Hemolysis induced by an extreme mountain ultra-marathon is not associated with a decrease in total red blood cell volume.

Prolonged running is known to induce hemolysis. It has been suggested that hemolysis may lead to a significant loss of red blood cells; however, its actual impact on the erythrocyte pool is unknown. Here, we test the hypothesis that prolonged running with high hemolytic potential decreases total red blood cell volume (RCV). Hemolysis (n = 22) and RCV (n = 19) were quantified in ultra-marathon runners before and after a 166-km long mountain ultra-endurance marathon (RUN) with 9500 m of altitude gain/loss. Assessment of total hemoglobin mass (Hbmass) and RCV was performed using a carbon monoxide rebreathing technique. RUN induced a marked acute-phase response and promoted hemolysis, as shown by a decrease in serum haptoglobin (P < 0.05). Elevated serum erythropoietin concentration and reticulocyte count after RUN were indicative of erythropoietic stimulation. Following RUN, runners experienced hemodilution, mediated by a large plasma volume expansion and associated with a large increase in plasma aldosterone. However, neither Hbmass nor RCV were found to be altered after RUN. Our findings indicate that mechanical/physiological stress associated with RUN promotes hemolysis but this has no impact on total erythrocyte volume. We therefore suggest that exercise 'anemia' is entirely due to plasma volume expansion and not to a concomitant decrease in RCV.

[State of the art and method validations: application to fidelity performance]. / Etat de l'art et validation de techniques: application aux performances de fidélité

Current events of clinical laboratories in France argue a lot about quality management. Setting up an assurance quality system can be realized in many approaches listed by increasing requirements: respect of reglementary Guide de bonne exécution des analyses (GBEA), BioQualite qualification, certification and at last accreditation. This last step corresponds to the recognition of the competence of the laboratory to execute specifics tasks. Validation of methods used in the laboratory is a key point when you realize an accreditation package. Fidelity (repetability and reproductibility) is one of the parameters to check in your lab for quantitative methods. These performances are validated in comparison with targets beforehand defined (according to biological variation or state of the art). This article reports fidelity performances obtained in 2000 and 2006 by the participants to ProBioQual internal quality controls. Considering these performances obtained in routine conditions, the different possible approaches to define acceptability limits were discussed.

[About the choice of acceptability limits in external quality assessment schemes]. / Réflexion sur le choix des limites acceptables dans les programmes d'évaluation externe de la qualité

Quality control schemes are a practical tool used in clinical laboratories and an essential element for any quality assurance process. In France, external quality assessment schemes (EQAS) can be mandatory (as national quality control organized by AFSSAPS) or voluntary as those suggested by French associations (ProBioQual, CTCB or Asqualab). These EQAS usually evaluate participants according to their performances: this ranking depends on acceptability limits which are here compared. Various examples based on ProBioQual's background illustrate difficulties to plan out analytical quality specifications. A comment is given about the best criteria (state of the art or biological variation mainly) to be considered to delimit analytic goals. This discussion includes approaches suggested by French committee on accreditation (Cofrac). All criteria could be criticized but it is important to compare oneself laboratory to peers and also to take account of biological variation.

External quality assessment of urine analysis in Europe. Results of a round table discussion during the symposium 'From uroscopy to molecular analysis', Seeon, Germany, September 18-20, 1999.

Interlaboratory surveys on urine quantities have only recently been introduced in several European countries. Representatives of 10 European countries exchanged their experiences during an international urinalysis meeting held in September 1999. Although still not mandatory in most areas, more than 5000 laboratories participated in external quality assessment programs in the countries represented. Qualitative (test strips and microscopic morphology) as well as quantitative chemical and immunochemical quantities were included. The maximal allowable deviations are reported as well as methods used to determine target values. Consensus scales up to reference methods were applied. The participants agreed that quality criteria need to be defined separate from those already existing for plasma/serum analytes. Besides higher biological variables and different medical needs, less standardisation of methods to quantify urine constituents was observed as a major cause of higher interlaboratory differences.

French experience of quality assessment of quantitative urinary analysis.

