Hairy-cell leukaemia variant (HCL-V) is a biologically distinct subtype of hairy-cell leukaemia with a specific clinical and immunophenotypic profile that requires a tailored first-line treatment strategy.
HCL-V typically presents with high lymphocyte counts (lymphocytosis). The circulating cells are nucleolated and monocytopaenia is absent. The immunophenotype is CD25-negative and the BRAF V600E mutation is not detected — features that distinguish HCL-V from classical hairy-cell leukaemia and directly inform the choice of treatment.
Initial management of HCL-V involves a combination of a purine analogue together with an anti-CD20 monoclonal antibody — an approach considered more effective than either agent used alone. Full sequencing, dosing, and scheduling are detailed in the complete protocol.
DOI: 10.1093/annonc/mdv200
HCL-V typically presents with high lymphocyte counts, with the cells being nucleolated and lacking monocytopaenia.
Although HCL-V patients lack the BRAF mutation, TP53 mutations are present in one-third of cases [13].
However, administration of 2-CldA immediately followed by rituximab, typically involving 2-CldA being given at a dose of 0.15 mg/kg on days 1–5, with 8 weekly doses of 375 mg/m2 rituximab beginning day 1, appears to be more effective than 2-CldA alone or rituximab alone and should be considered as the initial treatment of HCL-V patients [IV, B] [38, 63].
View source ↗