Jean H. Joncas

Lytic, nontransforming Epstein-Barr virus (EBV) from a patient with chronic active EBV infection

A new wild-type isolate of Epstein-Barr virus (EBV) was identified in follow-up studies of a case of chronic active EBV infection in an 8-year-old girl who had high titres of antibody to viral capsid antigen and early antigen (EA) (greater than 20 480 and 2560 respectively), persistent splenomegaly and abnormal immunologic features. More than 10 throat washings from this patient failed to transform cord blood lymphocytes (CBL), but at least 7 were able to induce EA in Raji cells. Supernatants from cultures of the lymphoblastoid cell line obtained by in-vitro infection of this patients leukocytes with the B95-8 strain of EBV revealed a herpesvirus particle when examined by electron microscopy. The same supernatants were unable to transform CBL but could induce EA in Raji cells upon superinfection. In 30 or more trials the patients lymphocytes never transformed spontaneously but did become positive for EBV nuclear antigen and EA in the first week of culture at least twice. Parallel studies performed on the father of the patient yielded similar results. This, then, is the first report documenting lytic activity associated with a wild-type EBV isolate.

Meningitis in a Canadian infant due to pneumococcus resistant to penicillin and chloramphenicol

STREPTOCOCCUS PNEUMONIAE resistant to penicillin and chloramphenicol and causing fatal meningitis in five patients was first described in 1977 and 1978 from Durban, South Africa.l, 2 Two other patients survived. One in Melbourne, Australia, 3 received an antibiotic combination of penicillin (intrathecally), lincomycin, and rifampin. The other, in Denver, 4 received an antibiotic combination of ampicillin, chloramphenicol, and rifampin. In Montreal, we retrospectively recognized in 1978 a case of meningitis caused by a pneumococcus resistant to penicillin and chloramphenicol; the disk agar diffusion method using the 10 U disk of penicillin, used at that t ime in our laboratory, failed to detect its penicillin resistance. The patient was given high doses of ampicillin intravenously, with success.

Epstein-Barr virus infection: Seroepidemiology in various population groups of the Greater Montreal Area

In vivo infection by the Epstein-Barr virus (EBV) results in the appearance of EBV antibodies against the viral capsid antigen (VCA), the early antigen (EA), and the Epstein-Barr nuclear antigen (EBNA), detectable by immunofluorescence. This paper reports the results of a study on the incidence of these antibodies in various groups such as infectious mononucleosis (IM) patients and their family members, controls, newborns and military recruits. A prospective study of IM patients showed a delay of 1–6 months in the appearance of EBNA antibodies compared to VCA antibodies. Family contacts and control groups showed a markedly different prevalence of antibodies: prevalence of EBV antibodies was lower in the families where IM occurred than in controls. The rate of EBV seroconversion in contacts during the first year following IM in the family was found not to be higher than that seen in the control group. In the military population, the appearance of heterophil agglutinins with EBV seroconversion but without symptom was noted. Study of EBV seroconversion in the neonatal period and in infancy showed some anomalies in the EBV antibody pattern. A longer delay in the appearance of EBNA antibodies might be explained by the relative inability to produce complement-fixing antibodies in early infancy. A VCA − EBNA + pattern was also noted for which no explanation could be found. This pattern was only seen once before [1]. A few hypotheses are offered in an attempt to explain these unusual phenomena.

Persistence of both human cytomegalovirus and Epstein-Barr virus genomes in two human lymphoblastoid cell lines.

By DNA-DNA reassociation kinetic analysis, less than one genome equivalent per cell of human CMV-DNA was found in two lymphoblastoid cell lines, one derived from the peripheral blood of a congenitally infected male infant at the age of 21 months (D4 cell line), the other obtained by co-cultivation of lethally X-irradiated cells from the 9-month lymphoblastoid cell line previously described by Joncas et al. (1975) with cord blood leukocytes of a female newborn (M1 cell line). Human CMV antigens could not be detected and virus could not be rescued from these cells by co-cultivation with fully permissive human fibroblasts. It may be that the CMV-DNA is defective. Epstein-Barr virus DNA as well as EBNA and EBV-EA antigens were present in these cell lines. Both lines express surface markers characteristic of thymus-independent, B lymphocytes. The CMV-DNA of the CMV-DU strain, isolated from this infants urine five times successively from the age of 1 day to 30 months, appears to be closely related to the DNA of the AD-169 strain by reciprocal hybridization and by electrophoretic pattern analysis of the restriction enzyme cleavage products. Experimental attempts to transform cord blood leukocytes with this urine strain of CMV before or after u.v. irradiation have so far failed.

Natural history of Epstein-Barr virus infection in a prospective pediatric cohort born to human immunodeficiency virus-infected mothers.

To determine whether Epstein-Barr virus (EBV) constitutes a contributing factor in AIDS and, conversely, whether the human immunodeficiency virus (HIV) alters the course of primary EBV infection in a pediatric population, 62 children born to HIV-infected mothers and prospectively followed were evaluated. EBV infection was documented by EBV-specific serology and polymerase chain reaction and by clinical history. HIV infection status was determined according to the Centers for Disease Control and Prevention pediatric classification system. Demographics from HIV-infected and HIV-uninfected children were comparable. The data suggest that HIV-infected children may acquire primary EBV infection earlier in life. The incidence of accompanying splenomegaly or hepatomegaly (or both) around the time of EBV seroconversion was higher among HIV-infected children than among HIV-uninfected children. In contrast, HIV disease progression and HIV-1 RNA load did not seem to be influenced by primary EBV infection.

The interaction of hydrocortisone, interferon and the Epstein--Barr virus in lymphoid cells.

