Electrophoretic analysis of polypeptides immune precipitated from cytomegalovirus-infected cell extracts by human sera.

Serodiagnosis of cytomegalovirus (CMV) infection by complement fixation tests depends on showing a fourfold rise in antibody titer from acute- to convalescent-phase sera. Freeze-thaw and glycine-extracted, infected cell culture antigens used for these tests give markedly different titers in reactions with the same sera. In this study, we characterized the CMV-infected cell polypeptides contained in freeze-thaw and glycine-extracted antigens and identified the proteins precipitated by 23 pairs of human acute and convalescent sera. Our results were as follows. First, freeze-thaw and glycine-extracted antigens prepared from infected cells radiolabeled with [35S]methionine and subjected to electrophoresis in sodium dodecyl sulfate-polyacrylamide gels yielded similar patterns, and the bulk of the label was contained in late structural proteins and glycoproteins. Glycine-extracted preparations contained a greater proportion of soluble 66,000- and 50,000-molecular-weight proteins than did freeze-thaw antigens. Second, convalescent sera precipitated proteins migrating with apparent molecular weights of 150,000, 130,000, 110,000, 96,000, 74,000, 66,000, 50,000, 34,000, 32,000, and 25,000. Of these the 130,000-, 110,000-, 96,000-, 66,000-, 50,000-, and 25,000-molecular-weight proteins comigrated with glucosamine-labeled polypeptides. Both immunoglobulin G and M antibodies in human sera precipitated these proteins from CMV-infected cell preparations. Implications of the results for serodiagnosis of CMV infections are discussed.     

Human cytomegalovirus strains associated with congenital and perinatal infections

The genotypes of human cytomegalovirus (HCMV) isolates from pediatric patients differs from those of infected adults in Australia. Genotypes were determined by PCR amplification of glycoprotein B (gB) sequences, with subsequent analysis by restriction fragment length polymorphism, single-stranded conformation polymorphism, heteroduplex mobility analysis and direct DNA sequencing. Restriction fragment length polymorphism analysis of gB showed genotypes gB1 (39%) and gB3 (30%) were more prevalent in infected children and two new genotypes (gB6 and gB7) were found. Single-stranded conformation polymorphism was used to group isolates into 22 further subtypes and suggested longitudinal co-infection or viral mutation was occurring over time. Heteroduplex mobility analysis was found to be the most accurate and concise of the four methods used for genotyping HCMV isolates. DNA sequencing was used to confirm the results obtained from heteroduplex mobility analysis, and identified two isolates that were incorrectly genotyped by restriction fragment length polymorphism analysis. Heteroduplex mobility analysis efficiently genotyped all samples and allowed estimation of sequence variation between isolates. These data suggest certain gB genotypes are associated more commonly with childhood infections, and these differ from strains associated with invasive disease in HIV patients.     

Presence of an acid-labile alpha-interferon in sera from fetuses and children with congenital rubella.

In congenital rubella an acid-labile alpha-interferon was present in sera collected from fetuses between weeks 21 and 29 of gestation and from children with active congenital rubella. This interferon was different from the interferon detected in normal amniotic fluid and was not found in sera from uninfected fetuses or from children with postnatally acquired rubella. The fetal interferon is of interest as a complementary marker to confirm the virus contamination of the fetuses during maternal rubella. The role of the prolonged synthesis of this interferon in congenital rubella disease and its immune defects are discussed.     

Bloodstream infections and perinatal mortality.

Bloodstream infection is demonstrable at necropsy in 21.1% of perinatal death but is almost invariably a secondary event, often terminal, contributing to death as a secondary cause. In only 3.8% is infection recorded as the primary cause of death. Escherichia coli predominates, and postmortem and antemortem studies alike confirm the tendency of this and other microbes to involve the meninges in the course of bloodstream infection. Fatal viral and fungal infections are rare, and life-threatening disease is overwhelmingly of bacterial origin. A separate, prospective study of septicaemia in the newborn is reported, and the data are tabulated. The overall incidence in inborn and outborn populations, together with the incidence of specific infections, is stated, and the relationship to birthweight is analysed. The overall mortality for treated cases is 40.7% the mortality being inversely proportional to birthweight, and highest at 62.5% in those born weighting less than 1000 g. The advent of meningitis (1 in 5 cases of septicaemia) aggravates the mortality (83%). The potential hazard of nursing seriously infected babies is emphasised.     

