[Respiratory syncytial virus infections and preventive options]. / Infectie met respiratoir syncytieel virus en mogelijkheden voor preventie.

Respiratory syncytial virus (RSV) is the most prominent pathogen found in respiratory tract infections in children and the most important cause of bronchiolitis in the first two years of life. In the Netherlands approximately 2000 children are admitted each winter season. A serious course is mostly seen in children younger than 3 months, (ex-)prematures, children with bronchopulmonary dysplasia or congenital cardiac anomalies, children with cystic fibrosis younger then 2 years and children with impaired T cell immunity; such cases not rarely require intensive care. Treatment (fluid, nutrition, bronchodilator agents, corticosteroids, oxygen and ventilation) is usually symptomatic. Antiviral therapy is only indicated in immunodeficient patients. For prevention by passive immunization palivizumab was recently registered in the Netherlands, a monoclonal antibody against RSV that has to be administered intramuscularly from the start of the RSV season (15 mg per kg bodyweight once a month during five months). In a number of large-scale American multicenter studies both the number of hospital admissions related to RSV infection and the mean duration of hospital stay showed a statistically significant reduction in high-risk children who had been treated with palivizumab. Palivizumab appears to be indicated in children from the categories with an increased risk for serious RSV disease.

The spectrum of antecedent infections in Guillain-Barré syndrome: a case-control study.

OBJECTIVE: To determine which antecedent infections are specifically associated with the Guillain-Barré syndrome (GBS). BACKGROUND: Infections with many agents have been reported preceding GBS. Some infections are related to specific clinical and immunologic subgroups in GBS. Most agents were reported in case reports and uncontrolled small series of GBS patients only, and their relation to GBS and its subgroups remains unclear. METHOD: A serologic study for 16 infectious agents in 154 GBS patients and 154 sex- and age-matched controls with other neurologic diseases. Acute phase, pretreatment samples were used from clinically well-defined GBS patients. The seasonal distribution of serum sampling in the GBS and control group was the same. RESULTS: Multivariate analysis showed that in GBS patients, infections with Campylobacter jejuni (32%), cytomegalovirus (13%), and Epstein-Barr virus (10%) were significantly more frequent than in controls. Mycoplasma pneumoniae infections occurred more often in GBS patients (5%) than in controls in univariate analysis. Infections with Haemophilus influenzae (1%), parainfluenza 1 virus (1%), influenza A virus (1%), influenza B virus (1%), adenovirus (1%), herpes simplex virus (1%), and varicella zoster virus (1%) were also demonstrated in GBS patients, but not more frequently than in controls. C. jejuni infections were associated with antibodies to the gangliosides GM1 and GD1b and with a severe pure motor form of GBS. Cytomegalovirus infections were associated with antibodies to the ganglioside GM2 and with severe motor sensory deficits. Other infections were not related to specific antiganglioside antibodies and neurologic patterns. CONCLUSIONS: Recent infections with C. jejuni, cytomegalovirus, Epstein-Barr virus, and M. pneumoniae are specifically related to GBS. The variety of infections may contribute to the clinical and immunologic heterogeneity of GBS.

Transmission of hepatitis B virus among heart transplant recipients during endomyocardial biopsy procedures.

