Monitoring of C0 and C2 blood concentrations of cyclosporine on the Roche Hitachi 902 analyzer.

This work provided parameters to perform the widely used enzyme multiplied immunoassay technique (Emit) cyclosporine assay on a Hitachi 902 analyzer. Instrument settings were optimized to arrive at assay characteristics regarding precision, linearity, and lower limit of quantitation among 105 samples from renal transplant recipients receiving cyclosporine. We compared successive results with Emit on a Cobas Integra 400 analyzer with HPLC-UV. We validated a quantitation range of 20-500 ng/mL. For all parameters tested total imprecision <5%. Calibration stability was at least 30 days. The reagent cartridge in the instrument was stable for 2 months between runs. We observed good correlations with other analytical methods. The following equations were obtained: Hitachi 902 = 0.984 Cobas Integra + 2.097; r = 0.998 and Hitachi 902 = 1.019 LC-UV + 3.143; r = 0.974. The mean bias was 1.68% for C0 and 0.02% for C2 concentrations between Hitachi 902 and Cobas Integra 400. Overestimations of 5.61% for C0 and 8.81% for C2 levels assayed with Emit Hitachi 902 were observed compared with LC-UV. The proposed, validated protocol enhanced the versatility of the Emit assay for routine therapeutic drug monitoring. The Hitachi 902 analyzer is an acceptable option for evaluation of C0 and C2 blood cyclosporine concentrations in transplant recipients.

[The EMIT Tacrolimus assay: development of application protocol for Roche Hitachi 902 analyzer]. / Adaptation de la trousse Emit 2000 Tacrolimus sur analyseur Roche Hitachi 902.

Tacrolimus (FK506, Prograf) is a potent macrolide immunosuppressant used for prevention of organ transplant rejection following transplantation. It has been clear for many years that, as a drug with a low therapeutic index and high inter-and intrapatients pharmacokinetic variability, it requires individualized monitoring of blood concentration. Several methods have been developed to monitor tacrolimus; immunoassays, bioassays and LCMSMS. The purpose of this study was to develop application for the EMIT Tacrolimus assay on the Hitachi 902 analyzer. Application protocol on this analyzer is nonexistent. We optimize the programm chemistry parameters to arrive at the following assay characteristics on the Hitachi 902. Assay results were linearly related to the concentration for the wide range which was examinated (0 - 40 ng/mL). We report the precision, accuracy, linearity, sensitivity of this assay. The CV was less than 10%. Calibration stability is at least 21 days. The reagent cartridge in the instrument is stable 2 months between runs. However, specimens from 87 kidney transplant patients were analyzed and results were compared to those from the Abbott MEIA II assay on IMx analyzer. Correlation between the methods was good (r = 0,961). This application for the EMIT 2000 Tacrolimus assay on the Hitachi 902 analyzer enhances the versatility of the immunoassay for routine therapeutic drug monitoring of this immunosuppressant in the clinical setting.

[The biochemical diagnosis of Gaucher disease]. / Le diagnostic biochimique de la maladie de Gaucher.

Gaucher disease is a disease of overload lyosomale which we often met since a score of years. Since 1980 we had to answer several requests for diagnosis of this metabolic disease. Requests emanating primarily from paediatric services. Twelve cases were confirmed within sight of measurement of the intra-leucocytic activity of the beta-glucocerebrosidase, enzyme intervening in the catabolism of the sphingolipides. We report here our experiment in the biochemical diagnosis of Gaucher disease by showing mainly the variability and the extreme heterogeneity of the activity of the beta-glucosidasic during practised measurements. In addition, we expose the problems of diagnosis etiologic which certain patients raise in front of the discordances between the measured enzymatic activity and clinical signs of the disease of left-handed person. In addition, we develop the biological parameters useful to proportion for the monitoring of the treatment which is finally available in our country.

[Evaluation of the assay of serum fructosamine in the surveillance of diabetes in children and adolescents]. / Evaluation du dosage de la fructosamine sérique dans la surveillance du diabète de l'enfant et de l'adolescent.

Serum fructosamine and glycosylated haemoglobin were measured 4 times over 2 month period (1st, 15th, 30th and 60th days) in 40 young diabetics and in 26 controls. A positive correlation was found between these two parameters at the 15th, 30th and 60th days (0.44 less than r less than 0.61, P less than 0.01). There was a milder correlation between glycosylated haemoglobin and fasting glycemia (r = 0.43), between serum fructosamine and mean glycemia of the last 4 weeks (r = 0.38) and between serum fructosamine and 24 h glycosuria (r = 0.39) (P less than 0.05). Serum fructosamine, which reflects the mean glycemia of the last 3 weeks appears as a useful parameter in diabetic control, in association with glycosylated haemoglobin which reflects the mean glycemia of the last 2 months.