A novel non-lineage antigen on human leucocytes: characterization with two CD-48 monoclonal antibodies.

Two murine monoclonal antibodies have been produced which identify a novel surface antigen expressed on human leucocytes in a non-lineage-restricted distribution. Antibodies WM-63 and WM-68 were derived after immunization of mice with human T-CLL cells and the leukaemic cell line HSB-2. Both antibodies were shown to react with over 90 per cent of normal T and B lymphocytes from peripheral blood and tonsil, and also with monocytes from peripheral blood. A subset of bone marrow leucocytes, including granulocyte-macrophage progenitors, were also reactive. No activity with non-haemopoietic cells or tissues could be identified, however WM-63 and WM-68 showed binding to virtually all cases of chronic B cell malignancy, including chronic lymphatic leukaemia and non-Hodgkin's lymphoma, as well as a proportion of cases of acute leukaemia. Although the antigen recognized by these antibodies could not be immunoprecipitated from membrane extracts, it was removed from the surface of intact cells using the proteolytic enzymes protease and papain. Re-expression on cultured cells was inhibited by incubation with puromycin, cycloheximide, and tunicamycin, indicating that the epitopes detected by WM-63 and WM-68 are likely to be carbohydrate moieties on a protein backbone. Removal of the antigen from the cell surface by treatment with the enzyme phosphatidyl-inositol phospholipase C indicates that it is linked by a phosphatidyl-inositol bond. WM-63 and WM-68 were both recently clustered at the Fourth International Workshop on Human Leucocyte Differentiation Antigens into CD-48, together with four other monoclonal antibodies. Although no biological function has been ascribed to the molecule detected by these antibodies, its restriction to the haemopoietic lineage suggests a role in regulation of leucocyte function.

Use of thymic grafts or thymic factors to augment immunologic recovery after bone marrow transplantation: brief report with 2 to 12 years' follow-up.

Thymus tissue implants, thymic epithelial cells obtained from third party donors sharing one HLA-A and -B locus with the recipient, or the thymic hormones thymosin fraction 5 and thymopentin were given to recipients of HLA-identical sibling bone marrow to prevent chronic graft-versus-host disease (GVHD) and accelerate immunologic reconstitution. The clinical courses of 17 patients receiving thymus tissue and 18 patients receiving thymic hormones were reported initially 5 years ago and showed no difference in the incidence of chronic GVHD or immunologic recovery from those of concurrent or historical controls. We report here for the first time nine new patients who received thymus tissue implants with modifications of the culture method to lower the number of lymphocytes in the transplanted tissue with the intent of reducing rejection of the thymus tissue grafts. The clinical outcomes and immunologic functions of these nine patients were similar to those of the recipients of the earlier thymus tissue implants. With follow-up now ranging from 2.2 to 12.3 years (median 6.7) for the total group, 16 patients are alive. Seven never developed chronic GVHD. Nine were treated for chronic GVHD, seven of whom recovered and are leading normal lives, one has chronic pulmonary insufficiency, and one is disabled from chronic GVHD. We conclude that thymus tissue grafts or thymic epithelial cells partially HLA-matched to the recipient, thymosin fraction 5, or thymopentin used as described were not effective in reducing the incidence of chronic GVHD, improving immunologic recovery, or altering long-term survival.

Hypertrophic pulmonary osteoarthropathy in Hodgkin's disease: reversal with chemotherapy.

A case of nodular sclerosis Hodgkin's disease, stage IVB, with lung involvement and hypertrophic pulmonary osteoarthropathy (HPOA), was treated with quadruple cytotoxic chemotherapy. The pulmonary lesions, which were thin walled cavities, and the lymphadenopathy resolved completely after two courses of chemotherapy. The clubbing and all evidence of periosteal new bone formation disappeared after six courses of treatment. Complete reversal of the syndrome by chemotherapy has not been previously described. A literature review revealed 13 more cases of Hodgkin's disease associated with HPOA. The syndrome occurred for the first time at the time of diagnosis of Hodgkin's disease in 11 cases, and at recurrence in two. Tha majority of patients had advanced disease (Stage IIIB or IV). Mediastinal involvement was present in all 12 cases for which data were given; lung involvement was present in six cases and pleural involvement in three. Three cases were of the nodular sclerosis type, and one of the lymphocyte-depletion type. The HPOA syndrome in young patients with malignancy is indicative of tumors other than primary bronchial carcinomas.

The xeroradiographic appearances of some uncommon malignant mammary neoplasms.

The clinical and xeroradiographic appearances are described of four patients with malignant lymphomatous involvement of the breast, two with breast involvement by acute leukaemia, and four with primary fibrosarcoma of the breast. In one patient with malignant lymhoma and multiple palpable masses, the radiological appearance resembled benign mammary dysplasia, but in the three other patients, one with a discrete clinical mass, and two with diffuse clinical involvement, radiological examination of the breast showed skin thickening with diffuse abnormalities of the trabecular pattern, most marked in the subdermal area. One of the patients with leukaemia had a discrete palpable mass and the other had diffuse clinical involvement, but the radiological appearances in both patients were similar and resembled those of a carcinoma. The clinical and radiological appearance of the patients with fibrosarcoma were those of a benign cyst or a fibroadenoma.