BACKGROUND: The unexpected conversion to HBsAg seropositivity of three cardiac allograft recipients prompted us to conduct a multidisciplinary study to identify the source, transmission mode, and extent of the hepatitis B virus (HBV) infection among the 256 cardiac allograft recipients of our hospital. METHODS: All recipients were retrospectively screened for serum markers of HBV infection. A selected genomic region defining subtypes of the viruses involved was amplified and sequenced. An epidemiologic case-control study for possible risk factors was conducted to identify the mode of transmission. RESULTS: Eighteen additional HBV-infected patients were identified, none of whom had shown symptoms of HBV infection. The involvement of one virus (subtype ayw 3) was shown in 20 of the 21 HBV-infected patients. This virus is found in less than 10% of HBV-infected individuals in The Netherlands. The demonstration of a common source of infection, combined with results of the epidemiologic study, identified posttransplantation endomyocardial biopsy procedures as the most likely mode of transmission. However, we also found evidence of secondary virus transmission by cardiac catheterization procedures to nonallograft recipients. CONCLUSIONS: The immunosuppressive therapy practiced in these patients to prevent allograft rejection may have not only facilitated virus transmission by causing high levels of viremia but also left the spreading of HBV undetected by causing a subclinical course of the infection. These findings stress the necessity of strict hygienic precautions during intravascular diagnostic procedures and indicate that vaccination against and routine monitoring for certain bloodborne infections in cardiac allograft recipients should be considered.

Diagnostic assays in cytomegalovirus retinitis: detection of herpesvirus by simultaneous application of the polymerase chain reaction and local antibody analysis on ocular fluid.

AIM: To determine the value of the polymerase chain reaction (PCR) technique and the analysis of intraocularly produced antibodies by calculating a Goldmann-Witmer quotient (GWq) as diagnostic assays in the confirmation of a clinically diagnosed cytomegalovirus (CMV) retinitis in a group of unselected AIDS patients. METHODS: Eleven samples of undiluted ocular fluid, obtained from nine AIDS patients with a clinically diagnosed CMV retinitis were analysed for the presence of genomic DNA from CMV, HSV-1, VZV, and EBV by PCR. Nine of these samples were analysed for the presence of locally produced IgG antibodies against these herpesviruses by calculating a GWq. Ten samples obtained from patients with various entities of clinical non-herpetic uveitis and 17 samples of aqueous humour obtained at cataract surgery were used as controls. RESULTS: In 10 out of 11 samples from AIDS patients (91%) the presence of CMV DNA was demonstrated. In four out of nine (44%) patients this was accompanied by CMV DNA in the blood indicating a CMV viraemia. In one sample, VZV DNA was detected and in another sample both CMV and VZV DNA were detected. No HSV-1 or EBV DNA could be demonstrated in these 11 samples. In contrast, simultaneous analysis of locally produced IgG antibodies against herpesviruses could not confirm the initial diagnosis of CMV retinitis. Ocular fluid samples obtained from 10 control uveitis patients were negative for DNA from CMV, VZV, and EBV by PCR. In one of 10 uveitis control samples HSV-1 DNA was detected; antibody analysis did not confirm this. In the uveitis control group, a significant GWq was calculated in one sample for HSV-1 and in another sample for VZV. The cataract control samples were all herpesvirus DNA negative by PCR. CONCLUSIONS: To establish the diagnosis of CMV retinitis in AIDS patients, ophthalmoscopic examination is a sensitive method. In confirming a diagnosis in indistinctive cases, application of a PCR assay detecting CMV DNA is a more sensitive method than analysis of locally produced antibodies by calculating a GWq. In clinical non-herpetic uveitis, secondary release of HSV-1 and VZV should be considered requiring additional therapeutic anticipation.

Successful treatment with ganciclovir of presumed Epstein-Barr meningo-encephalitis following bone marrow transplant.

Epstein-Barr virus-specific polymerase chain reaction was used to diagnose EBV-meningo-encephalitis in a bone marrow transplant recipient. The patient made complete recovery with ganciclovir treatment. Pitfalls in diagnosis with EBV-PCR and the potential therapeutic efficacy of ganciclovir in EBV infections are discussed.

[Hepatitis B in children in 4 university centers in The Netherlands]. / Hepatitis B bij kinderen in vier universitaire centra in Nederland.

