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Biomedical subjects

A Orfao

Publications and source records attributed to A Orfao.

At least 199 records · Page 11Linked to original sources
PubMed1990

[Usefulness of the immunologic phenotype in the diagnosis of chronic lymphoproliferative syndromes with splenomegaly as the dominant clinical manifestation].

From a total number of 221 patients with leukaemic lymphoproliferative syndromes studied at the Hospital dos Capuchos, in Lisbon, seven patients whose cell morphology differed from that of "classical" lymphoproliferative syndromes were separated; marked splenomegaly without lymph node enlargement was present in all of them. Immunophenotypic studies confirmed B-cell origin of the lymphoproliferation in the seven patients. Small lymphocytes with mature appearance predominated in three of these cases, presenting as: a) the only cell population (with immunophenotype RR+, FMC7-, CD5+), b) along with a significant amount of prolymphocytes (RR+, CD5+, FMC7+), c) accompanying a population of cells with lymphoplasmacytoid differentiation (RR-, CD5-, CD38+, associated to serum monoclonal IgM). Those data strongly suggested that these three lymphoproliferative syndromes corresponded, respectively, to a classic B-cell chronic lymphocytic leukaemia, a chronic lymphocytic leukaemia with prolymphocytes, and an immunocytoma. In three other cases the morphology of the proliferating cells was intermediate between prolymphocytes and hairy cells (i.e., variant hairy cells) and they strongly reacted with monoclonal antibodies FMC7 and LeuM5 (CD11c), showing low positivity with antigens CD5 and CD25, in the absence of receptors for mouse red blood cells. The remaining B-cell lymphoproliferative syndrome studied had small centrocytes in peripheral blood, their phenotype being RR-, CD5+, FMC7+/-, CD10+ and CD38+, which suggested a centrofollicular lymphoma with leukaemic expression. In summary, the present study seems to confirm the heterogeneity of the chronic lymphoproliferative syndromes showing splenomegaly as an outstanding clinical feature. Immunophenotype along with cell morphology are important in the differential diagnosis, especially whenever splenectomy cannot be carried out, in order to choose the appropriate therapy.

Antigens, Differentiation↗
PubMed1990

Surface phenotype and immunoglobulin levels in B-cell chronic lymphocytic leukaemia.

The aim of the present study is to analyze the relationship between serum immunoglobulin (Ig) levels and the immunological phenotype and the clinicohaematological features of B-cell chronic lymphocytic leukaemia (B-CLL) in a series of 126 patients. Eighty-eight of the cases (70%) had a decreased concentration of at least one Ig. IgM and IgA were the most frequently decreased (60% and 49% respectively). A serum monoclonal gammapathy was found in 4 patients, Ig M/k in two cases and IgM/l and IgG/k in one case. Patients with hypogammaglobulinaemia had a similar surface phenotype as patients with normal Ig levels (MRFC+, sIg+, CD20+, HLA/DR+, FMC7-, CD5+, CD9+). On the other hand the cases with hypogammaglobulinaemia displayed the features of a more advanced disease, a higher incidence of organomegalies (p less than 0.05), anaemia and/or thrombopenia (p less than 0.05), a diffuse bone marrow pattern (p less than 0.05), advanced clinical stages (p less than 0.05) as well as higher levels of both peripherial blood (p less than 0.02) and bone marrow lymphocytosis (p less than 0.02). These findings suggest that the presence of hypogammaglobulinaemia in B-cell patients is probably more related to a higher tumor burden than to either certain stages of B-cell differentiation or a particular cellular phenotype.

Agammaglobulinemia↗
PubMed1989

Identification by flow cytometry of two distinct rhodamine-123-stained mitochondrial populations in rat liver.

Isolated rat liver mitochondria were split into three fractions of increasing density when applied to a Percoll gradient. NADH-ubiquinone oxidoreductase, succinate dehydrogenase and cytochrome-c oxidase but not F1-ATPase activities increased with density as well as respiratory rate in state 3 and the respiratory control index. Flow cytometry of mitochondrial density fractions stained with rhodamine-123 revealed the occurrence in each density fraction of two distinct mitochondrial populations with different fluorescence intensity. The high fluorescence population was minor and its proportion decreased with density. The extent of high fluorescence population staining depended on the deenergized state of the mitochondria suggesting that this population represents an immature form of the mitochondria which may develop into a fully functional organelle by the incorporation of structural and/or functional proteins.

Animals↗
PubMed1989

B-cell chronic lymphocytic leukaemia: prognostic value of the immunophenotype and the clinico-haematological features.

