Characterization of antibodies directed against platelet cryptantigens detected during the immunological study of 356 consecutive patients with presumed autoimmune thrombocytopenia (AITP).

Cryptic antigens are detected by antibodies present in a wide spectrum of patients with or without thrombocytopenia, and even in healthy individuals. They are produced for unknown reasons and do not react with antigens of native platelets, but only with altered platelets. Cryptantigen antibodies may not only result in spuriously low platelet counts, but also in 'falsely' positive tests for platelet antibodies.

Combined autoimmune cytopenias.

Background: Autoimmune neutropenia (AIN) can occur in association with autoimmune hemolytic anemia (AIHA) and/or immune thrombocytopenic purpura (ITP), although these associations have not been studied in detail.

Methods And Results: Twenty cases of AIN were found in a group of 55 adults with unexplained neutropenia over a five-year period. Eight subjects with AIN had an associated AIHA and/or ITP (AIN+ITP, n = 2; AIN+AIHA, n = 2; AIN+ITP+AIHA, n = 4).

[Peripheral T-cell lymphoma. Morphologic, immunophenotypic and immunogenotypic studies of 10 cases].

We describe the histopathology, immunophenotype and immunogenotype of 10 cases of peripheral T-cell lymphoma. The majority of patients showed disseminated disease at the time of diagnosis. From a histopathological view point the cases were classified into 5 types: T zone lymphoma (4 cases); Lennert lymphoma (2 cases); pleomorphic lymphoma, small all type (2 cases); pleomorphic lymphoma of medium-sized cell type (1 case); pleomorphic lymphoma of large cell type (1 case).

Immunophenotype of blast cells in acute myelofibrosis.

The immunophenotype of peripheral blood blast cells from six patients with acute myelofibrosis was studied using a panel of monoclonal antibodies directed against granulocytic, erythroid, megakaryocytic and lymphoid antigenic determinants. In all patients most of the blast cells were labeled with anti-HLA-DR and with the early myelomonocytic antibodies My7 (CD13), My9 (CD33) and B1-3C5 (CD34) (3/3). In three cases, platelet antibodies Edu3 (CD41) and GPIIIa (CD61) reacted with about 30% of blast cells.