Evaluación de un nuevo reactivo monoclonal, N-Látex Free Light Chains, para la cuantificación nefelométrica de las cadenas ligeras Kappa y Lambda libres en suero

Abstract

Introduction: Evaluation of testing of serum free light chains Kappa and Lambda (FLC), to collaborate on the essential international standardization of this technique. Its usefulness in diagnosis and follow-up of myeloma, Gammapatías of undeterminated significance (MGUS), amyloidosis, solitary plasmocitomas etc. is amply demonstrated in the literature, the international clinical guidelines include them for the specific diagnosis of the discrasias of plasma cells. Material and methods: We evaluated a new reagent N-Látex CLL for Nephelometry, based on monoclonal antibodies, which leads attached a supplementary reagent specific, which was developed with mouse immunoglobulins. Results: The accuracy and precision of the method evaluated with 3 levels of concentration controls were acceptable. It has been compared this reagent with the existing 30 samples from patients with the nephelometer BNII (Siemens), false positives of the 2nd were overcome. Likewise compared the method by nephelometry (BN II) against turbidimetry (SPA PLUS) the results were favourable to the nephelometry reference technique. In terms of sensitivity and specificity of the evaluated method, ROC curves, with 60 patients were conducted and results with a moderate correlation. Discussion: We believe that the lack of reproducibility in the quantification of the FLC due to factors: high variability between batches of reagents in the same commercial House; differences in the results of the samples with high concentrations of FLC, for not including the checking of antigen excess, and differences in the principles of the used clinical measurement.