[Which sample for the transport of mycoplasma, eSwab® or dry swab?] / Quel prélèvement pour le transport des mycoplasmes, eSwab® ou écouvillon sec ?

Mycoplasma hominis (MH) and Ureaplasma urealyticum (UU), belonging to mycoplasmas, are implicated in genital and urinary infections. These bacteria are extremely sensitive to environmental factors but remain detectable by culture methods. This study aimed to compare performance of detection on samples performed on eSwab® or dry swabs. Eighty-five genital samples were prospectively collected on dry- and e-Swab, at the Dynabio Croix-Rousse laboratory (Lyon, France), from January to March 2017, searching for mycoplasma infection. After incubation for 48 hours, cultures were qualitatively and quantitatively analyzed by a single qualified operator. On these samples, 23 specimens sampled on dry swabs were positive for UU and 2 for MH (versus 26 and 4 for eSwab). Quantification on eSwab® and dry swabs were statistically correlated (r=0.9118; and r=0.7155; p< 0.01 respectively) without discrepant results. No sample was double-positive during this study. With an important sensitivity (without alteration of the bacterial quantification) and regarding to the gravity of this infection on at-risk patients, as young and/or pregnant woman, the eSwab® sampling seem to improve the pre-analytic phase. However, the benefice to use these sampling methods for long-term conservations has to be evaluated.

[Focus on preanalytics for Down's syndrome screening during first trimester of pregnancy]. / Dépistage de la trisomie 21 par les marqueurs sériques maternels au premier trimestre Aspect pré-analytique.

The aim of the study is to specify the pre-analytical conditions required for Down's syndrome screening in first trimester by maternal serum markers. The concentration variation of both markers, hCGß and PAPP-A, was analyzed at room temperature, at 4°C and during freezing-thawing cycles. Serum can be kept during 72h between 2 and 8°C with an acceptable bias of 5% for each marker. It can also undergo three freezing-thawing cycles without any variation of results. Preservation at room temperature (between 20 and 25°C) requires an analysis within 24h. From this study, writing recommendations enable to give a precise frame to pre-analytical processing and transport of blood samples, in a field where variations can lead to heavy therapeutic decisions.

Assessment of plasmatic immunoglobulin G, A and M levels in septic shock patients.

Polyvalent immunoglobulin (Ig) therapy has been tested as adjunctive treatment in sepsis and septic shock, but its efficacy is still a matter of debate. This has been explained because clinical trials were mostly performed on small numbers of patients. Moreover, the endogenous level of circulating Ig in patients was never taken into account. In this study, plasmatic Ig classes and protein concentrations were measured at Days (D) 1-2, D3-4 and D5-7 in 62 septic shock patients. At D1-2 as well as at D3-4, patients presented with a significant reduction of plasmatic IgG concentrations. Indeed, at D1-2, 61% of the patients had IgG level below the lowest limit of our age-matched reference values. Plasmatic IgM levels were decreased as well in comparison with reference values from the lab whereas IgA concentrations were not modified. Circulating IgG and IgM concentrations tends to increase overtime. Indeed, at D5-7, most patients (61%) had IgG and IgM levels within the range of normal values. These alterations did not appear to be associated with increased mortality, morbidity or severity after septic shock. However, at D1-2 and D3-4, decreased circulating Ig level was significantly correlated with reduced plasmatic protein concentrations. Overall, our results suggest that an apparent hypogammaglobulinemia is present at D1-2 and D3-4 in septic shock patients, which seems to be related with reduced circulating protein concentration after septic shock. These results need to be confirmed in a larger cohort of patients.