The use of a simple exercise test for the diagnosis of Pneumocystis carinii pneumonia in patients with AIDS.

Because Pneumocystis carinii pneumonia (PCP) is so common among patients infected with the human immunodeficiency virus-1 (HIV-1), a quick, simple test to evaluate for its presence or absence would be helpful. We report our results on the role of an exercise blood gas test as a useful procedure for the detection of Pneumocystis pneumonia in patients with respiratory symptoms who have or who are at risk for developing the acquired immunodeficiency syndrome (AIDS). Results show that a normal exercise test, as defined in the study and in our patient population, eliminated PCP from the differential diagnosis. An abnormal test was most useful in separating out a group of patients who urgently needed a diagnosis because PCP was a likely possibility. There were no significant complications associated with this test.