Cytomegalovirus DNA detection in sera from patients with active cytomegalovirus infections.

Using a specific and sensitive polymerase chain reaction method, we detected reliably the presence of human cytomegalovirus (HCMV) DNA directly in serum samples collected at an early stage of HCMV infection, even before immunoglobulin M (IgM) antibodies were measurable. HCMV DNA was detected in serum from all patients with active HCMV infection; in 91% of these patients, HCMV DNA was found in the acute-phase serum. In 13 of 44 patients, HCMV DNA was found in serum before HCMV-specific IgM. For four kidney transplant recipients, the occurrence of HCMV DNA in serum, virus isolation from urine and leukocytes, and HCMV IgG and IgM serology were determined. We found a correlation between HCMV DNA in serum and positive virus isolation from leukocytes. In three of five congenitally infected infants, HCMV DNA and HCMV IgM were detected in the same sample. Two other infants were HCMV DNA positive, although no HCMV IgM antibodies were measurable. HCMV was found in urine from these infants either by virus isolation or with the polymerase chain reaction. Serum from one of the 22 healthy HCMV-seropositive blood donors was HCMV polymerase chain reaction positive.     

Antibodies against polypeptides of purified Epstein-Barr virus in sera from patients with connective tissue diseases.

Antibodies to Epstein-Barr virus (EBV) were investigated in patients with systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD) by immunoblotting using purified virus. Compared with sera from Epstein-Barr virus seropositive healthy individuals who served as control, sera from patients less frequently recognized several polypeptides. In particular, a 100 kDa envelope polypeptide was recognized by 92% of healthy subjects and only 11% of patients (P less than 0.001). On the other hand, 62% of the patient sera had antibodies to the 42 kDa envelope polypeptide, whereas these antibodies were only present in 4% of the sera from the control subjects (P less than 0.001). These results could reflect either perturbations of the immune response associated with connective tissue disorders or a possible pathogenic role of EBV.     

Immune complexes and antibodies to BCG in sera from patients with mycobacterial infections.

We have examined the prevalence of circulating immune complexes in sera from patients with mycobacterial infections. Sera from 68 percent of patients with active M. tuberculosis and 58 percent of patients with M. intracellulare infections had significantly elevated Clq binding activity (Clq-BA). In general there was a fall in Clq-BA with treatment. Only 15 percent of M. tuberculosis patient with a bacteriological cure, 22 percent of non-tubercular patients with chronic obstructive pulmonary disease, and 3 percent of normal individuals had an elevated Clq-BA. Antibodies to a BCG-derived antigen were demonstrated in most of the individuals studied in all groups but, significantly elevated levels were seen only in patients with mycobacterial infections. In certain patients there appeared to be an inverse relationship between Clq-BA and BCG binding, suggesting that perhaps BCG-related antigens participated in the immune complexes found. Other possible antigen-antibody complexes are discussed.     

Complement-fixing reactivity of Varicella-Zoster virus subunit antigens with sera from homotypic infections and heterotypic Herpes simplex virus infections.

Various subunit antigens of varicella-zoster (V-Z) virus were examined for complement-fixing (CF) activity with sera from homotypic infections and from herpes simplex virus (HSV) infections in which a CF antibody titer rise was demonstrated with crude V-Z antigen. The subunit antigens included nucleocapsids, envelopes, a soluble antigen produced from infected culture fluids by sucrose density gradient centrifugation, a soluble antigen produced by reducing the volume of clarified infected culture fluids, a soluble antigen derived from infected cell lysates, a "viral" antigen consisting largely of enveloped particles with a few nucleocapsids, and a cell membrane-associated antigen. None was more suitable than crude V-Z antigen for serodifferentiation of V-Z virus and HSV infections. The envelope antigen, cell membrane antigen, and the soluble antigen prepared by density gradient centrifugation showed little reactivity with sera from varicella and HSV infections, but gave high antibody titers with sera from zoster infections, suggesting that a secondary V-Z virus infection is required to produce an antibody response to these subunit antigens. Patients with varicella and zoster infections and the selected patients with HSV infections all showed significant CF antibody responses to the other V-Z subunit antigens.     

