Semi-automated image analysis of gel electrophoresis of cerebrospinal fluid for oligoclonal band detection

International audienceDetection of oligoclonal electrophoretic bands in cerebrospinal fluid (CSF) is an important diagnostic tool for Multiple Sclerosis (MS). Electrophoretic profiles are difficult to interpret due to low contrast and artefacts. A semi-automated method to ease analysis and to reduce subjectivity is presented. The method sequentially converts color images to grayscale, realigns bands, removes artifacts, then converts 2D images to a signal, before detecting, thresholding and editing peaks to optimize profiles. Such treated profiles (21 positive and 15 negative) are compared to ground truth analysis of an expert biologist. 16 profiles over 21 are well detected positive and 12 profiles over 15 are detected negative, results seem similar to inter-experts variability reported in literature

Variations of IL2, IL6, TNF alpha plasmatic levels in relapsing remitting multiple sclerosis

We performed a longitudinal analysis of serum IL2, IL6 and TNF alpha concentrations in 40 relapsing remitting MS patients and 20 healthy subjects. Disease activity was quantified by Minimal Record of Disease (M. R. D.) for MS, every 2 or 3 months. IL2, IL6, TNF alpha production was analysed without and with PHA stimulation of whole blood for 2 hours at 37 degrees C. No significant change in IL2 level was found in MS serum. Individual TNF alpha production was significantly increased (P < 0.007) during relapses. The global spontaneous IL6 production was markedly higher in the relapse group than in the control group (p < 0.01) and than in the remission group (P < 0.002) without significant individual variations of cytokine levels regarding the disease activity. Productions of cytokines were enhanced by PHA stimulation, a condition that however suppressed the differences observed without mitogen stimulation. Our data suggest that TNF alpha could be a marker for relapses while IL6 might reflect the global activity of the immune system in MS

Evaluation of semi-automatic image analysis tools for cerebrospinal fluid electrophoresis of IgG oligoclonal bands

Background: IgG concentrations in cerebrospinal fluid generally range from 20 to 45 mg/L. In multiple sclerosis immune reactions lead to intrathecal synthesis of specific IgGs that can be detected in biological fluid samples both quantitatively and qualitatively by isoelectric focusing of supplementary oligoclonal IgG bands. Method: A simple tool, using the MATLAB application, to facilitate and improve isoelectric focusing profile analysis is presented and evaluated in terms of its sensitivity, repeatability and reproducibility. A comparison between human readers and semi-automatic method has also been performed. Results: Results from the semi-automatic method were found to be equivalent or superior to generally employed laboratory methods. Repeatability analysis for semi-automatic processing yielded coefficients of variation (CVs) in the 3–7% range, and using a sample with an estimated IgG concentration of 200 mg/L, four bands were still visible after dilution to 5 mg/L, corresponding to band concentrations of 1.1–1.6 mg/L. Discordances between visual inspection and automatic analysis only appear at threshold levels for interpretation (the gray zone). Conclusion: The semi-automatic method has acceptable performance for routine implementation

Patency and limb salvage after distal prosthetic bypass associated with vein cuff and arteriovenous fistula

OBJECTIVE: To assess the usefulness of vein cuff with or without arteriovenous fistula interposition as adjuvant techniques for improving patency and limb salvage in patients undergoing femorodistal bypass surgery using prosthetic grafts. METHOD: We undertook a retrospective study of 65 consecutive patients treated over a 5-year period with 67 prosthetic femorodistal bypasses with vein cuff, in whom an arteriovenous fistula was constructed at the distal anastomosis in 35. Patients were followed for a median time period of 23 months. RESULTS: Primary patency rates were 68, 53 and 44% at 1, 2 and 3 years, respectively. The corresponding figures for secondary patency, limb survival and patients' survival were 73, 64 and 58% for 1 year, 78, 76 and 73% for 2 years and 72, 66 and 63% for 3 years. None of the criteria analyzed influenced patency or limb salvage on prosthetic bypasses using adjuvant techniques. No statistical differences were found between patency and limb salvage rates in patients for whom the vein cuff was constructed with or without an arteriovenous fistula. But patients who managed with a supplementary arteriovenous fistula had significantly fewer distal residual arteries in the limb (p=0.001). CONCLUSION: Although results in patients treated with adjunctive techniques differed little from those in patients treated with direct prosthetic bypasses procedures, those who eventually had an adjunctive procedure had inferior runoff. This indicates that an arteriovenous fistula might be a valuable supplement in patients with poor runoff who have distal revascularisation using a prosthetic graft