Cutaneous accumulation of plasmacytoid dendritic cells associated with acute myeloid leukemia: a rare condition distinct from blastic plasmacytoid dendritic cell neoplasm.

A cutaneous infiltrate composed of plasmacytoid dendritic cells may occasionally occur in a patient suffering from a myeloid neoplasm. To date, the clinical and pathological features associated with this event remains poorly characterized. Herein, we report a patient with acute myeloid leukemia who developed pruritic papules or erythematous plaques scattered on the skin. Microscopic examination showed a dermal infiltrate rich in plasmacytoid dendritic cells expressing CD4, CD43, CD68, granzyme B, CD123, CD303 [blood dendritic cell antigen 2 (BDCA-2)], CD2-associated protein (CD2AP) and T-cell leukemia/lymphoma oncogene 1 (TCL1). Our observation illustrates further that cutaneous lesions associated with some myeloid neoplasms, especially those featuring a monocytic component, may be composed of plasmacytoid dendritic cells. Because of differences in clinical, pathological and genetic features, this rare condition should be distinguished from blastic plasmacytoid dendritic cell neoplasm.

Four- and five-color flow cytometry analysis of leukocyte differentiation pathways in normal bone marrow: a reference document based on a systematic approach by the GTLLF and GEIL.

BACKGROUND: The development of multiparameter flow cytometry (FCM) and increasingly sophisticated analysis software has considerably improved the exploration of hematological disorders. These tools have been widely applied in leukaemias, lymphomas, and myelodysplasias, yet with very heterogeneous approaches. Consequently, there is no extensive reference document reporting on the characteristics of normal human bone marrow (BM) in multiparameter FCM. Here, we report a reference analysis procedure using relevant antibody combinations in normal human BM. METHODS: A first panel of 23 antibodies, constructed after literature review, was tested in four-color combinations (including CD45 in each) on 30 samples of BM. After evaluation of the data, a second set of 22 antibodies was further applied to another 35 BM samples. All list-modes from the 65 bone marrow samples were reviewed collectively. A systematised protocol for data analysis was established including biparametric representations and color codes for the three major lineages and undifferentiated cells. RESULTS: This strategy has allowed to obtain a reference atlas of relevant patterns of differentiation antigens expression in normal human BM that is available within the European LeukemiaNet. This manuscript describes how this atlas was constructed. CONCLUSIONS: Both the strategy and atlas could prove very useful as a reference of normality, for the determination of leukemia-associated immunophenotypic patterns, analysis of myelodysplasia and, ultimately, investigation of minimal residual disease in the BM.

Contribution of flow cytometry to the diagnosis of malignant and non malignant conditions in lymph node biopsies.

In order to assess the contribution of FC to the diagnosis of lymph node disorders we retrospectively compared the pathological and the FC diagnosis made in 118 consecutive lymph node biopsies. Pathological diagnosis included non malignant conditions (n = 43), B-cell Non Hodgkin lymphoma (NHL) (n = 30), T-cell NHL (1 case), carcinoma (n = 18), Hodgkin lymphoma (HL) (n = 15), melanoma (n = 2), chronic myelocytic leukemia (n = 12), miscellaneous non-lymphoid tissues (n = 6) and undetermined conditions (n = 2). Among the 116 assessable samples, FC was in agreement with histology in 102 cases (87.9%; 95%CI = 81-93) which included 38 benign conditions (90%; 95% CI = 77-97%), 29 NHL (96.7%; 95% CI = 83-100), 18 carcinomas (100%; 95% CI = 81-100), and 12 HL (80.0%; 95% CI = 52-96). Discrepancies (14 cases) included 3 HL undiagnosed by FC and 2 granulomatous adenitis with an erroneous FC diagnosis of HL. Finally, a malignant condition was suspected only by FC in 5 cases (1 carcinoma, 2 B-cell and 2 T-cell NHL) and subsequently demonstrated by additional diagnostic procedures. In conclusion, this study confirms that FC performed on fresh lymph node samples is a powerful diagnostic tool in patients with malignant lymphoma. A few cases left undiagnosed by classical pathological analysis can be recognized by FC. Carcinoma is readily identified by FC analysis, while some benign conditions and Hodgkin lymphoma can be misdiagnosed with the use of FC, although the potential of FC to properly recognize HL is improving compared to previously reported studies. FC is a useful adjunct to pathological analysis of lymph node specimens.

Role of 2'-2' difluorodeoxycytidine (gemcitabine)-induced cell cycle dysregulation in radio-enhancement of human head and neck squamous cell carcinomas.

