[Accreditation of automated complete blood count by the LH750 Analyzer (Beckman Coulter) in Georges Pompidou Hospital (Paris, France)]. / Vérification de méthode en vue de l'accréditation : exemple de l'hémogramme automatisé sur deux analyseurs LH750 Beckman-Coulter à l'Hôpital européen Georges Pompidou.

Preliminary evaluation of quantitative clinical laboratory measurements is a prerequisite for the accreditation of clinical laboratories, according to the French Committee of Accreditation guidelines following the European reference Standard EN ISO 15189. Numerous papers have been published regarding biochemistry and immunology. However, data are lacking for automated complete blood count accreditation. We report here our experience at Hôpital européen Georges Pompidou hematology laboratory and present the performance characteristics of two mirrored LH750 Beckman-Coulter analysers, including precision, accuracy and uncertainty of measurement.

Trough levels and antibodies to infliximab may not predict response to intensification of infliximab therapy in patients with inflammatory bowel disease.

BACKGROUND: Infliximab is effective for the treatment of refractory inflammatory bowel disease (IBD). Nevertheless, up to 40% of patients lose response to infliximab over time. The aim was to assess the clinical value of measuring infliximab trough levels and antibodies to infliximab (ATI) concentrations in IBD patients who lost response to infliximab therapy. METHODS: We retrospectively studied records of IBD patients who lost response to infliximab therapy. We first assessed clinical responses of different therapeutic strategies that were applied when patients lost response to infliximab and then we looked at the correlation between clinical response and infliximab trough levels and ATI concentrations. RESULTS: Seventy-six IBD patients were included. 31/76 patients (41%) continued infliximab therapy without any modification, 39 patients (51%) had an intensification of infliximab therapy, five patients (7%) had switched to adalimumab therapy, and one patient (1%) underwent surgery. Clinical response was observed in 27 patients (69%) with an intensification of infliximab therapy. There was no significant difference in mean infliximab trough level at inclusion in patients who responded to intensification of infliximab therapy (3.3 ± 4.1 µg/mL) as compared with patients who did not respond (2.3 ± 2.2 µg/mL, P = 0.85). In all, 16/76 patients (22.4%) presented detectable ATI in the serum. Ten ATI-positive patients had an intensification of infliximab therapy and six (60%) demonstrated a clinical response. After intensification of infliximab therapy the ATI concentration decreased in five patients. CONCLUSIONS: In patients with IBD who lose response to infliximab, clinical improvement may occur upon intensification of infliximab therapy, irrespective of infliximab serum concentration or presence of ATI.

Treatment failure with antagonists of TNF-α: mechanisms and implications for the care of patients.

The use of TNF-α antagonists has substantially improved the care of many patients with inflammatory and autoimmune diseases. However, approximately one third of such patients fail to respond well to treatment, regardless of the antagonist used or of the underlying disease. The mechanisms underlying these failures are analyzed in this review, and proposals made concerning how best to adapt therapeutic decisions in these instances.