Fetal and perinatal infections. A consecutive study.

118 cases of second trimester abortions, stillbirths, and perinatal deaths together with the placentas and case records were studied histologically and microbiologically to evaluate the incidence of infection and to assess possible correlations to certain clinical parameters. The infection rate was 39.4%, highest in the second trimester abortions (58.2%), where infection was also considered the most frequent cause of death (45.5%), though mostly without maternal signs of infection. 36.6% of cases with histological inflammation exhibited positive culture results. The value of ordinary culture of the placenta and fetus is questionable, at least if not performed immediately after delivery. A significant correlation between infection and vaginal bleeding during pregnancy, ruptured membranes of more than 24 hours duration, and spontaneous labour was found. No protective effect of intact membranes was found.     

Differentiation of pathogenic Entamoeba histolytica infections from nonpathogenic infections by detection of galactose-inhibitable adherence protein antigen in sera and feces.

We determined whether epitope-specific monoclonal antibodies to the galactose-inhibitable adherence protein (GIAP) of Entamoeba histolytica could be used in an enzyme-linked immunosorbent assay (ELISA) to detect antigen in serum and feces and differentiate between nonpathogenic zymodemes and the potentially invasive pathogenic organisms that require treatment. Overall, 57% of subjects from Cairo, Egypt, with symptomatic intestinal amebiasis and 42% with asymptomatic infection possessed GIAP antigen in their sera, whereas 4% of uninfected controls or subjects with other parasitic infections possessed GIAP antigen in their sera (P < 0.001). In subjects from Durban, South Africa, only 6% of uninfected controls or those with nonpathogenic E. histolytica infection were positive for GIAP in serum, whereas 3 of 4 with asymptomatic pathogenic intestinal infection and 75% with amebic liver abscess were positive for GIAP in serum. Fifteen stool samples from patients with intestinal amebiasis were available for study; all had a positive ELISA result for fecal GIAP antigen. Epitope-specific monoclonal antibodies identified 8 of 15 subjects with fecal antigen from pathogenic strains. Seven of those eight subjects had adherence protein antigen in their sera, whereas none of seven with apparent nonpathogenic E. histolytica infection had adherence protein antigen in their sera. In summary, we were able to detect E. histolytica adherence protein antigen directly in serum and fecal samples by ELISA. The presence of amebic antigen in serum demonstrated 94% specificity for pathogenic E. histolytica infection, and amebic antigen is present during asymptomatic intestinal infection. In conjunction with antibody detection, this method should be very useful in the diagnosis and management of intestinal amebiasis.     

Immune response to herpes simplex virus infections: virus-specific antibodies in sera from patients with recurrent facial infections.

Radioimmunoprecipitation assays were used to identify antibodies against a number of herpes simplex virus type 1-specific antigens in serum samples from individuals with recurrent facial herpes virus infections and from seropositive individuals without recurrent infections. Individuals with recurrent infections contributed three sequential serum samples each: immediately after the appearance of lesions, 3 weeks later, and 3 months later. Antibodies against at least 18 viral polypeptides were present in all positive sera: these included antibodies against the major nucleocapsid polypeptide (approximate molecular weight, 150,000) and against two glycopolypeptides with molecular weights of 115,000 to 130,000. No significant differences were observed between the serum samples in regard to their virus-specific antibody composition. The high-molecular-weight glycopolypeptides were partially purified and used in quantitative titration experiments. All sera tested were equally reactive with this material. It was concluded that under the experimental conditions an individual's susceptibility to recurrent herpetic infections could not be correlated with quantitative or qualitative changes in the levels of virus-specific antibodies.     

