Format

Send to

Choose Destination
Exp Hematol. 2009 Oct;37(10):1186-1193.e7. doi: 10.1016/j.exphem.2009.07.005. Epub 2009 Jul 17.

JAK2(V617F) allele burden discriminates essential thrombocythemia from a subset of prefibrotic-stage primary myelofibrosis.

Author information

1
Institute of Pathology, Hannover Medical School, 30625 Hannover, Germany.

Abstract

OBJECTIVE:

Among Philadelphia chromosome-negative myeloproliferative neoplasms (Ph(-) MPN), essential thrombocythemia (ET) and the prefibrotic phase of primary myelofibrosis (PMF) represent two subtypes with considerable overlap.

MATERIALS AND METHODS:

In this study, histopathological classification of 490 MPN cases was correlated with the allelic burden of JAK2(V617F) and MPL(W515L).

RESULTS:

Ph(-) MPN entities largely overlap with regard to JAK2(V617F) and MPL(W515L) allele burden, but ET displayed mutant allele burden <50%. PMF with different stages of myelofibrosis all yielded similar JAK2(V617F) allele burden. At initial presentation one-quarter of prefibrotic PMF cases exhibited an allele burden exceeding 50% (38% median JAK2(V617F) alleles, n=102). In ET, its main differential diagnosis, not a single case was found with >40% JAK2(V617F) alleles (median, 24% JAK2(V617F) alleles; n=90; p<0.001). Increase in JAK2(V617F) alleles during follow-up could not be linked to fibrosis or blastic progression but was related to polycythemic transformation in ET. MPL(W515L) was found in 3% of ET and 8% of PMF, with a significantly higher percentage of mutated alleles in fibrotic than prefibrotic PMF (median, 78% MPL(W515L) alleles; p<0.05).

CONCLUSION:

Histopathological categories ET and prefibrotic PMF correlate with significant differences in mutant allelic burden of JAK2(V617F), but not of MPL(W515L) which, by contrast to JAK2(V617F), shows a higher percentage of mutated alleles in fibrotic than in prefibrotic cases. Thus, for Ph(-) MPN in which ET and prefibrotic PMF represent the most probable diagnoses, a JAK2(V617F) allele burden >50% favors a diagnosis of prefibrotic PMF.

PMID:
19616600
DOI:
10.1016/j.exphem.2009.07.005
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center