Diagnostic value of an antibody enzyme-linked immunosorbent assay using affinity-purified antigen in an area endemic for melioidosis.

Melioidosis, an infection caused by Burkholderia pseudomallei, is endemic in southeast Asia. The septicemic form of melioidosis is the leading cause of death from nonhospital-acquired septicemia in the northeastern part of Thailand. A major factor that contributes to the high mortality is the delay in isolation and identification of the causative organism. The present study was undertaken to evaluate the use of enzyme-linked immunosorbent assays based on an immunoaffinity-purified antigen for detecting specific IgG and IgM antibodies to this organism as a rapid serodiagnostic method for melioidosis. The diagnostic value of these tests was evaluated in an actual clinical situation in an area endemic for melioidosis. The specificity of specific IgG test (82.5%) and the specific IgM test (81.8%) were significantly better than that of the indirect hemagglutination (IHA) test (74.7%). The sensitivity of the specific IgG assay (85.7%) was higher than that of the IHA test (71.0%) and the specific IgM test (63.5%). Specific IgG antibody was detected in a majority of septicemic melioidosis (87.8%), as well as in localized forms (82.6%). The specific IgG test was also better than the specific IgM test and the IHA test in identifying acute melioidosis cases in the first five days after admission. In addition, the IgG antibody level to this antigen remained high over a period of more than five years in those who had recovered from melioidosis and remained clinically free of the disease. These results indicate that the detection of specific IgG antibody is clinically useful for the diagnosis of acute melioidosis in an endemic area.

Toxoplasma infection in healthy persons and in patients with HIV or ocular disease.

Toxoplasma infection is associated with acquired immune deficiency syndrome (AIDS), pregnancy, chorioretinitis, etc. Since the number of AIDS patients is increasing rapidly in Thailand and there are few reports about T. gondii immune status in this country. Toxoplasma-specific IgG and IgM antibodies (Ab) were determined in healthy persons and patients with different symptoms who were suspected of toxoplasmosis. Specific IgG Ab were detected in 3.2% of healthy persons, 12.5% of patients with ocular disease and in 42.5% in HIV positive patients. Only 3.1% of patients with ocular disease were positive for specific IgM Ab. No specific IgM Ab were found in the other samples studied.

Leiomyomas of the lower respiratory tract: a case report.

A rare case of leiomyoma of the left main bronchus in a 16-year-old female has been reported. Of the pulmonary leiomyomas reported, 18.3 per cent were found in the trachea, 33.8 per cent in the bronchi and 47.9 per cent in the parenchyma. Bronchial lesions tend to produce symptoms due to partial or complete obstruction of the affected bronchus, whereas, over 90 per cent of parenchymal lesions which are more common in women, are asymptomatic and usually discovered on routine chest radiographs. Tracheal lesions may present as bronchial asthma. The correct diagnosis is not usually made until the lesion has been resected. However, early and correct diagnosis may be made in suspicious cases by histological examination of bronchoscopic biopsy specimens or frozen section material obtained at thoracotomy. The surgical approach to these tumors is conservative but lobectomy or pneumonectomy is often necessary because of secondary pulmonary destruction.

DNA content by image analysis. An accurate discriminator of malignancy in pericardial effusions.

DNA analysis was performed on 20 cytologically equivocal pericardial effusions to determine if it would be a useful ancillary technique in identifying malignancy. Ploidy determination by interactive image analysis showed single diploid DNA peaks, with no cells > 5c, in all eight reactive cases studied. The reactive cases had a mean proliferation index of 1.3. All 12 malignant cases studied had cells with DNA content > 5c. A dominant DNA peak at 2c was present in 25%, dominant aneuploid stem lines were present in 25%, and multiple stem lines were present in 50% of the malignant cases. By image analysis, the presence of DNA content > 5c was both sensitive and specific for detecting malignancy in the group of pericardial effusions evaluated.

Diagnostic value of bronchoalveolar lavage and postbronchoscopic sputum cytology in peripheral lung cancer.

The objective of this study was to evaluate the value of bronchoalveolar lavage (BAL) and postbronchoscopic sputum cytology in diagnosing peripheral lung cancer. We performed a prospective study in 55 patients with lesions on chest radiographs who were suspected of having lung cancer and had non-endoscopically visible lesions on fiberoptic bronchoscopy. The sequence of procedures in all cases was BAL and transbronchial forceps biopsy. The final diagnosis of these patients were primary lung cancer in 30 patients, metatastic lung cancer in five and benign diseases in 20. In the primary lung cancer group, BAL was positive for malignant cells in 14 of the 30 patients (46.7%). In seven (50%) of these patients, the cell type diagnosed by BAL agreed with the final diagnosis. The diagnostic yield of BAL was influenced by the size and segmental location of the lesion. Bronchoalveolar lavage provided a higher diagnostic yield (46.7%) than transbronchial biopsy (16.7%). In five patients with metastatic lung cancer and 20 patients with benign disease, BAL gave negative results in all. Postbronchoscopic sputum cytology was positive in only two of the 26 patients (7.7%) from whom samples could be obtained. Bronchoalveolar lavage cytology proved to be a valuable diagnostic tool in detecting peripheral, primary lung cancer. Postbronchoscopic sputum cytology provided no significant additional information.