Splicing machinery dysfunctions have been associated to CLL

Splicing machinery dysfunctions have been associated to CLL, in particular gene mutations (splicing factor 3B subunit 1) which are present in about 15% of patients . To our knowledge, no gene mutation has ever been detected in CLL. In order to broaden our knowledge on the frequency of splicing mutations in CLL we studied systematically peripheral blood samples with a DNA high-resolution melting analysis test in a cohort of 115 patients diagnosed with CLL () and found only 1 mutated case. We report on a patient diagnosed with chronic lymphocytic leukemia (CLL) whose disease was characterized by marked clinical heterogeneity with episodes of rapid progression and disease stabilization and in which a gene mutation was identified in the absence of other commonly known mutations of CLL. A female patient aged 55 was observed in December 1995 at Sant\' Eugenio hospital in Rome with lymphocytosis. The patient past medical records included: malaria 7 years before, bilateral oophorectomy and hysterectomy due to uterine fibroma, and hypothyroidism under medication with levothyroxine sodium. Laboratory tests disclosed 19,7×10L leukocytes (15,5×10L lymphocytes), hemoglobin 130g/L, 218×10L platelets and normal levels of β2-microglobulin and lactate dehydrogenase. The microscopic analysis of blood smear was consistent with a lymphoproliferative process with multiple mature-like small lymphocytes with scant cytoplasm, regular nucleus (dense gpr40 agonist without nucleoli) and presence of Gümprecht cells. Flow cytometry analysis showed positivity for: CD5, CD23, CD 19 (LLCr score 5) CD38 and ZAP-70, with restriction to lambda light chain. The IGHV status of the patient was unmutated. Karyotype studies showed del13q. Sequencing analysis of the following genes resulted negative for molecular alterations: (Notch homolog 1, translocation-associated [Drosophila]) exon 34, (neuroblastoma RAS viral [v-ras] oncogene homolog) exons 1 and 2, (Kirsten rat sarcoma viral oncogene homolog) exons 1 and 2 and (tumor protein 53) exons 3, 4, 5, 6, 7 and 8 (exons 9–11 were excluded due to low mutation frequency). High resolution melting analysis screening for common mutations of (isocitrate dehydrogenase 1 and 2 [NADP+]) and (exons 12–15) genes resulted as well negative. Clinically, the patient presented only one small cervical lymphadenopathy and no systemic symptoms. CLL was diagnosed as Rai stage I (Rai modified) and Binet stage A according to the International Working group CLL criteria. The patient did not receive treatment until February 1997 (14 months later) when she rapidly progressed presenting splenomegaly and an increased number of lymphadenopathies (Rai II and Binet B), requiring treatment. A course of intravenous fludarabine 25mg/Kg/day for 5 days every 28 days for a total of 5 cycles was prescribed. In June 1997, treatment outcome assessment showed only partial response (50% reduction of lymphadenopathy). In December 1998, disease progression was observed with splenomegaly, increased number of lymphadenopathies and rapid increase of blood lymphocytes (lymphocyte doubling time <12 months). A course of oral chlorambucil 10mg/day with prednisone 25mg/day for 10 days every month was given for a total of 9 cycles. Maintenance therapy was started with subcutaneous interferon α-2b using alternating doses of 1.5MU and 3MU 3 times / week and the patient remained in partial remission for the following 7 years. A third disease progression occurred in March 2006 and a course of fludarabine 25mg/Kg/day was given for a total of 6 cycles, followed by intravenous rituximab 375mg/Kg every 28 days for a total of 4 cycles. Complete remission was achieved at the end of treatment. An additional cycle of rituximab was administered in June 2010, At present, the patient remains in complete remission with residual neutropenia and thrombocytopenia requiring treatment with low dose of prednisone. mutation was confirmed by Sanger sequencing of different blood DNA samples from the patient during her last two follow up visits to the hospital in April and June 2014 (). Unfortunately, DNA from disease onset was not available, making it difficult to correlate the clinical behavior of the disease with the presence of mutation. The anomaly could have been acquired as a late event following different treatment lines or, alternatively, it might have been present at diagnosis in the bulk leukemic population or at sub-clonal level. At diagnosis the patient presented 13q- as a sole genetic abnormality (which has been associated to good prognosis) and overexpression of ZAP-70 which is known to be associated to poor prognosis.