Monoclonal expansion of immunoglobulin not-secreting CD5+ CD11c+ CD38+ B-cells in a rare case of chronic lymphoplasmacytoid leukaemia.

Abstract

We present the clinical and immunological features of a rare case of chronic lymphoid leukaemia with lymphoplasmacytoid morphology. The patient was first admitted suffering from weakness, pallor, dyspnoea, marked splenomegaly, hepatomegaly and systemic lymphadenopathy and panhypogammaglobulinaemia. White blood cell count revealed important leukocytosis (220 x 10(9) WBC/l) with 2% neutrophils and 98% lymphoid cells showing lymphoplasmacytoid features, while lymphoid cells of identical morphology severely infiltrated the bone marrow and lymph nodes. The disease, initially controlled by non aggressive chemotherapy over a period of 30 months, later evolved to a clinical and haematological picture suggestive of Richter's syndrome. Immunophenotyping of the leukaemic cells demonstrated a monoclonal expansion of B-cells bearing surface markers of typical CLL (CD5, CD19, CD20, CD21, CD22, CD23, CD24, CD40 and low density IgM+IgD/kappa) and also the CD11c and CD38 antigens. A proportion of these cells expressed activation markers (CD25, CD69 and CD71). Following in vitro activation with TPA or PWM, the cells responded by weak incorporation of 3H-TdR but failed to secrete immunoglobulins. These findings confirm the broad morphological, phenotypical and clinical spectrum of chronic lymphoid leukaemias.