Plasma 3S gamma-1-globulin: identity with erythrocyte carbonic anhydrase B.

The 3S (gamma1), 2S (gamma2), and 0.5S (gamma2) fractions of human plasma are heterogeneous in protein composition. Although each fraction contained a relatively small amount of protein antigenically related to the immunoglobulin light chains, most of the proteins were unrelated to immunogloublin G or its light chains. Of the 3S (gamma1)-globulins the greater part was immunochemically identical to carbonic anhydrase B and had carbonic anhydrase activity. These findings explain earlier reports of an immunochemical similarity between 3S (gamma1)-globulins and immunoglobulin light chains in spite of marked differences in amino acid and peptide composition between the two. Apparently not all plasma gamma-globulins are necessarily immunoglobulins.

Acquired pure red-cell aplasia: a consequence of increased natural killer cell activity?

A 19-year-old man with severe pure red-cell aplasia is described. An unusually high proportion of this patient's lymphocytes were large granular lymphocytes (LGL), both in the blood (40%) and in the bone marrow (50%). His blood leukocytes displayed a strongly elevated natural killer (NK) cell activity in vitro against the erythroblastic leukemia line K562. The patient's non-T blood lymphocytes inhibited in vitro erythroid colony formation (BFU-E and CFU-E) but not the granulocyte-monocyte colony growth (CFU-GM) from autologous and allogeneic bone marrow. Neither T-cell-mediated cytotoxicity nor circulating antibodies against erythroid precursors could be demonstrated. The patient's haemoglobin values returned to normal levels after three weeks of glucocorticoid treatment and have since then remained stable with continued prednisone administration. Attempts to reduce the prednisone dose to less than 10 mg/day have led to relapses. It is tempting to suggest that the patient's disease might be caused by hyperactivity of cytotoxic non-T (NK) cells specific for K562 cells and early erythroid precursors.

Chromosome changes in human chronic lymphocytic leukemia.

Karyotypes were studied in B- and T-lymphocyte cultures from 66 patients with B-cell CLL and two patients wtih T-cell CLL. Thirty-one of the B-cell cases had not been treated for their disease; 35 had received radiotherapy, corticosteroids, or cytostatic drugs. Only one of the untreated patients had a clone with an abnormal karyotype. This was present in all her mitotic cells found in cultures containing lipopolysaccharide B (LPS, a B-cell mitogen) and 10% of those in cultures with pokeweed mitogen (PWM, a T- and B-cell mitogen). The karyotype of this clone was 46,XX,t(6;7),t(7;13),t(11;14). Four of the treated patients had clones with specific chromosome changes. These were 47,XY,+12 in 10% of leukoagglutinin (LA, T-cell mitogen) and protein A (PA, T- and B-cell mitogen) cultures in one case; 47,XX,+12,del(14) in 80% of LPS cultures and in all spontaneously dividing cells in another case; 46,XY,t(6;20) in all LPS cultures in another; and 46,XX,t(1;8) in all PA cultures in another. Both structural and numerical nonclonal chromosome aberrations (9%) were found in 24% of the different cultures of cells from untreated patients, and in 15% of the cells in 20% of the different cultures in the patient who had received treatment. Both patients with T-cell CLL had receive) in all PA cultures in another. Both structural and numerical nonclonal chromosome aberrations (9%) were found in 24% of the different cultures of cells from untreated patients, and in 15% of the cells in 20% of the different cultures in the patient who had received treatment. Both patients with T-cell CLL had receive) in all PA cultures in another. Both structural and numerical nonclonal chromosome aberrations (9%) were found in 24% of the different cultures of cells from untreated patients, and in 15% of the cells in 20% of the different cultures in the patient who had received treatment. Both patients with T-cell CLL had received treatment for their disease, and had a normal karyotype in all cultures.

Chromosome 1q+ in erythroid and granulocyte-monocyte precursors in a patient with essential thrombocythemia.

A 55-year-old man with essential thrombocythemia had multiplication of bands q21 to q32 of chromosome 1 in all studied mitoses from bone marrow, from unstimulated blood, and from erythroid and granulocyte-monocyte colonies grown in vitro. The multiplication was in the form of triplication in 16 out of 20 mitoses from the marrow and in 4 of 6 mitoses from the blood; the rest showed a duplication of this region. All 20 mitoses from erythroid and granulocyte-monocyte colonies showed the abnormality in the form of duplication. These findings indicate most probably a clonal evolution, the triplication having arisen in the clone with the duplication. This may be associated with early leukemic transformation. The detection of the 1q+ aberration in two different types of hematopoietic colonies indicates the involvement of multipotent stem cells in at least this patient with essential thrombocythemia.

Abnormalities of chromosome No. 17 in myeloproliferative disorders.

In routine analyses, abnormalities of chromosome No. 17 were found in the bone marrow cells of 28 patients with Ph1-positive and three patients with Ph1-negative chronic myeloid leukemia (CML), 4 patients with acute nonlymphocytic leukemia (ANLL), and 4 patients with preleukemia. With three exceptions, all patients were in the blastic (CML) or the terminal phase. In 28 patients, the aberrant chromosome No. 17 arose by clonal evolution from the karyotype found at diagnosis or before the terminal phase. The abnormalities encountered were an isochromosome for the long arm, i(17q), (26 cases), translocations involving No. 17 (12 cases), trisomy 17 (three cases), and ring 17 (one case). In 35 patients, there was an unbalanced structural aberration of at least one of the No. 17 chromosomes. In every case (35/35), detailed analysis of the structurally abnormal No. 17 revealed loss of the distal part of the short arm (or possibly most of the short arm). Gain of the long arm (or at least its proximal part) was also common, but not invariably present (26/35). It is suggested that loss of 17p is a highly nonrandom event related to blastic crisis in CML and the terminal phase in other myeloid leukemias.

The Finnish leukaemia group: levamisole in maintenance therapy of acute myeloid leukemia in adults.

The Finnish Leukaemia Group has carried out a randomized, multicenter trial to study the effect of levamisole on the remission maintained with 6-mercaptopurine and methotrexate in acute myeloid leukaemia in adults. Levamisole was given on 3 consecutive days every 2 weeks. Twenty-five patients received only chemotherapy, while 26 patients received levamisole as well. The patients receiving levamisole showed significantly better remission duration than those given only chemotherapy (P = 0.033, Mantel's summary chi 2-text). There are four long term survivors in the levamisole group versus none in the chemotherapy group. The remissions have lasted 48-75 months.

Lymphographic diagnosis of malignant lymphoma in the course of Sjögren's syndrome.

Three patients with Sjögren's syndrome complicated by malignant lymphoma are presented. During the benign stage, two showed non-specific hyperplastic lymph node patterns on lymphography. When the disease had become malignant, all cases revealed generalized involvement of the retroperitoneal lymph nodes. The lymphographic pattern was that of a malignant lymphoma: enlarged nodes, with a foamy, linear or reticular appearance but mostly preserved marginal sinuses. On lymphographic follow-up, the node alterations were consistent with the histological findings and the clinical status, including the therapeutic response.