Requirements for diagnosis of prenatal cytomegalovirus infection by amniotic fluid culture

BACKGROUND

Amniotic fluid culture is considered to be the best method for the detection of antenatal cytomegalovirus (CMV) infection and prediction of congenital CMV infection. Recently, however, some false-negative results have been reported.

OBJECTIVES

Prediction of congenital CMV infection by amniotic fluid culture with emphasis on false-negative results.

STUDY DESIGN

Retrospective study of 42 pregnant women with primary CMV infection. First, estimation of seroconversion related to the gestational age was established. Afterwards, results of amniotic fluid culture were compared either with CMV isolation from biopsies from aborted fetuses, or with viral culture of newborns' urine.

RESULTS

In 18 cases (43%), amniotic fluid culture gave negative results which coincided with 18 uninfected newborns. In 18 other cases (43%), amniotic fluid culture was positive for CMV: 7 newborns with CMV viruria and 11 terminations of pregnancy with CMV isolated from fetal biopsies. In the remaining 6 cases, amniotic fluid culture gave negative results, whereas the 6 newborns were all infected.

CONCLUSION

Amniotic fluid culture remains an accurate method for the diagnosis of CMV antenatal infection. However, in order to avoid false-negative results, the importance of a correct estimation of the gestational age of seroconversion and of a sufficient interval between primary infection and amniocentesis are stressed.

Specific IgE detected by ELISA and immunoblot after human cytomegalovirus infection (HCMV) in renal transplant (RT) recipients

BACKGROUND

Specific HCMV IgE response has been reported by some authors, and was proposed as a valuable virologic marker of CMV infection.

OBJECTIVES

we evaluated specific HCMV IgE in renal transplant patients with active (primary and secondary) HCMV infection with special interest to symptomatic infections.

STUDY DESIGN

Specific IgE was tested retrospectively by ELISA and immunoblot (IB) on sera of 55 RT patients who were followed before and after transplantation with virologic markers of CMV infection.

RESULTS

Total serum IgE levels were similar in control group and in patients with primary and secondary HCMV infections. Anti-CMV specific IgE response by ELISA was more frequently found in patients with primary infection (76.9%) than in patients with secondary infection (47.1%). These specific IgE reacted on immunoblot with a 150 kDa protein in 84.6% of patients with primary infection and 94.1% with secondary infections; and reacted with rp52 (pUL44) in 76.9% of primary infection and 47.1% of secondary infection.

CONCLUSIONS

Anti-CMV specific IgE tested by immunoblot and ELISA is a marker of CMV infection. It was clearly detected in cases of active infection (primary and secondary) and was present in cases with severe CMV clinical manifestations. In contrast, anti-CMV specific IgE, was consistently negative among healthy blood donors. This is the first report of CMV proteins detected by IgE immunoblot.

Early diagnosis of CMV infection by detection of pp65 antigen in 91 renal transplant recipients

We evaluated how accurately a CMU antigenemia test correlated with classical CMU infection markers. We studied 91 kidney transplant recipients from February 1991 to June 1992. Antigenemia (pp65 antigen) was positive in 100% of cases of primary infection and in 70% of cases of reactivation and/or reinfection. Furthermore, antigenemia detected more infections (71%) than viremia (16%). The antigenemia test proved to be highly specific: it remained consistently negative in 22 seronegative patients, as well as in 19 of 20 seropositive recipients without recurrent infection. pp65 Antigen in the polymorphonuclear leukocytes was detected earlier than, or simultaneously with, virus culture in 78% of cases and became positive before serologic tests of primary and secondary infection in nearly 90% of cases. Most importantly, the antigenemia test detected all of the symptomatic cases.

