JAK2 V617F detected in two B-cell chronic lymphocytic leukemia patients without coexisting Philadelphia chromosome-negative myeloproliferative neoplasms: A report of two cases

The JAK2 V617F mutation has been observed in patients with Philadelphia chromosome-negative myeloproliferative neoplasms (Ph-MPNs), including polycythemia vera, essential thrombocythemia and idiopathic myelofibrosis. This mutation has also been observed in a small number of other myeloid malignancies, such as acute myeloid leukemia, chronic myeloid leukemia and myelodysplastic syndrome. The JAK2 V617F allele has rarely been evaluated in lymphoproliferative disorders. In total, 28 JAK2 V617F-positive B-cell lymphocytic leukemia (B-CLL) patients have previously been reported and all presented with Ph-MPN concomitantly. However, following investigation of the JAK2 V617F mutation in 63 B-CLL patients at the Shanghai First People’s Hospital (Shanghai, China) between January 2008 and December 2012 via allele-specific polymerase chain reaction, two B-CLL patients without a history of Ph-MPN were identified to carry the JAK2 V617F allele.