Linfocitosis B policlonal persistente: estudio de 35 casos / Persistent polyclonal B-cell lymphocytosis: study of 35 cases

Fundamento y objetivo: La linfocitosis B policlonal persistente (LBPP) es una entidad muy poco frecuente que se relaciona con el tabaquismo e incide especialmente en mujeres. Cursa con aumento de IgM sérica, asociación al haplotipo HLA-DR7, anomalías citogenéticas y múltiples reordenamientos de IgH/BCL-2. Todavía no está clara su naturaleza premaligna o benigna. El objetivo de este trabajo fue analizar las características de la LBPP con especial interés en su evolución. Pacientes y método: Se han estudiado retrospectivamente 35 LBPP de 5 hospitales catalanes. Se realizó una valoración morfológica de las extensiones de sangre por los miembros del Grup Català de Citologia Hematològica (GCCH) en un microscopio de 16 cabezales y se analizaron los datos clínicos y biológicos. Resultados: La LBPP se presentó, en la mayoría de los casos, como linfocitosis en mujeres fumadoras. El distintivo morfológico es la presencia de linfocitos de aspecto activado, en ausencia de enfermedades víricas recientes, y de linfocitos bilobulados y/o hendidos, y algunos con bolsillos nucleares observados por ultraestructura. En la mayoría de los casos estudiados se detectó: aumento policlonal de IgM, expresión del haplotipo HLA-DR7, anomalías cromosómicas como i(3)(q10) y múltiples reordenamientos de IgH/BCL-2. Con una mediana de seguimiento de 70,7 meses, 34 de los 35 pacientes permanecen asintomáticos y vivos, uno falleció por un adenocarcinoma de pulmón y otro desarrolló un linfoma folicular, sin demostración de relación alguna entre éste y la LBPP. Conclusiones: La LBPP presenta un curso estable y asintomático, y se acompaña con frecuencia de alteraciones genéticas. Se desconoce si es una situación premaligna, a semejanza de las gammapatías monoclonales de significado incierto. Por ello, es fundamental una correcta interpretación de la linfocitosis y un seguimiento evolutivo (AU)

Background and objectives: Persistent polyclonal B-cell lymphocytosis (PPBL) is a rare entity, presenting especially in adult smoker women. It is characterized by an increase of serum IgM, DR7-HLA haplotype,cytogenetic abnormalities and multiple IgH/BCL-2 earrangements. To date, it has not been elucidatedwhether this is a benign or premalignant disorder. We analyzed the PPBL characteristics with especial attention to its evolution.Patients and methods: Thirty-five PPBL patients from 5 hospitals in Catalonia were retrospectivelyanalyzed. A simultaneous morphologic review of the blood smears was performed by members of the GCCH in a 16 multiple-observer optic microscope. Clinical and biological data were also analyzed. Results: PPBL presents in the majority of cases with persistent polyclonal B-cell lymphocytosis and affects primarily smoker women. The morphologic hallmark, in absence of viral infections, is the presence of activated lymphocytes with bilobulated and/or cleaved nuclei, and nuclear pockets in theultrastructural study. Increased serum IgM, HLA-DR7 haplotype, chromosomal abnormalities such asi(3)(q10) and multiple IgH/BCL-2 rearrangements were detected. Thirty-four out of 35 patients are alive after a median follow up of 70.7 months. One patient died because of lung adenocarcinoma and another developed a follicular lymphoma without relation to PPBL.Conclusions: PPBL has an asymptomatic and stable evolution, although it frequently presents genetic abnormalities. It remains unknown whether it is a premalignant entity, similar to monoclonal gammopathies of unknown significance. Hence, accurate cytologic diagnosis and follow-up are essential (AU)

[Persistent polyclonal B-cell lymphocytosis: study of 35 cases]. / Linfocitosis B policlonal persistente: estudio de 35 casos.