BACKGROUND AND PURPOSE: To try to get a better insight on the interaction between dFdC and ionizing radiation at the cellular level, we examined in vitro the effect of dFdC on the cell cycle of two human head and neck squamous cell carcinoma cell lines (SQD9 and SCC61). PATIENTS AND METHODS: Experimental conditions yielding radio-enhancement were used. Confluent cells were incubated with dFdC (5 microM) for different incubation times, washed, pulse-labeled with BrdUrd (10 microM), fixed and then processed for flow cytometry analysis. Alternatively, cells preincubated or not with dFdC were irradiated (5Gy) in drug-free medium, incubated at 37 degrees C for various times and then processed for flow cytometry analysis. RESULTS: In both cell lines, dFdC incubated between 1 and 6 h induced a DNA synthesis inhibition with accumulation of cells in the G1-S boundary followed, when DNA reinitiated, by a synchronous progression of cells throughout the cycle. A slightly different kinetics was observed in the two cell lines. A weak correlation between dFdC radio-enhancement and distribution of cells in the cell cycle was observed. It was also observed that for longer dFdC incubation times, DNA synthesis could reinitiate while cells were still incubated with dFdC. This reinitiation could be correlated with a decrease in the intracellular dFdCTP pool to non-inhibitory levels. Finally in both cell lines, dFdC modified neither the importance nor the kinetics of the radiation-induced G1 delay. CONCLUSIONS: This study provides evidence that gemcitabine used at radio-enhancing concentration induces alteration of cell kinetics and cell redistribution throughout the cell cycle. This effect is cell line-dependent. However, the weak correlation between dFdC radio-enhancement and cell cycle distribution suggests that the cell cycle effect does not constitute the most important mechanism of interaction with ionizing radiation. Our study also indicated that in the two cell lines studied, a modulation of the G1-S checkpoint was not implicated in enhancement of radiation response by dFdC.

Immunologic and other biological parameters as a function of smoking status and of residence in areas differing in terms of air pollution.

In the industrial region of La Louvière (Belgium), healthy persons, presenting at a consultation of preventive medicine, showed differences as a function of smoking and of residence in one of four areas differing in sources of emissions, population density and green zones. Smokers had significantly (P/=2.25, significantly so for the Power Station-Landfill area. A non-significant but consistent trend towards higher lymphocyte and CD8 lys counts and higher complement C3c serum levels further suggested an association between residence in a more polluted area and immunologic features. The number of CD3+CD56+ lys microl(-1), reported to be increased in cancer patients, showed a negative correlation with the CD4/CD8 ratio (r(2)=0.132, P<0.0001).

Immunophenotypic clustering of myelodysplastic syndromes.

Myelodysplastic syndromes (MDSs) are heterogeneous diseases of bone marrow (BM) cell precursors for which immunophenotypic characterization is still considered irrelevant despite the accuracy and sensitivity of flow cytometry techniques. The aim of this study was to determine whether immunophenotypic abnormalities could be defined in MDSs and could correlate with the French-American-British classification and cytogenetics. Analysis was performed on 275 BM samples (207 MDS patients, 68 controls) and 25 control blood samples. Immunophenotyping was based on a primary gating of blast cells, monocytes, and granulocytes according to CD45 antigen expression and side scatter light diffraction. Immunophenotypic hierarchical clustering was performed to analyze the results. The data obtained show that (1) immunophenotypic clustering partly discriminates patients with refractory anemia with excess blasts/refractory anemia with excess blasts in transformation (RAEB/RAEB-T), chronic myelomonocytic leukemia (CMML), and refractory anemia/refractory anemia with ring sideroblasts (RA/RARS) for CD45(lo) blast cells and patients with RA/CMML, RARS, and RAEB/RAEB-T for CD45(hi)/side scatter(hi) (SS(hi)) granulocytes; (2) the most discriminating markers were CD16, CD34, CD36, CD38, CD71, and HLA-DR for blast cells and CD11b, CD13, CD33, CD36, CD38, CD71, and HLA-DR for CD45(hi)/SS(hi) granulocytes; (3) clusters related to CD34 expression were associated with high levels of blast cells on BM smear; (4) clusters related to high levels of CD36 expression on CD45(lo) blast cells and CD45(hi)/SS(hi) granulocytes were associated with a poor International Prognosis Scoring System score; and (5) high levels of CD71 expression on CD45(hi)/SS(hi) granulocytes were associated with the RARS category. These results show a close relationship between immunophenotypic abnormalities and BM dysplasia and suggest that flow cytometry could be a future tool for the characterization of MDSs.

Clinical and biologic features of CD4(+)CD56(+) malignancies.

CD4(+)CD56(+) malignancies are rare hematologic neoplasms, which were recently shown to correspond to the so-called type 2 dendritic cell (DC2) or plasmacytoid dendritic cells. This study presents the biologic and clinical features of a series of 23 such cases, selected on the minimal immunophenotypic criteria defining the DC2 leukemic counterpart, that is, coexpression of CD4 and CD56 in the absence of B, T, and myeloid lineage markers. Clinical presentation typically corresponded to cutaneous nodules associated with lymphadenopathy or spleen enlargement or both. Cytopenia was frequent. Circulating malignant cells were often detected. Massive bone marrow infiltration was seen in 20 of 23 (87%) patients. Most tumor cells exhibited nuclei with a lacy chromatin, a blastic aspect, large cytoplasm-containing vacuoles or microvacuoles beside the plasma membrane, and cytoplasmic expansions resembling pseudopodia. Other immunophenotypic characteristics included both negative (CD16, CD57, CD116, and CD117) and positive (CD36, CD38, CD45 at low levels, CD45RA, CD68, CD123, and HLA DR) markers. The prognosis was rapidly fatal in the absence of chemotherapy. Complete remission was obtained in 18 of 23 (78%) patients after polychemotherapy. Most patients had a relapse in less than 2 years, mainly in the bone marrow, skin, or central nervous system. Considering these clinical and biologic features, the conclusion is made that CD4(+)CD56(+) malignancies constitute a genuine homogeneous entity. Furthermore, some therapeutic options were clearly identified. Finally, relationships between the pure cutaneous indolent form of the disease and acute leukemia as well as with the lymphoid/myeloid origin of the CD4(+)CD56(+) malignant cell are discussed.