Conversion from cyclosporine to FK506 for salvage of immunocompromised pediatric liver allografts. Efficacy, toxicity, and dose regimen in 23 children

Twenty-three pediatric liver transplant recipients (median age 3.9 years) were converted from cyclosporine A-based immunosuppression to FK506 for uncontrollable acute rejection (AR; n = 16), chronic rejection (n = 4), or predominantly nonspecific hepatitis (n = 3). Of these, 19 had received poly- or monoclonal anti-T lymphocyte antibodies either for AR prophylaxis or therapy before FK506 conversion. Full clinical and histologic responses to FK506 therapy were observed in 11/16 cases of AR compared with 0/7 cases of non-AR indications (P = 0.006). Acute FK506 toxicity included renal dysfunction in 12/23 children (52%), neurological disorders in 7/23 (30%), and isolated hyperkalemia in 2/23 (9%), with a poor correlation with the corresponding FK506 trough plasma level. Moreover, a significant impairment of glomerular filtration rate was recorded in the 12 children who received FK506 treatment for more than 6 months (P = 0.002). FK506 therapy had to be definitively withdrawn in 6 cases (fatal infections: n = 4; persistent tremor: n = 1; reason unrelated to FK506: n = 1). Five children developed a lymphoproliferative syndrome (LPS), leading to death in 3 cases despite cessation of the immunosuppressive therapy; in the other 2 patients, LPS was controlled, and the children were successfully retransplanted for chronic rejection under FK506. The occurrence of Epstein-Barr virus primary infection under FK506 therapy was found to constitute a significant risk factor for LPS (P = 0.027). In summary, full response to FK506 conversion was observed in 69% of uncontrollable AR cases; however, 74% and 22% of this probably over-immunosuppressed population experienced major adverse events and LPS under FK506 therapy, respectively.

Prenatal diagnosis of fetal cytomegalovirus infection

A prospective study (1988 to 1990) to evaluate the risk of fetal cytomegalovirus transmission was conducted with 1771 pregnant women; the test results of 861 were seronegative (48.6%). At each prenatal visit they were tested for serologic data and cytomegalovirus excretion in urine, saliva, and cervical secretions. If seroconversion occurred (with or without cytomegalovirus excretion), ultrasonography, amniocentesis, and cordocentesis were performed at 22 weeks' gestation; 7 cases of primary cytomegalovirus infection were investigated. In 5 cases the amniotic fluid cultures were positive; in 3 cases the fetal blood test results were positive for specific immunoglobulin M; and in 2 cases brain ultrasonography results were positive. Infection was confirmed with biopsies of fetal tissue. In two other cases, the cord blood and amniotic fluid test results were negative, and the neonates were free of infection.

Patterns of hepatitis delta virus reinfection and disease in liver transplantation

Twenty-seven carriers of the hepatitis B surface antigen who underwent liver transplantation in Italy and Belgium for terminal Hepatitis delta virus (HDV) cirrhosis were investigated. In 22 of the patients, HDV infection recurred. Two patients died of coexisting HDV and hepatitis B virus (HBV) reactivation. Four patients who died of unrelated causes were found to have HDV without signs of HBV reactivation. Five patients (18%) cleared both HBV and HDV after transplantation with no evidence of hepatitis (mean follow-up, 29 months). In many surviving patients. HDV infection recurred early without signs of HBV reactivation. Disease returned in the 11 HDV-infected patients in whom HBV also recurred. Histological hepatitis did not recur during an interim of 12-33 months in the 5 HDV-infected patients in whom HBV did not return. The overall medium-term survival in patients with HDV who underwent transplantation was 77.7%. Liver transplantation offers patients with HDV a hope of cure from disease despite a high risk of reinfection. In the transplantation setting. HDV can cause subclinical infections without any apparent assistance from HBV; these infections become symptomatic only if and when HBV reactivates. Thus, HDV may not be in itself pathogenic but requires cooperation from HBV to cause the appearance of the disease.

Assay of anti-HBs antibodies using a recombinant antigen and latex particle counting: comparison with five commercial tests

