Blood Pressure Profile and Hypertensive Organ Damage in COPD Patients and Matched Controls. The RETAPOC Study.

BACKGROUND: Several studies suggest that there is a pathogenic link between chronic obstructive pulmonary disease (COPD) and cardiovascular diseases. On the other hand, increased sympathetic tone has been described in several respiratory diseases. Our objective was to determine whether hypertension mediated by sympathetic overactivity is a mechanism that explains the association between COPD and cardiovascular diseases. METHODS: Prospective nested case-control observational study; 67 COPD patients were matched 1:1 by sex and age to controls with smoking history. 24 hour-blood pressure monitoring, urinary catecholamines and their metabolites measurement, echocardiography, carotid ultrasound examination, nocturnal oximetry and retinography were performed. FINDINGS: classic cardiovascular risk factors and comorbidities were similarly distributed between cases and controls. No significant differences for blood pressure variables (difference for mean systolic blood pressure: -0·13 mmHg; 95% CI: -4·48,4·20; p = 0·94; similar results for all blood presssure variables) or catecholamines values were found between both groups. There was a tendency for lower left ventricle ejection fraction in the COPD cases, that approached statistical significance (64·8 ± 7·4 vs 67·1 ± 6·2, p = 0·05). There were no differences in the retinal arteriovenous ratio, the carotid intima-media thickness, or the number of carotid plaques, between cases and controls. Fibrinogen values were higher in the COPD group (378·4 ± 69·6 vs 352·2 ± 45·6 mg/dL, p = 0·01) and mean nocturnal oxygen saturation values were lower for COPD patients (89·0 ± 4·07 vs 92·3 ± 2·2%, p < 0·0001). INTERPRETATION: Hypertension induced by sympathetic overactivity does not seem to be a mechanism that could explain the association between COPD and cardiovascular disease.

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 / Evaluation of a new monoclonal reagent, N-Látex Free Light Chains, for nefelometric quantification of free light chain kappa and lambda in serum

Introducción. Con la evaluación del ensayo de cadenas ligeras libres en suero Kappa y Lambda (FLC), pretendemos colaborar en la imprescindible estandarización internacional de esta técnica. Su utilidad en el diagnóstico y seguimiento de mielomas, gammapatías de significado incierto (MGUS), amiloidosis, plasmocitomas solitarios etc. está ampliamente demostrada en la bibliografía, las guías clínicas internacionales las incluyen para el específico diagnóstico de las discrasias de células plasmáticas. Material y métodos. Se evaluó un nuevo reactivo N-Látex CLL para nefelometría, basado en anticuerpos monoclonales, que lleva adjunto un reactivo suplementario específico, que fue desarrollado con inmunoglobulinas de ratón. Resultados. La exactitud y precisión del método evaluadas con controles de 3 niveles de concentración fueron aceptables. Se ha comparado este reactivo con el Freelite(R), procesando 30 muestras de pacientes, por el nefelómetro BNII (Siemens), se solventaron los falsos positivos del 2.°. Así mismo, se comparó el método por nefelometría (BN II) frente a turbidimetría (SPA PLUS) los resultados fueron favorables a la nefelometría. En cuanto a sensibilidad y especificidad del método evaluado, se realizaron las curvas ROC, con 60 pacientes y se obtuvieron resultados con una moderada correlación. Discusión. Consideramos que la falta de reproductibilidad en la cuantificación de las FLC existente, se debía a los factores: alta variabilidad entre los lotes de reactivos de la misma casa comercial; diferencias en los resultados de las muestras con elevadas concentraciones de FLC por no incluir el chequeo de exceso de antígeno, y diferencias en los principios de medida de los autoanalizadores utilizados (AU)

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 (AU)