OBJECTIVE: To evaluate the prevalence and the natural course of hepatitis B infection in children. DESIGN: Retrospective longitudinal. SETTING: Four university pediatric centres. METHOD: To explore the possibility of starting a trial with interferon alpha, data of viral and biochemical tests and biopsies of children younger than 16 years were studied. RESULTS: In a period of 10 years (1980-1990) 145 patients, of whom 74% were not of original Dutch descent, were found positive for HBsAg. The data of 142 patients could be analysed. Seroconversion was seen in 27 patients and 42 were already anti-HBe positive at the time of presentation. Chronic hepatitis, representing the category which could benefit from interferon alpha treatment, was found in 24 patients. Severe complications of the hepatitis were found in 4% of the children, including hepatocellular carcinoma and cirrhosis. Follow-up was insufficient so the seroconversion rate could only be estimated at 12% for the first year following the diagnosis. CONCLUSION: As a result of this study the authors present a proposal for a therapeutic trial with interferon alpha. This is a national protocol under the auspices of the section for pediatric gastroenterology of the Nederlandse Vereniging voor Kindergeneeskunde (Netherlands Pediatric Association).

[Non-Hodgkin lymphoma in patients with an HIV-infection]. / Non-Hodgkin-lymfomen bij patiënten met een HIV-infectie.

In the period 1985-1990, 111 patients with AIDS were treated in the University Hospital Rotterdam-Dijkzigt. In 8 out of 111 patients malignant non-Hodgkin lymphoma developed. The unusual and bizarre representation is highlighted by several clinical histories and a review of literature. HIV-related non-Hodgkin lymphoma is characterized by widespread extranodal disease, often at unusual sites, and high grade B-cell malignancy. The therapeutic outcome and survival in these cases has been disappointing. Prognosis is better for patients without a prior AIDS diagnosis, higher total CD4 cell counts, good performance score and absence of an extranodal site of disease. Treatment should be tailored to individual patients based upon a variety of prognostic features.

Selection of asymptomatic HIV carriers for antiviral therapy.

In order to find suitable markers for selection and monitoring of antiviral therapy in asymptomatic HIV-infected patients, we evaluated 18 anti-HIV positive individuals at three monthly intervals by HIV culture, HIV antigen, and core (p24) antibody testing as well as by measurement of lymphocyte subsets. Consistent results were obtained with HIV antigen, p24 antibody testing and T4 cell enumeration, whereas results of virus detection were variable. Therefore cumbersome and expensive virus culture is not of use in selecting patients for antiviral therapy. On the basis of our results and recent literature we currently propose using absence of p24 antibodies, presence of HIV antigen and low or falling T4 cells as eligibility criteria for antiviral therapy in asymptomatic infected individuals.

Acute ulcerative proctocolitis associated with primary cytomegalovirus infection.

The case is reported of a 39-year-old pregnant woman who presented with fever, abdominal complaints, and diarrhea. Laboratory investigation revealed mononucleosis in the peripheral blood. All microbiological studies were negative, with the exception of finding cytomegalovirus (CMV). Seroconversion was documented; the virus was cultured from urine and subsequently was demonstrated to be present in the inflamed mucosa of the rectum and distal sigmoid, which was found at sigmoidoscopy. This woman was delivered of a neonate with congenital CMV infection but without apparent malformations. The patient experienced recurrences of the bowel disease, in the first of which CMV could still be cultured from a biopsy specimen. In the follow-up period, an otherwise aspecific chronic inflammatory bowel disease remained present. No immunological abnormalities were found, and antibodies to human immunodeficiency virus were negative. This case demonstrates that inflammatory bowel disease can develop as a result of primary infection with CMV.

Respiratory syncytial virus infections in children admitted to the intensive care unit.

