Marrow donor immunity to herpes simplex virus: association with acute graft-versus-host disease.

The interactions between humoral and cellular immunity to herpes simplex virus (HSV) in bone marrow donors, the occurrence of active HSV infections, and the development of grades II-IV acute graft-versus-host disease (GVHD) in their HLA-A,B,C,DR-identical sibling recipients were studied. The absence of IgG-class HSV antibodies in the marrow donors was associated with a low incidence of GVHD: 38 of 53 recipients (72%) of marrow from HSV-seropositive donors developed GVHD versus only two of 15 recipients (13%) with HSV-seronegative donors (p = 0.0004). The cellular immunity to HSV was studied in vitro by evaluating the degree of lymphocyte proliferative responses to that virus and was also significantly associated with GVHD: 30 of 43 recipients (70%) of marrow from donors with a positive test developed GVHD versus 10 of 25 recipients (40%) of marrow from donors with a negative test (p = 0.03). The previously reported risk for GVHD attributed to donor CMV antibodies increased the risk of GVHD due to donor HSV antibodies. Of 31 recipients of marrow from donors who were both HSV- and CMV-seropositive, 27 (85%) developed GVHD versus 11 of 22 recipients (50%) of marrow from HSV-seropositive but CMV-seronegative donors (p = 0.008).

Analysis of antigenic relationships among influenza virus strains using a taxonomic cluster procedure. Comparison of three kinds of antibody preparations.

Hemagglutination inhibiting (HI) monoclonal antibody preparations (MA) were raised against six influenza A (H3N2) strains from the period 1977-1982. Twenty-three hybridomas were selected and titrated in HI assays against these strains and against 18 influenza A (H3N2) viruses isolated in The Netherlands during the seasons 1981-1982 and 1982-1983. Similar HI tests were performed with conventional post-infection ferret antisera and with ferret antisera adsorbed with heterologous strains of influenza A (H3N2) virus. The resulting serological data were subjected to a computerized taxonomic cluster procedure based on the Euclidean distance between viruses. With respect to the degree of separation between clusters the unadsorbed ferret antisera were inferior to the adsorbed antisera whereas the MA were superior to both. Our results demonstrate that computer programs based on numerical taxonomy can be helpful in processing large numbers of serological data and that MA are indispensable in epidemiological and diagnostic influenza studies.

Comparison of monoclonal antibodies with ferret sera for the characterization of influenza A (H3N2) virus strains in a computer system.

A panel of murine monoclonal antibodies was generated against five different influenza A (H3N2) virus strains, isolated between 1977 and 1980. Monoclonal antibodies with defined specificities in haemagglutination inhibition tests for the strains against which they had been raised were selected. Eventually 18 of these were chosen and tested against a large number of recent H3N2 isolates. The results were compared with those obtained with antisera from ferrets immunized with the five strains mentioned above and with similar ferret sera after adsorption with heterologous strains. The serological data obtained with these three panels of antibodies were subjected to a theoretical pattern fitting computer analysis. A good correlation was observed between the results obtained with these three systems. However, the unadsorbed ferret sera proved to be less discriminating whereas the monoclonal antibodies provided additional information which could not be obtained with the other two systems.

Antigenic heterogeneity within influenza A (H3N2) virus strains.

On the basis of their antigenic properties, influenza virus strains are classified into types and subtypes, which are further subdivided into variants that differ to various degrees in haemagglutination-inhibition assays. Evidence is presented that during infection with an influenza A(H3N2) virus the respiratory tract of a human patient often harbours more than one antigenic virus variant. These variants are frequently propagated by embryonated fowl eggs and monkey cells with different efficiencies, and this may lead to the selection of different variants by either of these host systems. Also, passage of virus by a given host is sometimes attended by changes in reactivity in haemagglutination-inhibition tests. In some cases the heterogeneity described also affects the specific immunogenicity of the virus in ferrets. Virus strains cloned in monkey kidney cell cultures gave variants that were stable upon further passage. These results may have implications for antigenic and biochemical investigations of epidemiologically relevant virus variants. It is argued that the antigenic drift of influenza A(H3N2) viruses is best characterized by analyses, both with post-infection ferret antisera and with panels of monoclonal antibodies, of virus strains isolated and passaged in monkey kidney cell cultures only.

Imipenem-cilastatin for empirical therapy in neutropenic patients with fever: an open study in patients with hematologic malignancies.

In adult neutropenic patients with hematological malignancies, we explored imipenem-cilastatin as empirical antibiotic therapy in a dose of 500 mg four times daily. Changing to second-line treatment was only resorted to if clinical deterioration, new infections or recurrence of fever occurred. A clinically or microbiologically documented infection was apparent in 115 of 150 episodes studied (76.7%). Imipenem-cilastatin was successful in 70.7% of all episodes and in 67.8% of all proven infections. Modification was necessary and successful in 22.0% of all episodes. 11 patients died while still febrile, 6 of them by infection (4%) and 5 because of progressive disease (3.3%). Imipenem-cilastatin is safe initial therapy in neutropenic febrile patients.

Isolation of swine-like influenza A(H1N1) viruses from man in Switzerland and The Netherlands.

Swine influenza A (H1N1) viruses were isolated from two people in Switzerland and one in the Netherlands in early 1986. In haemagglutination-inhibition and neuraminidase-inhibition assays, the three viruses were closely related to one another and to the A/New Jersey/8/76 strain. The Swiss patients showed only mild symptoms, whereas the Dutch patient suffered from severe pneumonia. Two of the patients had been in close contact with diseased pigs. No such contact could be established for the third patient. None of the three individuals was known to suffer from immunodeficiency. No man-to-man transmission of the virus has been detected.

Herpes-virus immunity and acute graft-versus-host disease.

The influence of pretransplant herpes-virus antibodies in 126 marrow-graft recipients and their HLA-identical (A, B, C, DR) sibling donors on the incidence of grades II-IV acute graft-versus-host disease (GVHD) was studied in relation to previously reported risk factors for GVHD. Logistic regression procedures were used to control for confounding factors. Increasing donor age (odds ratio 3.7 per decade; p = 0.02) and donor seronegativity for Epstein-Barr virus (EBV; odds ratio 10.1; p = 0.005) were associated with a high incidence of GVHD. Total rather than selective gastrointestinal decontamination (odds ratio 0.1; p = 0.004), donor seronegativity for herpes simplex virus (HSV; odds ratio 0.1; p = 0.003), and recipient EBV-seronegativity (odds ratio 0.05; p = 0.002) were associated with a low incidence of GVHD. Pretransplant EBV and HSV serology may thus contribute substantially to the estimation of the risk for GVHD.