Konoplev, S.Lu, X.Konopleva, M.Jain, N.Ouyang, J.Goswami, M.Roberts, K.Valentine, M.Mullighan, C.Bueso-Ramos, C.Zweidler-McKay, P.Jorgensen, J.Wang, S.2018-06-252018-06-252017American Journal of Clinical Pathology, 2017; 147(4):357-3630002-91731943-7722http://hdl.handle.net/2440/113046Cytokine receptor-like factor 2 ( CRLF2 ) rearrangement is found in approximately 50% of pediatric Ph-like B-cell acute lymphoblastic leukemia (B-ALL), and around 50% of CRLF2 + cases harbor JAK mutations. We analyzed CRLF2 expression and studied its correlation with CRLF2 rearrangement in adult patients with B-ALL.Multiparameter flow cytometry (MFC) was performed consecutively in 126 patients.CRLF2 overexpression was detected in 30 (27%) patients, 28 (41%) of 69 patients with B-ALL not otherwise specified, 14 (21%) of 67 untreated patients, and 16 (27%) of 59 patients with relapsed B-ALL, with the highest among Hispanic patients (25/55, 45%). Of CRLF2+ cases, 21 (100%) of 21 cases showed CRLF2 rearrangement by fluorescence in situ hybridization, preferentially involving IGH@CRLF2 (15/15). The entire coding region of JAK2 was sequenced in 14 patients with CRLF2+ B-ALL, and nine (64%) were positive for JAK2 mutations.MFC allows a rapid, inexpensive, and reliable detection of B-ALL with CRLF2 rearrangement that would further facilitate testing for JAK2 mutations for targetable therapy.en© American Society for Clinical Pathology, 2017. All rights reserved.B-lymphoblastic leukemia/lymphoma; BCR-ABL1–like; Ph-like B-ALL; CRLF2; Flow cytometry; FISH; JAK2 mutationJournal article003008343210.1093/AJCP/AQX0050004040159000022-s2.0-85019601295359173Mullighan, C. [0000-0002-1871-1850]