sodium-pertechnetate-tc-99m and Pneumonia--Pneumocystis

The value of immunoscintigraphy with technetium-99m (99Tcm) labelled anti-granulocyte monoclonal antibody (BW250/183) was studied prospectively in human immunodeficiency virus (HIV-1) antibody-positive patients presenting with fever without localizing symptoms or signs. Twenty-three studies were performed in 23 patients and the results of 99Tcm-anti-granulocyte imaging were compared with the definitive microbiological or cytological diagnosis. Twenty-one patients had an infective cause of pyrexia, one patient had disseminated lymphoma and one Kaposi sarcoma. 99Tcm-anti-granulocyte antibody imaging correctly identified the sites of infection in only five (24%) patients, four of whom had infective colitis (one also had bacterial pneumonia) and one of whom had cellulitis. Sixteen foci of infection were not localized by 99Tcm-anti-granulocyte immunoscintigraphy (false-negative scans). Six of these patients had Pneumocystis carinii pneumonia; other diagnoses in this group included bacterial or fungal pneumonia and bacteraemia secondary to line infections. 99Tcm-anti-granulocyte antibody did not accumulate in the patients with disseminated lymphoma and Kaposi sarcoma (true-negative scans). 99Tcm-anti-granulocyte imaging, therefore, appears useful in identifying extrathoracic infection in HIV-1 positive patients. Its lack of sensitivity for the identification of pulmonary infection means that its role in the investigation of HIV-1 antibody-positive patients with fever without localizing symptoms or signs is limited.

Topics: Adult; AIDS-Related Opportunistic Infections; Antibodies, Monoclonal; Antibody Specificity; Bacterial Infections; False Negative Reactions; False Positive Reactions; Fever of Unknown Origin; Granulocytes; HIV Infections; Humans; Immunoconjugates; Lung Neoplasms; Lymphoma, AIDS-Related; Male; Middle Aged; Mycoses; Pneumonia; Pneumonia, Pneumocystis; Prospective Studies; Radioimmunodetection; Sarcoma, Kaposi; Sodium Pertechnetate Tc 99m; Virus Diseases

Intense thyroidal Ga-67 accumulation was seen in a man with AIDS imaged for suspected Pneumocystis carinii pneumonia. Concurrent Tc-99m pertechnetate thyroid scanning demonstrated absent trapping, helping establish the diagnosis of painless thyroiditis. Occult hyperthyroidism, and not pulmonary infection, may have been responsible for the patient's original presenting symptoms.

Topics: Acquired Immunodeficiency Syndrome; Adult; Diagnosis, Differential; Gallium Radioisotopes; Humans; Male; Pneumonia, Pneumocystis; Sodium Pertechnetate Tc 99m; Thyroiditis, Subacute; Tomography, Emission-Computed, Single-Photon

Technegas, an ultra-fine dry aerosol with prolonged retention in the lungs, can be modified by altering the atmosphere in which the carbon particles are generated. The modified Technegas has much faster clearance from the lung. The half-time pulmonary clearances with modified Technegas were compared to those obtained with conventional 99mTc DTPA aerosol in 50 patients. Interstitial lung disease was suspected in 12 while 38 were infected with the human immunodeficiency virus and suspected of having opportunistic lung infection. In 22 nonsmokers in whom no evidence of active pulmonary pathology was demonstrable, the mean half-time with DTPA was 52.5 min whereas the mean half-time with modified aerosol was 10.1 min. The mean half-time in 14 smokers in whom there was also no evidence of active pulmonary disease was 28.3 min with DTPA and 7.0 min with the modified method. In the 14 patients in whom altered pulmonary permeability was demonstrated by a short DTPA half-time (mean 4.8 min) there was also an accelerated half-time with modified Technegas (mean 2.5 min). It is concluded that the modified Technegas procedure offers a simple but accurate method of identifying individuals having opportunistic infection or other diffuse lung pathology.

Topics: Acquired Immunodeficiency Syndrome; Adult; Aerosols; Female; Graphite; Half-Life; Humans; Lung; Male; Opportunistic Infections; Pneumonia, Pneumocystis; Radionuclide Imaging; Smoking; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Pentetate