ELEVATED LEVELS OF SHED SYNDECAN-1 CORRELATE WITH TUMOR MASS AND DECREASED MATRIX METALLOPROTEINASE-9 ACTIVITY IN THE SERUM OF PATIENTS WITH MULTIPLE-MYELOMA

Sera from 20 myeloma patients and 12 normal controls were analysed for the presence of syndecan-1 and matrix metalloproteinase-9 (MMP-9). Th e level of syndecan-1 in the serum was elevated in 7/20 (35%) myeloma patients whilst 6/19 patients (31%) had decreased serum MMP-9 activity The presence of increased syndecan-1 was associated with decreased se rum MMP-9. Both elevated syndecan-1 and decreased MMP-9 were associate d with higher marrow plasmacytosis, serum beta-2 microglobulin and par aprotein levels. These data provide evidence that the syndecan-1 ectod omain is shed in vivo. Quantitation of serum syndecan-1 may be a usefu l measure of tumour mass and may hare important implications for myelo ma biology.