Preparation of sera for typing of adenovirus infections by immunofluorescence.

The conditions for preparation of adenovirus antisera with group, subgroup and type-specific reactivity to be used in the immunofluorescence technique have been evaluated. Group-specific antibodies were prepared by passing an antiserum against virions or hexons of one serotype through an immunosorbent column containing soluble viral components of an adenovirus type belonging to a different subgroup. The group-specific antibodies were recovered from the solid phase by elution at pH 2.8. Reagents specific for subgroup I and II were obtained by passing anti-dodecon sera through an immunosorbent column containing soluble viral components from heterologous subgroups. In this case antibodies not attaching to the absorbent were recovered. Sera against fibers of subgroup III members could be used as subgroupspecific sera without absorption. Type-specific antibodies were prepared by removal of antibodies of other specificities by passing anti-virion or anti-hexon sera through immunosorbent columns containing soluble viral components of an adenovirus type belonging to the same subgroup. Reagents specific for seven adenovirus types representing Rosen's three subgroups were prepared according to the outlined procedures.     

Survey of congenital tumors in perinatal necropsies.

In an audit of 17,417 necropsies from 1939 to 1989 at the Royal Women's Hospital, Melbourne, Victoria, 46 congenital tumors comprising 24 teratomas, 8 vascular tumors, 6 neuroblastomas, three rhabdomyomas, two mesoblastic nephromas, one thyroid adenoma, one hepatic adenoma and one cerebellar medulloblastoma were found. The teratomas were generally large tumors and, because of their size and location, incompatible with extrauterine life. Ten teratomas were associated with polyhydramnios, three with obstructed labour, five of the fetuses were hydropic and four had malformations at sites distant to the tumor. Twenty teratomas occurred in stillbirths, half of whom were macerated. The vascular tumors were associated with polyhydramnios in three cases and hydrops fetalis in two. The neuroblastomas were all incidental findings. Four were intra-adrenal, one was an adrenal tumor which had metastasized to the liver and the remaining case was a small paravertebral lesion. Two of the three rhabdomyomas were multiple and one of these occurred in a case of tuberous sclerosis. One of the mesoblastic nephromas occurred in a hydropic fetus who had the Arnold-Chiari malformation. The thyroid and hepatic adenomas were small incidental lesions. The cerebellar medulloblastoma had led to marked hydrocephalus. Congenital tumors have different incidence, presentation and behaviour than those in childhood or adult life. The association of congenital tumors with congenital malformations and hydrops fetalis should always be remembered.     

Alternative complement pathway activity in sera from patients with sickle cell disease.

The low molecular weight cobra venom factor (CoVF) was used to activate the terminal sequence of the alternative complement pathway in thirty-one sera from patients with sickle cell disease (SCD). The SCD sera were compared with normal sera as a source of the alternative complement pathway factors C3 proactivator (C3PA) and C3PA convertase. These factors are required for formation of the enzymatically active CoVF-C3PA complex which is capable of cleaving C3 and thus initiating generation of the cytolytic C5b-9 complex. CoVF cofactor activity was significantly less than normal in SCD sera as measured in an indirect lysis assay, indicating reduced C3PA or C3PA convertase activity in these sera. Qualitative (immunoelectrophoresis) and quantitative (radial immunodiffusion) measurement of C3PA showed, however, that this protein is normal or elevated in SCD sera. Taken together, the reduced CoVF cofactor activity and normal or elevated C3PA in SCD sera suggests that sera from patients with sickle cell disease have reduced C3PA convertase activity.     

Autism and developmental abnormalities in children with perinatal cocaine exposure.

