Use of pleural fluid C-reactive protein in diagnosis of pleural effusions.

The aims of the study were to assess whether C-reactive protein (CRP) is a sensitive marker for discriminating between transudative and exudative and pleural effusions to evaluate whether it can be used to distinguish inflammatory pleural effusions from other types of effusion. Pleural fluid and serum CRP levels were obtained in 97 patients with pleural effusion, using an immunoturbidimetric method (Olympus AU-600 autoanalyser). We compared CRP levels between transudates and exudates, inflammatory effusions and other types of effusion. According to the criteria used, 16 patients were included in the transudate group and 81 patients in the exudate group. Pleural fluid CRP levels were significantly lower in the transudate group (P<0.04; 14.9 +/- 4.9 mg l(-1) and 35.5 +/- 4.9 mg l(-1) respectively). Also, the ratio of pleural fluid to serum was significantly lower in the transudate group (P<0.009; 0.8 +/- 0.5 mg l(-1) and 2.8 +/- 0.7 mg l(-1), respectively). In the exudate group, 35 patients had neoplastic effusions, 10 chronic non-specific pleurisy, 19 tuberculous pleurisy, 16 parapneumonic effusion and one Dressler Syndrome. When these sub-groups were compared, the parapneumonic effusion subgroup CRP levels (mean 89 +/- 16.3 mg l(-1)) were significantly higher than those in the other subgroups, other exudate of neoplastic effusion, tuberculous pleurisy and chronic non-specific effusion and the transudate group (P<0.0001; P<0.0001; P<0.0004 and P<0.0001, respectively). The ratio between pleural fluid and serum CRP was significantly higher in the parapneumonic effusion subgroup than in the neoplastic subgroup (P<0.0002; 6.6 +/- 2.7 mg l(-1) and 1 +/- 0.2 mg l(-1), respectively). Pleural fluid CRP levels > 30 mg l(-1) had a high sensitivity (93.7%) and specificity (76.5%) and a positive predictive value of 98.4%. In the differential diagnosis of pleural effusions, higher CRP levels may prove to be a rapid, practical and accurate method of differentiating parapneumonic effusions from other exudate types. Although the high level of CRP obtained in the exudate group may be due to the number of patients with parapneumonic effusion who were included, the pleural CRP level may also be helpful in discriminating between exudative and transudative pleural effusions.

Application of electrical impedance tomography in diagnosis of emphysema--a clinical study.

In this paper, electrical impedance tomography (EIT) ventilation images from a group of 12 patients (11 patients with emphysema and one patient with only chronic obstructive pulmonary disease (COPD) (chronic bronchitis) and a group of 15 normal subjects were acquired using a Sheffield mark 1 EIT system, at the levels of second, fourth and sixth intercostal spaces. Patients were diagnosed based on CT scans of the thorax, pulmonary function tests and posteroanterior x-ray graphs. One of the patients with emphysema has also a malignant lung tumour. Ventilation-related conductivity changes at total lung capacity (TLC) relative to residual volume were measured quantitatively in EIT images. These quantitative values demonstrate marked differences compared to those values obtained from the EIT images of 15 normal subjects. The EIT images of the patients were also compared with the CT images. In addition to the visual examination of the EIT images a statistical confidence test is applied to compare the images of the patients with the images of the normal subjects. Prior to statistical analysis all images are normalized with TLC to minimize the effect of mismatch between the TLC of different subjects. A normal mean image is created by averaging the normalized images from the normal subjects, at each intercostal space level. Than a 95% confidence interval is defined for each normal mean image. For each image of the patients, a confidence test image, which represents the deviations from the 95% confidence interval of the normal mean image, is created. The regions with emphysematous bulla and parencyhma are detectable in the confidence test images as regions of positive and negative deviations from the confidence interval of the normal mean, respectively. In the test images, it is possible to differentiate emphysematous parenchyma from emphysematous bulla, tumour structure, and COPD. However, the emphysematous bulla, the tumour structure, and COPD result in the same type of defect in the test images and are therefore indistinguishable from each other. In some case, off-plane contributions in the EIT images may result in underestimation of the defects. EIT may be a useful screening device in detecting emphysema rather than a diagnostic tool.

Pulmonary alveolar microlithiasis: review of Turkish reports.

Pulmonary alveolar microlithiasis is a rare disorder, only 173 cases having been reported worldwide. Fifty two cases from Turkey are reported, 49 of which have previously been described only in Turkish publications. The mean age of the patients was 27 (SD 12) years, 34 were male, and 10 were symptomless. In 40 of the 52 cases diagnosis was confirmed histopathologically. Nineteen cases were diagnosed in siblings. This high rate suggests that pulmonary alveolar microlithiasis is a familial disease, which, though rare, is for unknown reasons most common in Turkey.