PubMed Health⌕ Search

Biomedical subjects

Matthias F C Beersma

Publications and source records attributed to Matthias F C Beersma.

14 recordsLinked to original sources
PubMed2006

Parvovirus B19 infection in pregnancy studied by maternal viral load and immune responses.

OBJECTIVES: Facilitate risk assessment of vital complications in fetuses of pregnancies affected by acute parvovirus B19 (B19V) infection. DESIGN: Study of the natural course of maternal B19V infection in four cases, from early pregnancy on. SETTING: University Medical Center in the Netherlands. POPULATION: Pregnant mothers attending obstetric services. METHODS: Serial measurements of the maternal and fetal or neonatal viral load and antibody responses. MAIN OUTCOME MEASURES: Maternal and fetal/neonatal serum B19V viral DNA load and specific IgM and IgG antibodies in maternal serum. RESULTS: Peak viral load levels occurred within 1 week after maternal infection and peak IgM levels were observed 1 week after the peak viral load levels. Approximation of IgG and IgM ratios usually took place 4 weeks after infection. Vertical transmission occurred 1-3 weeks after maternal infection, suggesting that fetal infection occurs during the maternal peak viral load. CONCLUSIONS: Maternal B19V DNA load levels and IgM responses are useful to estimate the risk of parvovirus B19-associated fetal complications. The maternal peak viral load directly precedes the onset of fetal infection and may be used to indicate the stage of intrauterine B19V infection.

Adult↗
PubMed2006

Parvovirus B19 infection in pregnancy.

Parvovirus B19 is a small single-stranded DNA virus and a potent inhibitor of erythropoiesis, due to its cytotoxicity to erythroid progenitor cells. Infection with parvovirus B19 during pregnancy can cause several serious complications in the fetus, such as fetal anemia, neurological anomalies, hydrops fetalis, and fetal death. Early diagnosis and treatment of intrauterine parvovirus B19 infection is essential in preventing these fetal complications. Testing maternal serum for IgM antibodies against parvovirus B19 and DNA detection by PCR can confirm maternal infection. If maternal infection has occurred, ultrasound investigation of the fetus and measurement of the peak systolic flow velocity of the middle cerebral artery are sensitive non-invasive procedures to diagnose fetal anemia and hydrops. Intrauterine transfusion is currently the only effective treatment to alleviate fetal anemia, but if the fetus is (near) term, induction of delivery should be considered. Most maternal infections with parvovirus B19 occur through contact with infected children at home. Individual counseling of susceptible pregnant women will reduce unnecessary fetal deaths.

Anemia↗
PubMed2006

Fetal stroke and congenital parvovirus B19 infection complicated by activated protein C resistance.

UNLABELLED: Parvovirus B19 infection in gestation has been associated with severe fetal complications such as anaemia, hydrops and fetal demise. Fetal infection in the first trimester poses the greatest risk for these complications, but infection during the third trimester is more common than previously appreciated and can be associated with severe complications, i.e. fetal death, in the absence of hydrops or classical clinical symptoms. Parvovirus B19 infection has been associated with vasculitis and pathological changes in the central nervous system, which may cause stroke. We report a newborn infant with a rare combination of a recent central nervous system infection with parvovirus B19 and a factor V Leiden mutation, who developed fetal stroke. CONCLUSION: Factor V Leiden mutation leads to activated protein C resistance and increases the risk of thromboembolism. Thromboembolism occurs rarely in newborns with activated protein C resistance, but can be precipitated by dehydration, asphyxia and infection. Although parvovirus B19 infection of the central nervous system may be a precipitant in neonatal and/or fetal stroke, it can also cause stroke independent of a thrombophilic mutation. In this case, both causative factors may have coincided.

Activated Protein C Resistance↗
PubMed2006

Fourth human parechovirus serotype.

We identified a novel human parechovirus (HPeV) type (K251176-02) from a neonate with fever. Analysis of the complete genome showed K251176-02 to be a new HPeV genotype. Since K251176-02 could not be neutralized with antibodies against known HPeV serotypes 1-3, it should be classified as a fourth HPeV serotype.

Base Sequence↗
PubMed2005

Immune reconstitution and clearance of human adenovirus viremia in pediatric stem-cell recipients.