Sixty-two previously untreated patients with B-cell chronic lymphocytic leukaemia were analysed to study the prognostic value of both the immunologic phenotype and the clinicobiologic characteristics. Univariate studies showed that none of the immunological markers analysed, sheep-rosette, mouse-rosette, slg, and HLA/DR, CD20, FMC7, CD5, and CD9 antigens, had a significant influence on survival. On the other hand, several clinical and haematological characteristics were identified as being associated with survival: 1) clinical features--presence of lymphadenopathies (P less than .05) and hepatomegaly and/or splenomegaly (P less than .04); 2) haematologic parameters--presence of anaemia and/or thrombopenia (P less than .05), the absolute peripheral blood lymphocyte count (P less than .03), and the presence of hypogammaglobulinemia (P less than .08); 3) biochemical parameters--serum uric acid (P less than .03); and 4) bone marrow histopathological features--biopsy pattern (P less than .04) and the percentage of lymphocytes in bone marrow aspirate (P less than .03). Both the Rai staging and the International Workshop on CLL staging systems were effective in identifying groups of patients with significantly different prognoses (P less than .05). Multivariate regression analysis demonstrated that the combination of three clinicopathologic characteristics (bone marrow histopathologic pattern, absolute peripheral blood lymphocyte count, and the presence or not of hypogammaglobulinaemia) had the strongest predictive relationship with survival time. In summary, our findings show that the clinicobiological and anatomopathologic parameters have much more prognostic relevance than the immunological markers analysed in the present study.

Antigens, Differentiation↗
PubMed1989

Proliferation of B cells from chronic lymphocytic leukemia is selectively promoted by B cell growth factor.

B cell activation was studied in B cells from B cell chronic lymphocytic leukemia (B-CLL) patients. After in vitro stimulation, these B cells showed extensive proliferation in the presence of high-molecular-weight B cell growth factor (BCGF). In contrast, this effect was not observed upon addition of recombinant interleukin-2 (IL-2). In agreement, upon stimulation, B cells expressed Bac-1 antigen but failed to acquire the IL-2 receptor. These results demonstrate that the utilization of the BCGF pathway can be segregated from that of IL-2 in B cells from B-CLL patients.

B-Lymphocytes↗
PubMed1989

[Study of leukemic colony-forming units (CFU-L) in non-lymphoblastic malignant hemopathies].

CFU-L is considered as the clonogenic cell of acute non-lymphoblastic leukaemias (ANLL). Twenty-five malignant myelogenous hemopathies (5 blast crisis and 20 "de novo" ANLL) were studied in order to assess the proliferative capability of these cells and its relationship to FAB types and the achievement or not of complete remission (CR). The proliferative capability was assessed by culture on methylcellulose using conditioned leucocyte medium stimulated with phytohaemagglutinin as stimulating agent. Cell proliferation was observed in 21 cases, reaching 100% of the blast crisis and 80% (i.e., 16 cases) of the "de novo" ANLL. As regards the FAB types, it was found that the leukaemias with monocytic cells showed higher cell-growth than those of granulocytic lineage (90%, vs 60%). Of the patients not achieving CR (12 cases) colonies were formed in 66.6% (8 cases), while of the 8 patients who attained CR only in 3 (37.5%) were colonies observed. It was concluded that the FAB types of ANLL show different proliferative capability, which might influence the prognosis of the disease.

Blast Crisis↗
PubMed1989

Prognostic value of immunological markers in acute myeloblastic leukemia.

In order to investigate the prognostic value of immunologic markers together with the most relevant clinical and hematological disease characteristics in acute myeloblastic leukemia (AML), the reactivity of blast cells from 102 patients with AML was analyzed with a panel of twenty monoclonal antibodies. The univariate analysis showed that five parameters had an adverse effect on both complete remission (CR) and survival: advanced age (greater than 60 years), anemia (hemoglobin concentration (Hb) less than 10g/dl), the expression of the antigens detected by the anti-megakaryocytic antibodies (CDw41/CDw42), the monocytic antibodies (CD14), and the CD9 (FMC56, FMC8) antigen. In addition, the failure to obtain CR had a significant adverse effect on survival (p less than 0.0001). Multivariate analysis showed that only age and Hb had a significant influence on CR while for predicting survival the most important independent prognostic factors were: CR, age, number of platelets and reactivity with the CD9 antibody. These results show that immunological markers could represent a valuable tool in the assignment of risk categories in AML patients.

Age Factors↗
PubMed1988

Bone marrow histopathologic patterns and immunologic phenotype in B-cell chronic lymphocytic leukaemia.