Cocaine in all forms is the number one illicit drug of choice among pregnant women. Records of 70 children with cocaine exposure in utero who were referred for developmental evaluation at a large inner-city hospital were reviewed in an effort to determine whether a specific pattern of abnormalities could be discerned. Patients received physical examinations, neurological screenings, and behavioral and developmental assessments based on the Gesell Developmental Inventory, and the Denver Developmental Screening Test. Documentation of specified drug use was obtained by history. Mean age (SEM) at referral was 19.2 (1.7) months. All mothers used cocaine in one of its forms, although polydrug use was common. Growth parameters were low (median = 15th percentile). Significant neurodevelopmental abnormalities were observed, including language delay in 94% of the children and an extremely high frequency of autism (11.4%). The high rate of autistic disorders not known to occur in children exposed to alcohol or opiates alone suggests specific cocaine effects.     

Relationship between poliovirus and echovirus 6 antigens II. Antibody Patterns in sera from patients with poliovirus infections

Summary Sera from 40 patients infected with poliovirus 1, 2 or 3 were surveyed for antibody activity against antigens of these viruses and echovirus 6 by immunodiffusion. Antibody activity common to the virion (N) antigens of two or three poliovirus types were encountered in a few sera; cross absorption tests confirmed the findings. The same sera also contained antibodies directed to one single type of N antigen, this was, however, not that of the infecting virus. Antibodies to echovirus 6 N was found only in one serum.Antibodies to empty capsid antigens (H) of polioviruses and echovirus 6 were demonstrable in the majority of sera; the occurrence of common antibodies to the H antigens of echovirus 6 and poliovirus H antigens was evident.The antibody patterns of different sera varied. Even early during the course of the disease heterologous anti H activity was associated with 7 S type antibodies, whereas the early homotypic anti N activity was present in the 19 S serum fraction. The data indicate that the heterologous antibody responses seem to represent booster responses from earlier experience with similar antigens.Antibodies of the 19 S and 7 S type showed precipitating activity whereas CF activity was found with certainty only in the 7 S fractions of sera.     

The effect of sera from patients with connective tissue diseases on red cell binding and phagocytosis by monocytes.

The uptake by human blood monocytes of sheep erythrocytes treated with rabbit anti-sheep antibody with or without mouse complement was assessed by a radioactive method to discover whether immune complexes would inhibit this reaction. It was found that sera from SLE patients inhibited uptake whereas normal sera enhanced. Some rheumatoid sera and rheumatoid joint fluids inhibited uptake whereas sera from juvenile rheumatoid patients did not.     

Recognition of mycobacterial antigens by sera from patients with leprosy.

Mycobacterium leprae sonic extracts prepared from armadillo-derived bacteria were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting (immunoblotting) procedures and probed with serum or plasma samples from 20 patients with lepromatous leprosy and 14 healthy endemic controls. Five proteins of 33, 25, 18, 15, and 12 kilodaltons (kDa) were frequently recognized; the 33- and 15-kDa proteins were, respectively, recognized with high intensity by 16 and 13 of the 20 samples from patients with leprosy, whereas only one healthy donor had antibodies that recognized the 15-kDa protein. By the use of M. leprae-specific murine monoclonal antibodies it was demonstrated that the 33-, 25-, and 15-kDa antigens were different from those bound by the available murine monoclonal antibodies. The 18- and 12-kDa proteins detected had molecular masses similar to those detected by the corresponding murine monoclonal antibodies. The serum and plasma samples from patients with leprosy were also used to probe Western blots of a soluble extract of M. tuberculosis. They recognized, among others, antigens with molecular weights similar to those detected in the M. leprae antigenic preparations, although with less intensity and at a lower frequency.     

Immunoprecipitation of herpes simplex virus polypeptides with human sera is related to their ELISA titre.

Out of 485 human sera tested by neutralization and enzyme immunoassay 13 were negative in both tests, while a positive correlation was found in 457 samples (94.3%). The rest of sera (3.2%) showed discordant results. Selected sera were examined, in addition, by Western blot and immunoprecipitation assays with the aim to analyse the precipitation profile of discordant sera and correlate the ELISA titre with the precipitation profiles. High titre sera precipitated the main glycoproteins (gC, gB, gE, gD), the capsid polypeptides (VP 5, VP 19, VP 21, VP 22) and several other structural and nonstructural proteins. The ability of sera to precipitate viral structural proteins was related to their ELISA titre rather than to their neutralizing activity.