BACKGROUND: Human adenovirus (HAdV) infections are increasingly frequent complications of allogeneic stem-cell transplantation (SCT), especially in children. Only a few data on the correlation between immune recovery and the course of HAdV infection are available, and data on HAdV-specific responses are lacking. METHODS: In a prospective study, we determined the correlation between the HAdV DNA load in plasma and lymphocyte reconstitution in 48 children after allogeneic SCT. Additionally, HAdV-specific humoral and cellular immune responses were investigated. RESULTS: HAdV infection occurred in 21 patients (44%), and, in 6 of these patients, the infection progressed to viremia, as demonstrated by the presence of HAdV DNA in plasma. Low lymphocyte counts at the onset of infection were predictive of HAdV viremia. Survival of patients with HAdV viremia was associated with an increase in lymphocyte counts during the first weeks after infection. In these patients, HAdV-specific CD4+ T cell responses, as well as increases in titers of neutralizing antibody, were detected after clearance of HAdV DNA from plasma. CONCLUSIONS: Lymphocyte reconstitution appears to play a crucial role in clearance of HAdV viremia and survival of the host, warranting further development of therapeutic interventions aimed at improving immune recovery.

Adenovirus Infections, Human↗
PubMed2005

Parvovirus B19 viral loads in relation to VP1 and VP2 antibody responses in diagnostic blood samples.

BACKGROUND: Human parvovirus B19 infection is characterised by high peak viral load levels followed by episodes of prolonged viremia. The risk of transmission of parvovirus B19 by blood or blood products has been increasingly recognised and parameters that can predict the risk of transmission are subject of interest. OBJECTIVES: This study aimed to study correlations between B19 viral DNA loads and antibody responses to the viral antigens VP1 and VP2 in clinical serum samples. STUDY DESIGN: A panel of 1610 serum samples from patients clinically suspected from acute B19 infection were analysed. Antibodies were measured by the parvovirus anti-VP1 immuno-fluorescence assay (IFA) and the anti-VP2 enzyme immunoassay (EIA) from Biotrin. B19 viral loads were measured by a real-time PCR using the external WHO standard for DNA quantification. RESULTS: Positive IgM responses were found in 154 (9.6%) of the 1610 sera tested. Based on the PCR results in a subset of 312 sera, the anti-VP2 EIA IgM showed a better combination of sensitivity/specificity (91%/94%) compared to the anti-VP1 IFA (66%/97%). B19 DNA levels in the sera strongly correlated with the levels of IgM antibodies, all sera with high viral loads (>10(6)IU/ml) having VP2 EIA IgM ratios above 3.0. CONCLUSIONS: The B19 VP2 IgM ELISA is superior to the B19 VP1 IgM IFA if verified by PCR. Anti-VP2 IgM antibodies in sera are indicative for the presence B19 DNA and can be used to predict high levels of B19 DNA in diagnostic sera.

Adolescent↗
PubMed2005

Evaluation of 12 commercial tests and the complement fixation test for Mycoplasma pneumoniae-specific immunoglobulin G (IgG) and IgM antibodies, with PCR used as the "gold standard".

Serology and nucleic acid amplification are the main diagnostic tools for the diagnosis of Mycoplasma pneumoniae infection. Since no reference standard is generally accepted, serologic assays for M. pneumoniae have not been evaluated on a broad scale. In this study, 12 commercially available serologic assays (for immunoglobulin G [IgG] and IgM) and the complement fixation test (CFT) were evaluated by using M. pneumoniae DNA detection by real-time PCR as the "gold standard." The assays tested were Platelia EIA (Bio-Rad), SeroMP EIA (Savyon), Serion classic EIA (Virion/Serion), Biotest EIA (Biotest), Ridascreen EIA (r-Biopharm), AniLabsystems EIA (Labsystems), Novum EIA (Novum Diagnostica), Diagnosys EIA (MP products), Genzyme/Virotech EIA, ImmunoWell EIA (Genbio), ImmunoCard EIA (Meridian), and SerodiaMycoII microparticle agglutination (Fujirebio). Serum samples (n = 46) from 27 PCR-positive patients with a known first day of disease and sera (n = 33) from PCR-negative controls were obtained from prospective studies of acute lower respiratory tract infections. Additionally, control sera (n = 63) from patients with acute viral or bacterial respiratory infections other than those caused by M. pneumoniae were tested. The results showed low specificities for both the Novum and the ImmunoCard IgM assays. The IgM assays with the best performances in terms of sensitivity and specificity were AniLabsystems (77% and 92%, respectively), SeroMP (71% and 88%, respectively), and CFT (65% and 97%, respectively). Good receiver operating characteristic areas under the curve were found for CFT (0.94), the Platelia assay (0.87), and the AniLabsystems assay (0.85). We conclude that there are few commercial serologic assays for the detection of M. pneumoniae infections with appropriate performances in terms of sensitivity and specificity and that PCR has become increasingly important for the diagnosis of M. pneumoniae infections in defined groups of patients.