The present work analyzes the clinicobiological and immunological characteristics - the latter hitherto unexplored - of the different bone marrow histopathological patterns of the B-cell chronic lymphocytic leukaemia (B-CLL). In addition, we studied whether any or some of these parameters were able to predict the probability of a particular pattern of bone marrow involvement appearing. Of the 100 B-CLL cases studied 41 had a diffuse pattern and 59 were non-diffuse - interstitial 27, nodular 11 and mixed 21 -. Neither clinical nor immunological differences were observed among the distinct non-diffuse patterns. The patients in the diffuse group displayed an increased incidence of mu+ isotype and a higher proportion of HLA-DR and HAN-PC 1 positive cells while, conversely, reactivity with the FMC 8 McAb was lower. In addition, patients with a diffuse pattern of BM involvement displayed features of a more extensive disease: a higher incidence of adenopathies (p less than 0.05), hepatomegaly (p less than 0.01), splenomegaly (p less than 0.01), anaemia (p less than 0.01) and thrombopenia (p less than 0.01) as well as higher levels of peripheral blood lymphocytosis (p less than 0.05) and a higher percentage of BM lymphocytic infiltration (p less than 0.001). Multiple regression analysis showed that thrombopenia and splenomegaly were the two most important features in predicting the probability of a diffuse pattern.

Aged↗
PubMed1988

Clinical and immunological findings in large B-cell chronic lymphocytic leukemia.

In order to define the characteristics of B-CLL cases in which the predominant cell population is composed of large lymphocytes, we studied 97 patients with B-CLL, comparing the cell morphological features with the clinical and biological findings and the immunological phenotype of the proliferating cells. Multivariant analysis showed that there were three significantly different morphological groups: Typical CLL, large lymphocyte CLL (LLL), and CLL with prolymphocytes (CLL/PL). The LLL group showed a greater incidence of lymphadenopathies (P less than 0.05) and higher percentages of both mu + delta + cells (P less than 0.01) and Fmc/7+ cells (P less than 0.001) than in typical CLL. The main differences between LLL and CLL/PL were the peripheral blood lymphocyte count and the percentage of Fmc/7+ cells (P less than 0.002)--both higher in the CLL/PL group--and the percentage of mouse rosette-forming cells (P less than 0.01)--lower in CLL/PL. Further studies including functional assays and survival analyses could contribute to elucidating whether these groups are different entities or a single disease with marked heterogeneity.

Antibodies, Monoclonal↗
PubMed1988

Leukemias with megakaryoblastic involvement: clinical, hematologic, and immunologic characteristics.

The clinical, hematologic, and phenotypic features of 28 patients with acute leukemia with megakaryocytic involvement (AMKL) were analyzed. The prevalence of this type of leukemia in the entire series was 11.6%, with a higher incidence among patients with acute transformation of a previous myeloproliferative disorder (MPD) (24%) than among the transformed myelodysplastic syndrome (13%) patients. The incidence in the "de novo" ANLL was 8% and 16% among secondary leukemias. The presence of bone marrow fibrosis together with low WBC and normal or increased platelet counts despite a severe anemia are the most relevant features in these patients who otherwise displayed an apparently poor prognosis. Megakaryoblasts were morphologically recognized more frequently in the acute transformations of MPD than in de novo ANLL. Only two cases were considered pure AMKL, and in the remaining 26 patients, megakaryoblasts coexisted with other granulomonocytic and/or erythroid populations. Antiglycoprotein IIIa (anti-GPIIIa) (C17) and anti-GPIIb/IIIa (CDw41-, J15-) antibodies are probably the best markers for AMKL, although the monoclonal antibody against GPIX (FMC25) was also positive in a majority of cases but in a lower percentage of cells. On the other hand, megakaryoblasts were generally negative for granulocytic or monocytic markers (CD13, CD14, CD15); the expression of HLA-DR antigens in these cells was variable. Our present results indicate that megakaryoblastic involvement is more common than previously recognized. This is true not only in acute transformed leukemias but also in de novo ANLL. Although the diagnosis of these cases should be based on megakaryocytic markers, it is often possible to suspect a diagnosis according to certain clinical and hematologic features.

Adult↗
PubMed1987

Discrepancies between morphologic, cytochemical, and immunologic characteristics in acute myeloblastic leukemia.

This study was designed to compare the cytochemical pattern with the immunologic phenotype in 108 cases of acute myeloblastic leukemia (AML) classified according to the French-American-British (FAB) criteria. Special attention was paid to the cases where discrepancy existed between these approaches and to a group of 11 patients considered as unclassifiable mainly because a second cell population--megakaryoblastic--was detected. Three types of discrepancies were observed: cases with typical morphologic characteristics and cytochemistry but devoid of lineage-specific antigens; these mainly include poorly differentiated leukemias (eight M1, four M2, and eight M5a), suggesting that the cytochemical enzymes are earlier myeloid markers than the currently available monoclonal antibodies; cases in which immunologic characteristics were discordant with morphologic characteristics and cytochemistry; these include two M2 cases positive for monocytic monoclonal antibodies (CD14); six M5b cases positive for granulocytic monoclonal antibodies (CD15); and seven M4 cases lacking in CD14 or CD15 antigens; cases with discrepancies between morphologic characteristics and cytochemistry and in which the immunologic markers permitted the correct assessment of cell lineage (six cases). These results show that the classification of these patients is better achieved by a combined morphologic, cytochemical, and immunologic approach.

Antibodies, Monoclonal↗