be sicker and more likely to have sepsis than those with normal CHr. They were also more prone to complications, particularly acute renal failure (39 vs. 13% P = 0.02) and ICU-acquired infection (30 vs. 10% P = 0.04). The overall transfusion rate was 22.6%, being higher in low-CHr patients than in normal-CHr patients (39.1 vs. 12.8%, P = 0.02). After adjusting for severity of illness, age, trauma, and hemoglobin level, low CHr remained significantly associated with transfusion, with a hazard ratio of 3.6 (95% CI, 1.2-10.7; P = 0.02). Median ICU stay was also longer in patients with low CHr (8 vs. 5 days, P = 0.01). Differences in mortality did not reach statistical significance. CONCLUSION: Low CHr is common at ICU admission and is associated with higher transfusion requirements.

Effect of altitude on second-generation blood tests to detect erythropoietin abuse by athletes.

BACKGROUND AND OBJECTIVES: ON- and OFF-model scores derived from blood parameters sensitive to erythropoiesis have been shown to be a useful tool to identify athletes who are currently injecting erythropoietin to enhance performance or those who have recently stopped doing so. We investigated changes in blood parameters and model scores during and after exposure to terrestrial and simulated altitudes. DESIGN AND METHODS: We retrospectively evaluated changes in hematologic data collected from 19 elite cyclists who lived and trained 2690 m above sea level for 26-31 days, from six elite Kenyan runners who lived 2100 m above sea level but descended to compete at sea level competitions, and from 39 well-trained subjects who resided at sea level but slept at a simulated altitude of 2650-3000 m for 20-23 days of either consecutive or intermittent nightly exposure. RESULTS: Upon ascent to a terrestrial altitude, ON- and OFF-model scores increased immediately, mainly because of an increase in hemoglobin concentration. Scores had not returned fully to baseline three weeks after return to sea level, because of the persistence of the raised hemoglobin concentration for the ON and OFF scores and a fall in reticulocyte percentage for OFF scores. Effects were smaller or negligible for simulated altitude. For Kenyan runners, ON- and OFF-model scores decreased within seven days of descent to sea level. INTERPRETATION AND CONCLUSIONS: Our results reinforce the notion that caution should be exercised when interpreting blood results from athletes who have recently been exposed to either terrestrial or simulated altitude, and appropriate allowance should be made for the effect of altitude on blood model scores.