Zap-70 positive chronic lymphocytic leukemia co-existing with Jak 2 V671F positive essential thrombocythemia: a common defective stem cell?
Essential thrombocythemia (ET) co-existing with chronic lymphocytic leukemia (CLL) is extremely rare. We report two cases of ET with Jak 2 V617F in Zap-70+ CLL. ET is a myeloproliferative stem cell disease. Zap-70 expression in CLL correlates with non-mutated immunoglobulin genes. The occurrence of a less mature CLL in patients with a pluripotential stem cell disease raises the possibility that an initial "trigger hit" occurred in a pre-Jak 2 common early progenitor in these patients. Subsequent additional molecular events accumulated independently following myeloid and lymphoid differentiation, leading to the development of two diseases of likely identical origin but different lineages.
Tabaczewski
Piotr
P
Department of Internal Medicine, Texas Tech University Health Sciences Center, Amarillo, United States.
Nadesan
Sushani
S
Lim
Seah H
SH
D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D053614:Janus Kinase 2 / Q000235:genetics*; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000150:complications* / Q000201:enzymology / Q000235:genetics; D008297:Male; D014411:Neoplastic Stem Cells / Q000201:enzymology*; D013920:Thrombocythemia, Essential / Q000150:complications*; D051746:ZAP-70 Protein-Tyrosine Kinase / Q000235:genetics*
D053614:Janus Kinase 2; D051746:ZAP-70 Protein-Tyrosine Kinase