Biochip array technology for new psychoactive substances detection in biological samples: Evaluation of the specificity of the Randox Evidence Investigator®.

BACKGROUND: The need to detect new psychoactive substances in biological samples is of crucial interest. In this paper, the specificity of a benchtop immunoanalyzer commercialized by Randox was evaluated on real patient samples. METHOD: The Evidence Investigator was assessed to screen for NPS on 80 serum and urine samples coming from patients admitted to the emergency department. Targeted NPS were included in various categories such as synthetic cannabinoids, opioids and benzodiazepines. Results were compared with a chromatographic technique coupled with mass spectrometry. RESULTS: No NPS was detected by the reference technique. Concerning immunoanalysis, some piperazines were positive, caused by the presence of medicine containing this chemical structure. Clonazepam and fentanyl derivatives were confirmed in some cases, but sometimes the positivity was explained by other opiates or benzodiazepines, which also explained two samples falsely positive for etizolam. CONCLUSIONS: The Randox Evidence Investigator was rapid and easy to use. It can be used as a first intention but always followed by a more specific technique in order to detect false positive result.

Laboratory evaluation of the new Access ® cytomegalovirus immunoglobulin IgM and IgG assays.

BACKGROUND: Reliable laboratory methods for detecting congenital CMV infection are valuable since CMV infections are asymptomatic and because early detection is important for correct management and counseling of expectant mothers. OBJECTIVES: Compare the Beckman Coulter Access(®) method for the Unicel(®) DxI 800 analyzer with the bioMérieux VIDAS(®) method for two serological markers: CMV IgG and CMV IgM. STUDY DESIGN: Precision was determined with CLSI EP5-A2 protocol. Linearity of the Access CMV IgG was evaluated using selected high positive samples. Performance was assessed by testing non-selected pregnant women, frozen negative and positive samples with recent and old infections. Kinetics of the anti-CMV antibodies response was studied using samples from pregnant women with a recent infection. In a prospective study, 3992 pregnant women were screened for determining prevalence of a primo-infection and CMV IgM non-specific rate. RESULTS: Total CV is lower than 10% and 12% for Access CMV IgG and CMV IgM. The IgG method is linear (R(2)=0.999) with recoveries between 85% and 108%. Correlation between Access and VIDAS CMV IgG is highly significant (P<0.001). Observed agreement was 97.4% for CMV IgG and 93.7% for CMV IgM. Relative sensitivity and specificity was 97.2% and 100% for IgG and 100% and 97.4% for IgM. Kinetics of the antibody response measured with Access methods is significantly higher (P<0.02) when compared with VIDAS and probably easier to interpret. Prevalence of a recent infection was 0.85% and CMV IgM non-specific rate was 2.9%. CONCLUSION: Good sensitivity and specificity and pronounced anti-CMV antibody response make the Access CMV IgG and IgM tests suitable for screening prenatal CMV infections.