During the winter of 1986-1987, 64 children with respiratory syncytial virus (RSV) infection were admitted to our hospital. The diagnosis was made by direct immunofluorescent antibody technique. Twenty-three children (36%) needed intensive care treatment. Nearly 11 (52%) had a preexisting disease state, identified as a risk factor i.e., prematurity (n = 8), bronchopulmonary dysplasia (n = 2), congenital heart disease (n = 1). Twelve patients (50%) were intubated and ventilated. Conditions for intubation and ventilation were repetitive apnea with or without bradycardia (n = 4), clinical deterioration (n = 3) or hypercarbia (n = 5). Seventy-five percent of the patients who needed intensive care management were under three months of age compared to 34% of the children who were admitted to the clinical ward. The mean age for ventilated patients was 7.9 weeks. The mean duration of ventilation was 5.5 days. Volume controlled ventilation was initially applied to all patients. Pulmonary complications (atelectasis, pneumonia, pneumothorax or adult respiratory distress syndrome) were present in 15 (65%) IC patients. Nine (39%) of them also had symptoms of inappropriate antidiuretic hormone secretion (IADHS). Only two patients had symptoms of IADHS and two others had convulsions. Three children (5%) died as a result of respiratory insufficiency. Two of these infants belonged to the risk group.

Rapid demonstration of cytomegalovirus in clinical specimens.

An assay is described for handling clinical specimens for the detection of cytomegalovirus. It consists of low-speed centrifugation of the specimen on human embryonic lung cells, using a technique adapted from chlamydial culture, followed by detection using a monoclonal antibody against the cytomegalovirus early antigen in an immunofluorescence technique. This assay was compared with the conventional cell culture system. 161 specimens obtained from 52 patients were studied; from 14 patients CMV was isolated in at least one specimen (in total 28 specimens). The centrifugation technique led to positive results generally within 24 to 48 h, whereas the cell culture took an average of 16.5 days to develop the typical cytopathic changes. No cross-reactions between the cytomegalovirus monoclonal antibody and other viruses present (herpes simplex virus and adenovirus) were observed. The centrifugation technique is a reproducible and rapid method in the diagnosis of cytomegalovirus infection.

Flow cytometry of reticulocytes applied to clinical hematology.

Reticulocytes in fixed human blood samples were stained for RNA with the fluorescent dye pyronin Y and measured by flow cytometry. The resulting relative frequency distributions of the RNA fluorescence intensities concurred with the different stages in maturation from early reticulocytes to mature red cells. A computer program was written to calculate from these frequency distributions the relative number of reticulocytes, their relative RNA content, and the median of the reticulocyte population (RNA index). This method was applied to 30 healthy blood bank donors (control group), as well as to patients with various hematologic disorders showing abnormal erythropoietic activity. The measured percentage of reticulocytes, RNA content, and RNA index were found to correlate well with the various hematologic disorders. Changes in erythropoiesis could be clearly followed, as was demonstrated by analyzing blood samples from children with aplastic anemia or acute myeloid leukemia, who were treated with allogeneic bone marrow transplantation. Measurements on blood samples from healthy blood bank donors showed that with this method, small changes in the reticulocyte population, such as the appearance of polychromatic erythrocytes in the peripheral blood 5-8 hr after donation, can be detected. The statistical reliability and the information provided on the maturation stage of the entire reticulocyte population make flow cytometry of peripheral blood reticulocytes a more informative method for the study of hematologic abnormalities than conventional methods for reticulocyte counting and classification.

Immunofluorescence studies with 4-acetamido-4'-isothiocyanato stilbene-2,2'-disulphonic acid (SITS).

The application of the fluorochrome 4-acetamido-4'-isothiocyanato stilbene-2,2'-disulphonic acid (SITS) in immunofluorescence was studied. The optimal excitation wave length is 350 nm, and optimal fluorescence is obtained at 420 nm. After purification of the commercial compound, conjugation is performed in a strong buffer at pH 9.0-9.5. SITS conjugates were very satisfactory for immunofluorescence studies of the cytoplasmic antigens of cell preparations, but their blue emission was difficult to distinguish from autofluorescence in sections of human tissues. Good results with immunofluorescence on membrane bound antigens were obtained by using an ultra-violet laser beam as light source. SITS can be used simultaneously with FITC and TRITC conjugates thus making it possible to show three antigens in one preparation.