Although screening for maternal toxoplasmic seroconversion during pregnancy is based on immunodiagnostic assays, the diagnosis of clinically relevant toxoplasmosis greatly relies upon molecular methods. A problem is that this molecular diagnosis is subject to variation of performances, mainly due to a large diversity of PCR methods and primers and the lack of standardization. The present multicentric prospective study, involving eight laboratories proficient in the molecular prenatal diagnosis of toxoplasmosis, was a first step toward the harmonization of this diagnosis among university hospitals in France. Its aim was to compare the analytical performances of different PCR protocols used for Toxoplasma detection. Each center extracted the same concentrated Toxoplasma gondii suspension and tested serial dilutions of the DNA using its own assays. Differences in analytical sensitivities were observed between assays, particularly at low parasite concentrations (<2 T. gondii genomes per reaction tube), with "performance scores" differing by a 20-fold factor among laboratories. Our data stress the fact that differences do exist in the performances of molecular assays in spite of expertise in the matter; we propose that laboratories work toward a detection threshold defined for a best sensitivity of this diagnosis. Moreover, on the one hand, intralaboratory comparisons confirmed previous studies showing that rep529 is a more adequate DNA target for this diagnosis than the widely used B1 gene. But, on the other hand, interlaboratory comparisons showed differences that appear independent of the target, primers, or technology and that hence rely essentially on proficiency and care in the optimization of PCR conditions.

T oxoplasmosis is a widespread parasitic infection that is frequently asymptomatic in immunocompetent patients. However, this obligate intracellular protozoan parasite can evade the immune system (1, 2) and persist for the life of its host in cyst form, predominantly in the brain, retina, and muscles. Reactivation of latent cysts may occur when the immune system fails to maintain cytokine pressure, which mainly relies on gamma interferon (IFN-␥) (3). Cyst reactivation can lead to ocular toxoplasmosis, cerebral toxoplasmosis (CT), or disseminated toxoplasmosis, which involves most frequently the lungs but potentially all organs. Failure of an efficient Th1 immune response mainly results from acquired immunosuppression, through HIV infection or immunosuppressive therapy. Both primary acquired and reactivated infections are life-threatening in immunocompromised patients (ICPs). Definitive diagnosis can be obtained by the detection of parasites in blood, cerebrospinal fluid (CSF), bronchoalveolar lavage (BAL) fluid, or virtually any tissue by using PCR, which is the most sensitive method (4).Prevention of CT in patients with HIV is an object of consensus, and guidelines recommend co-trimoxazole (sulfamethoxazole-trimethoprim) chemoprophylaxis in Toxoplasma-seropositive patients when CD4 ϩ cell counts fall below 200 cells/l (4), a prophylactic regimen which also protects patients from Pneumocystis jirovecii pneumonia. Nevertheless, toxoplasmosis remains Citation Robert-Gangneux F, Sterkers Y, Yera H, Accoceberry I, Menotti J, Cassaing S, Brenier-Pinchart M-P, Hennequin C, Delhaes L, Bonhomme J, Villena I, Scherer E, Dalle F, Touafek F, Filisetti D, Varlet-Marie E, Pelloux H, Bastien P. 2015. Molecular diagnosis of toxoplasmosis in immunocompromised patients: a 3-year multicenter retrospective study.

The combination of growth hormone (GH) and recombinant erythropoietin (rEPO) is thought to be used particularly in endurance sports. Our objective was to reproduce a 2‐week administration of rEPO microdoses alone or in combination with GH microdoses (three times a week) on healthy and athletic male subjects and to evaluate if GH had any additional effects compared to EPO treatment alone. The effects of the treatments on hematological parameters and VO2max were studied as well as the detection of GH in serum. While the rEPO microdose regimen was associated with a significant increase in reticulocytes, no clear elevation in hemoglobin concentration (HGB) was observed. Using a correction by plasma volume did not reveal more effects of EPO on HGB. Our results did not show any additional effect when the GH microdoses were co‐administered. In addition, no clear increase in VO2max was observed after treatment, with an elevation in only half the subjects in both groups (EPO and EPO+GH). A clear effect of GH on insulin‐like growth factor I (IGF‐I) was seen but it was lower on procollagen III amino‐terminal propeptide (P‐III‐NP). GH detection using the direct isoform test identified only one subject 24 hours after receiving GH. The GH biomarker test combining IGF‐I and P‐III‐NP was not able to detect the GH administration. However, a longitudinal follow‐up of the intraindividual variations showed a significant increase in IGF‐I 24 and 48 hours after GH administration in most subjects, while the effect of GH microdoses on P‐III‐NP was less straightforward.

