A comparison of leukocyte aggregation, leukocyte migration and skin reactivity to recall antigens in patients with AIDS.

A study was made to evaluate the leukocyte aggregation test (LAT) in patients at risk for acquired immunodeficiency syndrome (AIDS) and with confirmed AIDS using tuberculin, streptococcus and candida as recall antigens. These patients were selected on the basis of their well known absence of delayed hypersensitivity, a fact which should avoid false positive tests. Antigen-induced human peripheral blood leukocyte aggregation was measured quantitatively. The results obtained have been compared with the leukocyte migration inhibition test (LMIT) in patient and control groups. Among the 46 patients, less than 7% were positive for the LAT, whereas more than 50% were LMIT positive (P less than 0.001). These results suggest that there are fewer false positive reactions with LAT which can therefore be considered as a reliable method for assessing CMI in human. Furthermore, a negative LAT correlated well with negative delayed skin tests in more than 90% of the patients for the three antigens. These patients had either an AIDS or an advanced AIDS-related complex (ARC). In only eight of the patients was there a discrepancy in the results of the two tests. A positive LAT and a negative skin test were seen in three cases lacking opportunistic infections (OI), whereas a negative LAT and a positive skin test were found in patients with or without OI. In the latter, a negative LAT could indicate a more advanced stage of disease and hence a poor prognosis.