EVALUATION OF POSSIBLE INTERFERENCE OF ANTIINFLAMMATORY DRUGS UPON SCINTIGRAPHIC IMAGING WITH MACROPHAGE TARGETING TC-99M-J001X - EFFECTS OF METHYLPREDNISOLONE, DEXAMETHASONE, INDOMETHACIN AND METHOTREXATE

J001X, an acylated poly-(1,3)-galactoside isolated from Klebsiella pne umoniae proteoglycan, has been developed to target cells from the mono cyte-macrophage lineage. Recent experimental work and initial clinical trials have proved the potential of this molecule labeled with Tc-99m for the scintigraphy of inflammatory foci. In a model of radiation-in duced inflammation in pigs, the scintigraphic contrast was observed to be very sensitive to a single injection of methylprednisolone given 1 2 h before scintigraphy. The present study was undertaken to confirm t his effect and to estimate the possible interference of various anti-i nflammatory agents on the in vivo targeting of macrophages by J001X. M ethylprednisolone, dexamethasone, indomethacin and methotrexate used a t an immunosuppressive dose were tested to assess the possible risk of false-negative examinations in patients thus treated. Analysis of the results indicated that among the four drugs tested, only methylpredni solone at 0.5-1 mg/kg could interfere with J001X scintigraphy.