A mouse monoclonal antibody (HC1/1) specific for a differentiation marker of human monocytes and ... more A mouse monoclonal antibody (HC1/1) specific for a differentiation marker of human monocytes and granulocytes has been generated by using as immunogen the monocytic cell line U937 differentiated with phorbol esters. This differentiation antigen has been characterized as the p150/95 member of the CD11 family of glycoproteins by cellular distribution studies, immunoprecipitation and competition experiments with MAb 3.9 specific for the CD11c antigen. Immuno-alkaline phosphatase staining of normal tissue sections with the HC1/1 MAb demonstrated that the CD11c antigen is a useful macrophage marker. Furthermore, the MAb HC1/1 stains specifically populations of macrophages on skin and lymph node sections from different pathologies such as Sarcoidosis, Granuloma annulare, Lepromatous leprosy and Toxoplasmosis.
Bone marrow involvement by lymphoma is considered a systemic dissemination of the disease arising... more Bone marrow involvement by lymphoma is considered a systemic dissemination of the disease arising elsewhere, although some tumors may arise primarily in the bone marrow microenvironment. Primary bone marrow lymphoma (PBML) is a rare entity whose real boundaries and clinicobiological significance are not well defined. Criteria to diagnose PBML encompass isolated bone marrow infiltration, with no evidence of nodal or extranodal involvement, including the bone, and the exclusion of leukemia/lymphomas that are considered to primarily involve the bone marrow. Twenty-one out of 40 lymphomas retrospectively reviewed by the International Extranodal Lymphoma Study Group from 12 institutions in 7 different countries over a 25-year period fulfilled the inclusion criteria. These cases comprised 4 follicular lymphomas (FLs), 15 diffuse large B-cell lymphomas (DLBCLs), and 2 peripheral T-cell lymphomas, not otherwise specified. The FL cases showed paratrabecular infiltration, BCL2 protein and CD10 expression, and BCL2 gene rearrangement. DLBCL showed nodular infiltration in 6 cases and was diffuse in 9 cases; it also showed positivity for BCL2 protein (9/10) and IRF4 (6/8). Median age was 65 years with male predominance. All but 3 FL patients were symptomatic. Most cases presented with cytopenias and high lactate dehydrogenase. Four patients (3 FL cases and 1 DLBCL case) had leukemic involvement. Most DLBCL patients received CHOP-like or R-CHOP-like regimens. The outcome was unfavorable, with a median overall survival of 1.8 years. In conclusion, PBML is a very uncommon lymphoma with particular clinical features and heterogenous histology. Its recognition is important to establish accurate diagnosis and adequate therapy.
The diagnosis of primary myelofibrosis (PMF) strongly relies on the bone marrow biopsy findings, ... more The diagnosis of primary myelofibrosis (PMF) strongly relies on the bone marrow biopsy findings, but a report model has not been standardised. Our aim was to establish general recommendations for bone marrow evaluation and standardised reporting in a case suspicious of PMF. The Delphi method was employed to obtain expert consensus. An advisory panel of 10 leading members identifies a total of 37 haematopathology experts to participate. The first Delphi round included a questionnaire with three main groups of items: minimal clinical and laboratory data considered necessary before reporting, minimal descriptive aspects to record and main histological differential diagnosis. The final report content was based on consensus obtained after the second Delphi round. The minimal data considered necessary were age, splenomegaly, haemoglobin, leucocyte and platelet counts, differential blood cell count, leucoerythroblastic blood picture, lactate dehydrogenase (LDH) level, BCR-ABL and JAK2 mutational status, reticulin stain and the internal control for the reticulin staining. The minimal descriptive aspects to report were cellularity, osteosclerosis, megakaryocytic morphology and localisation, dense megakaryocytic clusters, quantity of granulocytic precursors, grade of myelofibrosis in a scale of 4, and a proposed final diagnostic approach. The entities to be considered for differential diagnosis were mainly the other classical chronic myeloproliferative neoplasms. The Delphi method is a robust tool to determine essential information to be included in a pathology report. A standardised good-quality histopathological report form may help to homogenise PMF diagnosis. A close collaboration between the pathologist and the haematologist is desirable according to our survey.