Antibodies, Bacterial↗
PubMed2004

Validation of clinical application of cytomegalovirus plasma DNA load measurement and definition of treatment criteria by analysis of correlation to antigen detection.

Successful preemptive cytomegalovirus (CMV) therapy in transplant patients depends on the availability of sensitive, specific, and timely diagnostic tests for CMV infections. The pp65 antigenemia assay has been used for this purpose with considerable success. Quantification of CMV DNA is currently regarded to be an alternative diagnostic approach. The precise relationship between these two methods has still to be defined, but is essential to compare diagnostic results. This study compared the results of both assays with a large series of transplant recipients in different categories. An internally controlled quantitative real-time CMV DNA PCR was used to test 409 plasma samples from solid organ transplant (SOT) and stem cell transplant (SCT) patients. Levels of CMV DNA in plasma correlated well with classified outcomes of the pp65 antigenemia test. Despite this correlation, the quantitative CMV PCR values in a class of antigen test results were within a wide range, and the definition of an optimal cutoff value for initiating treatment required further analysis by a receiver-operating characteristic curve analysis. This is essential for reactivating infections in particular. For the SCT patients the optimal cutoff value of CMV DNA load defining relevant viral reactivation (in this assay, 10,000 copies/ml) was slightly higher than that for the SOT patients (6,300 copies/ml). Based on a comparison with the established pp65 antigenemia assay, quantification of CMV DNA in plasma appeared to be capable of guiding the clinical management of transplant recipients. This approach may have important advantages, which include a superior reproducibility and sensitivity, allowing the inclusion of kinetic criteria in clinical guidelines.

Antigens, Bacterial↗
PubMed2004

Rapid and sensitive method using multiplex real-time PCR for diagnosis of infections by influenza a and influenza B viruses, respiratory syncytial virus, and parainfluenza viruses 1, 2, 3, and 4.

Laboratory diagnosis of viral respiratory infections is generally performed by virus isolation in cell culture and immunofluorescent assays. Reverse transcriptase PCR is now recognized as a sensitive and specific alternative for detection of respiratory RNA viruses. A rapid real-time multiplex PCR assay was developed for the detection of influenza A and influenza B viruses, human respiratory syncytial virus (RSV), parainfluenza virus 1 (PIV1), PIV2, PIV3, and PIV4 in a two-tube multiplex reaction which used molecular beacons to discriminate the pathogens. A total of 358 respiratory samples taken over a 1-year period were analyzed by the multiplex assay. The incidence of respiratory viruses detected in these samples was 67 of 358 (19%) and 87 of 358 (24%) by culture and real-time PCR, respectively. Culture detected 3 influenza A virus, 2 influenza B virus, 57 RSV, 2 PIV1, and 2 PIV3 infections. All of these culture-positive samples and an additional 5 influenza A virus, 6 RSV, 2 PIV1, 1 PIV2, 1 PIV3, and 3 PIV4 infections were detected by the multiplex real-time PCR. The application of real-time PCR to clinical samples increases the sensitivity for respiratory viral diagnosis. In addition, results can be obtained within 6 h, which increases clinical relevance. Therefore, use of this real-time PCR assay would improve patient management and infection control.

Cell Line↗
PubMed2004

Sequential switching of DNA polymerase and thymidine kinase-mediated HSV-1 drug resistance in an immunocompromised child.

Sequential herpes simplex virus type 1 (HSV-1) isolates were obtained from a paediatric haematopoietic stem cell transplant (HSCT) patient who received prolonged therapy with acyclovir (ACV) followed by foscarnet (PFA) and topical cidofovir (HPMPC) for severe persistent mucocutaneous HSV-1 infection. The isolates were retrospectively studied for drug resistance. The first resistant isolate associated with clinical failure of antiviral therapy emerged 44 days post-ACV treatment initiation. Susceptibility testing revealed an ACV-resistant HSV strain that demonstrated cross resistance to PFA in the absence of any previous PFA treatment. The observed cross resistance was conferred by a single amino acid substitution, Ser724Asn, in the HSV DNA polymerase (DNA pol) gene. During the subsequent course of ACV therapy, the ACV/PFA-cross-resistant isolates were replaced by ACV-resistant, PFA-sensitive isolates. These isolates carried no DNA pol mutations, but had an Arg163His substitution in the thymidine kinase gene. Upon subsequent switching of antiviral therapy from ACV to PFA, the original ACV/PFA-cross-resistant DNA pol mutant re-appeared. Our study shows the emergence of different drug-resistant HSV variants during ongoing, unchanged ACV therapy. Furthermore, a rapid re-selection of the original resistant variant was observed after switch. For optimal antiviral management of HSV infections in HSCT recipients, therapeutic decisions should be guided by drug susceptibility results whenever therapeutic failure is observed and/or when changes in antiviral treatment are considered.