Since 1986, clinical biochemists from the Rhône alpes area, in collaboration with a non-profit-making association (Pro Bio Qual), have been conducting an inter-laboratory quality assurance program for quantitative urine analysis. We investigated the precision and accuracy of individual methods and measurement systems routinely used in the monthly control for 13 analytes: albumin, alpha-amylase, calcium, chloride, creatinine, glucose, magnesium, phosphorus, potassium, total protein, sodium, urea, and urate. The number of laboratories participating in the program increased from 60 in 1986 to 277 in 1999. In 1986, the greatest inter-laboratory imprecision occurred in the assay of urinary total protein, because the commonly used sulfosalicylic acid turbidimetric methods displayed poor precision. Since 1989, the increasing use of pyrogallol red or Coomasie Blue dye colorimetric methods has improved inter-laboratory precision markedly. The acceptable precision and good practicability have encouraged the general use of the pyrogallol red method. As for albumin analysis, which uses a specific immunologic method, the precision was reasonably good. Quality assessment of chloride and sodium decreased when the method performance improved for other analytes (calcium, creatinine, glucose, magnesium, phosphorus, potassium, urea, urate). This program has helped the laboratories to improve the quality of quantitative urine analysis, particularly for total protein.

Usefulness of the prognostic inflammatory and nutritional index (PINI) in hospitalized elderly patients.

The prognostic inflammatory and nutritional index (PINI) is a simple scoring system of overall health which aggregates two blood markers of inflammatory (C-reactive protein and alpha(1)-acid glycoprotein) and of nutritional (albumin and transthyretin) states. This study was undertaken with a view to evaluate, in comparison to currently used predictive approaches, the potential usefulness of PINI to forecast hospital mortality and outcome of patients hospitalized in an acute geriatric unit. 1,066 elderly patients, aged 82.7 +/- 6.6 years and fulfilling inclusion criteria, were enrolled in the study. Logistic regression analysis and calculation of relative risk (RR) were carried out for epidemiological data with a cut-off value of 25 for PINI. Immediate mortality (7.9%) of admissions) was predicted by PINI > or = 25 (RR = 4.34). Only 387 patients (36.3%) could rejoin their residence location (home or family). A sizeable proportion of acute patients (55.8%) failed to recover and/or developed diseased states requiring chronic care management. Incapacity to return home was predicted by PINI > or = 25 (RR = 2.04). Hypoalbuminaemia < or = 30 g/L was not found a predictor of mortality but was associated with total disability (RR = 9.08). The optimal PINI cut-off value to predict mortality was calculated at 8.8 using the ROC analytic approach. We conclude that the PINI formula is helpful to predict both nearest lethality and chronic institutionalization. This scoring system should take a place within the battery of tests used to identify and to follow up acutely ill elderly patients at risk of major complications.

Implication of cytokines in the aggravation of malnutrition and hypercatabolism in elderly patients with severe pressure sores.

The objectives of this work were to study the production of the cytokines Interleukin 1 (IL-1), Interleukin 6 (IL-6), and tumour necrosis factor (TNF) in elderly patients with severe pressure sores and to assess their potential contribution to the aggravation of malnutrition. Nineteen bedridden patients with stage III or IV pressure sores, 12 bedridden patients free from pressure sores, but at risk of them, and 12 control patients without risk of pressure sores were studied. Nutritional status was evaluated using anthropometry, serum albumin, prealbumin, retinol-binding protein analyses, and delayed hypersensitivity skin tests. Acute-phase proteins (APP), cortisol, and cytokines blood levels together with cytokine production were measured. Nutritional status was poor in patients with sores and their APP, and IL-6 blood levels were significantly increased; IL-1 and TNF serum concentrations were not elevated in these patients. A significant difference in cortisol levels was observed between patients with stage III and IV sores. A local cytokine origin (especially IL-6, and also IL-1) was demonstrated. Thus cytokines, mainly IL-6, produced by tissue cells in damaged areas together with cortisol may aggravate malnutrition and hypercatabolism in patients with sores.