An assay of anti-HBs antibodies based on agglutination of latex particles coated with recombinant HBs-antigen was compared with Abbott radioimmunoassay (Abbott-RIA), which uses a human plasma-derived antigen. The population examined consisted of 76 Abbott-RIA anti-HBs-negative prevaccinated subjects and 1044 serum samples anti-HBs found positive by Abbott-RIA, including 283 samples of subjects vaccinated either with a human plasma-derived vaccine (group A; n = 180) or with a recombinant vaccine (group B; n = 103). Correlation coefficients between the two techniques were respectively r = 0.89 for the whole population (n = 1044), r = 0.98 in group A and r = 0.74 in group B. Anti-HBs titres were higher with latex than with RIA in group B as shown by the regression slopes: latex = 508 + 1.11 RIA in group A and latex = -1138 + 3.97 RIA in group B, suggesting that some vaccinated subjects from group B produced antibodies against epitopes proper to the recombinant antigen. In the prevaccinated population and in group A, the latex results were compared with those of radioimmunoassays (Abbott, Sorin) and enzyme immunoassays (Behring, Roche, Pasteur). Only the Roche-EIA detected anti-HBs in the prevaccinated subjects. The correlation between the various immunoassays was r greater than 0.96 only for values higher than 100 IU/l.

Herpes simplex virus type 2 meningitis without genital lesions: an immunoblot study

Two sexually active female patients presented with acute meningitis. The CSF abnormalities were severe and persistent. In spite of the absence of genital lesions, serological studies revealed a primary infection by herpes simplex virus type 2. An immunoblot study revealed intrathecal synthesis of anti-herpes antibodies early in the course of the disease.

Epstein-Barr virus infection in 59 orthotopic liver transplant patients

Fifty-nine orthotopic liver transplant (OLT) patients were studied after transplantation to detect Epstein-Barr virus (EBV) primoinfection and reactivation. Nineteen, all children under 10 years, were EBV seronegative. Seroconversion occurred in 12 (63.3%) of the seronegative patients. Most of these patients (10/12) seroconverted 2 or 3 months after transplantation; 11 out of the 12 demonstrated clinical signs at the time of seroconversion. From 9 primoinfected patients tested for EBV excretion, 8 were found to be positive. Serological evidence of reactivation was found in 9 out 40 (22.5%) seropositive patients and EBV was isolated from 5 (56%). Eleven pediatric OLT patients with primoinfection showed high and persistent titers of anti-EA antibodies (from 1:32 to greater than or equal to 1:256), when tested at least 3 months after seroconversion; however, anti-EBNA antibodies failed to develop in 5 patients and remained persistently low in 4. These patients with high EA and with negative or low EBNA titers constitute an "at risk" group for EBV-related lymphoproliferative syndrome (LpS). At presently, after a period of follow-up ranging from 3 months to 3 years, none of our 12 primoinfected patients have developed any lymphoproliferative evolution. However, in 1, during the acute phase, lymphoblasts and lymphoproliferation were observed in a tonsil biopsy.

[Acute maternal anterior poliomyelitis in a non-endemic zone]

The authors report the case of a 26 year old woman with acute anterior poliomyelitis contracted during the vaccination of her baby. Despite having been herself vaccinated in infancy she was not protected against the poliovirus. The clinical interest of this uncommon case is a severe paralytic state with definitive paraplegia. The authors suggest serologic testing of patients born before 1967 especially if they are at risk of encountering the virus.

Immunoassay of hepatitis B surface antigen by particle counting after pepsin digestion

Particle counting immunoassay is based on latex agglutination, the reaction being measured by instrument counting of the particles remaining unagglutinated. Most interference which generally affects latex agglutination can be avoided by pepsin digestion of the sample, provided the antigen (Ag) of interest resists pepsin, which is the case of the hepatitis B surface antigen (HBsAg). Pepsin treatment has the additional advantage of inactivating antibodies and so releasing the Ag from immune complexes. We have set up an assay of HBsAg, proceeding in a prototype of Impact Instrument (Acade Diagnostic Systems, Belgium) at a rate of 60 samples.h-1 and a total running time of 2 or 4 h. This assay was compared with Abbott radioimmunoassay (RIA) in 706 consecutive patients (A) and 31 selected sera for which values close to the cut-off had been obtained by RIA (B). In A, 38 sera were found positive and 668 negative by both methods. In B, RIA after neutralization classified the samples as positive (n = 14), negative (n = 14), or dubious (n = 3). Complete agreement between latex and RIA was achieved for nine positive, 12 negative, and two dubious samples. Of five RIA-positive samples, two were classified as latex-negative and three as dubious in the latex assay. One sample dubious in RIA was found latex-positive and two RIA-negative samples were found, respectively, latex-positive and dubious; when retested after pepsin digestion, the first of them became RIA-positive.(ABSTRACT TRUNCATED AT 250 WORDS)

