Cytomegalovirus immune plasma in bone marrow transplant recipients.

The effects of passive immunization on cytomegalovirus infection and interstitial pneumonia in marrow transplants were evaluated in a randomized, controlled trial. Twenty-four patients received cytomegalovirus immune plasma before and after transplantation, and 24 patients were controls. Although the incidence of cytomegalovirus infection was similar in the control and plasma groups, symptomatic infection (12 of 24 versus five of 24, p = 0.07) and interstitial pneumonia (11 of 24 versus five of 24, p = 0.12) occurred less frequently in the group receiving plasma. Cytomegalovirus infection occurred in 11 of 13 recipients of leukocyte transfusions and in 16 of 35 patients not given leukocyte transfusions (p = 0.02). Among patients not given leukocyte transfusions, the incidence of cytomegalovirus infection was similar in the control and plasma groups, but symptomatic infection (eight of 18 versus one of 17, p = 0.03) and interstitial pneumonia (nine of 18 versus one of 17, p = 0.01) were significantly less in the group receiving plasma. These results suggest that passive immunization modifies cytomegalovirus infection in humans and prevents interstitial pneumonia in marrow transplants especially when leukocyte transfusions are not used.

Activation of classical complement pathway by naturally occurring heteroantibodies in normal rabbit serum. Effect on subpopulations of human lymphoid cells.

Heteroantibodies present in normal rabbit serum (NRS) are toxic to human B lymphocytes, T lymphocytes, and monocytes. Even NRS, which exhibits little back ground cytotoxicity for human lymphoid cells in conventional HLA or B-cell lymphocytotoxic assays, can be shown to contain considerable activity by making two modifications in usual procedures: by washing cells in saline or balanced salt solutions devoid of protein or sugar substances, and by increasing incubation time for 1 h to 3--4 h. Using such modifications, the cytotoxic activity of NRS towards human lymphoid cells was investigated and was found to involve activation of the classical complement pathway rather than activation of the alternate complement pathway. Residual unwanted background cytotoxicity of NRS toward human lymphoid cells can be decreased without loss of desired complement activity either by heating NRS for 15 min at 50 degrees C or by mixing NRS with small amounts of normal human serum.

Bone-marrow transplantation in acute leukaemia.

Survival in 33 patients with resistant leukaemia treated by marrow transplantation was compared with that of 37 matched patients treated by conventional and experimental chemotherapy. All patients in the transplant group were rendered free of detectable leukaemia for periods of from 36 days to more than 2 1/2 years, while only 6 patients in the chemotherapy group achieved a haematological remission. Overall survival in both groups was poor; however, 5 patients (15%) in the transplant group remain alive and in haematological remission 1--2 1/2 years after transplantation, while no patient in the chemotherapy group survived longer than 13 months. Bone-marrow transplantation appears to offer a small but distinct possibility of long-term survival in patients with acute leukaemia resistant to conventional therapy.

New groups and segregant series among B-cell alloantigens of the Merrit system. A study of leukemia cells, peripheral B cells, and lymphoblastoid cell lines.

On the basis of reactions with a chronic lymphatic leukemia cell panel, evidence for 6 new specificities of the Merrit B-cell alloantigenic system in man is presented, bringing the number of provisionally defined specificities to 19. These can be roughly divided into two segregant series. The system is well represented on both homozygous and heterozygous B-type lymphoblastoid cell lines. In the cell lines some specificities show a suggestive but inexact correlation with HLA-D locus factors. This correlation is represented also on peripheral blood B cells, on the non-T variety of acute lymphatic leukemia cells, and on acute myeloid leukemia cells. Although great similarities exist, each of the cell populations may manifest differences other than or in addition to mere differences in B-cell antigen frequencies.

Distribution of HLA-A, B, C and the Merrit B-cell alloantigen specificities in chronic lymphatic leukemia.

Based upon reactions with both normal peripheral B-lymphocytes and a CLL panel, an additional 3 new specificities of the Merritt B-cell alloantigenic system have been defined. this brings the number of provisionally designated specificities to 22. The system of antigenic determinants is well represented on normal B-lymphocytes, and has a roughly similar distribution when compared to the CLL panel; however, evidence is presented which suggests that certain speficities may have significantly idfferent distributions on the 2 different panels, but the number of cells tested is low.

Systemic giant-cell histiocytosis: report of a case and a review of the adult form of Letterer-Siwe disease.

The multiple classifications of histiocytic disorders, and the lack of specificity in their application, have degraded the utility of such diagnostic terms as "Letterer-Siwe Disease" and "Malignant Histiocytosis". A case is presented of a systemic histiocytic proliferation with erythrophagocytosis and giant-cell formation which does not fit into any presently accepted diagnostic niche. No similar case was found in the literature. Moreover, it appears that the entity "Adult form of Letterer-Siwe disease" has been uncritically accepted on the basis of a few poorly documented cases, and should be abandoned.

The merrit alloantigenic system of human B lymphocytes: evidence for thirteen possible factors including one six-member segregant series.

An analysis of the typing results of a 70-member chronic lymphatic leukemia B cell panel revealed evidence for 13 possible groups of the Merrit alloantigenic system. Six of these appeared possibly allelic and may represent a segregant series. The CLL panel was also fully typed for HLA and some degree of linkage dysequilibrium between Merrit and HLA seemed apparent from the data. Merrit antibodies can be absorbed out with selected surface membrane immunoglobulin (SMIG)-positive normal lymphocytes and less so or not at all with E rosette-forming T cells or Fc-positive SMIG-negative lymphocytes.

A new alloantigenic system on human lymphocytes.

Certain otherwise well-definedHL-Atyping sera contain extra antibodies which do not appear to be closely related to known HL-A specificites and which react in the cytotoxic test with chronic lymphaticleukemia lymphocytes but not with normal lymphocytes. Despite nonreactivity in thecytotoxic test, absorption studies show that the antigenic factors are well represented onnormal lymphocytes. Based on cross-absorption experiments using both normal andleukemic cells, followed by back-testing with the cytotoxic test against a leukemiccell panel, evidence is presented suggesting the existence of a complex, probablymultiple allelic system on human lymphoid cells which appears distinct from the, HL-Asystem, and is definable by serologic techniques.