Abstract Thirty-two human lymphoid cell lines of various origins were treated with hydrocortisone (HC) 20 μg/ml for 3 days and examined for cell viability, increase in the percentage of EBV antigen-positive cells, and interferon synthesis. Burkitts lymphoma (BL) cell lines ( 6 9 ) under the effect of HC were characterized by a decrease in cell viability, increase in the percentage of EA antigen-positive cells, and poor interferon response in contrast to lymphoblastoid cell lines derived from the peripheral blood of normal individuals ( 0 14 ) or patients with infectious mononucleosis ( 0 4 ). The enhancement in the expression of EBV-EA as shown by the increase in the percentage of EA antigen-positive cells following HC was exclusively seen in BL cell lines ( 6 9 ). This effect could be blocked by phosphonoacetic acid (PAA). In contrast the effect on cell viability could not be inhibited by PAA but was abolished by pretreatment of the cells with interferon.

Standardization and kinetics of in vitro bovine blood lymphocyte stimulation with bovine rotavirus

Abstract Two groups of 3-month old calves were immunized intramuscularly with attenuated bovine rotavirus and boosted 21 and 42 days later. The first group of three calves were vaccinated with live virus emulsified with incomplete Freunds adjuvant (IFA) and the second group was immunized with live virus suspended in phosphate buffered saline (PBS). Three other calves, serving as controls, were inoculated with PBS emulsified with IFA. The specific cell-mediated and antibody responses of the animals were studied. Preliminary analysis of in vitro peripheral blood lymphocyte transformation to bovine rotavirus determined optimal conditions as: 96 h culture period, 5 × 105 cells per culture in RPMI 1640 medium containing 10% heat-inactivated bovine fetal serum and the use of inactivated virus in the cell culture at a concentration of 5 × 106 median tissue culture infective dose before inactivation. Specific blastic stimulation was observed on calves immunized with the rotavirus emulsified with IFA after the second and third vaccine inoculation with stimulation index values varying from 2.00 to 5.73. Serum neutralizing antibody titers of 1 25,600 were also induced in the same calves. Calves immunized with rotavirus-PBS suspension developed a mean antibody titer of 1 1,600 , but showed no specific lymphocyte stimulation. No increase in specific immune responses was detected in the control animals.

Comparison of four enzyme immunoassays for the detection of cytomegalovirus IgG antibodies.

Four commercial enzyme immunoassays (EIA), namely the Behring Enzygnost EIA (BE-EIA), Abbott IMx, Whittaker CMV STAT Test Kit and Diamedix assay, were evaluated for the detection of CMV IgG. The methods were compared as to sensitivity, specificity, positive and negative predictive values, global agreement, ease of performance and, for a small number of specimens, reproducibility. Discordant results were resolved by using the Gull CMV indirect fluorescent antibody (IFA) method. Our data suggest that all four assays were valuable screening tools for the detection of CMV IgG based on their high sensitivity and high negative predictive value. However, differences were noted in the reproducibility level and in the incidence of false-positive, equivocal and nonspecific results regarding certain tests in particular. In our hands, the Abbott IMx and the BE-EIA ranked high in the performance characteristics for a good screening test, yet the Abbott IMx offers the added advantages of being the easiest to perform and having the most rapid turnaround time.

Comparison of two methods in the determination of the sensitivity of 84 herpes simplex virus (HSV) type 1 and 2 clinical isolates to acyclovir and alpha-interferon

Two methods, the colorimetric method (neutral red dye uptake), and DNA hybridization using a HSV thymidine kinase gene probe (TK) have been used to examine the sensitivity of 84 herpes simplex virus (HSV) type 1 and 2 clinical isolates to two antiviral drugs, acyclovir (ACV) and alpha-interferon (alpha-IFN). Using the colorimetric method, HSV isolates had ED50s ranging from 0.03 +/- 0.02 micrograms/ml to 0.164 +/- 0.03 micrograms/ml for ACV and 6.3 +/- 5.2 IU/ml to 55.0 +/- 11.4 IU/ml for alpha-IFN. With the DNA hybridization method, ED50s ranged from 0.033 +/- 0.012 micrograms/ml to 0.190 +/- 0.031 micrograms/ml for ACV and 8.5 +/- 5.0 IU/ml to 43.5 +/- 6.0 IU/ml for alpha-IFN. Two strains of HSV-1 were found to be resistant to very high concentrations of ACV (greater than 50.0 micrograms/ml). The values obtained by the two methods showed good correlation (r = 0.724, P = 0.002). Furthermore, our results demonstrate that the two methods are reproducible, reliable and the dye uptake assay is suitable for use in a diagnostic virology laboratory.

Killer Cell Defect and Lack or Loss of Antibodies to Epstein-Barr Virus Glycoproteins in Chronic Active EBV

A syndrome of chronic mononucleosis or chronic active EBV infection has been observed in recent years; two forms of this syndrome have been seen, a milder form mainly in adults and a more severe form usually but not exclusively in children (1,2). We have seen the more severe form of chronic active EBV infection in children and adolescents and studied it more intensively in three families. The syndrome was characterized by prolonged or recurrent mononucleosis including spleenomegaly, anemia and often pancytopenia, associated with a K-cell defect and the persistence of other immunological abnormalities, the most constant of which were low NK cytotoxicity, high EBV VCA and EA antibodies and hyper IgGl following the EBV infection. Inconstant features of the syndrome included the relative or absolute lack (or loss) of antibodies to EBNA and of antibodies to EBV-envelope and infected cell membranes, such as ADCC, NT, MA and gp 350/300 antibodies. Slow improvement over 2 to 10 years appeared to be the rule and was heralded by rising NK cytotoxicity.