INCREASES OF SICAM-1 DURING NEUTROPENIC PNEUMONIA IN LEUKEMIC PATIENTS

Aggressive chemotherapy of leukemia increases the risk of severe infec tions during treatment-induced myelosuppression. However, the assessme nt of an infectious origin of neutropenic fever is often difficult. Le ukocyte adhesion molecules such as E-selectin, intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) are involved in early inflammatory response. We studied plasma concentrat ions of their soluble isoforms during 48 treatment courses with myeloa blative chemotherapy in 32 leukemic patients. There were 35 febrile ep isodes during neutropenia. Pneumonia was clinically and microbiologica lly documented in 15 cases, six had proven infections but normal chest radiograph, and 14 were classified as fever of unknown origin. Longit udinal studies revealed a sustained increase of sICAM-1 plasma levels associated with pneumonia. Increase of sICAM-1 plasma levels distingui shed patients with pneumonia from those with fever not related to pneu monia (positive predictive value 0.87, negative predictive value 0.94) . Plasma levels of sICAM-1 were elevated in both, fungal and non-funga l pneumonia. Increases of sICAM-1 paralleled first radiographic eviden ce of pulmonary infiltrations in most cases. In contrast, no elevation of sVCAM-1 or sE-selectin was documented during febrile events prior to recovery of leukocyte counts.