Elevated tryptase levels selectively cluster in myeloid neoplasms: a novel diagnostic approach and screen marker in clinical haematology.
BACKGROUND
Recent data suggest that tryptase, a mast cell enzyme, is expressed in neoplastic cells in myeloid leukaemias. In several of these patients, increased serum tryptase levels are detectable.


METHODS
We have determined serum tryptase levels in 914 patients with haematological malignancies, including myeloproliferative disorders (n = 156), myelodysplastic syndromes (MDS, n = 241), acute myeloid leukaemia (AML, n = 317), systemic mastocytosis (SM, n = 81), non-Hodgkin's lymphoma (n = 59) and acute lymphoblastic leukaemia (n = 26). Moreover, tryptase was measured in 136 patients with non-neoplastic haematological disorders, 102 with non-haematological disorders and 164 healthy subjects.


RESULTS
In healthy subjects, the median serum tryptase was 5.2 ng mL(-1). Elevated serum tryptase levels were found to cluster in myeloid neoplasm, whereas almost all patients with lymphoid neoplasms exhibited normal tryptase. Among myeloid neoplasms, elevated tryptase levels (> 15 ng mL(-1)) were recorded in > 90% of patients with SM, 38% with AML, 34% with CML and 25% with MDS. The highest tryptase levels, often > 1000 ng mL(-1), were found in advanced SM and core-binding-factor leukaemias. In most patients with non-neoplastic haematological disorders and non-haematological disorders analysed in our study, tryptase levels were normal, the exception being a few patients with end-stage kidney disease and helminth infections, in whom a slightly elevated tryptase was found.


CONCLUSIONS
In summary, tryptase is a new diagnostic marker of myeloid neoplasms and a useful test in clinical haematology.
Sperr
W R
WR
Medical University of Vienna, A-1090 Vienna, Austria. wolfgang.r.sperr@meduniwien.ac.at
El-Samahi
A
A
Kundi
M
M
Girschikofsky
M
M
Winkler
S
S
Lutz
D
D
Endler
G
G
Rumpold
H
H
Agis
H
H
Sillaber
C
C
Jäger
U
U
Valent
P
P
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007951:Leukemia, Myeloid / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008407:Mast Cells / Q000378:metabolism*; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000235:genetics / Q000378:metabolism*; D009196:Myeloproliferative Disorders / Q000235:genetics / Q000378:metabolism*; D053802:Tryptases / Q000235:genetics; D055815:Young Adult
D015415:Biomarkers; D053802:Tryptases