Epstein-barr virus VCA IgM and EBNA IgG antibodies titered by immunofluorescence in microplates. A semi-automated method based on microtiter system

We describe methods of immunofluorescence in microplates for titration of EBV VCA-IgM and EBNA-IgG antibodies and compare the sensitivity of the methods with glass slides and with microplates, showing the reproducibility of the methods. Results of VCA-IgM and -IgG, EA and EBNA titers obtained in four groups of patients are given, comprising cases of infectious mononucleosis, renal graft recipients, lymphoproliferative diseases and controls.

Epstein-barr Virus (EBV) intracellular antigens: factors affecting the patterns of immunofluorescence

Immunofluorescent pictures of Epstein-Barr Virus (EBV) antigens were studied with regard to the lability of the antigens to heat and to solvents as well as to the modifications of the immunofluorescent patterns related to the length of drying time of the cell smears. The nuclear antigen (EBNA) and the early restricted antigen (EA-R) appeared to be sensitive to heating 30 minutes at 56 degrees C. Lengthening of the drying time of the cell smears results in a progressive dispersion of three antigens; viral capsid antigen (VCA), early diffuse antigen (EA-D) and EA-R in the cell and in some apparent loss of EBNA. Petroleum benzine which can be used as a fixative on plastic, support, allows the detection of all four antigens.

Epstein-Barr virus early antigen titer by immunofluorescence in microplates. A new semi-automated method based on microtiter system

For the titration of antibodies directed against Epstein-Barr Virus early antigen (EBV-EA) we describe a method in microplates with the Microtiter System (Cooke Engineering Co., Alexandria, Va). Using this technique, which allows rapid epidemiological investigations, we have titered anti-EBV-EA antibodies in different groups of patients and controls, and particularly in group which had recent contact with infectious mononucleosis. In this group the percentage of individuals having antibodies directed against the EBV-EA antigen was significantly higher than in the group of controls.

[Rapid detection of viruses by electron microscopy. Interest of negative staining for the diagnosis of some skin lesions of viral origin (author's transl)]

Viral particles can be visualized by electron microscopy using negative staining. Such an approach, widely used in research, provides a method for detecting virions which are present in clinical specimens. It is considered to be the method of choice in cases with suspicion of smallpox. Direct visualization has been systematically applied for the diagnosis of viral diseases in dermatology. Negative staining by pseudoreplication appears to be simple, rapid and efficient. It was thus possible to detect viruses in vesicle fluids, in scrapings and in crusts. During the course of this study 66 cases have been analyzed and viruses have been demonstrated in 49. If a skin lesion seems to be of viral origin, direct examination may confirm the clinical impression.

Rat ileocecal immunocytoma. An ultrastructural study with special attention to the presence of viral particles

Fifteen spontaneous immunocytomas originating in the ileocecal lymph nodes of Lou/C/Wsl rats were studied by means of electron microscopy. The histology was characteristic, the tumor being formed by an accumulation of large, rounded cells with slightly eccentric ovoid nuclei, large nucleoli, and finely condensed chromatin along the nuclear walls; the cytoplasma was rich in polyribosomes. The appearance of the rough endoplasmic reticulum was apparently the same whether or not the tumor was secretory. Its development varied from one cell to another, and in only a small proportion of cells did it attain any considerable volume. In all the tumors examined, we noted the presence of intracisternal A-particles. In its morphology, the rat immunocytoma resembled the plasmacytomas induced in mice, and it also resembled certain human tumors such as Burkitt's lymphoma.

Epstein-Barr virus viral capsid antigen titer by immunofluorescence with microplates: new semiautomated method based on the microtiter system

A semiautomated method of an indirect immunofluorescence technique for the titration of antibodies directed against viral capsid antigens of Epstein-Barr virus has been developed with Microtiter system units. By this method, a technician is able to titrate some hundred samples daily. The technique is safe, easy, and reproducible. The various procedures are described, and the sensitivity of the test is discussed.