title: Serum tryptase measurements in patients with myelodysplastic syndromes.
abstract: Abnormal differentiation and maturation of hemopoietic cells are characteristic features of myelodysplastic syndromes (MDS). Tryptases (alpha- and beta-type) are lineage-restricted serine proteases primarily expressed in mast cells (MC). We have analyzed expression of tryptase in 89 de novo MDS patients (refractory anemia (RA), n = 30; RA with ringed sideroblasts (RARS), n = 21; RA with excess of blasts (RAEB/RAEB-t), n = 27; chronic myelomonocytic leukemia (CMML), n = 11). Serum levels of total tryptase (alpha - protryptase + beta - tryptase) were measured by FIA. The numbers of tryptase+ cells were determined in paraffin-embedded bone marrow (bm) sections by immunohistochemistry and morphometry. In healthy individuals, serum total tryptase levels ranged between < 1 and 15 ng/ml (5.6 +/- 2.8 ng/ml). Tryptase levels of > 20 ng/ml were detected in 5/22 patients with RA (22.7%), 4/17 with RARS (23.5%), 0/16 with RAEB/RAEB-t, and 3/8 with CMML (37.5%). Thus, serum tryptase concentrations were higher in RA (16.6 +/- 14.3 ng/ml), RARS (12.9 +/- 8.2), and CMML (16.5 +/- 7.6) compared to RAEB/-t (8.7 +/- 3.8). By morphometry, elevated numbers of tryptase+ bm cells were detected in all MDS groups (RA: 139 +/- 131; RARS: 118 +/- 98; RAEB/RAEB-t: 80 +/- 79; CMML: 105 +/- 114 cells/mm2) compared to controls (54 +/- 51 cells/mm2). As assessed by Northern blotting and protein analysis, bm cells in MDS primarily produced alpha-(pro)tryptase, but little or no beta-tryptase. Together, our data show that elevated levels of tryptase are detectable in a group of patients with MDS probably because of an increase in neoplastic (mast) cells producing the enzyme(s). In addition, serum tryptase levels appear to correlate with MDS variants. Follow up studies should clarify whether an elevated tryptase concentration in MDS is of prognostic significance.
authors.affiliation: wolfgang.r.sperr@univie.ac.at
authors.forename: W R
authors.initials: WR
authors.lastname: Sperr
authors.forename: B
authors.initials: B
authors.lastname: Stehberger
authors.forename: F
authors.initials: F
authors.lastname: Wimazal
authors.forename: M
authors.initials: M
authors.lastname: Baghestanian
authors.forename: L B
authors.initials: LB
authors.lastname: Schwartz
authors.forename: M
authors.initials: M
authors.lastname: Kundi
authors.forename: H
authors.initials: H
authors.lastname: Semper
authors.forename: J H
authors.initials: JH
authors.lastname: Jordan
authors.forename: A
authors.initials: A
authors.lastname: Chott
authors.forename: J
authors.initials: J
authors.lastname: Drach
authors.forename: U
authors.initials: U
authors.lastname: Jäger
authors.forename: K
authors.initials: K
authors.lastname: Geissler
authors.forename: A
authors.initials: A
authors.lastname: Greschniok
authors.forename: H P
authors.initials: HP
authors.lastname: Horny
authors.forename: K
authors.initials: K
authors.lastname: Lechner
authors.forename: P
authors.initials: P
authors.lastname: Valent
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002898:Chromosomes, Human, Pair 8; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000201:enzymology* / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D012697:Serine Endopeptidases / Q000097:blood* / Q000235:genetics; D014314:Trisomy; D053802:Tryptases
chemical_list: D012333:RNA, Messenger; D012697:Serine Endopeptidases; D053802:Tryptases