Amino Acid Substitution↗
PubMed2004

Genotypic and phenotypic characterization of acyclovir-resistant herpes simplex viruses isolated from haematopoietic stem cell transplant recipients.

Thirty-one herpes simplex virus type one (HSV-1) isolates from 12 haematopoietic stem cell transplant recipients with persistent HSV infections despite acyclovir (ACV) prophylaxis or treatment, were genotypically and phenotypically characterized. The relationship between drug susceptibility of the isolates and mutations in thymidine kinase (TK) and DNA polymerase (DNA pol) genes was examined. In all 12 patients, HSV infections were due to ACV-resistant, foscarnet-sensitive viruses. Out of 31 isolates examined, 23 were resistant and eight were sensitive to ACV; eight patients carried viruses with frameshift mutations in the TK gene (due to addition or deletion of single nucleotides in homopolymeric repeats). These mutations were found at codon 61 (G deletion, one patient), 146 (G insertion, five patients) and 153 or 185 (C deletion, one patient each). In four patients, viruses were selected during ACV therapy that contained novel amino acid substitutions in the TK gene (H58R, G129D, A189V, R216H, R220C). Their possible role in ACV resistance was further confirmed phenotypically and by the absence of any resistance-associated mutations in the DNA pol gene. These substitutions were located in ATP- or nucleoside-binding sites or in conserved regions of the TK gene. In addition, a single mutation, Q570R, in the delta-region C of the DNA pol gene, was identified in an isolate from a single patient with resistance to ACV. Our study confirms and expands previous data on genotypic changes associated with ACV resistance of HSV-1 clinical isolates.

Acyclovir↗
PubMed2003

Comparison and evaluation of real-time PCR, real-time nucleic acid sequence-based amplification, conventional PCR, and serology for diagnosis of Mycoplasma pneumoniae.

Mycoplasma pneumoniae is a common cause of community-acquired pneumonia and lower-respiratory-tract infections. Diagnosis has traditionally been obtained by serological diagnosis, but increasingly, molecular techniques have been applied. However, the number of studies actually comparing these assays is limited. The development of a novel duplex real-time PCR assay for detection of M. pneumoniae in the presence of an internal control real-time PCR is described. In addition, real-time nucleic acid sequence-based amplification (NASBA) on an iCycler apparatus is evaluated. These assays were compared to serology and a conventional PCR assay for 106 clinical samples from patients with lower-respiratory-tract infection. Of the 106 samples, 12 (11.3%) were positive by all the molecular methods whereas serology with acute sample and convalescent samples detected 6 (5.6%) and 9 (8.5%), respectively. Clinical symptoms of the patients with Mycoplasma-positive results were compared to those of the other patients with lower-respiratory-tract infections, and it was found that the results for mean lower age numbers as well as the presence of chills, increased erythrocyte sedimentation rate, and raised C-reactive protein levels showed significant differences. Molecular methods are superior for diagnosis of M. pneumoniae, providing more timely diagnosis. In addition, using real-time methods involves less hands-on time and affords the ability to monitor the reaction in the same tube.

Adult↗
PubMed2002

Monitoring of clinical and laboratory data in two cases of imported Lassa fever.

During 2000, four cases of fatal Lassa fever were imported from Africa to Europe. In two patients, consecutive serum samples were available for monitoring of virus load and cytokine levels in addition to standard laboratory data. Both patients had non-specific early clinical symptoms including high fever. Patient 1 developed multi-organ failure and died of hemorrhagic shock on day 15 of illness, while patient 2 died of respiratory failure due to aspiration without hemorrhage on day 16. Ribavirin was administered to both patients beginning only on day 11. High serum aspartate aminotransferase and lactate dehydrogenase (LDH) levels were remarkable in both patients. Patient 1 had an initial virus load of 10(6) S RNA copies/ml as measured by real-time RT-PCR. Viremia increased steadily and reached a plateau of approximately 10(8)-10(9) copies/ml 4 days before death, while IFN-gamma and TNF-alpha rose to extremely high levels only shortly before death. In contrast, in patient 2 the virus load decreased from 10(7) to 10(6) copies/ml during the late stage of illness which was paralleled by a decrease in the IFN-gamma and TNF-alpha levels. The IL-10 level increased when specific IgM and IgG appeared. These data suggest that a high virus load and high levels of pro-inflammatory cytokines in the late stage of Lassa fever play an important role in the pathogenesis of hemorrhage, multi-organ failure, and shock in Lassa fever.

Adult↗