Switching from HPLC/UV to MEIA for whole blood sirolimus quantitation: comparison of methods.

Sirolimus is a immunosuppressive agent for renal transplant recipients. Monitoring of whole blood sirolimus concentration is necessary in order to improve clinical outcomes. An increasing number of clinical laboratories (4-14% during 2005) are using microparticle enzyme immunoassay (MEIA) for sirolimus quantitation but previous reports indicated a high variability, with a mean difference of 17% for MEIA method vs. high-performance liquid chromatography/ultraviolet (HPLC/UV). This study was aimed at comparing the reliability of MEIA with the HPLC/UV method. Blood samples from transplant patients were processed using both HPLC/UV and MEIA assays. Comparison and Bland-Altman plots, as well as regression analysis and paired t-test were used to compare results of the assays. Concentrations were stratified into three groups and used to investigate whether any observed difference between methods could be influenced by sirolimus concentration. Regression analysis yielded a coefficient of correlation R of 0.9756, the line of best fit being y=0.9832x+0.1976. The statistical analysis showed no difference between the two sets of experimental data. The average percentage difference between the two methods was found to be -0.2+/-19.2%. On the basis of our present results, the tested MEIA assay is able to quantify sirolimus concentration with a clinically acceptable imprecision, similar to that of HPLC/UV method.

Prevalence of abuse of alcohol and other drugs among injured drivers presenting to the emergency department of the University Hospital of Modena, Italy.

Among those drivers responsible for injury-producing traffic crashes in a town of northern Italy (Modena) and its surrounding territory, we evaluated the percentage that was positive for alcohol or other drugs affecting CNS function. A total of 115 crash-responsible injured drivers (90 males and 25 females) consecutively presenting to the emergency department at the University Hospital of Modena were enrolled. A urine sample was requested from each driver; the presence of alcohol or drugs was detected by means of various procedures (enzyme immunoassay, liquid or gas chromatography, mass spectrometry). Among the 115 enrolled drivers, 46 (40%) were positive for at least one drug and/or alcohol. Of these 46 drivers, 66% were positive for a single drug, 25% for two drugs, 9% for three or more drugs. Recent use of marijuana was found most frequently (19% out of the total 115 enrolled drivers), surpassing alcohol (10%), amphetamines (7%) and cocaine (6%); 11 drivers (about 10%) tested positive for benzodiazepines. The majority of drivers positive for benzodiazepines were 41-70 years old, while most drivers positive for alcohol or other drugs were 21-40 years old. Thirty-nine (85%) of the positive injured drivers were males and seven (15%) were females. The present data confirm that a significant percentage of injury-producing traffic crashes involves drivers who are under the influence of drugs of abuse, alcohol, or other drugs affecting the CNS.