BACKGROUND AND OBJECTIVES: Persistent polyclonal B-cell lymphocytosis (PPBL) is a rare entity, presenting especially in adult smoker women. It is characterized by an increase of serum IgM, DR7-HLA haplotype, cytogenetic abnormalities and multiple IgH/BCL-2 rearrangements. To date, it has not been elucidated whether this is a benign or premalignant disorder. We analyzed the PPBL characteristics with especial attention to its evolution. PATIENTS AND METHODS: Thirty-five PPBL patients from 5 hospitals in Catalonia were retrospectively analyzed. A simultaneous morphologic review of the blood smears was performed by members of the GCCH in a 16 multiple-observer optic microscope. Clinical and biological data were also analyzed. RESULTS: PPBL presents in the majority of cases with persistent polyclonal B-cell lymphocytosis and affects primarily smoker women. The morphologic hallmark, in absence of viral infections, is the presence of activated lymphocytes with bilobulated and/or cleaved nuclei, and nuclear pockets in the ultrastructural study. Increased serum IgM, HLA-DR7 haplotype, chromosomal abnormalities such as i(3)(q10) and multiple IgH/BCL-2 rearrangements were detected. Thirty-four out of 35 patients are alive after a median follow up of 70.7 months. One patient died because of lung adenocarcinoma and another developed a follicular lymphoma without relation to PPBL. CONCLUSIONS: PPBL has an asymptomatic and stable evolution, although it frequently presents genetic abnormalities. It remains unknown whether it is a premalignant entity, similar to monoclonal gammopathies of unknown significance. Hence, accurate cytologic diagnosis and follow-up are essential.

Observation versus antiplatelet therapy as primary prophylaxis for thrombosis in low-risk essential thrombocythemia.

The effectiveness of antiplatelet therapy as primary prophylaxis for thrombosis in low-risk essential thrombocythemia (ET) is not proven. In this study, the incidence rates of arterial and venous thrombosis were retrospectively analyzed in 300 low-risk patients with ET treated with antiplatelet drugs as monotherapy (n = 198) or followed with careful observation (n = 102). Follow-up was 802 and 848 person-years for antiplatelet therapy and observation, respectively. Rates of thrombotic events were 21.2 and 17.7 per 1000 person-years for antiplatelet therapy and observation, respectively (P = .6). JAK2 V617F-positive patients not receiving antiplatelet medication showed an increased risk of venous thrombosis (incidence rate ratio [IRR]: 4.0; 95% CI: 1.2-12.9; P = .02). Patients with cardiovascular risk factors had increased rates of arterial thrombosis while on observation (IRR: 2.5; 95% CI: 1.02-6.1; P = .047). An increased risk of major bleeding was observed in patients with platelet count greater than 1000 x 10(9)/L under antiplatelet therapy (IRR: 5.4; 95% CI: 1.7-17.2; P = .004). In conclusion, antiplatelet therapy reduces the incidence of venous thrombosis in patients with JAK2-positive ET and the rate of arterial thrombosis in patients with associated cardiovascular risk factors. In the remaining low-risk patients, this therapy is not effective as primary prophylaxis of thrombosis, and observation may be an adequate option.

Beta2-microglobulin is a better predictor of treatment-free survival in patients with chronic lymphocytic leukaemia if adjusted according to glomerular filtration rate.

Even in the era of newer and sophisticated prognostic markers, beta(2)-microglobulin (B2M) remains a simple but very powerful predictor of treatment-free survival (TFS) and overall survival (OS) in patients with chronic lymphocytic leukaemia (CLL). However, B2M levels are heavily influenced by the patient's glomerular filtration rate (GFR) and this study aimed to evaluate whether GFR-adjusted B2M (GFR-B2M) had improved prognostic value compared to unadjusted B2M in a cohort of over 450 consecutive CLL patients from two separate institutions. Multivariate analysis identified a significantly shorter TFS in patients who were ZAP-70 + (P < 0.001), with increased GFR-B2M (P < 0.001), and del(11q) or del(17p) as detected by fluorescence in situ hybridization (FISH; P < 0.001). When OS was evaluated by multivariate analysis, age 65 years or older (P < 0.001) and poor risk FISH abnormalities (P < 0.001) had a confirmed adverse prognostic impact, but the predictive value of GFR-B2M was lost in the validation analysis. In all survival models, B2M did not attain independent significance unless GFR-B2M was eliminated from the analysis. In conclusion, GFR-B2M is a better predictor of TFS than unadjusted B2M in CLL patients.

