Apport de la biologie et de la clinique dans l'évaluation des intoxications aiguës

Acute poisoning, both intentional and accidental, are common. Fortunately, most of these cases are benign and do not need any particular treatment or only require clinical observation. Conversely in a few cases, there is an actual danger but the rapid initiation of an appropriate elimination technique or antidotal therapy may improve the prognosis. It is thus very important to rapidly identify clinical and paraclinical signs that have been shown to be of value as prognosis factors or severity criterias. Clinical chemistry values and EKG parameters play a prominent role whereas the tox lab role is paradoxically limited. The purpose of this work is to recall some of these evaluation tools.     

Apport de l'étude de l'avidité des IgG spécifiques pour l'exclusion d'une toxoplasmose évolutive: adaptation à l'automate alpha 4®

The study of anti-Toxoplasma gondii IgG avidity of 108 sera from patients affected by toxoplasmosis and 85 sequential sera from pregnant women presenting an acute infection allows to confirm the interest and the pertinence of the Toxo IgG Avidity test (SFRI Laboratoire), entirely automatised on the Alpha 4^® (SFRI Laboratoire). The avidity test of IgG SFRI^® has been compared to a method to date the infection based on a report of titers obtained between 2 different IgG determinations. (Abbott Diagnostic). Sequentials sera have also been studied by determining specific IgG, IgM, and IgA. The results obtained confirm that an Avidity Index (AI) higher or equal to 0.6 corresponds to a toxoplasmosis acquired more than one year before, an AI between 0.3 and 0.6 is characteristic to a toxoplasmosis acquired more than three months and less than one year before and that an AI higher than 0.3 exludes a recent infection of less than 3 months in 97 % of cases. The interest of the study of IgG avidity to exclude a recent infection, notably when a first sample reveals the presence of anti-Toxoplasma gondii IgM, is confirmed.     

Intérêt de l'hémovigilance dans l'amélioration de la démarche diagnostique et dans la prévention des incidents transfusionnels liés à la contamination bactérienne des produits sanguins

Through the hemovigilance system implemented in France in 1994, 185 cases of transfusion reactions due to the bacterial contamination (TRBC) of blood components (BC) have been recorded over 5 years, thus confirming the frequency and severity of bacterial risks in transfusion medicine. Activation of the hemovigilance network and awareness raising among the virus actors involved (clinicians, nurses…) have made it possible to both prevent possible related TRBCs (due to the transfusion of a BC derived from the same donation) and improve case reporting. The first results obtained through the alert system thus developed have led the Agence Française du Sang to assess and better understand, in a joint study, transfusion-related risks as well as determine factors likely to prevent them. Continuous analysis, in real time, of the reported cases have improved prevention strategies at every stage of the transfusion chain, from blood collection to blood component transfusion.     

Place de la cytométrie en flux pour le diagnostic et le suivi des leucémies aiguës

Immunophenotyping has become essential to the diagnosis of acute leukemia, lymphoblastic as well as myeloid. The use of CD45 antibody improves the discrimination of cellular populations and the identification of blast cells.Immunophenotyping allows to define several subgroups, some of them being correlated with cytogenetic or molecular abnormalities. It identifies rare forms of AL.A systematic immunophenotyping of acute leukemia is also interesting for the detection of leukemia-associated phenotypes, which are the basis of the minimal residual disease analysis by flow cytometry.     

Interêt de la détection des papillomavirus humains par hybridation en phase liquide en routine: comparaison avec l'examen cytologique classique pour le dépistage des lésions pré-cancéreuses et cancéreuses du col utérin

Human papillomavirus (HPV) infection, especially by oncogenic types is the major cause of human cervical precancerous and cancerous lesions. HPV detection in routine has given rise to numerous contradictory studies using various and different techniques and is still debated. The aim of the present work is to test the reliability of HPV detection for the screening of cervical lesions, in a series of 2385 unselected women attending cervical screening and in 165 fresh cone biopsy samples. For that, a simple, easy to perform liquid hybridization assay in microtiters, Hybrid Capture (HC II, Digene®) has been used to detect 18 HPV types (5 non oncogenic and 13 oncogenic). In our experience, the general sensitivity of HC II to detect high grade lesions is close to 100 %, with a specificity of 84.7 %, a positive predictive value of 15.3 % and a negative predictive value of 100 %. Classic cytologic examination gives a sensitivity of 87.5 % and a specificity of 93.8%. Thus the HC II assay could be used in routine in association with cytology to improve significantly the screening of cervical lesions.