Between 2002 and 2004, panels of amniotic fluid containing varying concentrations of Toxoplasma gondii were sent to up to 23 laboratories in France for molecular (PCR-based) detection as part of a national quality assurance initiative in the molecular prenatal diagnosis of toxoplasmosis. Participants were free to enroll and no fees were required. The general level of sensitivity was high, and the rate of false-positive reactions was relatively low. Considerable diversity among PCR methods and primers was revealed. This external quality assurance scheme provided the opportunity to improve laboratory practice and performance, and to increase communication among laboratories involved in making this diagnosis.

A direct detection method for anti-doping control of recombinant human erythropoietin (rHuEPO) abuse in racehorses is proposed. This method involves screening of plasma (or serum) by an enzyme-linked immunosorbent assay specific for human EPO and confirmation in urine samples by characterization of the urinary EPO isoelectric profile. This method was tested on horses that were administered epoetin alpha (rHuEPO) and the hyper-glycosylated form of this drug (darbepoetin alpha).

Blood oxygenation is a fundamental factor in optimising muscular activity. Enhancement of oxygen delivery to tissues is associated with a substantial improvement in athletic performance, particularly in endurance sports. Progress in medical research has led to the identification of new chemicals for the treatment of severe anaemia. Effective and promising molecules have been created and sometimes used for doping purposes. The aim of this review is to present methods, and drugs, known to be (or that might be) used by athletes to increase oxygen transport in an attempt to improve endurance capacity. These methods and drugs include: (i) blood transfusion; (ii) endogenous stimulation of red blood cell production at altitude, or using hypoxic rooms, erythropoietins (EPOs), EPO gene therapy or EPO mimetics; (iii) allosteric effectors of haemoglobin; and (iv) blood substitutes such as modified haemoglobin solutions and perfluorochemicals. Often, new chemicals are used before safety tests have been completed and athletes are taking great health risks. Such new chemicals have also created the need for new instrumental strategies in doping control laboratories, but not all of these chemicals are detectable. Further progress in analytical research is necessary.

In a precedent study we observed that overall adiposity evaluated with the body mass index (BMI) was correlated with plasma viscosity and red blood cells (RBC) aggregation while abdominal obesity as assessed with the waist to hip ratio (WHR) was correlated with hematocrit. We investigated this issue in 129 women (age 15-65 years, BMI: 15 to 44 kg/m 2 , WHR: 0.65 to 1.13, fatness: 12-58%) who were divided into fatness groups: 17 underweight women (BMI <18.5), 75 normal weigh (BMI 18.5-24.9), 11 overweight (BMI 25-29.9), and 26 obese (BMI >30) divided according to WHR into 13 lower body and 13 upper body obese women. Whole blood viscosity significantly increases across obesity classes, and is higher in upper body than in lower body obesity (2.84 ± 0.08 vs 3.29 ± 0.09 mPa.s, p < 0.05). The correlations between whole blood viscosity and BMI (r = 0.383 p < 0.01) and WHR (r = 0.364 p < 0.01) are found again. The former is explained by correlations of BMI with plasma viscosity (r = 0.303 p < 0.01) and red cell rigidity (r = 0.356 p < 0.01) and the latter is only explained by a correlation between WHR and hematocrit (r = 0.524 p < 0.01). BMI is also correlated with RBC aggregation parameters. Actually, when total fatness is evaluated with the percentage of fat (%fat) given by bioimpedance analysis (BIA), the picture is slightly different, since %fat is correlated with whole blood viscosity and RBC aggregation parameters but not with hematocrit, plasma viscosity and red cell rigidity. Fat free mass is also correlated with whole blood viscosity (r = 0.227 p < 0.02) due to a correlation with hematocrit (r = 0.483 p < 0.01) but neither RBC rheology nor plasma viscosity. This study shows that fatness by its own is associated with increased red cell aggregation, that abdominal fat increases blood viscosity due to a rise in hematocrit, and that overall body size as assessed with the BMI is associated with increased plasma viscosity and red cell rigidity.

No abstract