Biodistribution, long-term survival, and safety of human adipose tissue-derived mesenchymal stem cells transplanted in nude mice by high sensitivity non-invasive bioluminescence imaging.

Cultivated murine bone marrow mesenchymal stem cells (MSCs) frequently accumulate chromosome abnormalities, become oncogenically transformed, and generate sarcomas when transplanted in mice. Although human MSCs appear to be more resistant, oncogenic transformation has also been observed in MSCs cultivated past the senescence phase. Cell therapy for tissue regeneration using human autologous MSCs requires transplantation of cells previously expanded in vitro. Thus, an important concern is to determine if oncogenic transformation is a necessary outcome of the expansion procedures. We have analyzed the proliferation capacity, organ colonization, and oncogenicity of enhanced green fluorescent protein and luciferase-labeled human adipose tissue-derived mesenchymal stem cells (hAMSCs), implanted in immunocompromised mice during a prolonged time period (8 months) using a non-invasive bioluminescence imaging procedure. Our data indicates that the liver was the preferred target organ for colonization by intramuscular or intravenous implantation of hAMSCs. The implanted cells tended to maintain a steady state, population did not proliferate rapidly after implantation, and no detectable chromosomal abnormalities nor tumors formed during the 8 months of residence in the host's tissues. It would appear that hAMSCs, contrary to their murine correlatives, could be safe candidates for autologous cell therapy procedures since in our experiments they show undetectable predisposition to oncogenic transformation after cultivation in vitro and implantation in mice.

Acute erythroid neoplastic proliferations. A biological study based on 62 patients.

BACKGROUND AND OBJECTIVES: The terms acute erythroleukemia and AML-M6 are defined in the FAB classification as proliferations of dysplastic erythroid elements mixed with blasts of myeloid origin, but pure erythroid leukemias are not included. The recent WHO classification has a category of acute myeloid leukemia not otherwise categorized, which includes acute erythroid leukemia (M6) of two subtypes: M6a-erythroleukemia (erythroid/myeloid) and M6b-pure erythroid leukemia. The aims of this co-operative study were to discover the incidences of these different subtypes, and pay special attention to the morphology of these entities. DESIGN AND METHODS: We reviewed a series of 62 patients with erythroid neoplastic proliferations. Previous medical history, age, sex, peripheral blood and bone marrow cell counts, cytochemical stains, immunophenotype, and cytogenetics were evaluated at presentation. We analyzed the incidence of erythrocyte, leukocyte and platelet abnormalities in the peripheral blood. In bone marrow we analyzed dysplastic features of erythroblasts, granulocytic elements and the megakaryocytic lineage. RESULTS: Fifty-three patients met the criteria of M6a subtype of the WHO classification, and 2 were classified as having pure erythremia (M6b); 7 cases could not be classified according to the WHO criteria. Fifty-five patients presented with de novo acute leukemia, and seven patients had secondary acute leukemia. The most frequent dysplastic features in blood smears were: schistocytes, tear-drop and pincered cells in erythrocytes; hypogranulation and hyposegmentation in leukocytes; gigantism and hypogranulation in platelets. In bone marrow, megaloblastic changes, multinuclearity, karyorrhexis and basophilic stippling in erythroblasts; hypogranulation and gigantism in granulocytic series, and micromegakaryocytes and unconnected nuclei in megakarocytes were the most dysplastic features. A positive PAS reaction and increase of bone marrow iron with ring sideroblasts were common features. Trilineage dysplasia was present in 54% of cases. Dysplastic features in granulocytic elements were absent in 26% of patients and minimal erythroblastic dysplasia was observed in seven patients. A complex karyotype was seen in 27% of patients; chromosomes 5 and 7 were the most frequently involved. INTERPRETATION AND CONCLUSIONS: De novo acute erythroid leukemia was more frequent than secondary cases in our series. The most frequent type of acute erythroid proliferation was the WHO M6a subtype and the least the pure erythroid leukemia. We found a group of seven patients (11%) who could not be classified according to the WHO criteria. Morphologic findings of erythrocytes in peripheral blood, such as schistocytes, tear-drop and pincered cells, were outstanding features. Morphologic aspects remain one of the most important tools for diagnosing these entities.