Cytotoxic CD8+ T lymphocytes recognize viral antigens in the context of human leukocyte antigen c... more Cytotoxic CD8+ T lymphocytes recognize viral antigens in the context of human leukocyte antigen class I molecule coexpression by target cells. Analysis of beta 2-microglobulin reactivity is useful in evaluating changes in human leukocyte antigen class I antigen distribution. In this study we analyzed liver biopsy specimens obtained from 15 patients with chronic active hepatitis type C who underwent a clinical trial with recombinant interferon-alpha 2b. We comparatively studied by immunohistochemical analysis the expression of human leukocyte antigen class I antigens in frozen liver samples obtained before entry in the protocol and in specimens taken 8 mo after initiation of treatment. Six normal liver samples were used as controls. For immunohistochemical analysis, a panel of several human leukocyte antigen class I monoclonal antibodies, specific for beta 2-microglobulin or different heavy-chain determinants, was used. In addition, we included a novel monoclonal antibody (HP-1H8), c...
The diagnosis of primary myelofibrosis (PMF) strongly relies on the bone marrow biopsy findings, ... more The diagnosis of primary myelofibrosis (PMF) strongly relies on the bone marrow biopsy findings, but a report model has not been standardised. Our aim was to establish general recommendations for bone marrow evaluation and standardised reporting in a case suspicious of PMF. The Delphi method was employed to obtain expert consensus. An advisory panel of 10 leading members identifies a total of 37 haematopathology experts to participate. The first Delphi round included a questionnaire with three main groups of items: minimal clinical and laboratory data considered necessary before reporting, minimal descriptive aspects to record and main histological differential diagnosis. The final report content was based on consensus obtained after the second Delphi round. The minimal data considered necessary were age, splenomegaly, haemoglobin, leucocyte and platelet counts, differential blood cell count, leucoerythroblastic blood picture, lactate dehydrogenase (LDH) level, BCR-ABL and JAK2 mutational status, reticulin stain and the internal control for the reticulin staining. The minimal descriptive aspects to report were cellularity, osteosclerosis, megakaryocytic morphology and localisation, dense megakaryocytic clusters, quantity of granulocytic precursors, grade of myelofibrosis in a scale of 4, and a proposed final diagnostic approach. The entities to be considered for differential diagnosis were mainly the other classical chronic myeloproliferative neoplasms. The Delphi method is a robust tool to determine essential information to be included in a pathology report. A standardised good-quality histopathological report form may help to homogenise PMF diagnosis. A close collaboration between the pathologist and the haematologist is desirable according to our survey.
A mouse monoclonal antibody (HC1/1) specific for a differentiation marker of human monocytes and ... more A mouse monoclonal antibody (HC1/1) specific for a differentiation marker of human monocytes and granulocytes has been generated by using as immunogen the monocytic cell line U937 differentiated with phorbol esters. This differentiation antigen has been characterized as the p150/95 member of the CD11 family of glycoproteins by cellular distribution studies, immunoprecipitation and competition experiments with MAb 3.9 specific for the CD11c antigen. Immuno-alkaline phosphatase staining of normal tissue sections with the HC1/1 MAb demonstrated that the CD11c antigen is a useful macrophage marker. Furthermore, the MAb HC1/1 stains specifically populations of macrophages on skin and lymph node sections from different pathologies such as Sarcoidosis, Granuloma annulare, Lepromatous leprosy and Toxoplasmosis.
Bone marrow involvement by lymphoma is considered a systemic dissemination of the disease arising... more Bone marrow involvement by lymphoma is considered a systemic dissemination of the disease arising elsewhere, although some tumors may arise primarily in the bone marrow microenvironment. Primary bone marrow lymphoma (PBML) is a rare entity whose real boundaries and clinicobiological significance are not well defined. Criteria to diagnose PBML encompass isolated bone marrow infiltration, with no evidence of nodal or extranodal involvement, including the bone, and the exclusion of leukemia/lymphomas that are considered to primarily involve the bone marrow. Twenty-one out of 40 lymphomas retrospectively reviewed by the International Extranodal Lymphoma Study Group from 12 institutions in 7 different countries over a 25-year period fulfilled the inclusion criteria. These cases comprised 4 follicular lymphomas (FLs), 15 diffuse large B-cell lymphomas (DLBCLs), and 2 peripheral T-cell lymphomas, not otherwise specified. The FL cases showed paratrabecular infiltration, BCL2 protein and CD10 expression, and BCL2 gene rearrangement. DLBCL showed nodular infiltration in 6 cases and was diffuse in 9 cases; it also showed positivity for BCL2 protein (9/10) and IRF4 (6/8). Median age was 65 years with male predominance. All but 3 FL patients were symptomatic. Most cases presented with cytopenias and high lactate dehydrogenase. Four patients (3 FL cases and 1 DLBCL case) had leukemic involvement. Most DLBCL patients received CHOP-like or R-CHOP-like regimens. The outcome was unfavorable, with a median overall survival of 1.8 years. In conclusion, PBML is a very uncommon lymphoma with particular clinical features and heterogenous histology. Its recognition is important to establish accurate diagnosis and adequate therapy.
