Diffuse large B-cell non-Hodgkin lymphomas: the clinical relevance of histological subclassification.

In the REAL classification the diffuse large B-cell non-Hodgkin lymphomas (NHL) are grouped together, because subclassifications are considered to lack both reproducibility and clinical significance. Others, however, claim that patients with an immunoblastic NHL have a worse prognosis than patients with other types of diffuse large B-cell NHL. Therefore, we investigated the prognostic and clinical significance of histological subclassification of diffuse large B-cell NHL in a uniformly treated series of patients. For this retrospective study, all patients diagnosed as having an immunoblastic (IB) B-cell NHL by the Lymphoma Review Panel of the Comprehensive Cancer Center Amsterdam (CCCA) between 1984 and 1994, and treated according to the guidelines of the CCCA, were analysed. Patients with a centroblastic polymorphic subtype (CB-Poly) or centroblastic (CB) NHL by the Lymphoma Review Panel who were treated in the Netherlands Cancer Institute during the same period according to CCCA guidelines were used as reference groups. All patients' records were reviewed. Clinical parameters at presentation, kind of therapy and clinical outcome were recorded. All available histological slides were separately reviewed by two haemato-pathologists. One hundred and seventy-seven patients were included in the study: 36 patients (20.3%) with an IB NHL, 69 patients (39%) with a CB-Poly NHL and 72 patients (40.7%) with a CB NHL. The patients with an IB NHL tended to be older and presented more often with stage I or II and one extranodal site than patients with a CB and CB-Poly NHL. None of the subtypes showed a clear preference for localization in a particular site. The patients with IB or CB-Poly NHL showed a significantly worse prognosis than patients with CB NHL, with a 5-year overall survival for patients with CB NHL of 56.3% and for patients with IB or CB-Poly NHL 39.1% and 41.6% respectively. The 5-year disease free survival was 53.2% for the patients with CB, 32% for the patients with CB-Poly and 26.9% for the patients with IB NHL. A multivariate analysis showed that histological subtyping was of prognostic significance independent of the International Prognostic Index. This finding merits further exploration in prospective studies in order to judge the value of subclassification of large B-cell NHL as a guideline in therapy choice.

Specific antisera against human blood cells applicable in the indirect immunofluorescence technique.

The preparation of antisera against various cells of the human peripheral blood applicable in the indirect immunofluorescence technique (IIFT) is described. Such antisera will be a great interest for the study of cell-specific membrane antigens, for example during haematopoiesis. Purified erythrocytes, lymphocytes, neutrophils, monocytes, and thrombocytes from healthy donors were injected into rabbits. The antisera thus produced were not spontaneously specific. Only by extensive absorption of the crude antisera with purified cells from healthy donors was it possible to obtain antisera that were specific for erythrocytes, lymphocytes, and thrombocytes. By injection of small doses of leukocyte lysate and by absorption of the resulting antiserum with mononclear cells a specific antineutrophil serum was produced. So far it has not been possible to prepare a specific anti-monocyte antiserum. The specific antisera were applicable in the IIFT on paraformaldehyde-fixed cells in suspension and on cells on slides.