HAIRY CELL LEUKAEMIA (HCL)

 

BRAF p.(Val600Glu) Variant Testing

The BRAF p.(Val600Glu) variant has been reported to be present in Classic Hairy Cell Leukaemia but not in other peripheral B-cell lymphomas or leukaemias with similar clinical and morphologic features, including VH4-34+ HCL, HCL variant, splenic marginal zone lymphomas or unclassified splenic lymphomas or leukaemias (Tiacci et al. 2011 NEJM 24: 2305-2315, Arcaini et al. 2012 Blood 119:188-191, Xi et al. 2012 Blood 119:3330-3332). The BRAF p.(Val600Glu) variant has been identified in 57% of patients with Langerhan’s cell histocytosis (Badalian-Very et al. 2010 Blood: 116 1919-1923).

BRAF p.(Val600Glu) variant analysis can therefore be used as a tool in the differential diagnosis of Classic Hairy Cell Leukaemia. However, BRAF p.(Val600Glu) variant data MUST be interpreted in combination with clinical and morphologic features.

BRAF p.(Val600Glu) variants are identified by bi-directional DNA sequencing, which will detect variants present at a level of greater than 10%.

Laboratory contact:  Dr. Caroline Wickham 01392 408252 caroline.wickham@nhs.net Clinical contact: Dr. Paul Kerr 01392 402917 paul.kerr1@nhs.net