The diagnosis of primary myelofibrosis (PMF) strongly relies on the bone marrow biopsy findings, ... more The diagnosis of primary myelofibrosis (PMF) strongly relies on the bone marrow biopsy findings, but a report model has not been standardised. Our aim was to establish general recommendations for bone marrow evaluation and standardised reporting in a case suspicious of PMF. The Delphi method was employed to obtain expert consensus. An advisory panel of 10 leading members identifies a total of 37 haematopathology experts to participate. The first Delphi round included a questionnaire with three main groups of items: minimal clinical and laboratory data considered necessary before reporting, minimal descriptive aspects to record and main histological differential diagnosis. The final report content was based on consensus obtained after the second Delphi round. The minimal data considered necessary were age, splenomegaly, haemoglobin, leucocyte and platelet counts, differential blood cell count, leucoerythroblastic blood picture, lactate dehydrogenase (LDH) level, BCR-ABL and JAK2 mutational status, reticulin stain and the internal control for the reticulin staining. The minimal descriptive aspects to report were cellularity, osteosclerosis, megakaryocytic morphology and localisation, dense megakaryocytic clusters, quantity of granulocytic precursors, grade of myelofibrosis in a scale of 4, and a proposed final diagnostic approach. The entities to be considered for differential diagnosis were mainly the other classical chronic myeloproliferative neoplasms. The Delphi method is a robust tool to determine essential information to be included in a pathology report. A standardised good-quality histopathological report form may help to homogenise PMF diagnosis. A close collaboration between the pathologist and the haematologist is desirable according to our survey.
Cytotoxic CD8+ T lymphocytes recognize viral antigens in the context of human leukocyte antigen c... more Cytotoxic CD8+ T lymphocytes recognize viral antigens in the context of human leukocyte antigen class I molecule coexpression by target cells. Analysis of beta 2-microglobulin reactivity is useful in evaluating changes in human leukocyte antigen class I antigen distribution. In this study we analyzed liver biopsy specimens obtained from 15 patients with chronic active hepatitis type C who underwent a clinical trial with recombinant interferon-alpha 2b. We comparatively studied by immunohistochemical analysis the expression of human leukocyte antigen class I antigens in frozen liver samples obtained before entry in the protocol and in specimens taken 8 mo after initiation of treatment. Six normal liver samples were used as controls. For immunohistochemical analysis, a panel of several human leukocyte antigen class I monoclonal antibodies, specific for beta 2-microglobulin or different heavy-chain determinants, was used. In addition, we included a novel monoclonal antibody (HP-1H8), c...
The diagnosis of primary myelofibrosis (PMF) strongly relies on the bone marrow biopsy findings, ... more The diagnosis of primary myelofibrosis (PMF) strongly relies on the bone marrow biopsy findings, but a report model has not been standardised. Our aim was to establish general recommendations for bone marrow evaluation and standardised reporting in a case suspicious of PMF. The Delphi method was employed to obtain expert consensus. An advisory panel of 10 leading members identifies a total of 37 haematopathology experts to participate. The first Delphi round included a questionnaire with three main groups of items: minimal clinical and laboratory data considered necessary before reporting, minimal descriptive aspects to record and main histological differential diagnosis. The final report content was based on consensus obtained after the second Delphi round. The minimal data considered necessary were age, splenomegaly, haemoglobin, leucocyte and platelet counts, differential blood cell count, leucoerythroblastic blood picture, lactate dehydrogenase (LDH) level, BCR-ABL and JAK2 mutational status, reticulin stain and the internal control for the reticulin staining. The minimal descriptive aspects to report were cellularity, osteosclerosis, megakaryocytic morphology and localisation, dense megakaryocytic clusters, quantity of granulocytic precursors, grade of myelofibrosis in a scale of 4, and a proposed final diagnostic approach. The entities to be considered for differential diagnosis were mainly the other classical chronic myeloproliferative neoplasms. The Delphi method is a robust tool to determine essential information to be included in a pathology report. A standardised good-quality histopathological report form may help to homogenise PMF diagnosis. A close collaboration between the pathologist and the haematologist is desirable according to our survey.
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Papers by A. Acevedo